The 89th Hiroshima University Biomass Evening Seminar
(The73th Hiroshima University ACE Seminar)was held.
Date & Time: Thu.5 Nov., 2020 16:20-17:50
Place: Engineering 110 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University
<Program>
Commentary: Yukihiko MATSUMURA
Professor, Graduate School of Advanced Science and Engineering, Hiroshima University
Lecture: Fumika KAMAGATA
B4 student, Graduate School of Advanced Science and Engineering, Hiroshima University
“Potassium removal rate from bamboo using methanol “
Bamboo has a high growth rate and is expected as a raw material for combustion. However, due to the high alkali metal content, the ash melts at low temperatures, hindering the smooth operation of the furnace. Washing bamboo with water helps remove alkali metals, but the resulting bamboo has a high water content. Therefore, this study used flammable methanol, which does not require a drying step. The purpose is to determine the potassium removal rate when methanol is used as the solvent.
Lecture: Bailun CHEN
M2 student, Graduate School of Advanced Science and Engineering, Hiroshima University
“Supercritical water gasification of fine biomass powder “
Supercritical water gasification gasifies biomass in hot compressed water whose temperature and pressure are both above critical point (647K, 22.06MPa). Biomass is solid, and from the gas-solid or liquid-solid reaction viewpoint, effect of particle size should be considered. However, there has not been sufficient study to predict solid biomass behavior in supercritical water. The purpose of this study is to conduct supercritical water gasification of solid particles to determine the particle size effect. A laboratory scale reactor was employed which was a continuous reactor made of stainless tubing. Wood particles and particles of empty fruit bunch were employed. Pulverization for different particle sized samples. Gasification efficiency was found to decrease with particle size, implying the similar mechanism as gas-solid reaction or liquid- solid reaction exists in the supercritical water reactor, too.
Lecture: Yukihiko MATSUMURA
Professor, Graduate School of Advanced Science and Engineering, Hiroshima University
“Superiority of supercritical water gasification effluent over hydrothermal liquefaction effluent as algae cultivation media”
Hydrothermal treatment of algae such as hydrothermal liquefaction and supercritical water gasification has attracted attention as renewable energy production system. One of the ideas to achieve further renewability is to reuse its effluent for algae cultivation itself. The effluent of the hydrothermal processes contains nutrition such as potassium, phosphorus, and nitrogen produced from algae and can be used for algae cultivation. Various researches have been conducted to cultivate algae using the effluent of hydrothermal treatment of algae, mainly using the hydrothermal liquefaction effluent. A problem they encountered was inhibition of algae growth by some compound in the effluent. In this study, effluent of supercritical water gasification from different temperature was employed to cultivate algae after mixing with the standard medium. It was found that supercritical water gasification at 400 °C had higher non-purgeable organic carbon compared to that at 600 °C. Other nutrition concentration was almost the same. However, algae growth was better for the effluent of 600 °C. This result should be attributed to the decomposition of inhibitory compound at 600 °C.
Lecture: Shunsuke KOBAYASHI
M2 student, Graduate School of Integrated Sciences for Life, Hiroshima University
“Elucidation of the mechanism of growth inhibition by H2 in the ethanol-producing strains of Moorella thermoacetica”
We have tried to establish a fermentation process for ethanol production by metabolically engineering a microorganism Moorella thermoacetica that can utilize sugar and CO2. Although CO2 is emitted in the conventional fermentation process, CO2 can be recycled as a carbon source in the new process using M. thermoacetica. Energy from H2 is used for the CO2 metabolism, but growth of the engineered strain was inhibited by H2. In this presentation, I talk about our study on the mechanism of this inhibition.
Chair: Yukihiko MATSUMURA
Professor, Graduate School of Advanced Science and Engineering, Hiroshima University