Gradient environment-type biogas production system with an electron transfer control mechanism for microorganisms

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H03080
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 41040:Agricultural environmental engineering and agricultural information engineering-related
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: TOJO SEISHU 東京農工大学, (連合)農学研究科(研究院), 教授 (40155495)
• Co-Investigator(Kenkyū-buntansha): 帖佐 直 東京農工大学, (連合)農学研究科(研究院), 准教授 (10355597)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 環境傾度型発酵槽 / 水素発酵 / メタン発酵 / pHギャップ / 微生物電解セル / 光合成水素生成菌 / 加圧熱水処理 / COD

Outline of Final Research Achievements

In the biogas production using organic waste as a raw material, two different gradient environment-type fermenters were investigated to improve the connectivity between the microbial communities involved in hydrogen fermentation and methane fermentation and their optimum pH ranges. For relatively low concentration substrates, two-phase hydrogen fermentation, which periodically changes the dark period and light period conditions, can continue hydrogen production with stable pH range. For high concentration substrate, hydrogen-methane two-stage fermentation is effective, and the optimum pH gap in the transition process from hydrogen fermentation to methane fermentation can be adjusted by using the electron transfer control of the microbial electrolysis cell.

Free Research Field

農業環境工学

Academic Significance and Societal Importance of the Research Achievements

環境傾度型発酵槽は、光や温度の環境条件を人為的に変化させることで水素やメタン等のバイオガス生産に関わる発酵の高速化と高効率化を目指す発酵システムである。発酵の高速化が可能な水素発酵では、明発酵と暗発酵を周期的に組み合わせた水素二相発酵が有効との結果が示された。高濃度原料に有用な水素－メタン二段発酵では、そのpH調節に電子伝達制御機能を有する微生物電解セルが利用できることが示され、化学薬品に依存しないバイオガス生産システムの運用の見通しが得られた。