Biomass Project Research Center, Hiroshima University, and HOSTY Association are co-organizing the Hiroshima University Biomass Evening Seminar. This seminar covers topics from the fundamentals of biomass to the latest information so that it can contribute the activities on biomass in this district. The 31th seminar will be held as follows. Please join.

• Date & Time: Mon.18　May, 2015 16:20-17:50

• Place: Engineering 109 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University

＜Program＞

• Commentary: Yukihiko MATSUMURA
  
  Professor, Institute of Engineering, Hiroshima University

• Lecture: Thachanan SAMANMULYA
  
  Assistant Professor, Institute of Engineering, Hiroshima University

“Supercritical water gasification characteristics of Isoleucine and Phenylalanine”

Utilization of model compounds is effective to evaluate the kinetic parameter of supercritical water gasification. Studying behavior of the protein is important, especially for food waste and animal matter. For model compound of protein, amino acids are good candidate considering hydrolysis of protein produces amino acids. Previously, glycine, alanine, valine, leucine, and proline have been studied for their gasification characteristics and they showed different gasification rate but only gasification rate of glycine and alanine were identical. Leucine gasification rate has been determined to be similar with gasification rates of glycine and alanine, which implies that they have the same rate determining step. It is of interest to elucidate the characteristics of isoleucine, in which the carbon atom arrangement of functional group is different from that in leucine. Moreover, alanine and phenylalanine are both amino acids which are different only by additional of phenyl group. Comparing gasification characteristics of these amino acids should provide the effect of phenyl group on supercritical water gasification which should be interesting in understanding decomposition of amino acids in supercritical water. The experiments are conducted in continuous system and simultaneously to evaluate the effects of temperature and residence time. The various reaction products obtained (gas, liquid and solid fractions) are evaluated based on qualitative and quantitative manner.

• Lecture: PAKSUNG NATTACHA
  
  D1 Student,Graduate School of Engineering, Hiroshima University

“Detailed mechanism of xylose decomposition under hydrothermal thermal condition”

Biomass derived energy has drawn attention to be utilized due to its carbon neutral characteristics and since it is a kind of renewable energy. Among many conversion techniques, supercritical water gasification has relatively high hydrogen selectivity and high conversion efficiency. However, biomass consists of various compounds that make it difficult to optimize the process. For lignocellulosic biomass, few studies have focused on behavior of hemicellulose in supercritical water although it is a major component other than cellulose and lignin. Therefore, this study attempted to investigate the kinetics mechanism of xylose as a model compound of hemicellulose in wide range of temperature. The experiment was carried out at temperature of 350-450 oC and pressure of 25 MPa using a continuous reactor. Liquid intermediate was found to be products from isomerization of xylose, dehydration and retro-aldol condensation. Reaction network was proposed and kinetics parameters of each reaction were calculated based on data fitting assuming the first order for all reactions. Finally, the effect of temperature was used to classify the reactions into radical reaction, which showed Arrhenius behavior, and ionic reaction, which showed non-Arrhenius behavior in supercritical region.

• Lecture: Tomohiro YANO
  
  M1 Student,Department of Molecular Biotechnology
  
  Graduate School of Engineering, Hiroshima University

“Methane production from various marine algae by marine sediments”



Macroalgae, that have attracted the attention as the third generation biomass, is a suitable feedstock for anaerobic digestion because of their high water content. However, they contain high concentration of salt that inhibits anaerobic digestion by conventional methanogenic microbial flora. Thus, we have explored salt-tolerant methanogenic microbial flora. We found that marine sediments are methanogenic microbial resource for anaerobic digestion of brawn algae under high salinity. In this study, we carried out the detailed analysis to know kinetics of anaerobic digestion of brawn algae under high salinity.

When grinded macroalgae was treated in the anaerobic bottles containing the acclimated marine sediment with different concentration of NaCl, stable methane production was observed up to 3% (w/v) NaCl. Furthermore, it was also investigated that the feasibility of the marine sediments to variety of macroalgae; Laminaria japonica, Sargassum fusiforme (brawn algae), Ulva spp. (green algae), and Gelidiaceae (red algae). Among them, active methane production was observed from L. japonica, S. fusiforme and Ulva spp. while little production from red algae. In the medium treating with red algae, volatile fatty acids were not accumulatied, suggesting that there were few microorganisms hydrolyzing and consuming agar that is a major carbohydrate in red algae.

• Chair: Thachanan SAMANMULYA
  
  Assistant Professor, Institute of Engineering, Hiroshima University

Hiroshima Universty Biomass Project Research Center

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