Publisher：Fuel  

Aqueous phase of bio-oil (APB) is a general stream of waste produced from biomass pyrolysis and fractional condensation of pyrolytic volatiles and has very limited applications. We have demonstrated a sequence of leaching of alkali and alkaline earth metallic species (AAEMs) from char and catalytic hydrothermal gasification (CHTG) for valorizing char and APB, respectively. The majority of AAEMs can be removed from the char by leaching with APB and the removal rates were almost equivalent to those leached with HCl (1.0 M). CHTG of an aqueous solution of the spent APB with a total organic carbon of 14,450 ppm was performed in a continuous flow reactor, employing an activated carbon-supported Ru catalyst (Ru loading, 4.6 wt%). The catalyst exhibited a stable activity for carbon conversion of 98.8 % at 350 °C for at least 360 min while gaseous product consisting of H2, CH4, and CO2 was produced with a cold gas efficiency of 101–103 %, on a higher heating value basis. The cold gas efficiency exceeding 100 % is mainly because of the generation of H2 from water through water-gas shift reaction. The CHTG performance of APB was enhanced by char leaching through the uptake of coke-forming precursors of APB onto char and the enrichment of AAEMs in the spent APB. These AAEMs played roles in suppressing coke formation and deposition onto the catalyst and maintaining Ru particle size by providing a less acidic hydrothermal environment.

DOI： 10.1016/j.fuel.2024.132264

Scopus

Publisher：Energy and Fuels  

The replacement of coal with lignocellulosic biomass as feedstock for blast furnace coke is a crucial approach to decarbonizing the steel industry, which is a sector that is difficult to abate. Unlike the addition of a small amount of biomass or its charcoal to blended coal for conventional coke, the use of 100% biomass as a raw material is possible with formed coke, while its practical application requires an improvement in strength. Here, we report that the addition of a low-molecular-weight fraction obtained from degradative solvent extraction of biomass, called Soluble, is highly effective in enhancing the strength of the formed coke from softwood biomass. When used alone as a raw material, Soluble foams during carbonization, preventing coke formation. However, when mixed with woody biomass, it disperses within and between biomass particles during pelletization (hot press at 130 °C) or carbonization (cold press). Soluble has a minimal impact on the pyrolysis of biomass and dimensional changes of the biomass-derived carbonaceous substrate during carbonization, but it acts as a binder to sustain the strength of the resulting coke. As a result, the tensile strength of formed coke from biomass alone, which was 1.2 MPa with a cold press and 7.5 MPa with a hot press, improved with the increasing addition of Soluble, reaching around 25 MPa at 30 wt % addition. The effect of addition varied significantly depending on the preparation method and properties of Soluble, particularly highlighting the importance of the resolidification temperature during the carbonization process. This method was also effective for formed coke derived from lower-quality raw materials such as rice husk and lignite compared to softwood, but the optimal addition amount varied due to differences in the Soluble retention capacity.

DOI： 10.1021/acs.energyfuels.4c02892

Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Fuel  

This research aimed to investigate the hot strength of coke prepared by briquetting and carbonization of lignite (Coke D) and mechanisms causing the strength, which have not been well understood. The Coke D samples underwent heating in a nitrogen atmosphere and up to 1000 °C. Three different gasification conditions were employed: inert condition (Inert), 6 min CO2 gasification time (React6), and 9 min CO2 gasification time (React9). The samples were imaged by three-dimensional X-ray computed tomography (CT), and their pore structure was evaluated. Coke D-Inert and Coke D-React6 exhibited decreasing porosity due to the expansion of coke matrix at elevated temperatures. Conversely, the porosity of Coke D-React9 increased owing to the significant disappearance of coke matrix by gasification, despite some expansion of coke matrix. Furthermore, material constants (i.e., Young's modulus) were predicted using the finite element method with coke models derived from the CT images. In the numerical simulation, fracture strains obtained from experiments in our previous work were applied as boundary conditions. The estimated Young's modulus was 30.6 (maximum value 48.1; minimum value 14.9) on the outer side and 24.4 (max. 41.5; min. 12.4) on the inner side in Coke D-Inert, 16.6 (max. 21.1; min. 13.7) on the outer side and 17.1 (max. 20.4; min. 13.7) on the inner side in Coke D-React6, and 29.4 (max. 30.9; min. 26.5) on the outer side and 22.5 (max. 26.0; min. 19.6) on the inner side in Coke D-React9. Comparing Young's modulus of Coke D-React6 and Coke D-React9, Coke D-React9 showed a higher Young's modulus. These results suggested the significant impact of fracture strain on the predicted value of Young's modulus. The fracture strain was likely influenced by the effects of creep and matrix disappearance due to the reaction with CO2. Nano-indentation measurements of Coke D-Inert (average value 23.4; max. 29.4; min. 15.3) and Coke D-React9 (average 25.4; max. 28.3; min. 22.4) microstructures suggested no change in the material constants at room temperature but the potential for alterations at elevated temperatures.

DOI： 10.1016/j.fuel.2023.130656

Scopus

Other Link： https://doi.org/10.1016/j.fuel.2023.130656

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Chemical Engineering Journal  

T- and V-shaped (or arrow-shaped) micromixers enable the control of rapid chemical reactions by permitting accelerated mixing. Their mixing performance has been extensively investigated at moderate flow rates, which correspond to Reynolds numbers of the order of several hundreds. However, this operating range does not align with the recent applications of microreactors in organic synthesis. Therefore, this study examined mixing times in T- and V-shaped micromixers with 250-µm-wide channels at high flow rates (Reynolds numbers of up to 1500). The progress of mixing between an acidic solution and a basic solution containing a pH-sensitive fluorescent molecule was visualized by fluorescence microscopy imaging. An image analysis of 200 frames for each condition helped evaluate the degree of mixing and its stability over time under chaotic flow. The performance and stability of the V-shaped micromixer were significantly enhanced when the flow-rate ratio was changed from 1:1 to 1:2. The difference in momentum between the two inlet streams suppressed the undesirable alternation of the flow patterns at the junction. The effects of the choice of fluids (in the lower- and higher-flow-rate sides) on the reaction selectivity were explored through a numerical analysis. It was clarified that the substrate-side flow rate has to be set lower than that of the reactant side in the competing consecutive reaction system. Moreover, a short mixing time of 1 ms was achieved using the V-shaped micromixer at a flow-rate ratio of 1:2 and Re of 1500. These findings provide practical guidelines for the design and operation of microreactor systems.

DOI： 10.1016/j.cej.2024.151183

Scopus

Other Link： https://doi.org/10.1016/j.cej.2024.151183

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Flow Chemistry  

Abstract: Although gas-liquid-solid reactions, such as catalytic hydrogenation, have a long history, a fundamental understanding of the flow behavior and its effect on the reaction is lacking for flow chemistry applications using powder catalysts. This study revealed the distinctive effect of gas-solid direct contact on the surface of a powder catalyst. Direct gas–solid contact accelerates the reaction beyond the theoretical maximum of the batch reaction system, where gaseous species are supplied to the catalyst surface after dissolution into the liquid. The benefit of direct contact is further pronounced in systems with low-solubility gaseous species. Liquid holdup analysis revealed that the micro-concavities of the catalyst support is crucial for sustaining the liquid using capillary forces and supplying the liquid substrate to the catalyst surface even under high gas flow rate conditions. The gas-to-liquid flow rate ratio (G/L) is a decisive factor for direct gas–solid contact, whereas the flow direction, whether upflow or downflow, has no impact on powder catalysts with a size of a few hundred microns. Graphical Abstract: (Figure presented.)

DOI： 10.1007/s41981-023-00295-9

Scopus

Other Link： https://doi.org/10.1007/s41981-023-00295-9

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Biomass Conversion and Biorefinery  

Wooden particleboards generally involve formaldehyde-based binders in the furniture industry, which facilely release hazardous substances. All-natural boards derived from non-wooden biomass are attractive candidates to substitute wooden products due to their green and sustainable properties. Herein, waste bamboo particles were processed into binder-free and high-strength plates without external binder through a sequential hydrothermal treatment (HT), pulverization, and hot pressing. The effects of HT time (2–137 min) and temperature (160–250 °C) on the structure and strength of the plates were investigated. The tensile strength and fracture energy of the obtained plates were maximized in HT at 180 °C with a holding time of 77 min. The corresponding tensile strength (28 MPa) and fracture energy (2100 mJ) were increased by 1.9 times and 3.5 times, respectively, compared with that of the original bamboo plates. The mechanism of strength based on HT time was also systematically discussed, combined with solvent extraction of treated bamboo. Hemicellulose, lignin, and solvent-soluble matter (SSM) contributed to the strength as binder/matrix, while the resulting cellulose-rich fibrous particles provided the reinforcement in densified plates. This work optimizes the hydrothermal treatment process and offers an environment-friendly route to valorize agricultural and forestry wastes.

DOI： 10.1007/s13399-024-05437-0

Scopus

Other Link： https://doi.org/10.1007/s13399-024-05437-0

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Chinese Journal of Chemical Engineering  

Mixing behavior is critical for enhancing the selectivity of fast chemical reactions in microreactors. A high Reynolds number (Re) improves the mixing rate and selectivity of the reactions, but some exceptions of increasing side product yield with the higher Re have been reported. This study investigated the mixing uniformity in microreactors with in-line UV–vis spectroscopy to clarify the relationship between reaction selectivity and chaotic mixing with the higher Re. A colorization experiment of thymolphthalein in an acidic solution was conducted with an excess acid amount to the base to indicate a non-uniformly mixed region. Non-uniformity significantly increased with Re. At the same time, the degree of mixing, which was measured by a usual decolorization experiment, showed that the mixing rate increased with Re. The in-line analysis of the Villermaux–Dushman reaction during the mixing clarified that side product yield significantly increased with Re at around 300 and then decreased at around 1100. These results suggest the compensation effect between the mixing uniformity and mixing rate on the selectivity of the mixing-sensitive reactions. Faster mixing, characterized by a larger Re, can disturb mixing uniformity and, in some cases, decrease reaction selectivity.

DOI： 10.1016/j.cjche.2023.09.009

Scopus

Other Link： https://doi.org/10.1016/j.cjche.2023.09.009

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Reaction Chemistry and Engineering  

Catalytic reactions of mixed substrates sometimes behave differently from those of individual substrates. For example, the hydrogenation of propylbenzene over Rh/SiO2 proceeds 120% faster in the presence of toluene. Such an acceleration effect does not agree with the well-accepted Langmuir-Hinshelwood reaction model. In this paper, we examined its mechanism experimentally and computationally. The hydrogenation experiment of vaporised aromatics confirmed that the acceleration was specific to the liquid phase with the isopropanol solvent. Direct adsorption measurements revealed that toluene adsorption synchronises with propylbenzene adsorption. Density functional theory calculations confirmed the associates of toluene and propylbenzene on the catalyst surface in the polar environment. The formation of associates increased the adsorption energy of toluene and decreased that of propylbenzene. Lowered adsorption energy reduces the activation barrier for catalytic reaction and intensifies the reaction rate beyond the Langmuir-Hinshelwood model prediction.

DOI： 10.1039/D3RE00032J

Scopus

Other Link： https://pubs.rsc.org/en/content/articlehtml/2023/re/d3re00032j

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Fuel  

This contribution reports the effects of product recovery methods on the yields and properties of hydrochars produced from hydrothermal carbonization (HTC) of algal biomass. A slurry of Chlorella vulgaris with 10 wt% of solid loading was hydrothermally carbonized at 180 – 220 °C with holding time of 15 and 60 min. The resulting hydrochars were recovered by two prevailing methods, namely direct filtration and dichloromethane (DCM)-aided filtration. The results indicate that, under identical HTC conditions, compared with DCM-aided filtration, direct filtration always results in higher hydrochar yield because of the biocrude retained on its surface. The presence of residue biocrude in the hydrochars from direct filtration further leads to considerable differences in their properties, as compared with their counterparts from DCM-aided filtration. Specifically, under identical HTC temperature and holding time, DCM-aided filtration yields hydrochars of lower volatile matter contents but higher fixed carbon and ash contents, as compared with the hydrochars from direct filtration. Direct filtration generally recovers hydrochars of greater higher heating values and energy-based yields as compared to DCM-aided filtration. The product recovery methods show considerable impacts on the concentrations of Na, K, Mg, and Ca and their retentions in the hydrochars at 220 °C for 60 min, with higher concentrations and retentions of these elements being observed in the hydrochars from DCM-aided filtration. The hydrochars at 220 °C for 15 and 60 min from DCM-aided filtration show higher specific reactivity of 0.040 – 0.058 min−1 and 0.066 – 0.096 min−1 at hydrochar conversions of ≤ 82 % and ≤ 78 %, respectively, as compared with their direct-filtration counterparts, due to their higher concentrations of catalytic alkali and alkaline earth metals. These findings highlight the importance of considering product recovery methods when comparing the yields and properties of hydrochars from HTC of algae reported in the literature.

DOI： 10.1016/j.fuel.2022.126029

Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ISIJ International  

Torrefaction, pulverization, hot briquetting, and carbonization in sequence successfully produce highstrength coke from woody biomass. This method was further improved by introducing washing of torrefied biomass with acidic water from torrefaction before briquetting. The primary purpose of the washing was to remove alkali, and alkaline-earth metallic species of which catalyses were responsible for high reactivity of the coke. The acidic water (AW) from 275°C torrefaction of Japanese cedar contained 12, 0.9, and 39.4 mass% of acetic and formic acids, and the other organic compounds, respectively. A simulated AW (SAW) was prepared with the same composition as that of AW. SAW with pH of 1.95 removed 96-97% of K, Mg, and Ca and 48% of Na from the torrefied cedar. These removal rates were higher than those by washing with an aqueous solution of acetic acid, hydrogen chloride, or oxalic acid with pH of 2.35, 1.05, or 0.77, respectively. Organic compounds dissolved in SAW helped water and acids penetrate the matrix of the cedar. The washing with SAW increased the tensile strength of coke from 16 to 21 MPa by promoting volumetric shrinkage of the briquette during the carbonization and then particle bonding and coalescence. More importantly, the washing greatly reduced coke reactivity. The times required for gasifying 50% and 99% of coke with 50 kPa CO2 at 900°C, t0.50 and t0.99, respectively, were extended by factors of 24 and 46, respectively. It was thus demonstrated that the coke reactivity was controllable over such a wide range.

DOI： 10.2355/isijinternational.ISIJINT-2022-537

Scopus

Other Link： https://doi.org/10.2355/isijinternational.ISIJINT-2022-537

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ISIJ International  

The mechanisms of expansion and shrinkage behavior of the briquettes of coal or torrefied biomass were investigated by measuring the weight loss of coal and torrefied biomass and the expansion and shrinkage of the briquettes. In the case of torrefied biomass, particularly large expansion occurred at temperatures below 600°C. In the case of hot briquetting, the expansion was small below the briquetting temperature, suggesting that the expansion originated from relaxation of residual stresses during briquetting process. When coal and biomass were blended, the maximum strain was slightly close to the briquette of coal, and the temperature at which the maximum strain was taken was almost the same as that of the briquette of torrefied biomass, and in both cases, additivity was not valid. The expansion and shrinkage behavior of the briquettes was modeled as thermal expansion unique to the material, expansion due to relaxation of stresses accumulated during molding, and shrinkage due to the release of volatiles.

DOI： 10.2355/isijinternational.ISIJINT-2022-532

Scopus

Other Link： https://doi.org/10.2355/isijinternational.ISIJINT-2022-532

Language：English   Publisher：Interdisciplinary Graduate School of Engineering Sciences, Kyushu University  

RgCl(B,C,D) excimers were produced for Rg = Ar, Kr, and Xe by the positive ion-negative ion recombination reactions of Rg^+(^2P_<1/2,3/2>) with C_6F_5Cl^- in the flowing afterglow. Spin-orbit state selectivity of RgCl(B,C,D) excimers by the Rg^+(^2P_<1/2>) and Rg^+(^2P_<3/2>) components was examined by using appropriate filter gases of one spin-orbit component. The RgCl(B,D) ratio was determined to be 0.35:0.65, 0.05:0.95, and 0.24:0.76 in the Ag^+(^2P_<1/2>), Kr^+(^2P_<1/2>), and Xe^+(^2P_<1/2>) reactions, whereas the RgCl(B,C) ratio was estimated to be 0.74:0.26, 0.71:0.29, and 0.70:0.30 in the Ag^+(^2P_<3/2>), Kr^+(^2P_<3/2>), and Xe^+(^2P_<3/2>) reactions, respectively. The Rg^+(^2P_<1/2>) reactions had a high propensity to give RgCl(D) plus a lesser amount of RgCl(B), whereas the Rg^+(^2P_<3/2>) reactions gave only RgCl(B,C). These results show that Rg^+(^2P_<1/2>) + Cl^- and Rg+(^2P_<3/2>) + Cl- characters are conserved well for the formation of RgCl* in the ion-ion recombination reactions between Rg^+(^2P_<1/2,3/2>) and C_6F_5Cl-. Higher conservation of Rg^+(^2P_<1/2>) character in the Rg^+(^2P_<1/2>)/C_6F_5Cl- reactions than that in the Rg(^3P_0)/halides reactions is discussed by using correlation diagram between entrance and exit product channels.

DOI： 10.15017/6786939

CiNii Research

Language：English   Publisher：Interdisciplinary Graduate School of Engineering Sciences, Kyushu University  

The positive ion¬negative ion reactions of Kr^+(^<2>P_<1/2,3/2>) The positive ion-negative ion reactions of Kr^+(2P1/2,3/2) with C_6F_5Cl^-, and Xe+(2P1/2,3/2) with SF_6-, C_6F_6^-, and C_6F_5Cl^- have been spectroscopically studied in the He flowing afterglow. KrCl* excimer and excited Kr* atoms were produced in the Kr^+/C_6F_5Cl^- reaction, whereas XeF*, Xe*, and XeCl* and Xe* were formed in the Xe^+/SF_6-, Xe^+/C_6F_6-, and Xe^+/C_6F_5Cl^- reactions, respectively. The branching ratios between recombination and neutralization reactions leading to RgX* (Rg = Kr, Xe, X = F, Cl) excimers and excited Rg* atoms, respectively, were found to be 0.69:0.31 for the Kr^+/C_6F_5Cl^- reaction and 1.00:0.00, 0.00:1.00, and 0.89:0.11, for the Xe^+/SF_6^-, Xe^+/C_6F_6^-, and Xe^+/C_6F_5Cl^- reactions. These results suggested that the branching ratio between recombination and neutralization reactions depends strongly on the negative ion. It was concluded that dissociation energies of target anions leading to X^- and electron affinities of target molecules play a significant role in the ion-ion recombination and neutralization reactions of Rg^+ with SF_6^-, C_6F_6^-, and C_6F_5Cl^-.

DOI： 10.15017/6786937

CiNii Research

Language：English   Publisher：Interdisciplinary Graduate School of Engineering Sciences, Kyushu University  

The positive ion–negative ion reactions of Kr^+ and Xe^+ with C_6F_5Br^- and C_6F_5CF_3^- have been spectroscopically studied in the He flowing afterglow. The branching ratios of recombination and neutralization reactions leading to RgX* excimers and excited Rg* atoms (Rg = Kr, Xe, X = Br, F), respectively, were determined to be 0.14:0.86 and 1.00:0.00 for the Kr^+/C_6F_5Br^- and Xe+/C_6F_5Br^- reactions and 0.00:1.00 for both the Kr^+/C_6F_5CF_3^- and Xe^+/C_6F_5CF_3^- reactions. It was concluded that electron affinities of target molecules and dissociation energies of C_6F_5X^- leading to X^- play a significant role in determining the branching ratio of ion–ion recombination and neutralization reactions.

DOI： 10.15017/6790820

CiNii Research

Language：Japanese   Publisher：The Japan Wood Research Society  

<p>Japanese cedar (<i>Cryptomeria japonica</i>) is a forest tree species, and widely distributed in Japan. The lumber of Japanese cedar has been used for building materials, furniture, and traditional crafts, but the “leaf” is rarely used for practical applications. In this study, the physiological activity in the water extracts of Japanese cedar leaf which extracted by the two-step hot/hot-compressed water percolation evaluated by the <i>in vitro</i> assay and the experiment using human keratinocyte, HaCaT cells. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and total polyphenol concentration in 180 °C extract were significantly higher than those in 80 °C extract. Additionally, the suppressive effects of 180 °C water extract of Japanese cedar leaf on the cellular reactive oxygen species (ROS) level were more effective than that of 80 °C water extract in HaCaT cells. Therefore, it was indicated that the 180 °C water extracts of Japanese cedar leaf contained more antioxidant compounds than that of 80 °C water extract.</p>

DOI： 10.2488/jwrs.69.109

CiNii Research

Language：Japanese   Publisher：The Japan Institute of Energy  

DOI： 10.20550/jieenermix.102.3_267

CiNii Research

Language：Japanese   Publisher：The Japan Institute of Energy  

<p>バイオマスや褐炭の熱分解とこれに続く炭化物（チャー）のガス化，揮発成分改質におけるアルカリ・アルカリ土類金属種の挙動や触媒活性，揮発成分とチャーの転換に著しい影響を及ぼす両者の化学的相互作用等を明らかにした。これらの知見を踏まえ，新たな触媒ガス化法を提案し，700℃程度の低温におけるチャーおよび揮発成分の完全ガス化・改質の概念を提案し，これを実証した。 チャー，ガスおよび軽質油を併産する熱分解に関しては，原料の重質油分吸着・吸収能力，重質油と原料の共炭化性等を見出し，これらの物性と反応特性を利用した重質油分のリサイクルによる高温・触媒不要の重質油分フリー熱分解を概念実証した。 加熱時の軟化溶融性を持たない褐炭，バイオマスはコークス原料に不適とされてきたが，これらの資源が200℃以下の加熱と機械的加圧によって可塑化すること，さらに，この物性を利用して得た成型物中の粒子が炭化中に結合・合一する焼結的現象を見出し，高炉用コークスの数倍の強度を持つコークスを製造することに成功した。 </p>

DOI： 10.20550/jieenermix.102.3_274

CiNii Research

Language：Japanese   Publisher：The Japan Institute of Energy  

<p>本稿は，まず，炭素循環社会実現に向けて期待されるバイオマスの転換システムを俯瞰し，そのなかにガス化および関連プロセスを位置付け，ガス化がcarbon-neutralおよびcarbonnegativeプロセス，廃棄物を含むバイオマス炭素の循環プロセスとして機能することを述べる。 これらの機能を実現するには炭素ないし化学エネルギーの歩留りを最大限に高められる低温ガス化が有効である。本稿は，最近約15年間のバイオマス気固系ガス化，とくにその速度論・反応機構に関する研究の進展をレビューする。これに加えて，気固系ガス化とは異なる原理で作動する電気化学的ガス化に関する最新の研究を紹介する。 </p>

DOI： 10.20550/jieenermix.102.2_229

CiNii Research

Language：English   Publisher：Interdisciplinary Graduate School of Engineering Sciences, Kyushu University  

DOI： 10.15017/5208233

CiNii Research

Language：English   Publisher：Interdisciplinary Graduate School of Engineering Sciences, Kyushu University  

DOI： 10.15017/5208234

CiNii Research

Publisher：Chemical Engineering Journal  

Fast mixing is an essential feature of a microreactor. This study reveals the critical role of microscopic fluid incorporation on fast chemical reactions in a microreactor. The vortices in a microreactor produce tiny fluid segments, and the incorporation of these segments into the surrounding fluid triggers chemical reactions. The selectivity of chemical reactions highly depends on the type of the fluid segment incorporated into the fluid. Microreactor operations that consider incorporative mixing can achieve better reaction results, even with slow mixing. For example, a tee mixer showed better reaction performance with the vertical confluence configuration than with the symmetric configuration, although the symmetric 180-degree confluence provides more intense mixing. Computational fluid dynamics (CFD) simulations showed that vertical confluence enabled the division and incorporation of a stream from the horizontal inlet into another stream. The appropriate inlet designation is vital when two inlets of a microreactor differ in dimensions, directions, or positions because the different inlets provide different mixing profiles. The two inlets of the microreactor were distinguishable even though the fabrication error was insignificant. For instance, feed orientations changed the side-product yield seven times in a 3D-printed microreactor. Moreover, the impact of incorporative mixing on particle synthesis was confirmed. Switching the two inlets significantly influenced the morphology and size of the synthesized particles by changing the initial nucleation environment. In conclusion, considering incorporative mixing and optimal inlet orientation will enhance the performance and flexibility of microreaction technology.

DOI： 10.1016/j.cej.2022.138942

Scopus

Language：English   Publishing type：Research paper (scientific journal)  

DOI： doi.org/10.1016/j.cej.2022.138942

Publisher：ISIJ International  

The strength, pore structure, and material constants of coke prepared from caking coal (Coke A) and non- or slightly caking coal (Coke C) were experimentally and numerically investigated with a particular focus on those values at high temperatures. Coke A showed higher strength and lower porosity than Coke C. The pore structure imaged by X-ray computed tomography was translated to the finite element mesh with the image-based modeling, and the stress analysis based on the finite element method was performed to calculate the mode value of maximum principal stress at different Young’s modulus and Poisson’s ratio. Young’s modulus of Coke A and Coke C at a constant Poisson’s ratio decreased and increased, respectively by heating. When the temperature increased, the compression stress of Coke A increased. The result indicated that the coke strength could be increased by heating because of the decrease in apparent Young’s modulus, accompanied by the occurrence of creep.

DOI： 10.2355/isijinternational.ISIJINT-2022-190

Scopus

Publisher：ISIJ International  

The hot strength of coke prepared from an acid-washed lignite by briquetting-carbonization before and after CO2 gasification was, for the first time, investigated in this work. The hot strength at 1 000°C before gasification was higher than coke strength measured at a room temperature. CO2 gasification resulted in a linear decrease of the hot strength with the reaction time. The lignite-coke showed faster decrease in the strength during gasification, compared to conventional cokes derived from caking coal or non-or slightly caking coal, due to the high reactivity caused by its porous structure and catalytic metal species remaining even after the acid-washing, while it showed superior hot strength at the initial stage of gasification.

DOI： 10.2355/isijinternational.ISIJINT-2022-143

Scopus

Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://www.tj.kyushu-u.ac.jp/g_public/img/report_img/44-22-29.pdf

Publisher：Journal of Analytical and Applied Pyrolysis  

Torrefaction of Japanese cedar (TR) and in-situ vapor-phase pyrolytic reforming of volatile matter from TR (PYR) were investigated with three main objectives; quantification of the heats required for TR and PYR (QTR and QPYR, respectively), demonstration of high conversion of bio-oil into syngas by PYR without either catalyst or oxidizing agent, and clarification of effects of water washing of the cedar prior to TR on QTR and QPYR as well as the product distribution. The cedar was subjected to TR and PYR at temperatures of TTR = 250–350 °C and TPYR = 500–800 °C, respectively. QTR was defined as the difference in enthalpy between the TR products at TTR and dry cedar at 25 °C, and determined from compound or elemental composition of char, bio-oil, water, and non-condensable gases. QTR increased with TTR in a range of 1.0–4.0% of the cedar HHV, which could be covered by burning the gas and a small portion (0.5–13.0%) of bio-oil from TR at TTR ≥ 280 °C. The water washing removed substantial portions of the inherent alkali and alkaline earth metallic species. This resulted in slight increase in QTR, 0.2–0.8%-HHV and decrease in the gas yield, in particular, those of CO and CO2. PYR converted substantial portions of the bio-oil from TR at TTR = 300 °C. The bio-oil conversion into CO/H2–rich gas was 85–90% at TPYR = 800 °C. QPYR, which was defined as the enthalpy difference between the volatile matter from TR at 300 °C and that from PYR at TPYR, increased with TPYR but as small as 1.4–5.8% of the cedar HHV. The water washing slightly decreased QPYR, and this was quantitatively explained by slightly smaller bio-oil yield from TR of the water-washed cedar at TTR = 300 °C than that of the cedar. QPYR was a function of decrease in the bio-oil yield by PYR, which was not influenced by the water washing.

DOI： 10.1016/j.jaap.2022.105658

Scopus

Language：English   Publisher：Interdisciplinary Graduate School of Engineering Sciences, Kyushu University  

DOI： 10.15017/4795519

CiNii Research

Language：English   Publisher：Interdisciplinary Graduate School of Engineering Sciences, Kyushu University  

Ion-molecule reactions of Ar_2^+, N_3^+, and N_4^+ cluster ions with CH_4, C_2H_2, C_2H_4, and C_2H_6 have been studied by using a thermal ion-beam apparatus. Rate constants were determined and compared with those obtained from Langevin theory. Rate constants of the Ar_2^+ + C_2H_2, Ar_2^+ + C_2H_4, and N_3+ + C_2H_6 reactions, which have not been measured, were determined to be 1.4, 8.1, and 3.6 × 10^<-10> cm3 s^-1, respectively. These values correspond to 14%, 74%, and 28% of calculated rate constants from Langevin theory, respectively.

DOI： 10.15017/4795521

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ISIJ International  

Oxalic acid is an attractive chemical platform potentially available from CO2 due to its established applications and chemical characteristics enabling it to serve as a mediator in hydrometallurgy including iron-making. However, a method for synthesizing oxalic acid from CO2 has yet to be established. In the present work, the formation of oxalate scaffold during heating of cesium carbonate (Cs2CO3) in the presence of CO2 and H2 as reactants was experimentally investigated with a particular focus on the influence of supporting Cs2CO3 over porous materials. Among the support materials examined, activated carbon (AC) had a notable effect in improving the reaction rate and yield of total carboxylates (formate and oxalate) during experiments with an autoclave. An important problem was the dominant presence of formate, the intermediate between carbonate and oxalate, accounting for over 90% of the carboxylates. Changing the reaction conditions, including temperature, reaction time, partial pressure of gas components, and amount of loaded Cs2CO3, did not alter the situation. Alternatively, re-heating of the formate-rich salts over AC under CO and CO2 enhanced the oxalate fraction while maintaining the total carboxylates yield. Benefiting from the employment of support material, the two-step conversion was carried out using a gas-flow type reactor with a packed bed of Cs2CO3 supported over AC. In this reaction system, because water, acting as a promoter, was absent, the total carboxylates yield was lower than that in the autoclave, while the oxalate fraction was higher, being 71.8% with a yield of 43.2% on a Cs2CO3-carbon basis.

DOI： 10.2355/isijinternational.ISIJINT-2022-159

Scopus

Other Link： https://doi.org/10.2355/isijinternational.ISIJINT-2022-159

Language：English   Publishing type：Research paper (scientific journal)  

The strength, pore structure, and material constants of coke prepared from caking coal (Coke A) and non- or slightly caking coal (Coke C) were experimentally and numerically investigated with a particular focus on those values at high temperatures. Coke A showed higher strength and lower porosity than Coke C. The pore structure imaged by X-ray computed tomography was translated to the finite element mesh with the image-based modeling, and the stress analysis based on the finite element method was performed to calculate the mode value of maximum principal stress at different Young's modulus and Poisson's ratio. Young's modulus of Coke A and Coke C at a constant Poisson's ratio decreased and increased, respectively by heating. When the temperature increased, the compression stress of Coke A increased. The result indicated that the coke strength could be increased by heating because of the decrease in apparent Young's modulus, accompanied by the occurrence of creep.

DOI： doi.org/10.2355/isijinternational.ISIJINT-2022-190

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2355/isijinternational.ISIJINT-202

Other Link： https://doi.org/10.2355/isijinternational.ISIJINT-202

Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

In continuation of our previous study on production of high-strength metallurgical coke from torrefied softwood (cedar), we studied coke production from a mixture of torrefied cedar (TC) and noncaking coal by pulverization to sizes <100 μm, mixing, binderless hot briquetting, and carbonization. These sequential processes produced coke with a tensile strength of 5–17 MPa, which was equivalent to or greater than that of conventional coke (5–6 MPa), from TC-coal mixtures over the entire ranges of TC mass fraction in briquette of 0–100%, torrefaction temperature of 250–300 °C, and choice of coal (sub-bituminous or medium-volatile bituminous coal). The mixing of TC and coal hindered densification of coke due to hindrance of shrinkage of more-shrinkable TC-derived particles during the carbonization under many of the conditions. Nevertheless, positive synergy occurred in the coke strength at TC mass fractions of over 50%, where coal-derived particles were dispersed in the matrix of TC-derived particles, bonded to them during the carbonization, and behaved as a reinforcement of the matrix. The bonding between TC-derived and coal-derived primary particles was revealed by scanning electron microscopy. Copulverization of mixed TC and coal to sizes <40 μm before the briquetting gave cokes having strengths as high as 23–28 MPa. The fine pulverization increased the frequencies of mutual bonding of TC-derived particles and coal-derived particles and bonding between TC-derived and coal-derived particles per coke volume. The strength of coke from the TC-coal mixture generally followed volume-based additivity of strengths of cokes from TC and coal. This was realized by mixing primary particles of TC and coal within ≈10 μm scale or even smaller.

DOI： 10.1021/acs.energyfuels.2c01722

Scopus

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

Torrefaction of Japanese cedar (TR) and in-situ vapor-phase pyrolytic reforming of volatile matter from TR (PYR) were investigated with three main objectives; quantification of the heats required for TR and PYR (QTR and QPYR, respectively), demonstration of high conversion of bio-oil into syngas by PYR without either catalyst or oxidizing agent, and clarification of effects of water washing of the cedar prior to TR on QTR and QPYR as well as the product distribution. The cedar was subjected to TR and PYR at temperatures of TTR = 250–350 °C and TPYR = 500–800 °C, respectively. QTR was defined as the difference in enthalpy between the TR products at TTR and dry cedar at 25 °C, and determined from compound or elemental composition of char, bio-oil, water, and non-condensable gases. QTR increased with TTR in a range of 1.0–4.0% of the cedar HHV, which could be covered by burning the gas and a small portion (0.5–13.0%) of bio-oil from TR at TTR ≥ 280 °C. The water washing removed substantial portions of the inherent alkali and alkaline earth metallic species. This resulted in slight increase in QTR, 0.2–0.8%-HHV and decrease in the gas yield, in particular, those of CO and CO2. PYR converted substantial portions of the bio-oil from TR at TTR = 300 °C. The bio-oil conversion into CO/H2–rich gas was 85–90% at TPYR = 800 °C. QPYR, which was defined as the enthalpy difference between the volatile matter from TR at 300 °C and that from PYR at TPYR, increased with TPYR but as small as 1.4–5.8% of the cedar HHV. The water washing slightly decreased QPYR, and this was quantitatively explained by slightly smaller bio-oil yield from TR of the water-washed cedar at TTR = 300 °C than that of the cedar. QPYR was a function of decrease in the bio-oil yield by PYR, which was not influenced by the water washing.

DOI： https://doi.org/10.1016/j.jaap.2022.105658

Language：English   Publishing type：Research paper (scientific journal)  

DOI： https://doi.org/10.2355/isijinternational.ISIJINT-2022-013

Language：Japanese   Publisher：The Japan Institute of Energy  

<p>In the future systems of carbon recycling and biomass utilization, gasification is expected to play roles of syngas production integrating various types of biomass and biomass-derived wastes into syngas (CO/H₂). In this lecture are discussed requirement of gasification for maximized syngas yields, and also introduced emerging technologies and concepts.</p>

DOI： 10.20550/jietaikaiyoushi.31.0_iv

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACS Omega  

Processing agricultural wastes into densified materials to partially substitute wooden product production is significant for reducing the consumption of forest resources. This work proposes the fabrication of high-strength rice husk (RH)-based composite materials with poly(vinyl alcohol) (PVA) via densification by hot pressing. RH was pretreated in hot-compressed water (HCW) prior to pulverization and blending with PVA or PVA/glycerol (GL). The incorporation of PVA greatly improved the strength, toughness, and waterproofness of the composite plate, which was discussed with the help of a variety of composite characterizations. The tensile strength, flexural strength, and toughness of a composite of HCW-treated RH, PVA, and GL with a mass ratio of 80:20:2 were 42, 81 MPa, and 5.9 MJ/m3, respectively. The HCW treatment and blending with PVA and GL improved those properties of the hot-pressed original RH plate by factors of 2.5, 2.3, and 6.7, respectively, and reduced the water uptake and swelling ratio in water by 57 and 53%, respectively, despite the hydrophilic nature of PVA and GL. Altogether, this work outlines a valuable and sustainable approach to the efficient utilization of agricultural wastes.

DOI： 10.1021/acsomega.2c03286

Scopus

PubMed

Publisher：Journal of Material Cycles and Waste Management  

Peanut shell was used to prepare activated carbon (PSAC) by the hydrothermal activation in KOH. The synthesized PSAC was modified using PANI. The functionalized waste peanut shell activated carbon/polyaniline (PANI/PSAC) composite was used for wastewater treatment. The impact of PANI acid doping and the synergistic effect of activated carbon of the adsorbents on MB dye removal were investigated. HCl, H2SO4 and CH3COOH were used as dopants for the composite functionalization. The composites were characterized using SEM, TEM, EDX, XRD, and FTIR. The acid dopants formed nanorods, nanofibers, and nanotubes PANI structures. The PSAC had a surface area of 582 m2/g and pore diameter of 1.9052 nm. Adsorption parameters: contact time, pH, adsorbent dose, and solution temperature, were examined. The HCl-P/PSAC had the highest adsorption capacity of 220 mg/g and about 90% removal of the 100 mg/L within 60 min which is 2.3 times the adsorption capacity of PSAC (94.67 mg/g). The adsorption isotherms, kinetics and thermodynamics were investigated. All the prepared composites followed both Langmuir, Freundlich isotherm and the PSO model. The adsorption mechanisms were explained using FTIR. To the author’s knowledge, this study represents the first examination of doping acids impact on the PANI/PSAC composite for dye removal.

DOI： 10.1007/s10163-022-01408-7

Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Fuel  

This study proposes a new process that treats pyrolytic wastewater (PWW) from biomass pyrolysis with char-assisted drying. It can be operated at two modes: (I) one-stage drying for PWW treatment; and (II) two-stage drying and condensation for both treating PWW and recovering valuable chemicals (e.g., acetic acid). The process is proved via drying the mixture of a char and a synthetic PWW solution containing acetic acid, acetol, furfural, and phenol at different temperatures (60, 80, and 105 °C) and char-to-PWW mass ratios (1.0, 1.5, and 2.0). The results, supported by density functional theory (DFT) calculations, demonstrate that under Mode I, the char captures over 97.1% of the organic compounds in the PWW at 60 °C and a char-to-PWW ratio of 2.0, while evaporating almost all the water. The evaporated stream can be potentially discharged into the atmosphere without condensation or condensed into wastewater with a significantly reduced content of total organic carbon. Under Mode II, the char-PWW mixture is sequentially dried at 60 and 105 °C, with the exhaust gases being separately condensed. This yields a stream of purified acetic acid solution (concentration: ∼76 wt%) concentrated by a factor of ∼6.3 (compared with the PWW), with a recovery rate of ∼29%.

DOI： 10.1016/j.fuel.2021.122825

Scopus

Other Link： https://www.sciencedirect.com/science/article/pii/S0016236121026880

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

Lignocellulosic biomass is an attractive resource for metallurgical coke. The hot pelletization of powdered biomass followed by carbonization produces a high-strength biocoke. However, the fate of a major portion of biomass after carbonization is the production of low-value volatiles. Here, we enabled the valorization of woody biomass as valuable chemicals, such as anhydrosugars and phenols, and strong coke by loading mineral acid over wood and staged conversion consisting mainly of torrefaction, pelletization, and then carbonization. The loading of H2SO4 or H3PO4 at an amount equal to or slightly less than that of metals inherent in the wood, having catalysis for promoting the formation of valueless light oxygenates from carbohydrates, was effective for passivating those metals and drastically improving the anhydrosugar yield in torrefaction at 300–320 °C. The total yield of anhydrosugars from wood and the yield of levoglucosan, a dominant anhydrosugar, from cellulose in the wood reached 12.1 and 25.3 wt %, respectively. It was noteworthy that torrefaction altered the composition of components in wood and positively influenced the strength of coke prepared by pelletization and carbonization. In particular, torrefaction in the presence of H2SO4 led to a remarkable densification of pellets during carbonization. The resulting coke had a strength (tensile strength) of up to 24.2 MPa, which was much higher than that of coke directly pelletized and carbonized from wood (9.0 MPa). Moreover, the lignin-enriched torrefied wood selectively produced phenols and combustible gas with H2 as the major component in the carbonization. Under the most optimal conditions examined in this work, 45.7 wt % of the wood was converted into the desired products with the remainder being water and heavy condensable volatiles, while the yield of light oxygenates was greatly reduced.

DOI： 10.1021/acs.energyfuels.2c01352

Scopus

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

Hydroxyapatite (HA) has been extensively investigated and used in the field of biomaterials, while its application is more recently extended to the catalysis. Large number of catalytic processes are currently exploring the unique structural and chemical features of HA. The existence of diverse pair set of Ca 2+ ions results in exclusive catalytic features and provides scope for metal replacement and enables characteristic tuning according to the targeted catalytic application. This chapter explains the kinetics and mechanisms of selected reactions on HA‐based catalysts. Oxidative coupling of methane, partial oxidation of methane, acetone to methyl isobutyl ketone, and ethanol coupling reaction are the major reactions considered for this chapter.

DOI： doi.org/10.1002/9783527830190.ch5

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Environmental Chemical Engineering  

This contribution evaluates the impacts of reaction conditions on the yields and properties of biocrude and aqueous phase from hydrothermal carbonization (HTC) of Chlorella vulgaris (solid loading: 10.0 wt%) at 180-220 °C for 15 and 60 min. The results indicate that increasing HTC temperature (THTC) from 180 to 220 °C enhances biocrude yield from 8.8 to 34.6 wt%, for the holding time (th) of 60 min, and from 4.9 to 26.0 wt% for 15 min. The carbon recovery and higher heating value (HHV) of biocrude elevate with increasing both THTC and th, with the highest values of 50.6% and 34.0 MJ/kg, respectively, observed at 220 °C and 60 min. Among inorganic species, Na, Fe, and Zn display reasonable retentions in the biocrude with a pronounced effect of THTC observed at 15 min. The yield of aqueous phase increases first when THTC rises from 180 to 200 °C but decreases with further increasing THTC to 220 °C due to the re-polymerization of water-soluble organics into biocrude and/or the formation of gaseous products. The aqueous phase experiences a reduction of total organic carbon with increasing reaction severity because of the transfer of carbon to biocrude and/or gases. The aqueous phase is rich in organic nitrogen, dihydrogen phosphate, acetate, and potassium, which are required for its recycling as cultivation media. The concentrations of heavy metals (Fe, Cr, Mn, Co, Ni and Zn) in the aqueous phase are all below 9 mg/kg under the studied HTC conditions.

DOI： 10.1016/j.jece.2022.107953

Scopus

Other Link： https://www.sciencedirect.com/science/article/pii/S2213343722008260

Language：English   Publishing type：Research paper (scientific journal)  

Herein, the influence of group 1 and 2 metal cations on base-catalyzed dehydrogenative coupling of formate to form oxalate is reported. Treatment of sodium formate with a various types of bases (group 1 and 2 metal carbonates or metal hydroxides) revealed that, compared with carbonate salts, group 1 metal hydroxides behaved as efficient bases for the formation of oxalate, in which cesium hydroxide (CsOH) showed the best catalytic activity. DFT calculation for the reaction mechanism suggested that its kinetic advantage was generated from not only an increase of basicity but also destabilization of the intermediate species due to Na/Cs mixed cation system. The effect of cations in formate salts were also discussed both experimentally and theoretically, in which the yield of oxalic acid depended on thermodynamic stability of both products (oxalate salts) and intermediates.

DOI： 10.26434/chemrxiv-2022-6r93n D O I: 10.26434/chemrxiv-2022-6r93n

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

<jats:p>21 types of modifiers are screened for palladium catalysed semi-hydrogenation of alkynes with varying catalyst type, reaction time, and target substrate using an automated flow reactor system.</jats:p>

DOI： 10.1039/d2re00147k

Scopus

CiNii Research

Other Link： https://pubs.rsc.org/en/content/articlehtml/2022/re/d2re00147k

Language：English   Publisher：Interdisciplinary Graduate School of Engineering Sciences, Kyushu University  

DOI： 10.15017/4763150

CiNii Research

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Wood Research Society  

<p>Disposition of the waste sawdust substrate from sawdust-based cultivation of shiitake mushrooms (<i>Lentinula edodes</i>) is an important issue. In this study, we evaluated the physiological activity in the water extracts of waste sawdust substrate which had been extracted by the two-step hot/hot-compressed water percolation. The 180°C water extract of waste sawdust substrate contained some isoprenoid and high amounts of polyphenol. Additionally, high antioxidant activity was found in the 180°C water extract of the waste sawdust substrate in in vitro experiment (DPPH scavenging activity) and the human keratinocyte, HaCaT. This study suggested that the two-step hot/hot-compressed water percolation elutes the antioxidant components in the 180°C fraction from the waste sawdust substrate.</p>

DOI： 10.2488/jwrs.68.26

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acssuschemeng.1c07877

Other Link： 10.1021/acssuschemeng.1c07877

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Bioresource Technology  

This work presents the selective production of the versatile bio-based platform levoglucosenone (LGO) using deep eutectic solvents (DESs) as catalysts during cellulose pyrolysis. Among 18 types of DESs examined, those containing p-toluenesulfonic acid as a hydrogen bond donor possessed the requisite thermal stability for use in the pyrolysis of cellulose. When those DESs were combined with cellulose, the pyrolysis temperature could be reduced which led to greater selectivity for LGO, the highest yield being 41.5% on a carbon basis. Because of their thermal stability, the DESs could be recovered from the pyrolysis residue and reused. The DESs recovery reached 97.9% in the pyrolysis at a low temperature with the LGO yield of 14.0%. Thus, DES-assisted cellulose pyrolysis is a promising methodology for LGO production.

DOI： 10.1016/j.biortech.2021.126323

Scopus

PubMed

Other Link： https://www.sciencedirect.com/science/article/pii/S0960852421016655

Publisher：Key Engineering Materials  

Carbon-based materials are widely used in various fields such as wastewater treatment, gas sensing, and energy storage applications. In this study, waste peanut shell (PSH), available in Egypt, were transformed into useful materials by physical, chemical, and thermal treatments. The physical properties of materials from the different processing combinations were investigated. The activated (APSH), carbonized (CPSH), and activated/carbonized (A/CPSH) forms were successfully prepared. The prepared solids were characterized by SEM, FTIR, XRD, and nitrogen gas adsorption. Ball milling at 5 runs for 45 min resulted in 84 wt% of the ground PSH passing through the 212 μm mesh. Accordingly, the activation, carbonization, and activation/carbonization increased the surface areas of resulting solids by 6, 34, and 580 times, respectively. Among the materials prepared, the activated/carbonized PSH had a mean pore diameter of 1.9 nm, mesoporous material, and the highest electrical conductivity of 0.0042 Ω-1cm-1. This PSH is available as adsorbent in water treatment and materials for gas sensing and energy storage.

DOI： 10.4028/p-f1rqwl

Scopus

Publisher：ISIJ International  

This paper proposes a method of preparing high-strength formed coke from woody biomass without binder. Chipped and pre-dried Japanese cedar was heat-treated in an inert atmosphere (i.e., torrefied) at 225–325°C (Tt), pulverized to sizes in three different ranges, molded into briquettes (in the form of thick disk with diameter/thickness ≈ 2.5) at temperature up to 200°C by applying mechanical pressure of 128 MPa. The torrefied/briquetted cedar (TBC) was then converted into coke by heating to 1 000°C in an inert atmosphere at normal pressure. This process sequence enabled to prepare coke having indirect tensile strength (St) of 8–32 MPa, which was much higher than that without torrefaction, below 5 MPa. The torrefaction greatly improved pulverizability of the cedar, which was further promoted by increasing Tt. St of TBC and that of coke both increased as the particle sizes of TBC decreased, but this explained only a minor part of significant effect of Tt on St of the coke. St was maximized at Tt = 275°C regardless of the degree of pulverization. The Tt effects on physicochemical properties of TBC and coke were investigated in detail. The difference in St of coke by Tt was mainly due to that in the increment of St along the carbonization at 500–1 000°C. Fracture surfaces of the coke had particular morphologies that had been inherited from the original honeycomb structure of the cedar.

DOI： 10.2355/isijinternational.ISIJINT-2022-013

Scopus

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.apcata.2021.118286

Other Link： https://www.sciencedirect.com/science/article/pii/S0926860X21003008

Language：English   Publishing type：Research paper (scientific journal)  

The removal of alkali and alkaline-earth metallic (AAEM) species from biomass and/or its pyrolysis-derived char is often required to mitigate ash-related issues during their combustion. Leaching of biomass with an acidic aqueous phase (AP) produced from its pyrolysis is a promising strategy but encounters several issues, including high moisture content in wet biomass after dewatering and loss of organic carbon from biomass. Here, we propose a new process that leaches char with pyrolytic AP for the removal of AAEM species from and the uptakes of water-soluble organics by char. The char and pyrolytic AP produced from the pyrolysis of wheat straw at 450 °C in an auger reactor were subjected to time-dependent leaching at a liquid-to-solid mass ratio of 20. The results demonstrate that the majority of K, Mg, and Ca are leached within the first hour. Nonacidic compounds in the pyrolytic AP slightly hinder the leaching of K but have no impacts on that of Mg and Ca. Except for acetol, the uptakes of other organic compounds (e.g., furfural and phenolic compounds) by char are rapid in the first hour, become slower in 1–2 h, and then reach equilibrium. The results from density functional theory (DFT) calculations suggest the presence of chemisorption for the interactions between these organic compounds and char. Repeated leaching runs at the optimized leaching time (1 h) suggest that the pyrolytic AP is sufficient for leaching the char from the same run, achieving removal rates of ∼63.7 wt % for K, ∼43.7 wt % for Mg, and ∼60.7 wt % for Ca. After repeated leaching, there are only four organic compounds, including 2,3-butanedione, acetol, 2(5H)-furanone, and the remaining acetic acid, left in the leachate, simplifying the compositions of the pyrolytic AP. Leaching the char, instead of wheat straw, with the pyrolytic AP offers significant advantages, including the reduced moisture content in the wet solid after dewatering, negligible loss of organic carbon, and enhanced capture of phenolic compounds.

DOI： 10.1021/acs.energyfuels.1c01889

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1051/matecconf/202133305005

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1252/jcej.20we171

Other Link： https://doi.org/10.1252/jcej.20we171

Language：English   Publishing type：Research paper (scientific journal)  

Levoglucosenone (LGO) is a biobased compound that is generated during the pyrolysis of cellulose under catalysis. After several decades of foundational research into production methods, the relatively large-scale industrial production of LGO recently commenced. As a result, research on the application of LGO has increased and extended to the production of commodity chemicals, such as solvents, polymers, resins, and fuels, with LGO as the feedstock, while seeking to minimize production costs. An analysis and summary of previous achievements can help to inform the development of better production methods. We found that existing production methods can be organized into three categories depending on the strategies for exploiting catalysis. This minireview summarizes advances in the technologies used to produce LGO based on each catalytic strategy and recommends possible directions for future research by drawing on knowledge synthesized from the database.

DOI： 10.1021/acs.energyfuels.1c01062

Other Link： https://pubs.acs.org/doi/full/10.1021/acs.energyfuels.1c01062

Language：English   Publishing type：Research paper (scientific journal)  

Understanding evolution of the functionalities of biochar versus temperature is a prerequisite for exploring application of biochar as functional carbon materials. In this study, pyrolysis of lignin with different heating rates was conducted. The results indicated that the higher heating rate promoted formation of more gases via the accelerated cracking of both the organic components of biochar and the volatile products. In addition, the deoxygenation reactions were suppressed at higher heating rate with short residence time, leading to the biochar with lower heating value and energy yield. The in situ Diffuse Reflection Infrared Fourier Transform Spectra (DRIFTS) characterization of the lignin pyrolysis indicated monotonous increase of the abundance of =C−H, C=C and C−O−C functionalities versus increasing pyrolysis temperature. However, the −OH, −CH3 and C−H2 in alkanes and the C=O were not thermally stable. Abundance of −OH maintained a plateau in 200−450 °C, while that for −CH3 and C−H2 in alkanes also reached maximum at ca. 450 °C and the further increasing heating temperature led to significant decomposition. The decomposition of C=O started at the lower temperatures of 200–325 °C, and the lactones, unconjugated alkyl aldehydes, alkyl esters, conjugated aldehydes/ketones experienced distinct temperature-abundance histories.

DOI： 10.1016/j.jaap.2021.105031

Other Link： https://www.sciencedirect.com/science/article/pii/S0165237021000176

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ISIJ International  

Oxalic acid has been identified as a sustainable chemical enabling an efficient recovery of target metals from industrial minerals by dissolution. The dissolution process recently has attracted attention as a key reaction in a potential clean iron-making. In this application to efficiently produce a high-purity iron, the dissolution is required to occur in the absence of light, with no addition of other chemical reagents, and to produce high concentration iron oxalate aqueous solution as fast as possible. To reveal the chemistry of iron oxide dissolution for this application, in the present study, the dissolution experiments are carried out under various conditions with a particular focus on the iron oxide highly loaded in the oxalic acid aqueous solution. Highly acidic oxalic acid solution for dissolving the highly loaded iron oxide enabled the production of iron oxalates aqueous solution with the concentration of up to 0.56 mol-Fe/L. Different from conventional studies under diluted conditions with pH control, the dissolution followed a non-reductive mechanism, producing [Fe3+HC2O4] 2+ as a dominant iron species, and highly correlated with a concentration of proton in the solution. The experimental results and proposed stoichiometries identified a minimum amount of oxalic acid required for the complete dissolution of iron oxide independently from the concentration and type of loaded iron oxide. Among iron oxides tested (α-Fe2O3, FeOOH and Fe3O4) as the feedstock, Fe3O4 had an advantage in the dissolution rate, but showed a relatively low iron recovery in the solution (80–90%) because of an unavoidable formation of FeC2O4· 2H2O precipitates.

DOI： 10.2355/isijinternational.ISIJINT-2020-726

Scopus

Other Link： https://doi.org/10.2355/isijinternational.ISIJINT-2020-726

Language：English   Publishing type：Research paper (scientific journal)  

The pyrolysis of cellulose produces anhydrosugars, levoglucosan (LGA) in particular, as a primary product. In this work, the liquid phase conversion of anhydrosugars over solid acid catalysts was investigated, mainly using LGA, as a method for producing levoglucosenone (LGO), which is a bio-renewable platform for fine and commodity chemicals. The screening of typical organic solvents revealed they had a significant influence on the type of reaction selectivity and identified dimethyl sulfoxide (DMSO) as a suitable solvent. Among the solid acid catalysts examined, Amberlyst 70 in combination with DMSO was found to work the best, producing LGO with a yield of up to 32.3%-C. The yield of LGO was further improved to 40.4%-C by in-situ removal of water, which promoted undesired reactions, such as hydrolysis of LGA and isomerization of LGO to hydroxymethylfurfural. Moreover, an experiment using bio-oil, derived from cellulose pyrolysis, as the feedstock showed that a portion of heavier saccharides contributed as a source of LGO without inhibiting the conversion of LGA.

DOI： 10.1016/j.fuproc.2020.106625

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1051/matecconf/202133305006

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acsomega.0c05154

Language：English   Publishing type：Research paper (scientific journal)  

Delignification is essential in effective utilization of carbohydrates of lignocellulosic biomass. Characteristics of the delignification are important for the yield and property of the resulting carbohydrates. Oxidation with O2 of biomass in alkaline water can potentially produce high-purity cellulose at high yield. The present authors chose a Japanese cedar and investigated its oxidative delignification at 90 °C. The delignification selectivity was determined mainly by the chemical structures of lignin and cellulose. Treatment conditions, except for temperature, hardly changed the relationship between delignification rate and cellulose retention. During the treatment, dissolved lignin underwent chemical condensation in the aqueous phase. This “unfavorable” condensation consumed O2-derived active species, slowing down further delignification. Repeated short-time oxidation with renewal of alkaline water suppressed the condensation, enhancing the delignification. Repetition of 2-h treatments four times achieved 96% delignification, which was 8% higher than a single 8-h treatment at 130 °C.

DOI： 10.1021/acsomega.0c03953

Other Link： https://doi.org/10.1021/acsomega.0c03953

Language：English   Publishing type：Research paper (scientific journal)  

We have demonstrated a sequence of degradation, dissolution and catalytic hydrothermal gasification (CHTG) oflignite in alkaline water. A Victorian lignite was subjected to hydrothermal treatment (HT) in an aqueous so-lution of NaOH at 250 °C, and then oxidation with pressurized O2at 100 °C. The sequential HT and oxidationsolubilized a 95% portion of the lignite on mass/carbon bases. The resulting solution was further converted byCHTG in a flow reactor at 350 °C for 10 h, employing a ruthenium/activated-charcoal catalyst (rutheniumloading; 16 wt%). The initial carbon conversion to gas was as high as 98% while CH4, CO2and H2were pro-duced. The conversion gradually decreased due to coke deposition over the catalyst but was near steady around83% at 8–10 h. The solubilized lignite consisted of compounds with molecular mass up to 5,000. The heavierportion (molecular mass > 1,000) was responsible for the coke formation and accumulation that caused thecatalyst deactivation.

DOI： 10.1016/j.fuel.2020.118329

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acssuschemeng.0c03593

Language：Japanese   Publishing type：Research paper (scientific journal)  

Abatement of emissions of greenhouse gases such as methane and carbon dioxide is crucial to reduce global warming. For that, dry reforming of methane allows to convert methane and carbon dioxide into useful synthesis gas, named ‘syngas’, a gas mixture rich in hydrogen and carbon monoxide. However, this process requires high temperatures of about 900 °C to activate methane and carbon dioxide because dry reforming of methane reaction is highly endothermic. Therefore, a solid catalyst with appropriate thermal properties is needed for the reaction. As a consequence, efficient heating of the reactor is required to control heat transfer and optimize energy consumption. Microwave-assisted dry reforming of methane thus appears as a promising alternative to conventional heating. Here we review the recent research on microwave-assisted dry reforming of methane. We present thermodynamical aspects of the dry reforming of methane, and basics of microwave heating and apparatus. We analyse reformers that use microwave heating. Catalysts used in a microwave-assisted reformer are presented and compared with reactors using conventional heating. Finally, the energy balance is discussed.

DOI： 10.1007/s10311-020-01055-0

Language：English   Publishing type：Research paper (scientific journal)  

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DOI： 10.1016/j.jaap.2019.104728

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DOI： doi.org/10.1021/acs.energyfuels.9b03156

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DOI： 10.1021/acs.energyfuels.9b02946

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DOI： 10.1021/acs.energyfuels.9b02939

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.apt.2019.12.005

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acs.energyfuels.9b02925

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acs.energyfuels.9b02925

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DOI： 10.1021/acs.energyfuels.9b00465

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DOI： 10.1007/s13762-019-02404-5

Language：English   Publishing type：Research paper (scientific journal)  

In continuation of the present authors’ studies on production of high strength coke from lignite by sequential binderless hot briquetting and carbonization, this study has been carried out aiming at proposing methods to produce high strength coke from non-/slightly caking coals of subbituminous to bituminous rank. This paper firstly demonstrates preparation of cokes with cold tensile strengths above 10 MPa from two single non-caking coals (particle size; < 106 μm) by applying briquetting at temperature and mechanical pressure of over 200°C and 100 MPa, respectively. Such strength of coke is obtained over a wide range of heating rate, 3–30 °C/min, during carbonization with final temperature of 1000°C. Then, a simple pretreatment, fine pulverization of coal to particle sizes smaller than 10 or 5 μm, is examined. This pretreatment enables to prepare coke with tensile strength even over 25 MPa, by decreasing porosity of resulting coke and more extensively the size of macropores simultaneously. The coke strength changes with carbonization temperature having a particular feature; significant development of strength at 600–1000°C, i.e., after completion of tar evolution, in which macropores and non-porous (dense) part of coke shrink in volume, inducing bonding and coalescence of particles and thereby arising the strength.

DOI： 10.2355/isijinternational.ISIJINT-2018-819

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2355/isijinternational.ISIJINT-2018-816

Language：English   Publishing type：Research paper (scientific journal)  

Sequential coal briquetting and carbonization was applied to preparation of cokes from 9 non- or slightly caking coals with carbon contents (fC) of 67–85 wt%-daf. Coal pulverization to sizes of <106 μm and briquetting at 40°C enabled to prepare cokes with tensile strength (!) over 10 MPa from 4 coals with fC of 82–85 or 67 wt%-daf. Then, by introducing fine pulverization to sizes of < 10 μm before the briquetting, 7 coals were converted successfully into cokes with !"= 11–25 MPa. Increasing the briquetting temperature to 240°C further increased ! to 19–35 MPa for all the 9 coals. It was thus demonstrated that the hot briquetting of finely pulverized coal was a method to prepare high strength coke regardless of the rank of parent coal. Cokes were also prepared from 14 binary coal blends. All the cokes prepared by applying the fine pulverization and hot briquetting had ! of 20–35 MPa, which agreed well with that calculated by weighted average of those from the component coals. On the other hand, positive and also negative synergistic effects of blending occurred when blends were briquetted at 40°C. Characteristics of bonding/coalescence among particles of different types of coals were responsible for such synergies.

DOI： 10.2355/isijinternational.ISIJINT-2018-847

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2355/isijinternational.ISIJINT-2018-816

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.fuproc.2019.03.014

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acssuschemeng.8b05873

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11356-019-04475-w

Language：English   Publishing type：Research paper (scientific journal)  

Kinetics of thermal decomposition of benzene on lignite-derived char was investigated at 900 °C by applying a new method to continuously monitor the char surface activity. Benzene vapor was continuously forced to pass through a micro fixed bed of char with residence time as short as 7.6 ms, and then detected continuously by a flame-ionization detector. Results showed the presence of two different types of char surfaces; consumptive Type I surface and non-consumptive (sustainable) Type II surface. Type I surface of a partially CO2-gasified char had an capacity of carbon deposit from benzene over 20 wt%-char and an initial activity (represented by a first-order rate constant) as high as 160 s−1. Both of them decreased with increasing carbon deposit due to consumption of micropores accessible to benzene, and finally became zero leaving Type II surface that had a very stable activity with rate constant of 4 s−1. The chars without gasification had capacities of Type I surfaces smaller by two orders of magnitude than the partially gasified char, while the Type II surfaces had activities similar to that of the partially gasified char. It was found that Type II surface converted benzene into not only carbon deposit but also diaromatics and even greater aromatics. Composition of the greater aromatics was unknown because they were deposited onto the reactor wall immediately after passing through the char bed.

DOI： 10.1016/j.crcon.2018.12.001

Language：English   Publishing type：Research paper (scientific journal)  

Inherent metallic species retained by coal char or coke, such as Na and Ca, behave as catalysts in gasification. The char/coke normally contains inherent SiO2, which can react with the inherent catalysts to form silicates, resulting in catalyst deactivation over the range of pyrolysis, carbonization and gasification, and thereby re- ducing the char/coke reactivity. The present authors simulated the inherent catalyst deactivation experimentally by blending a Victorian lignite with SiO2, briquetting the SiO2/lignite blend, carbonizing the briquette, and then gasifying the coke with CO2. The kinetic analysis of the gasification employed a comprehensive model, which assumed progress in parallel of non-catalytic and catalytic gasification. The model quantitatively described the measured kinetics of the coke gasification with different SiO2 contents over a range of coke conversion up to 99.9%. The kinetic analysis revealed that the SiO2 deactivated substantial and entire portions of the most active catalyst and its precursor, respectively, before the gasification (i.e., during the carbonization). The catalyst deactivation also occurred during the gasification, but mainly following a self-deactivation mechanism that involved no silicates formation.

DOI： 10.1016/j.crcon.2018.09.002

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s40789-017-0175-0

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s11356-018-2103-2

Language：English   Publishing type：Research paper (scientific journal)  

Other Link： https://doi.org/10.1016/B978-0-08-101971-9.00003-X

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DOI： 10.1016/B978-0-08-101975-7.00002-6

Language：English   Publishing type：Research paper (scientific journal)  

The utilization of a typical Chinese low-rank coal (Zhundong coal) usually gives rise to severe fouling and slagging in equipment due to its excessively high content of sodium-bearing corrosive substances. This study systematically clarifies the occurrences and transformation mechanism of corrosive materials during pyrolysis of Zhongdong coal by combining solid-state nuclear magnetic resonance (SSNMR), in situ high-temperature X-ray diffraction (HT-XRD), and Factsage simulation. For the first time, the experimental evidence in this study shows that the corrosive elements demonstrated distinct forms in coal and could be significantly varied by thermal treatment. Specifically, homogeneously distributed Na ions could mutually transform between inorganic and organic-bounded form under the influence of ionic force, resulting in its elutable feature. During pyrolysis, Na was successively transformed to be inorganic form and completely volatilized above 800 °C, thus diversifying Na-related fouling propensity in various pyrolysis stages. The Cl was unlikely to entirely exist as inorganic form; nevertheless it was strongly restrained by functional groups of coal matrix. The organic Cl-containing functional groups was gradually decomposed to volatile Cl at pyrolysis temperature higher than 500 °C, whereas the inorganic Cl was more stable and possibly exposed on the surface of char particle. In situ analysis further revealed that the formation of aerosol by the diffused corrosive elements was the key step leading to the deposition. More importantly, Factsage thermodynamic calculation demonstrates that the sequential release of Cl as well as S, and their interactions with Na are the prerequisite and essential factor governing the generation of low-temperature-eutectic and subsequently initial corrosion.

DOI： 10.1021/acs.energyfuels.8b00661

Language：English   Publishing type：Research paper (scientific journal)  

A detailed chemical kinetic model has been developed to theoretically predict the pyrolysis behavior of phenol-type monolignol compounds (1-(4-hydroxyphenyl)prop-2-en-1-one, HPP; p-coumaryl alcohol, 3-hydroxy-1-(4-hydroxyphenyl)propan-1-one, HHPP; 1-(4-hydroxyphenyl)propane-1,3-diol, HPPD) released from the primary heterogeneous pyrolysis of lignin. The possible thermal decomposition pathways involving unimolecular decomposition, H-addition, and H-abstraction by H and CH₃ radicals were investigated by comparing the activation energies calculated at the M06–2X/6–311++G(d,p) level of theory. The results indicated that all phenol-type monolignol compounds convert to phenol by side-chain cleavage. p-Coumaryl alcohol decomposes into phenol via the formation of 4-vinylphenol, whereas HPP, HHPP, and HPPD decompose into phenol via the formation of 4-hydroxybenzaldehyde. The pyrolytic pathways focusing on the reactivity of the hydroxyl group in HPP and producing cyclopentadiene (cyc-C₅H₆) were also investigated. The transition state theory (TST) rate constants for all the proposed elementary reaction channels were calculated at the high-pressure limit in the temperature range of 300–1500 K. The kinetic analysis predicted the two favorable unimolecular decomposition pathways in HPP: the one is the dominant channel below 1000 K to produce cyc-C₅H₆, and the other is above 1000 K to yield phenol (C₆H₅OH).

DOI： 10.1002/kin.21164

Language：English   Publishing type：Research paper (scientific journal)  

A sequence of hot briquetting and carbonization (HBC) is a promising technology for the production of coke with a high mechanical strength from lignite, but factors affecting the coke strength have not yet been fully understood. The HBC cokes prepared from 12 lignites in this study showed diverse tensile strength (e.g., from 0.2 to 31.2 MPa in the preparation at 200 °C and 112 MPa for hot briquetting and 1000 °C for carbonization), and the coke strengths could not be explained by differences in commonly used structural properties of the parent lignites, such as elemental composition and contents of volatile matter/fixed carbon and ash. In this study, two methods were proposed for correlating the coke strength with the lignite properties, which employed the chemical structure analyzed by solid-state ¹³C nuclear magnetic resonance or the volumetric shrinkage during carbonization. A stronger coke was obtained from lignite that contained more aliphatic carbons (less aromatic carbons) or shrank more considerably. These characteristics contributed to intensified compaction of lignite in the briquetting and suppression of the formation of large pores, which are a cause of coke fracture. Two empirical equations, predicting the coke strength from the parameters of lignite properties, were established to be criteria for selection of lignite as HBC coke feedstock, although further investigation with more experimental data would be necessary for the validation.

DOI： 10.1021/acs.energyfuels.7b03155

Language：English   Publishing type：Research paper (scientific journal)  

A total of 18 chars from the pyrolysis of six trios of sugar cane bagasses (SCBs; original, water-washed, and acid-washed) were gasified with CO₂ at 900 °C, aiming at a quantitative description of the rate of gasification catalyzed by inherent metallic species and a correlation of the catalytic activity and its change during the gasification with the metallic species composition. The measured kinetics was described quantitatively over a range of char conversion, 0-0.999, by a model that assumed progress in parallel of the catalytic gasification and non-catalytic gasification, together with the presence of a catalytic precursor and three to four types of catalysts having different activities and deactivation characteristics. A series of regression analyses was scrutinized and reached expression of initial catalytic activity as a linear function of Na, K, Ca, Fe, and Si concentrations in the char with a correlation factor (r²) of >0.98. The catalyst precursor contributed fully by water-soluble Na, K, and Ca. Si was responsible for the catalyst deactivation during the pyrolysis but not during the gasification. The chars produced from original SCBs followed a linear relationship between the initial catalytic deactivation rate and initial activity (r² > 0.99), while such a linear relationship was not valid for those formed from the water-washed SCBs. This was explained mainly by more rapid deactivation of the Fe catalyst in the chars from water-washed SCBs than that in the chars formed from the original SCBs. Na and K in char from the original SCBs, originating from the water-soluble SCBs, chemically interacted with the Fe catalyst, slowing its deactivation.

DOI： 10.1021/acs.energyfuels.7b03147

Language：English   Publishing type：Research paper (scientific journal)  

A comparative study was carried out on the degradation of methyl orange (MO) by TiO₂ and Au/TiO₂ photocatalysts in neutral and acidic solutions. Au/TiO₂ photocatalysts with an Au : Ti atomic ratio of 1.5±0.1% : 98.5±0.1% were prepared by using a microwave-polyol method in the presence of P25 TiO₂. Initial degradation rates of MO by TiO₂ and Au/TiO₂ were 0.13 and 0.22 min⁻¹ at pH 7, whereas they increased to 0.96 and 3.06 min⁻¹ at pH 2, respectively. These results indicate that the MO degradation rates are enhanced by loading Au nanoparticles on TiO₂ in neutral and acidic solutions by factors of 1.7 and 3.2, respectively. Mass spectroscopic studies lead us to conclude that major reaction products are formed by demethylation and OH addition of benzenoid form of MO in neutral solutions, whereas they are produced through ring opening and carboxylation of quinonoid form of MO after scission of a center N-NH bond in acidic solutions. The relative importance of electron trapping and surface plasmon resonance (SPR) effects of Au nanoparticles is discussed for the enhancement of photocatalytic activity of Au/TiO₂.

DOI： 10.1002/slct.201702664

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Chemical vapour infiltration (CVI) is widely used for fabricating carbon fibre-reinforced carbon materials for aircraft brake disks. This study aims at developing a numerical simulation method for predicting densification of the material during the CVI. Based on the multi-step reaction and deposition models, including the hydrogen inhibition model of pyrocarbon growth, transient 3D simulations of the CVI using methane as a precursor of the pyrocarbon were carried out via the finite element method coupling the mass transfer (by convection and diffusion) and the evolutive porous structure model with gas-phase and surface chemical reactions. The CVI of two different types of preforms was studied. The pore structure evolution models were derived not analytically but numerically with the aid of a computational tool for visualizing the fibre structures. An acceptable agreement was found between the predicted densification profiles and the experimental data obtained using a laboratory CVI reactor at a temperature of 1343 K, a methane pressure of 30 kPa and a total deposition time of 120 h.

DOI： 10.1016/j.ces.2017.10.029

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s13762-018-2131-y

Language：English   Publishing type：Research paper (scientific journal)  

This paper theoretically investigated a large number of reaction pathways and kinetics to describe the vapor-phase pyrolytic behavior of several syringol-type monolignol compounds that are derived from the primary pyrolysis of lignin: 1-(4-hydroxy-3,5-dimethoxyphenyl)prop-2-en-1-one (HDPP), sinapyl alcohol, 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)propan-1-one (HHDPP), 1-(4-hydroxy-3,5-dimethoxyphenyl)propane-1,3-diol (HDPPD), and syringol. The possible pyrolytic pathways involving unimolecular decomposition, addition, and abstraction reactions were investigated by comparing the energy barriers calculated at the B3LYP/6-311++G(d,p) level. In the proposed pathways, all syringol-type monolignols containing a side chain undergo its cleavage to form syringol through the formation of syringaldehyde or 4-vinylsyringol. Syringol is then converted into two products: (a) pyrogallol via the homolysis of the O-CH₃ bond and hydrogenation or (b) guaiacol via addition of an H atom with a carbon bearing methoxyl group in syrignol and the subsequent demethoxylation. The pyrolytic pathways of pyrogallol are classified into two processes: (a) the concerted dehydrogenation of the two hydroxyl H atoms and the unimolecular decomposition to produce acetylene (C₂H₂), ethynol (C₂HOH), and CO or (b) the displacement of an OH with H to produce catechol and resorcinol. Additionally, HDPP undergoes O-CH₃ bond cleavage to form but-1-en-3-yne. The high-pressure limit rate constants for all the proposed elementary reaction steps were evaluated on the basis of transition state theory.

DOI： 10.1021/acs.jpca.7b09450

Language：English   Publishing type：Research paper (scientific journal)  

Flower-like AuPd alloy nanoparticles (NPs) are prepared by reducing a mixture of HAuCl₄/H₂PdCl₄ in an aqueous solution. Transmittance electron microscope (TEM), TEM-energy dispersed X-ray spectroscopy, and X-ray diffraction data indicate that AuPd alloy NPs are composed of Pd rich core and Au rich shell. Crystal growth mechanism of ununiform AuPd alloy NPs is discussed in terms of oxidative etching by Cl^-/O₂. Even when AuPd alloy NPs are covered by SiO₂ shells for the use of dye-sensitized solar cells (DSSCs), ununiform alloy structure of AuPd NPs is reserved after sintering at 450 °C. When 0.36-4.8 wt% of AuPd@SiO₂ NPs are added to TiO₂-N719-DSSCs, the photoconversion efficiency (PCE) is enhanced by 7-38% in comparison with that obtained without addition of metallic NPs. The enhancement of PCE by the addition of AuPd@SiO₂ NPs is discussed in terms of near-field surface plasmon resonance (SPR) effect of metallic NPs and far-field light-scattering effect of large TiO₂ aggregates formed by the addition of a small amount of distilled water into TiO₂ pastes. On the basis of the short-circuit current density (J_sc) and the open-circuit voltage (V_oc) changes upon the addition of AuPd@SiO₂, the enhancement of PCE is attributed to synergy effects of far-field scattering of large TiO₂ aggregates and near-field SPR of AuPd@SiO₂ NPs.

DOI： 10.1002/ppsc.201700396

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A numerical approach is presented for predicting the yields of char and volatile components obtained from fast pyrolysis of three types of lignin (enzymatic hydrolysis lignin, EHL; organic extracted lignin, OEL; and Klason lignin, KL) in a two-stage tubular reactor (TS-TR) at 773–1223 K. The heating rate of lignin particle in the TS-TR was estimated at 10²–10⁴ K/s by solving the heat transfer equation. The pyrolytic behavior of lignin and the formation of products in the temperature rising process were predicted using a semi-detailed kinetic model consisting of 93 species and 406 reactions, and the predicted yields of 8 primary products (i.e., char, tar, CO, CO₂, H₂O, CH₃OH, C₂H₆, and C₃H₆) were compared with experimental data for the critical evaluation. For EHL, the predicted yields of char and H₂O were in good agreement with the experimental results at all temperatures. However, the numerical simulation overestimated tar yield and underestimated CO yield at high temperature probably due to a lack of the kinetic model of the tar cracking reaction. The predicted yields of CH₃OH, C₂H₆, and C₃H₆ were close to the experimental values at high temperature by adding the detailed chemical kinetic model of the secondary vapor-phase reaction. Moreover, the model reproduced the experimental observation that among the three types of lignin the char yield increased in the order of EHL < OEL < KL, whereas the tar yield decreased.

DOI： 10.1016/j.fuel.2017.10.079

Language：English   Publishing type：Research paper (scientific journal)  

In this study, we investigated current situation of biomass gasification plants in 5 cities (c.a. Murayama City, Chichibu City, Ueno Village, Oshu City and Yamaguchi City) in Japan, and make R&D policy proposals to expand the biomass gasification plants. Four cities have commonly promoted the efficient heat utilization such as snow melting, drying the wood and supplying hot water into mushroom bed and hot spring. However, heat utilization is limited in a small area because heat loss is generated during the long-distance transportation. In order to obtain energy forms suitable for the long-distance transportation, such as hydrogen gas and electricity, the R&D of biomass gasification with hydrogen production or combined with Solid Oxide Fuel Cell (SOFC) should be promoted in the future.

Language：English   Publishing type：Research paper (scientific journal)  

The theoretical aspects of the development of a chemical kinetic model for guaiacol and catechol pyrolysis are presented to describe the pyrolysis behaviors of the individual lignin-derived components. The possible pyrolysis pathways involving both unimolecular and bimolecular decomposition were investigated by the potential energy surfaces (PES) calculated at CBS-QB3 level. The high-pressure limiting rate constants of each elementary reaction step were evaluated based on the transition state theory (TST) to determine the dominant pyrolysis pathways. The kinetic analysis results predicted the most favorable catechol unimolecular decomposition pathways, where catechol isomerization to 2-hydroxycyclohexa-2,4-dien-1-one occurred via migration of the hydroxyl H atom, followed by decomposition into 1,3-cyclobutadiene, acetylene, and CO. In the case of the bimolecular reaction of catechol, a hydrogen radical is coupled to the carbon atom in the benzene ring, leading to the formation of phenol and a hydroxyl radical through dehydroxylation. On the other hand, guaiacol is likely to form catechol and phenol via the O-CH₃ homolysis and coupling of a hydrogen radical to the carbon atom with the methoxyl group, respectively.

DOI： 10.1021/acs.jpca.7b08112

Language：English   Publishing type：Research paper (scientific journal)  

Nanoscience and nanotechnology present ubiquitous possibilities in almost any scientific field because of property enhancement occurring in nanoparticles with unique size and shape. The physicochemical characteristics of nanoparticles play an imperative role in their prospective applications. This article reports an in-depth study on the variance of the physicochemical characteristics, the methane decomposition activity, and the sustainability of nano-NiO/SiO₂ (n-NiO/SiO₂) catalysts with different preparation parameters. The influence of nickel/silicate ratio, octadecyltrimethoxysilane (C18TMS)/tetraethylorthosilicate (TEOS) ratio, and of different solvents was investigated. The characteristic features of the prepared catalysts were inspected using N₂ adsorption–desorption measurements, X-ray diffraction, hydrogen temperature-programmed reduction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and methane cracking catalytic activity in a fixed bed reactor. Methane decomposition activity was evaluated by measuring the instantaneous hydrogen production (vol %) and carbon yield (%) at the end of the examination. The results showed that C18TMS has extensively improved the microporosity of the material, hence resulting in the improvement of the catalytic performance. The microporosity of the n-NiO/SiO₂ catalyst has increased from 10.7% to 26.8% when the quantity of C18TMS was increased from 0 to 1.2 mL in the synthesis mixture. Catalysts prepared with a maximum quantity of C18TMS and a minimum quantity of tetraethylorthosilicate exhibited a minimum activity loss of 17.46%.

DOI： 10.1016/j.crci.2017.06.007

Language：English   Publishing type：Research paper (scientific journal)  

Hydrogenolysis is an important approach for depolymerization of lignin, which provides attractive new sustainable platforms of fuels, chemicals, and materials. The theory of lignin hydrogenolysis is, however, still unsound, which limits the development of this approach and causes inconsistencies among experimental studies. In this paper, density functional theory is employed to investigate the initial hydrogenolytic cleavages of recognized five different types of interaromatic unit linkages of lignin, assuming the presence of hydrogen free radicals. The relative free energies of reactant complexes, reaction free energy changes, and rate constants for candidate reactions are calculated comprehensively at 298-538 K. On the basis of the results of calculation and a rapid equilibrium hypothesis, the major reaction channel is decided for each linkage, and its kinetics is assessed. It is concluded that the hydrogenolysis occurs at β-O-4 ether, diphenyl ether 4-O-5′, and β-1′ diphenylmethane linkages instantaneously if these are accessible to hydrogen free radicals, while β-5 phenylcoumaran and β-β′ pinoresinol linkages are virtually inert to hydrogenolysis. (Graph Presented).

DOI： 10.1021/acs.jpca.7b00602

Language：English   Publishing type：Research paper (scientific journal)  

Carbon-supported PtY alloy nanoparticles were prepared as oxygen reduction reaction (ORR) catalysts by reducing a mixture of cis-[Pt(NH₃)₂(NO₂)₂] or Pt(C₅H₇O₂)₂ and Y(CH₃COO)₃⋅4 H₂O in ethylene glycol (EG) with microwave (MW) heating. Microstructure and composition analyses of products by using TEM, TEM–energy-dispersive X-ray spectroscopy (EDS), XRD, X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma atomic emission spectroscopy (ICP-AES) data showed that Pt–YO_x/C (Y/Pt=0.11–0.75) catalysts involving amorphous yttrium oxide were formed as major products. When the YO_x component in the catalysts was removed by using HNO₃ treatment, Pt_99.1–99.6Y_0.4–0.9/C alloy catalysts with low Y contents remained. Higher ORR activity was shown by Pt–YO_x/C and PtY/C catalysts than by Pt–Y(OH)₃/C, Pt–YO_x/C, or PtY/C catalysts prepared by using other conventional chemical reduction methods and thermal treatment methods under a H₂/Ar or Ar atmosphere. The mass activity (MA) and surface specific activity (SA) of the best Pt_99.5Y_0.5/C catalyst, MA=245 A g_Pt ⁻¹ and SA=711 μA cm_Pt ⁻², were equal to or higher than those of the commercially used Pt₈₆Co₁₄/C catalyst, MA=245 A g_Pt ⁻¹ and SA=512 μA cm_Pt ⁻². The major reasons for the high ORR activity of these Pt–YO_x/C and PtY catalysts are discussed. These Pt_99.1–99.6Y_0.4–0.9/C alloy catalysts prepared by using acid treatment are new and promising catalysts for use in proton exchange membrane fuel cells (PEMFCs).

DOI： 10.1002/cctc.201601479

Language：English   Publishing type：Research paper (scientific journal)  

Possible pathways for the pyrolysis of resorcinol with the formation of CO and CO₂ as final products were proposed and evaluated using ab initio calculations. Our experimental study revealed that large quantities of CO₂ are generated in the pyrolysis of 1,3-dihydroxybenzene (resorcinol), while the pyrolysis of the dihydroxybenzene isomers 1,2-dihydroxybenzene (catechol) and 1,4-dihydroxybenzene (hydroquinone) produces little CO₂. The fate of oxygen atoms in catechol and hydroquinone was essentially the formation of CO. In the proposed pathways, the triplet ground state m-benzoquinone was generated initially from simultaneous cleavage of the two O-H bonds in resorcinol. Subsequently, the direct cleavage of a C-C bond of the m-benzoquinone diradical yields 2-oxidanylcyclopenta-2,4-dien-1-yl-methanone, which can be converted via two channels: release of CO from the aldehyde radical group and combination of the ketone radical and carbon atom in the aldehyde radical group to form the 6-oxabicyclo[3.2.0]hepta-2,4-dien-7-one, resulting in the release of CO₂. Potential energy surfaces along the proposed reaction pathways were calculated employing the CBS-QB3 method, and the rate constants at the high-pressure limit were also evaluated based on transition-state theory to assess the feasibility of the proposed reaction pathways.

DOI： 10.1021/acs.jpca.6b05168

Language：English   Publishing type：Research paper (scientific journal)  

Co-synthesis of hydrogen and nanocarbon via methane cracking is a single step technique which meets ever growing need of greenhouse gas (GHG) free energy. Additionally, as produced multifunctional nano-carbon that have a variety of technological applications reduces the process cost. This review is intended to provide a critical and wide-ranging assessment of impact of metal catalyst characteristics and methane decomposing parameters on hydrogen and nanocarbon yield, as well as the alteration of characteristic properties of as-produced nanocarbon. The major factors influencing thermocatalytic decomposition of methane (TCD) includes catalyst support, porosity, surface area, particle size, metal loading, calcination temperature, feed flow rate, partial pressure, and reaction temperature. Literature survey emphasizes that higher temperature and partial pressure together with lower feed flow is the reliable experimental condition to yield high purity hydrogen. Furthermore, initial catalytic activity resembles to the chemical structure of the catalyst and long term activity corresponds to the physical characteristics of catalyst. The structural features of as-produced nanocarbon have inevitable association with catalytic characteristics, such as textural supporters, particle size and material dispersion by physical interactions or chemical interaction. The interaction of metal and support results in modification of electronic properties of metal particles and subsequently influence their catalytic characteristics. In addition to investigation of one-factor-at-a-time experiments, the latest studies with Design of Experiment are also thoroughly reviewed, which analyze the influence of each process variables and their interactions simultaneously. The manuscript, then, extended to the microscopic level understandings on TCD for synthesis of nanocarbon and hydrogen via computational study in the finishing section.

DOI： 10.1016/j.rser.2017.03.088

Language：English   Publishing type：Research paper (scientific journal)  

A novel triple-bed combined circulating fluidized-bed (TB-CFB) coal gasifier, consisting of a downer (pyrolyzer), a bubbling fluidized bed (gasifier), and a riser (combustor) was proposed for realizing low-temperature coal gasification. Several key thermochemical reactions were extracted from those expected in the downer unit: the reforming of refractory tar in both the gas phase and over the char surface, and the steam gasification of the nascent char. This review highlights our recent progress, both experimental and numerical, in studies of thermochemical coal conversion including the various reaction processes, by employing a drop-tube reactor that well approximates the reaction environment in a downer reactor. This discussion can be utilized in designing TBCFBs and optimizing their operation.

DOI： 10.14356/kona.2017008

Language：English   Publishing type：Research paper (scientific journal)  

Novel Fe₃C carbon composite was proposed as new low cost and low environmental impact anode for Li-ion battery. Although the delithiated capacity of Fe₃C without AB were 100mAhg^-1 in the first cycle at a rate of 7mAg^-1, that of Fe₃C with AB was improved to 230mAhg^-1 at a rate of 50mAg^-1. Moreover, nanoparticle-Fe₃C carbon composite including a relatively high-purity Fe₃C could be obtained from α-Fe₂O₃ and ion-exchange resin. The best initial delithiated capacity more than 320mAhg^-1 at a rate of 50mAg^-1 and improved anode performance were obtained in the Fe₃C-carbon composite sintered at 650°C.

DOI： 10.5796/electrochemistry.85.630

Language：English   Publishing type：Research paper (scientific journal)  

This paper presents a novel method for continuous production of a biomass-derived platform chemical, levoglucosenone (LGO), from cellulose without its pretreatment or use of solvent. First, cellulose is pyrolyzed, and then the volatiles are reformed over a catalyst consisting of a type of ionic liquid supported over porous char. The ionic liquid, having a moderate hydrogen-bond basicity, performs well in the dehydrative conversion of levoglucosan (LGA) and anhydrosugar oligomers in the volatiles to LGO at 275 °C. The catalytic reforming to LGO is highly selective, and consequently, the yield of LGO is determined mainly by the pyrolysis conditions that produce the LGO precursors. The highest LGO yield we obtained was 31.6% on a cellulose carbon basis (24.6 wt %) with fast pyrolysis that produced more precursors than the slow one. Furthermore, the reaction system is applicable to the production of dihydrolevoglucosenone (DLGO), a promising biobased alternative to dipolar aprotic solvents. Addition of hydrogen in carrier gas and a hydrogenation catalyst in the catalytic bed enables the production of DLGO, although improvement in hydrogenation selectivity is required in the present reforming system.

DOI： 10.1021/acssuschemeng.6b02463

Language：English   Publishing type：Research paper (scientific journal)  

This paper reports, for the first time, complete arene hydrogenation of phenolic compounds as lignin monomers over a non-noble metal catalyst supported by a general material. A type of nano-sized Ni catalyst was prepared in ethanol and in situ supported by ZSM-5 zeolite through general borohydride reduction of Ni²⁺ to Ni⁰, but with application of a simple ligand, pyridine. This catalyst showed an activity so high as to completely or near completely hydrogenate the aromatic rings of phenol and its twelve derivatives as potential lignin monomers at 180 °C. The activity was clearly higher than that of another type of conventional Ni catalyst prepared in the absence of pyridine. Analyses of the catalysts by TEM/EDS, XPS, XAFS and others demonstrated that pyridine had crucial roles in selective formation of nano-sized Ni and maintenance of its activity by appropriate interaction with the support. This paper also shows our theoretical approach to the mechanism of the borohydride reduction. First-principles calculations based on density functional theory (DFT) revealed the reaction pathway from Ni²⁺ to Ni⁰ and the role of pyridine, which was validated by some experimental facts. The DFT calculations also explain the variety of reactivities of the lignin monomers, which are strongly influenced by their molecular electrostatic and steric nature.

DOI： 10.1039/c6ta08538e

Language：English   Publishing type：Research paper (scientific journal)  

Inspired by the results of calculation on the basis of density functional theory and a semi-empirical method, we found an easy, robust, and efficient approach to solve the problem of folded lignin macromolecules, which is a key factor for impeding their breakdown into monomers by hydrogenolysis. Oxidation and hydrogenolysis, which appear to be independent and contradictory of each other in many past studies, were combined and successively performed in this study. Hydrogen peroxide was used to damage the strong intramolecular hydrogen bonds of kraft lignin efficiently, transforming the folded three-dimensional geometries of the lignin macromolecules into stretched ones in an alkaline aqueous medium. Following the pretreatment of stretching lignin molecules, catalytic hydrogenolysis was performed in the presence of a Ni catalyst supported by the ZSM-5 zeolite, reported by the authors. Because of more chemisorption sites of the stretched lignin macromolecules onto the catalyst surface and the remission of lignin re-polymerization/self-condensation, conversion of the kraft lignin into oil reached 83 wt% lignin, 91 wt% which was accounted for by nine types of monomers. This study has thus demonstrated high yield monomer production from lignin dissolved in aqueous media.

DOI： 10.1039/c7gc01121k

Language：English   Publishing type：Research paper (scientific journal)  

Ion-attachment mass spectrometry (IAMS) is a technique used for measuring easily ionized organic compounds in a non-fragmenting mode by softly attaching a Li⁺or another type of alkaline ion to the gaseous molecule. In this study, a prototype device for Li⁺IAMS is developed for real-time quantitative monitoring of the vapor produced from thermochemical conversion of coal. Simulated tar vapor containing a suite of aromatics and the real vapor produced from the pyrolysis of coal are monitored by IAMS with a Li⁺source. It is confirmed that both the simulated and real vapors are ionized without undergoing fragmentation and the sensitivities of these detected aromatic molecules are similar to one another. In addition, when the feeding rate of the coal sample is changed from 0.5 to 1.0 g/min, the peak intensities increase nearly twice as much. These results show the possibility of applying IAMS to the quantitatively monitoring of coal-derived volatiles.

DOI： 10.1016/j.fuproc.2016.12.001

Language：Japanese   Publishing type：Research paper (scientific journal)  

Density functional theory (DFT) has become a widely applied computational tool in most chemistry fields. Because of its applicability, DFT calculations involving metal complexes are reviewed. The achievements in the applications of DFT and the diverse DFT usage modes are shown. Developments of exchange–correlation functionals and weak interaction corrections are concisely illustrated. Moreover, practical applications of different functionals are compared and suggestions regarding the selection of functionals are presented. There are basically two methods of obtaining highly accurate exchange–correlation functionals, and borrowing the concept of orbitals from ab initio method is still unavoidable in DFT for the foreseeable future.

DOI： 10.1039/C6RA16168E

Language：English   Publishing type：Research paper (scientific journal)  

This paper investigated the interactions between volatiles and char during pyrolysis of biomass with an emphasis on those between the reactive compounds in volatiles and the oxygen-containing functional groups in char. On the basis of a comparative study on the products from biomass pyrolysis with and without heavy oil (HO) recycling, which represented a maximization and minimization of the volatile-char interactions, respectively, levoglucosan (LG) was selected as the typical reactive compound in the volatiles. The interactions between LG and functionalized graphitized multiwalled carbon nanotubes with hydroxyl and carboxyl groups (HGMCN and CGMCN, respectively) as char models were surveyed at 300, 350, 400, and 450 °C. The results show that temperature plays an important role in the interactions between LG and GMCNs. HGMCN interacted with LG only at 400 °C, while the LG-CGMCN interactions started at 400 °C and intensified at 450 °C with a significant increase in gas yield. The GC-MS analyses indicated that the liquid products from the LG-GMCNs interactions were predominant in furfural and 5-methyl-2-furancarboxaldehyde.

DOI： 10.1021/acs.energyfuels.6b00725

Language：Japanese   Publishing type：Research paper (scientific journal)  

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DOI： 10.1016/j.cej.2014.12.041

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Language：English   Publishing type：Research paper (international conference proceedings)  

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We have developed a Ni/ZSM-5 catalyst and utilised it to completely hydrogenate a series of condensed arenes, including naphthalene, anthracene and phenanthrene, under relatively mild conditions. The yields of decalin, perhydroanthracene and perhydrophenanthrene reached 100%, 98.8% and 25.8%, respectively. By analyzing the isomer distribution of the perhydroarenes, we proposed a mechanism of biatomic hydrogen transfer, which was further proven via the hydro- genation of 9,10-diphenylanthracene. Through hydrotreatment over the Ni/ZSM-5 catalyst, both high-temperature coal tar rich in condensed arenes and low-temperature coal tar mixing arenes with alkanes were greatly upgraded. The majority of arenes in the coal tars were deeply and even completely hydrogenated, which may open up a route for further processing and application of coal tar as clean fuels.

DOI： 10.1039/c3ra47701k

Language：English   Publishing type：Research paper (scientific journal)  

Flow behaviors of binary mixture of silica sand and nylonshot (coal char substitute) were investigated in a triple-bed circulating fluidized bed (TBCFB) as a cold model of coal gasifier. The TBCFB consisted of a downer (/ 0.1 m 6.5 m), a bubbling fluidized bed (0.75 m 0.27 m 1.9 m), a riser (0.1 m 16.6 m) and a gas-sealing bed (GSB, / 0.158 m 5 m). The initial fraction of the nylonshot in the solid mixture (Xnylon,i) was 15.4 and 30% on mass and volume bases, respectively, or otherwise, 30.7 and 50%. The maximum solids mass flux (Gs) at Xnylon,i of 15.4 and 30.7 wt% were 394 and 349 kg/ m2 s, respectively, when the gas velocity in the riser (Ugr) was 10 m/s. Apparent solids holdups of silica sand and nylonshot were calculated separately from the static pressure gradient across the riser and the downer. The results showed possibility of large-mass-flux circulation of char in the gasifier, which plays a significant role in decomposition of tar from pyrolysis as the primary step of gasification. A newly developed pressure balance model successfully predicted Gs of the binary mixtures in TBCFB.

DOI： 10.1016/j.apt.2013.06.007

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

We performed pyrolysis analyses of various biomasses and biomass-derived materials using a thermo- gravimetry device and a wire-mesh reactor. Kinetic parameters, which were a frequency factor and an activation energy, were derived based on a distributed activation energy model. We validated the predic- tion of thermogravimetric curves calculated using the kinetic parameters in the case of rapid pyrolysis of biomass having the least interaction between particles and volatiles. Unlike coal, the kinetic parameters of the samples changed markedly with progression of pyrolysis. We estimated that the low activation energy in the initial step was caused by hydration and the volatilisation of lighter components. Some bio- mass samples showed a decrease in both the frequency factor and activation energy during pyrolysis. Changes in the chemical structures of xylan and cellulose from cyclic aliphatic units to aromatic units, accompanying amorphism, softening, or melting of part of the solid phase in some cases, caused a decrease in kinetic parameters during pyrolysis. Both the frequency factor and activation energy of all biomass samples increased in the final stages, which was considered to be the result of char forming by carbonisation. Analysing in detail the changes in kinetic parameters provided information on the behaviour of the volatilisation, the change in solid state, and the extent of char structural development.

DOI： 10.1016/j.fuel.2012.04.023

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/cctc.201300547

Language：English   Publishing type：Research paper (scientific journal)  

A novel circulating fluidized bed (CFB) gasifier, which consists of a downer and two bubbling fluidized beds, was developed. Coal is continuously pyrolyzed in the downer and the resultant char is sent to the bubbling bed gasifier for steam gasification while evacuation of the volatiles avoids the char–volatile interactions. Any ungasified char is transferred from the gasifier to the bubbling bed combustor, where it is either completely combusted or partially combusted and then recycled to the downer. Steam gasification was successfully performed in the absence of pyrolysis-derived volatiles, which strongly inhibit gasification. The recycling of the partially combusted char greatly increased its concentration in the downer thereby enhancing the reforming of the volatiles, in particular that of tar over that of char, and the resultant gas formation. The total yield of gases from the downer and bubbling bed gasifier was 45% higher than that obtained under direct feeding of the coal into the bubbling bed gasifier and full combustion of the char, i.e., with steam gasification of char in the presence of volatiles and subsequent reforming over char at a much lower concentration.

DOI： 10.1016/j.fuproc.2013.07.017

Language：English   Publishing type：Research paper (scientific journal)  

Production of coke from lignites was studied in continuation of a previous study that demonstrated effectiveness of a sequence of hot briquetting and carbonization on preparation of high strength coke from a lignite. Cokes were prepared from four Indonesian lignites with or without pretreatments such as hydrothermal treatment (HT) at 200−300 °C, acid washing (AW), and a combination of them (HT−AW). The hot briquetting of the raw lignites at temperature and mechanical pressure of 200 °C and 128 MPa, respectively, enabled cokes to be produced with a tensile strength (TS) of 7−22 MPa. The pretreatments, AW and HT at 200 °C (HT200), increased TSs of resulting cokes to 18−24 and 13−36 MPa, respectively. A sequence of HT200 and AW further increased TSs of cokes to 27−40 MPa. AW and HT200 modified the macromolecular structure of the lignites by different mechanisms. AW removed alkali and alkaline earth metallic species that played roles of cross-links in the macromolecular network, while HT200 rearranged macromolecules physically. Both HT and AW enhanced plasticization and then deformation/coalescence of lignite particles during the briquetting, which formed high strength briquettes. There were strong correlations between TS of coke and that of briquette and also between TS and bulk density of coke from the individual lignites.

DOI： dx.doi.org/10.1021/ef4016558

Language：English   Publishing type：Research paper (scientific journal)  

A Victorian brown coal (Loy Yang, LY) was co-fed with char prepared from the same coal in an atmospheric drop-tube reactor (DTR) at 900 and 950 °C in the presence of 50% steam to study in situ reforming of tar derived from rapid pyrolysis of brown coal over a char surface. Two different chars were prepared, including devolatilised LY at 800 °C under nitrogen flow (LYC, surface area 524 m2/g) and LYC gasified with steam at 900 °C (GLYC, surface area 734 m2/g). The concentrations of chars in the blended samples varied from 50% to 85% on a carbon basis. The yield of tar derived from LY (no char was blended) was 4.2 wt.% at 900 °C and particle residence time around 3–4 s. The yield decreased with increasing char concentration, and was 0.5 wt.% at a GLYC concentration of 85% at 900 °C. Tar conversion over GLYC was more extensive than that over LYC and occurred more significantly at a higher temperature. Increasing the feeding rate of sample particles enhanced tar reforming, suggesting that solid hold-up was an important factor determining tar conversion characteristics. Liquid chromatography (LC) showed that the major components of heavy tar included typical polycyclic aromatic hydrocarbons (PAHs) ranging from three-membered rings (acenaphthylene) to seven-membered rings (coronene).

DOI： 10.1016/j.fuel.2011.12.030

Language：English   Publishing type：Research paper (scientific journal)  

A kinetic model of steam gasification of Ca-loaded lignite char has been proposed through the analysis of 41 sets of kinetic data obtained by thermogravimetry with different combinations of Ca concentration, temperature, and partial pressures of hydrogen and steam. The model quantitatively describes the change with time of the char conversion over its entire range by assuming progress of non-catalytic gasification and two different types of Ca-catalyzed gasification (Type-1 and Type-2) in parallel, all of which obey Langmuir−Hinshelwood mechanisms. The model attributes the catalysts for Type-1 and Type-2 to nanosized Ca-based particles and Ca species dispersed in an atomic scale, respectively. The initial concentration of Type-2 catalyst is saturated at a total Ca concentration over 1.0 wt %, while that of Type-1 increased in a linear manner with the total Ca concentration. The catalysis of Type-1 catalyst is more significant but diminished more quickly than that of the Type-2 one. Consequently, there was an optimum initial Ca concentration in the char around 2.0 wt % in terms of the time required for 99% char conversion. This trend is clearly different from that predicted from previous models that simply assumed loading saturation levels (LSLs). The kinetic model predicts characteristics of the steam gasification of the Ca-loaded char in an atmospheric bubbling fluidized bed at 800 °C. The characteristic time for the char gasification, which is given by the amount of in-bed char at steady state per feeding rate of the char (mc/Fc), is reduced by virtue of Ca by a factor of 7−8.

DOI： dx.doi.org/10.1021/ef401688h

Language：English   Publishing type：Research paper (scientific journal)  

Cost of catalysts is a crucial factor in realizing coal catalytic gasification process. In this study, inexpensive raw materials, soda ash (Na2CO3) and slaked lime (Ca(OH)2), were selected as catalyst precursors, and Na-, Ca- and Ca/Na-loaded coals were prepared by an ion-exchange procedure using a sub-bituminous coal (Adaro coal, Indonesia). These coal samples were rapidly pyrolyzed and in-situ gasified in an atmospheric drop-tube reactor (DTR) at 850–1000 °C under a steam partial pressure of 0.05 MPa. The Na and Ca catalysts showed remarkable activity for gasification, and the Ca/Na-loaded coal exhibited the highest reactivity among the coal samples prepared. The char yield of the Ca/Na-loaded coal at 1000 °C was as low as 17.6 mol-C per 100 mol-C of coal, and more than 70% (on carbon basis) of its primary char was gasified within 3 s. At 900 °C, the coal with Ca-loading of 3.2 wt.% showed catalytic activity higher than the coal with Ca-loading of 0.52 wt.%. At 950 and 1000 °C, however, the coal with the lower Ca-loading showed higher activity. The XRD analysis suggested that the Ca catalyst with the lower loading was more resistant to coarsening along with the progress of char gasification.

DOI： 10.1016/j.fuproc.2013.03.009

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Thermal dissolution (TD) of Shengli lignite (SL) in ethyl acetate (EA) was carried out under different conditions, including temperature, solvent to SL ratio (RS/SL), and time. The yields of EA-extractable fractions (EAEFs) increased with raising temperature from 240–300°C, but then decreased when the temperature was higher than 300°C, and the effects of RS/SL and time on
EAEF yields was slight when RS/SL and time exceeded 20/1 and 1 h, respectively. These results suggest the optimal conditions for the TD of SL are 300°C, 20/1 of RS/SL, and 1 h. Then a couple of scale-up experiments were carried out under the optimal conditions with SL and dehydrated SL. According to analysis with a gas chromatography/mass spectrometry, major species in the
EAEF from the TD of SL are oxygen-, sulfur-, and nitrogen-containing organic compounds along with elemental sulfur. The sulfur- and nitrogen-containing organic compounds detected include thioethers, thiophenes, amines, and nitrocyclic compounds. According to the structural characteristics of organic compounds in the EAEF, the mechanism for the TD of SL with EA was presumed.

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

A method is proposed to estimate the enthalpy of bio-oil in the vapor phase, Hbo, as a function of temperature in the range 298.15–1000 K, of which experimental determination has not been done so far. The two equations proposed in this work allow estimation of the standard enthalpy of formation, Hbo,0, and the difference in the enthalpy between 298.15 K and a given temperature, ΔHbo(T), respectively, only based on the overall C, H, and O contents of crude bio-oil of that N and S contents are lower than 0.5 and 0.1 wt %-daf, respectively. These equations were optimized using thermodynamic data of 290 and 141 organic compounds for Hbo,0, and ΔHbo(T), respectively. Given the yields of bio-oil, char, and gas, elemental compositions of the bio-oil and char, and chemical composition of the gas, proposed equations predict the heat required for biomass pyrolysis, Qpy(Tpy), which is defined as the enthalpy difference between the products at the pyrolysis temperature, Tpy, and the biomass at 298.15 K. The predicted Qpy at Tpy = 773–823 K for five different types of dry biomass was in the range of 1.1–1.6 MJ kg–1.

DOI： 10.1021/ef400199z

Language：English   Publishing type：Research paper (scientific journal)  

Pyrolysis of biomass or coal, if operated at temperatures high enough to complete tar evolution, is expected to give resulting char a tar-free nature. Use of such tar-free char instead of the original fuel in gasification would reduce or even completely eliminate the need for use of complex devices/mechanisms for tar/soot removal. Increasing pyrolysis temperature may not only decrease content of residual tar in the char, but also reduce its reactivity with gasifying agents. There is thus a range of optimum pyrolysis temperatures depending on the original fuel and type/mode of gasification, which yields char of suitable quality. In this work, a variety of char samples were prepared by pyrolysis (first pyrolysis) of three different woody biomass feedstock and a Victorian lignite with heating rate and peak temperature of 10 °C/min and 450–750 °C, respectively, and were further subjected to flash pyrolysis (second pyrolysis) at 920 °C. A gas-chromatography mass-spectrometry (GC/MS) detected more than 200 compounds in the volatile products from the second pyrolysis, and quantified 56 aromatic compounds over a range from benzene to coronene, which accounted for more than 85% of the compounds detected on a TIC peak area basis. Total emission of tar, defined as the aromatics except mono-aromatic hydrocarbons, from the biomass chars was 0.03–0.08 wt%-char even at the first pyrolysis temperature of 450 °C, and further decreased to a level around 0.01 wt% by raising the temperature to 600 °C. It was also found that despite containing as much as 20-27 wt.% of residual volatile matter, chars produced by pyrolysis at 500 °C contained less than 0.1 wt.% of residual tar.

DOI： 10.1021/ef4001192

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Conversion of refractory aromatic hydrocarbons was studied with an atmospheric flow reactor that simulated the reducing section of a two-stage entrained-flow coal gasifier in air-blown and O2/CO2-blown (CO2 recycling) modes at temperatures of 1100–1400 °C. Mixed vapors of benzene and naphthalene (7/3 on a carbon basis) were fed into the reactor at total concentration in a range from 3.7 to 37 g·Nm–3 together with a CO–CO2–H2–H2O mixture in the O2/CO2-blown mode or CO–CO2–H2–H2O–N2 mixture in the air-blown mode. Soot was the major fate of the aromatics at the inlet benzene/naphthalene concentration of 35–37 g·Nm–3, and its yield was not influenced significantly either by the mode of gasification or temperature at 1200–1400 °C. The contribution of gas-phase reforming to the conversion of the aromatics became more important as their inlet concentration decreased. At the inlet concentration of 3.7–7.5 g·Nm–3, the O2/CO2-blown mode was clearly more effective in reducing the soot yield than the air-blown mode and increasing the gas yield. It was explained on the basis of a detailed chemical kinetic model that the increased partial pressure of CO2 induced a higher concentration of key active species such as hydroxyl radicals that initiated the oxidative decomposition of the aromatics.

DOI： 10.1021/ef301658d

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/ef301366x

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DOI： 10.1016/j.fuel.2012.04.023

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DOI： 10.1016/j.fuel.2011.04.003

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DOI： 10.1016/j.fuel.2011.12.030

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DOI： 10.1016/j.fuel.2011.07.045

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DOI： 10.1016/j.fuel.2011.06.074

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DOI： 10.1016/j.fuel.2010.01.007

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DOI： DOI:10.1021/ef100161q

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The menace of the disposal of agricultural wastes and water contamination is on the increase. Thus, the need to find a way to recycle these agriculture wastes and make water safe for use. In this study, raw Peanut shell (PSH) and Carbonized Peanut Shell (CPSH) were used as biobased adsorbents in the decontamination of methylene blue (MB) dye from solution. The prepared materials were characterized by SEM, FTIR, XRD, and BET surface area analysis. The batch adsorption method was selected in the MB removal process to maintain adsorbent dosage and dye concentration. The surface area was increased from 1.03 to 34.96 m2 /g. also the pore diameter reduced form macropore (93 nm) to micropores (2.39 nm) after carbonization. The CPSH has an adsorption capacity of 104 mgg-1 and about 90% removal of the 50 mg/L MB with 40 mins at a pH of 6.5. The pseudo-second-order kinetic model best suits the adsorption performance of the CPSH adsorbent. Also, the dye adsorption procedure onto the PSH corresponds to the Langmuir isotherm while the CPSH best fitted with the Freundlich isotherm. This study presents PSH as an alternative resource for the preparation of a cheap and efficient adsorbent from agricultural waste for the removal of laden dye.

DOI： 10.4028/p-rc33cb

Scopus

Language：Japanese   Book type：Scholarly book

DOI： ISBN978-4-86693-542-3

Responsible for pages：ISBN978-4-88890-537-4   Language：Japanese   Book type：Scholarly book

Responsible for pages：3.1.4.2 低品位石炭資源の革新的な改質・輸送・転換技術とエネルギー・製鉄分野への利用、pp.127–135   Language：Japanese   Book type：Scholarly book

Language：Japanese   Book type：Scholarly book

Language：English   Book type：Scholarly book

Event date： 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本   Country：Japan  

Event date： 2014.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：岐阜   Country：Japan  

Event date： 2013.12

Language：English   Presentation type：Oral presentation (invited, special)  

Venue：Wuhan   Country：China  

Event date： 2013.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Wuhan   Country：China  

Event date： 2013.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Unzen   Country：Japan  

Event date： 2009.9

Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Event date： 2009.9

Presentation type：Oral presentation (general)  

Venue：東京都   Country：Japan  

Event date： 2009.8 - 2009.9

Presentation type：Oral presentation (general)  

Venue：Qindao   Country：China  

Event date： 2009.8

Presentation type：Oral presentation (general)  

Venue：東京都   Country：Japan  

Event date： 2024.1

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Other Link： https://www.youtube.com/watch?v=NsY9fjJC3YA

Event date： 2023.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2022.8

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：東京   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2021.12

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Novel iron-making process using organic acid derived from CO2

Other Link： https://web.apollon.nta.co.jp/CUUTE-1/index.html

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

反復酸素アルカリ処理による木質バイオマスの脱リグニン率向上

Event date： 2021.6 - 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州市   Country：Japan  

カーボンニュートラルおよびネガティブな炭素資源の転換利用

Event date： 2021.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2020.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.6

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪府   Country：Japan  

Event date： 2020.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州市   Country：Japan  

Event date： 2019.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2019.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2019.1

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：つくば市   Country：Japan  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：鹿児島市   Country：Japan  

Event date： 2018.9 - 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：徳島   Country：Japan  

Event date： 2018.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Ulanqab   Country：China  

Event date： 2018.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Ulanqab   Country：China  

Event date： 2018.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌   Country：Japan  

Event date： 2018.5

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：東京   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2017.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Perth   Country：Australia  

Event date： 2017.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Daejeon   Country：Korea, Republic of  

Event date： 2017.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Auckland   Country：Japan  

Event date： 2017.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Auckland   Country：New Zealand  

Event date： 2017.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Auckland   Country：New Zealand  

Event date： 2017.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Daejeon   Country：Korea, Republic of  

Event date： 2017.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Daejeon   Country：Korea, Republic of  

Event date： 2017.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Daejeon   Country：Korea, Republic of  

Event date： 2017.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Daejeon   Country：Korea, Republic of  

Event date： 2017.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島   Country：Japan  

Event date： 2017.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島   Country：Japan  

Event date： 2017.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島   Country：Japan  

Event date： 2017.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島   Country：Japan  

Event date： 2017.11

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2017.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Barcelona   Country：Spain  

Event date： 2017.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2017.9

Language：Japanese  

Venue：名古屋   Country：Japan  

Event date： 2017.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Gwangju   Country：Korea, Republic of  

Event date： 2017.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州   Country：Japan  

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2017.2 - 2018.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岡山市   Country：Japan  

Event date： 2017.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2016.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Miyazaki   Country：Japan  

Event date： 2016.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Miyazaki   Country：Japan  

Event date： 2016.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Miyazaki   Country：Japan  

Event date： 2016.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Miyazaki   Country：Japan  

Event date： 2016.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Miyazaki   Country：Japan  

Event date： 2016.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Miyazaki   Country：Japan  

Event date： 2016.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Miyazaki   Country：Japan  

Event date： 2016.12

Language：Japanese  

Venue：千葉   Country：Japan  

Event date： 2016.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2016.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2016.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2016.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2016.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2016.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2016.10

Language：English  

Venue：Kuala Lumpur   Country：Malaysia  

Event date： 2016.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Miyazaki   Country：Japan  

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Miyazaki   Country：Japan  

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：徳島   Country：Japan  

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：徳島   Country：Japan  

Event date： 2016.5

Language：English   Presentation type：Oral presentation (general)  

Venue：Nancy   Country：France  

Event date： 2016.3

Language：Japanese  

Venue：大阪   Country：Japan  

Event date： 2016.3

Language：Japanese  

Venue：大阪   Country：Japan  

Event date： 2016.3

Language：Japanese  

Venue：大阪   Country：Japan  

Event date： 2016.1

Language：Japanese  

Venue：新潟   Country：Japan  

Event date： 2016.1

Language：Japanese  

Venue：新潟   Country：Japan  

Event date： 2016.1

Language：English  

Venue：Niigata   Country：Japan  

Event date： 2016.1

Language：English  

Venue：Niigata   Country：Japan  

Event date： 2015.12

Language：English  

Venue：Wuhan   Country：China  

Event date： 2015.12

Language：English  

Venue：Wuhan   Country：China  

Event date： 2015.10

Language：Japanese  

Venue：伊勢   Country：Japan  

Event date： 2015.10

Language：English  

Venue：Kuala Lumpur   Country：Malaysia  

Event date： 2015.10

Language：Japanese  

Venue：東京   Country：Japan  

Event date： 2015.9 - 2015.10

Language：English  

Venue：Melbourne   Country：Australia  

Event date： 2015.9 - 2015.10

Language：English  

Venue：Melbourne   Country：Australia  

Event date： 2015.9

Language：Japanese  

Venue：東京   Country：Japan  

Event date： 2015.9

Language：Japanese  

Venue：北海道   Country：Japan  

Event date： 2015.9

Language：Japanese  

Venue：北海道   Country：Japan  

Event date： 2015.8 - 2015.9

Language：English  

Country：China  

Event date： 2015.7

Language：Japanese  

Venue：東京   Country：Japan  

Event date： 2015.5

Language：English   Presentation type：Oral presentation (general)  

Venue：La Rochelle   Country：France  

Event date： 2015.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2015.3

Language：English   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2015.2

Language：English   Presentation type：Oral presentation (general)  

Venue：Perak Darul Ridzua   Country：Malaysia  

Event date： 2015.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば   Country：Japan  

Event date： 2015.1

Language：English   Presentation type：Oral presentation (general)  

Venue：つくば   Country：Japan  

Event date： 2015.1

Language：English   Presentation type：Oral presentation (general)  

Venue：つくば   Country：Japan  

Event date： 2015.1

Language：English   Presentation type：Oral presentation (general)  

Venue：つくば   Country：Japan  

Event date： 2014.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Kanchanaburi   Country：Thailand  

Event date： 2014.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2014.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Kuala Lumpur   Country：Malaysia  

Event date： 2014.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Kuala Lumpur   Country：Malaysia  

Event date： 2014.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Yeosu   Country：Korea, Republic of  

Event date： 2014.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Yeosu   Country：Korea, Republic of  

Event date： 2014.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Yeosu   Country：Korea, Republic of  

Event date： 2014.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台   Country：Japan  

Event date： 2014.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2014.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台   Country：Japan  

Event date： 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2014.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Bangkok   Country：Thailand  

Event date： 2014.8 - 2016.9

Language：English  

Venue：Dunhuang   Country：China  

Event date： 2014.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2014.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2014.7

Language：English   Presentation type：Oral presentation (invited, special)  

Venue：Fukuoka   Country：Japan  

Event date： 2014.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

Event date： 2014.5

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2014.1

Language：English   Presentation type：Oral presentation (general)  

Venue：Kochi   Country：Japan  

Event date： 2014.1

Language：English   Presentation type：Oral presentation (general)  

Venue：Kochi   Country：Japan  

Event date： 2013.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Pusan   Country：Korea, Republic of  

Event date： 2013.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Pusan   Country：Korea, Republic of  

Event date： 2013.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Pusan   Country：Korea, Republic of  

Event date： 2013.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Pusan   Country：Korea, Republic of  

Event date： 2013.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Pusan   Country：Korea, Republic of  

Event date： 2013.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Hiroshima University   Country：Japan  

Event date： 2013.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本   Country：Japan  

Event date： 2013.11

Language：English   Presentation type：Oral presentation (general)  

Venue：San Francisco   Country：United States  

Event date： 2013.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学   Country：Japan  

Event date： 2013.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyushu University   Country：Japan  

Event date： 2013.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyushu University   Country：Japan  

Event date： 2013.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyushu University   Country：Japan  

Event date： 2013.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyushu University   Country：Japan  

Event date： 2013.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyushu University   Country：Japan  

Event date： 2013.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyushu University   Country：Japan  

Event date： 2013.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyushu University   Country：Japan  

Event date： 2013.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyushu University   Country：Japan  

Event date： 2013.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyushu University   Country：Japan