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出版者・発行元：RSC Sustainability  

Phytic acid (PA) is a cheap organophosphorus compound readily available from agricultural wastes, with the potential to serve as a biogenic source of phosphorus compounds currently derived from finite phosphate rock. Developing applications for PA is important for its industrial implementation. This study demonstrates that PA serves as an effective organocatalyst during the pyrolysis of cellulose, promoting the selective formation of the high-value platform chemical levoglucosenone (LGO). With a loading of only 0.3 wt% PA (<0.1 wt% on a phosphorus basis), the onset temperature of cellulose pyrolysis decreased by over 60 °C. A detailed analysis of the catalytic performance, mainly during slow pyrolysis, revealed that PA penetrates the cellulose particles and fibers during the heating process, forming various chemical bonds and promoting dehydration. As a result, the LGO yield, which was only 2 wt% for pure cellulose, increased to 19.6 wt% (25.0% on a carbon basis) with a loading of 0.75 wt%. Excessive loading promoted char formation. The amount of PA required to maximize the LGO yield was about two-thirds that of conventional phosphoric acid (based on phosphorus content), suggesting superior catalytic performance and lower P loadings are possible. PA also led to the selective formation of LGO in the pyrolysis of lignocellulosic biomass, though in poorer yield compared to pure cellulose. Although it was difficult to extract PA from pyrolysis char for direct reuse, this residue could, in principle, re-enter the phosphorus cycle, possibly as a fertilizer.

DOI： 10.1039/d4su00502c

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掲載種別：研究論文（学術雑誌）   出版者・発行元：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

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掲載種別：研究論文（学術雑誌）   出版者・発行元：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

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：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

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その他リンク： https://link.springer.com/article/10.1007/s13399-024-05437-0/fulltext.html

記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：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

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：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

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その他リンク： https://link.springer.com/article/10.1007/s41981-023-00295-9/fulltext.html

記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：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

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Chemical Engineering Journal  

The multiphase segmented flow, which consisted of the material, extraction, and recovery phases, was applied to the chiral separation. The use of simultaneous extraction and back-extraction with multiple phases aims to prevent the accumulation of target material in the extraction phase by efficiently removing it in the recovery phase, thereby enabling extraction performance beyond the equilibrium. This study demonstrated the chiral separation of an aqueous racemic amino acid derivative (3,5-dinitrobenzoyl-(R,S)-leucine) with a cinchona alkaloid chiral host. A droplet manipulation system comprising PFA manifolds and valves was utilized to alternately form an acidic material phase slug and a basic recovery phase slug in a 1-octanol oil phase containing the chiral host. Two aqueous phases were collected separately using valves controlled by an optical sensor signal. The manipulation system achieved stable operation across various conditions, including flow rate, residence time, and slug lengths. The enantiomeric excess, which represents the purity of the chirality, could be increased to 50 % through 200 s extraction in a one-step operation.

DOI： 10.1016/j.cej.2023.143891

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Reaction Chemistry and Engineering  

<jats:p>We have studied the unique reaction acceleration phenomenon in the mixture and discussed the limitations of the Langmuir–Hinshelwood model for a solid-catalysed reaction.</jats:p>

DOI： 10.1039/d3re00032j

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：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

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Fermentation  

<jats:p>An enzyme membrane reactor is an attractive tool for producing oligosaccharides from biomass-based polysaccharides. However, kinetic modeling and reactor design based on the rate equations have rarely been reported for enzyme membrane reactors because of the difficulty in tracing the depolymerization process. In this study, a simplified reaction model based on Michaelis–Menten-type kinetics has been built to simulate the enzyme membrane reactor. Ramping various species into reactant, target, and byproduct worked well for discussing reactor performance. The use of a membrane with a molecular weight cut-off (MWCO) of 10 kDa with continuous feeding of the reactant was suggested for the efficient production of chitosan hexamer and pentamer by enzymatic hydrolysis of chitosan.</jats:p>

DOI： 10.3390/fermentation8120701

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：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

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：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

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記述言語：その他  

DOI： 10.1002/9783527830190.ch5

記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Key Engineering Materials  

Glucose is a key compound for future biomass-based energy and chemical industry. An availability of glucose from abundant lignocellulosic biomass is limited because of a slow reaction rate and costly feed materials in a conventional enzymatic hydrolysis of cellulose. The present work investigated the production of glucose with hydrolysis of anhydrosugars produced by cellulose pyrolysis that is a fast reaction with no requirement for other chemicals to feed. A commercially available solid acid was employed as the hydrolysis catalyst for enabling a direct use of glucose aqueous solution without posttreatment such as separation. The experiments using a model anhydrosugar, levoglucosan (LGA), as feedstock revealed a selective activity of the catalyst to produce glucose even at the high concentration of 2.7 M and the catalytic stability in 15 h run of the reaction using a continuous flow reactor. The catalyst worked for the reaction with a cellulose-derived bio-oil as the feedstock to selectively produce glucose mainly from LGA. However, the activity gradually decreased due to deposition of carbonaceous materials from compounds other than LGA over the catalyst, indicating the necessity for eliminating those compounds before the hydrolysis.

DOI： 10.4028/p-3800i8

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Energy and Fuels  

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

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：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 ironmaking. 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

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：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

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：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

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Reaction Chemistry and Engineering  

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.

DOI： 10.1039/d2re00147k

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Energy and Fuels  

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 H2SO4or H3PO4at 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 H2SO4led 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 H2as 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

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：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

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACS Sustainable Chemistry and Engineering  

Treatment of herbaceous biomass in hot-compressed water (HCW) depolymerizes and extracts substantial portions of hemicellulose and lignin together with silica, which are all useful chemical feedstocks. The present study proposes processing of rice husk (RH) into high-strength material after pretreatment in HCW. A type of RH was treated in HCW at 140-200 °C in a tubular percolator, dried, pulverized, and then molded into rectangular or circular plates by hot pressing without a binder. The plates of HCW-treated RH had greater tensile and flexural strengths than those of the original RH, while having smaller water absorptivity and swellability. The plates of RH pretreated at 160 °C had the best properties such as tensile strength of 26 MPa (2.8 times that of the nontreated RH), flexural strength of 21 MPa (2.6 times), fracture energy of 1453 mJ (7.8 times), water uptake of 40 wt % (0.74 times), and swelling ratio in water of 1.37 (0.92 times). These properties were attributed mainly to greatly improved pulverizability, resulting occurrence of fibrous reinforcement material, and optimized fractions of cellulose and silica (as reinforcement materials) and those of hemicellulose and lignin (as the matrix and binder). This paper also reports and discusses combined effects of the conditions of HCW treatment, pulverization, and hot-press molding on the strength of plates.

DOI： 10.1021/acssuschemeng.1c07877

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記述言語：その他   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.energyfuels.1c01889

記述言語：その他   掲載種別：研究論文（学術雑誌）  

An automated microflow measurement system for the kinetic study of racemization of dynamic chiral molecules was developed. This system facilitated the analysis of fast racemization within several seconds at elevated temperatures owing to its rapid heating ability, high performance for controlling short residence times, and ease of connection to HPLC systems for direct measurement of the enantiomeric purity. A more precise analysis was realized by combination of microflow and common batch measurements over a broad range of temperatures.

DOI： 10.1021/acs.joc.1c00914

記述言語：その他   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.energyfuels.1c01062

記述言語：その他   掲載種別：研究論文（学術雑誌）  

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&#37;-C. The yield of LGO was further improved to 40.4&#37;-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

記述言語：その他   掲載種別：研究論文（学術雑誌）  

The present study investigated oxidation of pulverized Japanese cedar with O2 in hot-compressed alkaline water, employing a newly developed flow-through fixed-bed reactor (percolator). It allowed us to determine the rate of the primary extraction that was free from the secondary reactions of extract in the aqueous phase and those over the residual solid, solubility of extractable matter, and mass transport processes. Quantitative kinetic analysis revealed that the cedar consisted of three kinetic components (C1-C3) that underwent extraction in parallel following first-order kinetics with different rate constants. Further analysis revealed the chemical compositions of the kinetic components, which were mixtures of carbohydrates and lignin. C1 was converted most rapidly by nonoxidative reactions such as alkali-catalyzed hydrolysis, while C2 was converted by oxidative degradation. The product distributions from C1 and C2 (CO2, lower organic acids, oligosaccharides, acid-soluble, and acid-insoluble lignins) were steady throughout their conversion. Both C1 and C2 thus behaved as single reactants; nevertheless, those were lignin/carbohydrates mixtures. It was also demonstrated that the extraction rate of C2 was proportional to the concentration of dissolved O2. C3 was the most refractory component, consisting mainly of glucan and very minimally of the lignin, xylan, mannan, galactan, and arabinan.

DOI： 10.1021/acsomega.0c05154

記述言語：日本語  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

This study demonstrates the possibility of “contactless” mass transfer between two aqueous slugs (droplets) separated by an oil slug in Taylor flow inside milli-channels. Separation of the alternating aqueous slugs at the outlet was performed by switching a couple of solenoid valves at branched outlets according to signals obtained by an optical sensor at the branch. Transfer of bromothymol blue (BTB) from acidic to basic aqueous slugs was performed for demonstration. In some cases, aqueous slugs separated by oil, merged catching on each other due to the velocity difference. Interfacial tension which was affected by the solute concentration was responsible for the velocity difference. Position-specific mass transfer activity at the rear end of the aqueous slugs was found on the course of the experiment. A meandering channel decreased the velocity difference and enhanced mass transfer. Almost complete (93%) transfer of BTB was achieved within a short residence time of several minutes under optimized conditions. The presented system opens a way for advanced separation using minimum amounts of the oil phase and allows concentrating the solute by altering relative lengths of the sender and receiver slugs.

DOI： 10.1038/s41598-020-64520-4

記述言語：その他   掲載種別：研究論文（学術雑誌）  

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&#37; delignification, which was 8&#37; higher than a single 8-h treatment at 130 °C.

DOI： 10.1021/acsomega.0c03953

記述言語：その他   掲載種別：研究論文（学術雑誌）  

We have demonstrated a sequence of degradation, dissolution and catalytic hydrothermal gasification (CHTG) of lignite in alkaline water. A Victorian lignite was subjected to hydrothermal treatment (HT) in an aqueous solution of NaOH at 250 °C, and then oxidation with pressurized O at 100 °C. The sequential HT and oxidation solubilized a 95&#37; portion of the lignite on mass/carbon bases. The resulting solution was further converted by CHTG in a flow reactor at 350 °C for 10 h, employing a ruthenium/activated-charcoal catalyst (ruthenium loading; 16 wt&#37;). The initial carbon conversion to gas was as high as 98&#37; while CH , CO and H were produced. The conversion gradually decreased due to coke deposition over the catalyst but was near steady around 83&#37; at 8–10 h. The solubilized lignite consisted of compounds with molecular mass up to 5,000. The heavier portion (molecular mass > 1,000) was responsible for the coke formation and accumulation that caused the catalyst deactivation. 2 4 2 2

DOI： 10.1016/j.fuel.2020.118329

記述言語：その他   掲載種別：研究論文（学術雑誌）  

Global iron and steel production continues to expand. The iron-making industry is, however, one of the main contributors to global warming due to its reliance on fossil fuel-based high temperature processes. Therefore, alternative green approaches to iron-making are highly desired. Herein, we propose a new concept of iron-making, which consists of a sequence of known reactions: the dissolution of iron from iron ore using oxalic acid to obtain a Fe(III) oxalate aqueous solution, followed by the photochemical reduction of Fe(III) oxalate to Fe(II) oxalate as a solid precipitate, and the pyrolytic reduction of Fe(II) oxalate to metallic iron. By harnessing the chemical characteristics of oxalic acid and iron oxalates, the method is expected to produce high-quality iron at low temperatures. Moreover, the recovery of carbon oxides, generated during iron-making, for the synthesis of oxalic acid enables the iron-making without having carbon in the stoichiometry. The present study explains the key chemical concepts of the process, experimentally demonstrates the iron-making, and discusses the challenges and barriers to industrial application. In the experiment, according to the proposed scheme, three different iron sources were successfully converted into metallic iron. The yield and quality (purity) of the iron product depended on the metallic composition of the feedstock. In the absence of impurity metals, near-complete recovery of pure iron was possible. Alkaline earth and transition metals were identified as impurities that affected process performance and product quality. The iron dissolution needed a relatively long reaction time to achieve sufficient conversion under the conditions employed in this study, rendering it a rate-determining step that influenced overall iron productivity.

DOI： 10.1021/acssuschemeng.0c03593

記述言語：その他   掲載種別：研究論文（学術雑誌）  

Pyrolysis is the simplest way to convert lignin into phenolic compounds as monomers but inevitably producing oligomers as heavy oil (HO). We propose a particular type of pyrolysis, which recycles such oligomers entirely to pyrolysis, employing the parent lignin for their capture/recycling without any chemicals and catalysts. Continuous pyrolysis of a Japanese cedar lignin was simulated by repeating fixed-bed pyrolysis of HO-loaded lignin and demonstrated steady state of yields of gas, water, char, and light oil (LO) that consisted solely of monomers and furans and lower acids, with neither discharge of HO from the system nor accumulation therein. HO was converted to char, water, and LO with once-through conversion of around 47&#37;, which was contributed by not only self-pyrolysis of HO but also its copyrolysis/carbonization with the parent lignin. The HO recycling increases the LO yield by a factor of 1.4. Catechols (catechol and methylcatechols) and guaiacols (guaiacol, 4-ethylguaiacol, creosol, vanillin, and apocynin) constitute 42 and 22 wt &#37; of LO, respectively. The char shows an increased production in the sequential runs with a near-unchanged elemental composition, volatile matter content, and calorific value.

DOI： 10.1021/acs.energyfuels.0c01164

記述言語：その他   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acsomega.0c00399

記述言語：英語   掲載種別：研究論文（学術雑誌）  

This study aimed to investigate the effect of carbon derived from glucose (C) on the physicochemical characteristics and catalytic activity of Ni, supported over SiO , ZSM-5, and TiO in methane dry reforming. Among the Ni catalysts without C, Ni/SiO exhibited the highest CH -CO conversion and stability at all experimented temperatures. On the other hand, the C-incorporated catalysts prepared by glucose impregnation, followed by pyrolysis, showed dissimilar performances. C improved the stability of Ni/SiO in the reforming at 650 C and 750 C and increased the CH and CO conversion to the level close to the thermodynamic equilibrium at 850 C. However, this element did not substantially affect the activity of Ni/ZSM-5 and exerted a retarding effect on Ni/TiO . Characterizations with H -TPD, XRD, EXAFS, and STEM-EDS revealed that the different influences of C by the supports were attributed to the extent of metal dispersion and metal-support interaction. 2 2 2 4 2 2 4 2 2 2 ◦ ◦ ◦

DOI： 10.3390/catal10010021

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Potassium (K)-catalyzed CO gasification of lignite char was studied with a particular focus on the change in catalyst activity with the char conversion (X) at 800-900 °C. Char samples were prepared from an Indonesian lignite by a sequence of complete removal of inherent metallic species and mineral matter, K-loading by ion-exchange, and pyrolysis. The catalytic activity of K (kcat′) was defined as the rate of catalytic gasification (after elimination of the rate of non-catalytic gasification and that of K volatilization from total mass release rate from char) per amount of K retained by the gasifying char. kcat′ increased by a factor of 5-20 with X over its range up to 0.98-0.99, depending on the initial K concentration in the char (m ), ranging 0.16-1.4 wt %-daf. Such significant increase in kcat′ was due to the change in not the intrinsic reactivity of char but its porous nature, that is, the size and volume of pores that retained the K catalyst. At X < 0.4, the entire portion of the K catalyst was confined in micropores (width <2.0 nm) having relatively small kcat′, although it increased gradually. At X > 0.4, the gasification created greater mesopores (width >2.0 nm), providing spaces for growth in the size of the K catalyst and allowing promotion of its activity. However, for low m , its major portion continued to stay in micropores with a limited increase in kcat′. 2 cat,0 cat,0

DOI： 10.1021/acs.energyfuels.9b03630

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.energyfuels.9b02939

記述言語：その他   掲載種別：研究論文（学術雑誌）  

This study has experimentally proven an approach to integrate electric energy and chemical energy of biomass into chemical energy of hydrogen by biochar-assisted water electrolysis (BAWE). This type of electrolysis, in other words, electrochemical gasification, consists of hydrogen formation at the cathode and biochar oxidation at the anode, instead of O formation. Different from traditional gasification of biochar, BAWE is operated at a temperature below 100 °C and normal pressure. Linear sweep voltammetry showed that the electrolysis of acidified water, when suspended with biochar, occurred at an interelectrode potential as low as 0.5 V, which was much smaller than 1.23 V, the standard potential to split water into hydrogen and oxygen at 25 °C. The performance of biochar depended significantly upon the carbonization temperature for its preparation. It was found that 850 °C was the best carbonization temperature that provided an optimum combination of specific surface area and carbon-type distribution. It was revealed by continuous BAWE that the formation of O-containing functional groups on the biochar surface was predominant over CO formation at the anode, while H was formed obeying stoichiometry at the cathode. Accumulation of the O-containing groups on the biochar surface decreased its electrochemical reactivity, slowing the electrolysis. Thermal treatment at 850 °C removed the major portion of O-containing groups from the spent biochar, fully recuperating its electrochemical reactivity. CO gasification enhanced the biochar activity, and its effect went far beyond the heat treatment. On the basis of the above-mentioned characteristics of BAWE, its combination with CO gasification as the biochar recuperator as well as syngas producer is proposed. 2 2 2 2 2

DOI： 10.1021/acs.energyfuels.9b02925

記述言語：その他   掲載種別：研究論文（学術雑誌）  

An inkjet mixing system was investigated to synthesize lipid nanoparticles (LNP) by mixing lipid ethanol and aqueous saline solutions. The system was employed to help minimize drug loss. The quick mixing of the droplets enabled the synthesis of small LNP while reducing the excess amount of saline solution that would contain drugs. The system also features minimal usage of reagents. A high relative velocity of the droplets and moderate values of the impact parameter were necessary for successful mixing. Faster droplets should collide with the upper or horizontal level of slower droplets to promote mixing. A horizontal spin of the coalesced droplets was favored rather than a vertical spin.

DOI： 10.1002/ceat.201900041

記述言語：その他   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.energyfuels.9b02946

記述言語：その他   掲載種別：研究論文（学術雑誌）  

Microreactors have been utilized for controlling fast chemical reactions. However, the scale-up strategy for fast reactions is not established enough due to the difficulty in quantifying the effect of the reactor size on the mixing performance, heat removal, and observable reaction rate. We present a chart for analyzing the effect of the mixing rate on the observable kinetic constant and a chart for estimating the temperature increase in the reactor. By using these charts, the validity of the rate analysis and the maximum reactor diameter, which control the reaction temperature, were determined. Commercial computational fluid dynamics (CFD) software was employed to solve the partial differential equations and to build the charts, and experiments were conducted to validate the results. We demonstrated the concept by using the ultrafast organolithium reaction in milliseconds. The product throughput was increased eight times with a reactor diameter that was twice as wide as the original reactor.

DOI： 10.1021/acs.oprd.8b00356

記述言語：その他   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.langmuir.8b03516

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We extensively examined and discussed the performance of microjet mixers that consisted of two concentrically arranged tubes. The orientation of the feed streams with respect to the inner and outer inlets was the crucial factor for promoting the desired reaction. The Reynolds number after jetting and the velocity ratio of the inner and outer fluids were the key variables for promoting vigorous jetting and efficient mixing. By choosing the appropriate operating conditions, the microjet mixers exhibited excellent performance. The design protocol for microjet mixers was established based on mixing time measurements. We successfully maximized the throughput in one channel and numbered-up the microjet mixers. The microjet mixers also proved to be useful for treating viscous fluids with the appropriate choice of the feed orientation. The complete mixing of water with a 200 times more viscous fluid was achieved in 20 ms.

DOI： 10.1039/c7re00051k

記述言語：その他   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.cep.2017.05.016

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The relationship between mixing history and reaction performance in microreactors using computational fluid dynamics (CFD) simulations is identified. In the idealized, simplified mixing model, mixing proceeds linearly and only the mixing time determined the reaction performance. However, in the case of realistic models where mixing proceeds unequally, the partial rapid progression of mixing, more than the mixing time, significantly impacts the reaction. The use of the fluid segment size distribution to capture this effect is proposed. The effective Damköhler number derived from the fluid segment size distribution predicted the reaction yield well. To demonstrate the utility of the mixing profile design strategy, we fabricated a novel micromixer with multiple partial rapid mixing zones. This micromixer achieved excellent results both in a CFD simulation and an experiment.

DOI： 10.1002/aic.15082

開催年月日： 2020年12月 - 2020年6月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Wuhan   国名：中華人民共和国  

開催年月日： 2020年6月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2020年6月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Wuhan   国名：中華人民共和国  

開催年月日： 2020年6月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：鹿児島   国名：日本国  

開催年月日： 2020年6月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：鹿児島   国名：日本国  

開催年月日： 2020年6月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Hokkaido   国名：日本国  

開催年月日： 2020年6月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Fukuoka   国名：日本国  

開催年月日： 2020年6月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2020年6月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：Fukuoka   国名：日本国  

開催年月日： 2020年6月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Hokkaido   国名：日本国  

開催年月日： 2020年6月

記述言語：日本語   会議種別：口頭発表（一般）  

国名：日本国  

開催年月日： 2019年5月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Wuhan   国名：中華人民共和国  

記述言語：英語  

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記述言語：英語   会議種別：口頭発表（一般）  

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会議種別：口頭発表（招待・特別）  

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会議種別：口頭発表（招待・特別）  

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会議種別：口頭発表（招待・特別）  

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