||野中 壯泰, 平島 剛, 熊谷 聡, Monosaccharide Recovery from Peat and Peatified Wood by Ultrasonication Pretreatment and hydrothermal Treatment, International Journal of Clean Coal and Energy, 2017.06, Peat and peatified wood are significant carbohydrate resources in tropical
rainforests. The carbohydrates of cellulose and hemicellulose are important
sources of monosaccharides for both vital activities and industrial applications,
such as furan production of furfural and hydroxymethyl furfural. Hydrothermal
treatment at 200˚C and ultrasonic irradiation pretreatment were
used to recover monosaccharides from the abovementioned resources. The
monosaccharide recovery from peat was shown to be higher than that from
peatified wood. The conversion to organic acids is considered to proceed
rapidly because acids are always detected with monosaccharides. This conversion
is outstripped by the organic acid-to-gas reaction for treatment
times longer than 20 min. The monosaccharide recovery from peatified
wood was improved by the ultrasonication pretreatment. It is considered
that ultrasonic irradiation broke down lignin blockages, enabling water molecules
to access the carbohydrates more easily in the subsequent hydrothermal
||野中 壯泰, 平島 剛, 熊谷 聡, 笹木 圭子, Hydrothermal treatment of lignite for CO2 gasification, 資源素材学会, 131, 5, 219-225, 2015.05, Hydrothermal treatments of lignite, Loy Yang Coal, having high water content of about 60 % were conducted at temperatures ranging from 200 ºC to 380 ºC. The solid products were examined from various angles like fuel characterization, equilibrium moisture content, solid state VACP (Variable Amplitude Cross Polarization)/MAS 13C-NMR spectroscopic study and thermogravimetry. As a result, the treatment produced upgraded solid fuel; the rising treatment temperature yielded increasing carbon content, fixed carbon, fuel ratio and carbon aromaticity. The advantages of the solid products obtained at harsh condition, 300 ºC or higher, were low moisture content, high calorie and their slight variation regardless of wide variety in humidity. On the other hand, mild hydrothermal treatments at 250 ºC or lower demonstrated advantages in terms of energy recovery and solid yield. Addition of a small amount of alkali at hydrothermal treatment improved the gasification reactivity of the solid phase in the successive gasification stage more than twofold, rather decreasing the ash content. Further alkali dose may influence the coal structure that leads to a decrease in the slope of the Arrhenius plot..
||熊谷 聡, Limsuwan Pilasinee, 野中 壯泰, 平島 剛, Separation of furfural generated by hydrothermal treatment of coconut shell, 木質炭化学会誌, 10, 2, 87-93, 2014.10, In this study, hydrothermal treatment of coconut shell and separation of the reaction products were investigated.
At first, coconut shell was conducted by hydrothermal treatment at 200℃ for 30 min. Then solid-liquid separation of the
reaction products was done by a filtration, after that furfural recovery from the filtrates was treated by several commercial
activated carbon (FP-1, FP-3, FP-6, FP-9, Japan EnviroChemicals Ltd.). Finally, desorbed of the adsorbed furfural in the
activated carbon was conduction with acetone elution. It required a three-fold amount of water used in the hydrothermal
treatment for separation of the water-insoluble products and the water-soluble products. The main component of the watersoluble product was xylose, acetic acid and furfural. Their each concentration in the first filtrates was 5.1, 6.6 and 5.8 g/L, respectively. Though the recovery ratio xylose and acetic acid were more than 90% by only one time filtration, on the other hand, the furfural was 75%. We concluded that it was necessary to wash with same amount of water used in the
hydrothermal treatment. The furfural could be separated selectively by the activated carbon (FP-3) adsorption from the
filtrates, and then it could be desorbed by acetone elution..
||In this study, hydrothermal treatment of coconut shell and separation of the reaction products were investigated.
At first, coconut shell was conducted by hydrothermal treatment at 200℃ for 30 min. Then solid-liquid separation of the reaction products was done by a filtration, after that furfural recovery from the filtrates was treated by several commercial activated carbon (FP-1, FP-3, FP-6, FP-9, Japan EnviroChemicals Ltd.). Finally, desorbed of the adsorbed furfural in the activated carbon was conduction with acetone elution. It required a three-fold amount of water used in the hydrothermal treatment for separation of the water-insoluble products and the water-soluble products. The main component of the watersoluble product was xylose, acetic acid and furfural. Their each concentration in the first filtrates was 5.1, 6.6 and 5.8 g/L, respectively. Though the recovery ratio xylose and acetic acid were more than 90% by only one time filtration, on the other hand, the furfural was 75%. We concluded that it was necessary to wash with same amount of water used in the hydrothermal treatment. The furfural could be separated selectively by the activated carbon (FP-3) adsorption from the filtrates, and then it could be desorbed by acetone elution..
||Limsuwan, P, Kumagai, S, Moriyasu Nonaka, Keiko Sasaki, Tanthapanichakoon, W, Tsuyoshi Hirajima, Application of plasma treated activated carbon to enhancement of phenol removal by ozonation in three-phase fluidized bed reactor , Advanced Materials Research
, 701, 305-309, 2013.08, Plasma treatment of activated carbon (AC) was found to be an efficient method to enhance phenol removal by ozonation in a three-phase fluidized-bed reactor. The plasma treatment extended porous structure, changed surface morphologies, and produced oxygen functional groups on the surface of AC. Plasma-treated activated carbon together with O3 gave the best removal result, in which phenol was completely decomposed within 10 min (with pseudo first-order rate constant k = 0.286 min-1), while untreated AC without O3 showed the worst result (k = 0.024 min-1). Consequently, AC modified by plasma was shown to be a good material for removal of organic pollutants and yield superb performance in an integrated process with ozone in a fluidized-bed reactor. .
||Moriyasu Nonaka, Tsuyoshi Hirajima, Keiko Sasaki, Gravity Separation and Its Effect on CO2 Gasification, Fuel, 103, 37-41, 2013.01, The CO2-blown integrated coal gasification combined cycle (IGCC) is a promising electric power generation technology that will reduce CO2 emission, due to its high efficiency. Recent studies have found that base metals improve the coal char gasification in cases when they can interact with the char matrix at an atomic level. An attempt to clarify the effect of heavy medium separation, which is one of the most popular coal cleaning technologies, on the CO2 gasification of the char derived from the coal fractionated as a function of specific gravity is presented in this publication. Before the sink and float test and thermogravimetric analysis, Datong Coal from China was ground to below 20 mesh, which is a size usually used for a coal cleaning process. The highest separation efficiency was expected to be obtained at a specific gravity of 1.45 where the ash content would be reduced dramatically from 10.2 % for the raw coal to about 4 %; also, about 85 % of combustibles would be recovered. The chars derived from different macerals showed different gasification reactivity; Inertinite-derived char has agasification reactivity higher than Vitrinite-derived char. Inorganic base metals did not show a significant catalytic effect. It was considered that heavy medium separation was an effective pretreatment technique without any significant deterioration of CO2 gasification ability..
||Dewi A Iryani, Satoshi Kumagai, Moriyasu Nonaka, 笹木 圭子, Tsuyoshi Hirajima, Hot compressed water treatment of solid waste material from the sugar industry for valuable chemical production, International Journal of Green Energy, 10.1080/15435075.2013.777909, 2012.12.
||Moriyasu Nonaka, Tsuyoshi Hirajima, Keiko Sasaki, Upgrading of Low Rank Coal and Woody Biomass Mixture by Hydrothermal Treatment, Fuel, 10.1016/j.fuel.2011.03.028, 90, 2578-258, 2011.08, Attempts to produce high-grade fuel from biomass and low rank coal are important from the viewpoint of renewable energy and the utilization of unused resources. In this paper, the authors reported on the hydrothermal treatment of biomass and low rank coal at 300 °C using a bench scale continuous apparatus and a batch autoclave. The results show that coalification takes place during the hydrothermal treatment of both the low rank coal and biomass, and the upgraded solid products show similar chemical compositions, gross calorific value and effective calorific value, independent of the mixing ratio. The solid product also becomes hydrophobic and unable to re-adsorb the lost moisture. The characteristics of the solid produced by the bench scale continuous apparatus can be predicted by the results of the batch process. Thermogravimetric analysis shows that the solid product has a wide range of molecular weight but the thermally stable heavy molecules are found more in the treated coal as opposite to the thermally unstable light molecules, more of which are found in the treated biomass. This may correlate with that the solid product of higher biomass mixing ratio has a higher volatile matter content. Polymerization is synergistically promoted during mixed hydrothermal treatment of low rank coal and biomass..
||Moriyasu Nonaka, Tsuyoshi Hirajima, Keiko Sasaki, Effect of Gravity Separation on CO2 Gasification, Second international symposium on gasification and its application (ISGA2010), CD-R, No. 90, ID. B21, 2010.12.
||Moriyasu NONAKA, Tsuyoshi HIRAJIMA and Keiko SASAKI, Upgrading and Gasification of Low Rank Coal and Woody Biomass, The Third International Symposium on Novel Carbon Resource Sciences: Advanced Materials, Processes and Systems toward CO2 Mitigation, 2009.11.
||Moriyasu Nonaka, Tsuyoshi Hirajima and Keiko Sasaki, Washability Study and Gasification Reactivity of Coal, International symposium on earth science and techonolgy 2009, 157-160, 2009.12.
||Tsuyoshi HIRAJIMA and Moriyasu NONAKA, Upgrading of Low Rank Coal and Woody Biomass by Hydrothermal Treatment, Proc. 2nd International Symposium of Novel Carbon Resource Science, Earth Resource Science and Technology, I1-I9, 2009.05.
||Moriyasu NONAKA, Tsuyoshi HIRAJIMA, Keiko SASAKI, Effective Utilization of Biomass Waste Using Hydrothermal , Proc. XXIV International Mineral Processing Congress, Vol.3, pp.3625-3629, 2008.09.
||Fly ash is a by-product in coal power plants and a rich source of hollow and spherical particles. Hollow and spherical particles having density less than 1 g/cm3 are known as cenospheres. Their concentration in coal fly ash is around 1%. Particles are widely used as fillers and insulators with high performances in rubber, plastics, oil industry, space industry, glass steels, etc. due to their shape, specific surface, excellent physical and chemical properties; as a consequence, their value is relatively high. However, hollow and spherical particles are filled up with N2 and/or CO2 gas bubbles so their densities can vary from 0.6g/cm3 to near or greater than 2.0 g/cm3. Fly ash can consist of more than 80% hollow and spherical particles having particle diameter less than several hundred m and density less than 2.0 g/cm3, but there is no efficient and economic way to selectively recover them.
The authors study on the recovery of cenospheres and hollow and spherical particles having density more than 1 g/cm3 from coal fly ash using a two-inch hydrocyclone and laboratory/pilot scale Mozley multi-gravity separator(MGS). A two-inch hydrocylone having 6.4 mm of spigot diameter was used to effectively concentrate cenospheres in overflow product. A very small amount of cenospheres having density less than 1 g/cm3 were recovered as a float of overflow product. Underflow product and overflow product without cenospheres were supplied to MGS and the influence of MGS parameter such as drum rotation speed and wash water rate was studied. As a result, 54% of hollow and sphercal particles having 2.08 g/cm3 of density and 61.6 m of median diameter in underflow product was recovered as MGS lighter product and 17% of hollow and sphercal particles having 2.19 g/cm3 of density and 8.4 m of median diameter in overflow product was recovered as MGS lighter product. These results show that hollow and spherical particles having median diameter less than one hundred m with middle density can be recoverd.
||A fundamental investigation on the extraction from biomass, low rank coal and their mixture during hydrothermal treatment was conducted by using a circulative equipment having a 10 cm3 cell. Beluga coal from Alaska, and Cryptomeria Japonica and empty fruit bunch of oil palm (EFB) were used as material samples of low rank coal and biomass, respectively. Biomass started to be decomposed at a temperature lower than that of low rank coal, which suggests that amorphous cellulose and hemicellulose were hydrolyzed. Frans such as furfural and 5-hydroxymethyl-2-furaldehyde (HMF) extracted from biomass were unstable as compared to phenol, and therefore decomposed and partially cyclized. It was considered that low rank coal adsorbed extracts from biomass due to the porous morphology. The possibility to predict the TOC from an on-line monitoring of the absorbance intensity in UV region during hydrothermal treatment was also shown..