Continuous hydrocarbon extraction from microalgae by non-toxic solvent

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K19163
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 41:Agricultural economics and rural sociology, agricultural engineering, and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Imou Kenji 東京大学, 大学院農学生命科学研究科(農学部), 教授 (40184832)
• Co-Investigator(Kenkyū-buntansha): 古橋 賢一 東京大学, 大学院農学生命科学研究科(農学部), 助教 (10779739)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 微細藻類 / 炭化水素 / 抽出 / オイル / バイオ燃料

Outline of Final Research Achievements

While general oil-producing microalgae accumulate oils such as fats and fatty acids in their cells, Botryococcus braunii differs from others in that it accumulates hydrocarbons equivalent to heavy oil in extra-cellular matrix. A method called "milking," in which the oil is extracted without killing the cells and then re-cultured, has been considered, but it is toxic in common organic solvents and reduces cellular activity. In this study, we found that the method of reducing the production of fiber structures around the colony periphery, which inhibit solvent entry into the extracellular structures, can be applied to other than existing varieties in order to increase extraction efficiency. In addition, hydrocarbons were extracted without reducing photosynthetic activity using a different non-toxic organic solvent.

Free Research Field

バイオマスエネルギー工学

Academic Significance and Societal Importance of the Research Achievements

微細藻類は陸上植物よりもオイル生産性が高いため、航空燃料やトラクタ等のバイオ燃料代替の資源として期待されている。しかし、その培養～回収～オイル抽出の工程で、多くのエネルギーや資源が投入されるため、生産プロセスでのGHG排出量削減が求められている。本研究の手法は、微細藻を殺さずに再培養してオイルを再生産させる新たな手法について行ったものであり、培養工程での生産性向上ならびに投入エネルギー削減に大きく貢献が期待されるものである。