The 60th Hiroshima University Biomass Evening Seminar(The 25th Hiroshima University ACE Seminar)

The 60th Hiroshima University Biomass Evening Seminar

(The 25th Hiroshima University ACE Seminar)was held.


Date & Time: Thu .11  Jan., 2018   16:20-17:50

Place: Engineering 110 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University




Commentary: Yukihiko MATSUMURA

   Professor, Graduate School of Engineering, Hiroshima University


Lecture: Kiyoto KIHARA

M2 Student,Graduate School of Engineering, Hiroshima University

“Kinetics of Enzymatic Hydrolysis for Dissolved Cellulose”


Biomass energy which is one of the renewable energy is not popular because the efficiency is not good. Because enzymatic hydrolysis which is one of the main process of bioethanol production takes too long time and enzyme is expensive. Dissolved cellulose can be decomposed earlier than crystalline cellulose. However, that kinetics was not analyzed. In this study, kinetics of enzymatic hydrolysis for dissolved cellulose was examined. Dissolved cellulose was produced by hydrolyzing crystalline cellulose at sub-critical condition. (300 oC, 15 MPa) Dissolved cellulose was hydrolyzed by enzymes which were cellulase and β-glucosidase. The result was analyzed by Michaelis-Menten model.



Lecture: Kengo HISHIDA

M2 Student,Graduate School of Engineering, Hiroshima University

“Effect Between Initial Grain Size and Disk Gap under Hydrothermal Disk Milling”


Pretreatment is an important process to obtain high ethanol yield on bioethanol production using lignocellulosic biomass. On this research, the effect of initial grain size and disk gap under hydrothermal disk milling was investigated. The result showed that the optimum initial grain size was different with each disk gap. It is likely that there were different milling mechanisms during hydrothermal disk milling which caused different results.



Lecture: Farida RAHAYU  

D3 Student, Graduate School of Advanced Sciences of Matter, Hiroshima University

“Optimization of thermophilic ethanol fermentation from lignocellulosic hydrolysate by ethanol-producing transformant of Moorella thermoacetica ”


A transformant of Moorella thermoacetica was constructed for thermophilic ethanol production from lignocellulosic biomass by deleting two phosphotransacetylase genes, pdul1 and pdul2, and introducing the native aldehyde dehydrogenase gene (aldh) controlled by the promoter from glyceraldehyde-3-phosphate dehydrogenase. The transformant successfully fermented sugars in hydrolysate prepared through the acid hydrolysis of lignocellulose to ethanol, suggesting that this transformant can be used to ferment the sugars in lignocellulosic biomass for ethanol production. In the present study, we used the transformants to determine the ability to ferment hydrolysate from actual lignocellulosic feedstock to ethanol, a fermentation test was conducted for three different types of lignocellulosic hydrolysate; cedar plant, forest residue and rice straw in optimally condition at 55 °C for 168 hours periods of fermentation. Our present findings demonstrated that thermophilic fermentation by genetically engineered M. thermoacetica is a feasible process for producing ethanol from lignocellulosic biomass.



Lecture: Kunassanan Siribunyaroj

M2 Student,Graduate School of Engineering, Hiroshima University

  “Glycine Decomposition in Supercritical Water Gasification”


Since non-renewable fossil fuel consumption causes the global warming problems, using energy from renewable source such as biomass instead of fossil fuel to avoid worsening the environmental problem is now being sought. Supercritical water gasification (SCWG) is a favorable technology to convert wet biomass into renewable energy under temperature and pressure above 374 °C and 22.1 MPa, respectively. In the previous study, glycine, which is the simplest amino acid, was chosen as a model protein for investigating the behavior of amino acid decomposition under supercritical water gasification. However, they just followed gasification efficiency. The behavior of both nitrogen and carbon should be followed for the complete understanding of the reaction. The purpose of this study is to gasify glycine in supercritical water, and determine the behavior of both carbon and nitrogen. The experiment was conducted at 25 MPa, 450 °C, with the residence time of 5 s, using tubular flow reactor. The feedstock percentage concentrations are 1-5 percent by weight, respectively. According to this experiment, most of nitrogen compounds in glycine are in form of ammonia and methylamine. Carbon dioxide, hydrogen and methane were the main gaseous products found in this experiment.


Chair: Nattacha PAKSUNG

  Researcher , Graduate School of Engineering, Hiroshima University