Establishment of methods for the measurement and analysis of electrochemical properties in organic matter of benthic sediment, and the utilization of benthic sediment as fuel

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01437
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 22040:Hydroengineering-related
• Research Institution: Hiroshima University
• Principal Investigator: Hibino Tadashi 広島大学, 先進理工系科学研究科(工), 准教授 (50263736)
• Co-Investigator(Kenkyū-buntansha): TOUCH NARONG 東京農業大学, 地域環境科学部, 准教授 (50707247) ; 中下 慎也 広島大学, 先進理工系科学研究科(工), 助教 (90613034)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 鉄鋼スラグ / 燃料電池 / CO2固定 / CO2変換水素 / ブルーカーボン / カーボンネガティブ / 水素生産

Outline of Final Research Achievements

A mechanism has been developed to facilitate the conversion of immense energy stored in benthic sediments into electricity using by-products such as steel slag. In the study of rapid conversion of benthic sediment energy to electricity via SMFCs, a method to measure the electrochemical properties was established, and semiconductor properties were confirmed in the organic matter of the benthic sediment. The conductivity properties of the organic matter in the bottom sediment were verified by measuring the formation of electric fields and the variation in potential distribution caused by electron transfer in the benthic sediment layer mixed with metal ions, soil particles, and other inorganic matter. The limited electron recovery range, which is a weakness of SMFCs using diffused sludge, was significantly expanded by utilizing steel slag as an auxiliary fuel. Consequently, this SMFC achieved the ability to generate the world’s highest level of electrical energy.

Free Research Field

沿岸環境

Academic Significance and Societal Importance of the Research Achievements

底泥を燃料とするSMFCの弱点である電子回収効率を画期的に向上させるため，鉄鋼スラグにより底泥有機物を活性化させる手法を開発し，電子の生産能力を格段に高上させた．
提案する電極技術は鉄鋼スラグに含まれる鉄を利用して下水処理困難な生活排水で覆われた場を広範な水素生産場に変え，かつ健全な生態系場に再生してCO2の固定に貢献できる等，社会への経済的効果が大きく期待される．この技術の東南アジア等の下水処理の未熟な国への移転も可能であり，劣悪な環境下での生態系再生，水素生産，さらにCO2を多量に固定する技術に発展させれば，世界的な環境問題，エネルギー問題の解決に貢献できる．