バイオ水素生成とCO2回収を両立する発酵システムを開発(Wollastonite-Enabled Fermentation System Boosts Biohydrogen Yield While Capturing Carbon Dioxide)

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2026-05-08 中国科学院(CAS)

中国科学院応用生態研究所の研究チームは、バイオ水素生産と二酸化炭素(CO2)固定を同時に実現する新たな発酵システムを開発した。暗発酵法による水素生産では、有機酸蓄積によるpH低下が微生物活性を阻害する課題があった。研究では天然ケイ酸塩鉱物ウォラストナイト(CaSiO3)を添加し、酸によって鉱物を徐々に溶解させることで、水素イオンを消費しながらカルシウムイオンを放出し、pHを6.5~7.0に安定化させた。最適濃度10 g/Lでは水素生成開始時間が約50%短縮し、水素収率は約33%向上した。また、酢酸型発酵への転換により水素生成菌Clostridiumが増加した。一方、高濃度条件ではCO2鉱物固定が進むが水素生成が低下するため、研究チームは二段階プロセスを提案。最終的にCO2を炭酸カルシウムとして固定しつつ、水素濃度58%超のバイオガス生成を達成した。ライフサイクル評価でも消費電力と温暖化負荷の低減が確認され、負炭素型バイオ水素生産への応用可能性が示された。

<関連情報>

負の炭素バイオ水素を目指して:発酵促進とCO2隔離のための二重機能ウォラストナイト戦略 Towards negative-carbon biohydrogen: A dual-function wollastonite strategy for enhanced fermentation and CO2 sequestration

Weiming Li, Can Jin, Huida Duan, Fangcao Li, Zhangxun Huang, Haodong Zhao, Xiaoman Yu, Yimei Xi, Xiangfeng Zeng, Yongfeng Jia, Chi Cheng

Chemical Engineering Journal  Available online: 13 April 2026

DOI:https://doi.org/10.1016/j.cej.2026.176164

Graphical abstract

バイオ水素生成とCO2回収を両立する発酵システムを開発(Wollastonite-Enabled Fermentation System Boosts Biohydrogen Yield While Capturing Carbon Dioxide)

Highlights

  • Wollastonite as a pH buffer boosts bio-hydrogen production rate and yield.
  • Metabolic flux shifts from lactate to acetate, enhancing H2 production.
  • In-situ CO2 sequestration is achieved via wollastonite-induced mineralization.
  • A two-stage strategy co-optimizes H2 production and CO2 sequestration.
  • LCA confirms a 37% process energy saving and lower environmental impacts.

Abstract

Dark fermentation for biohydrogen requires continuous alkaline dosing to control process acidification and expensive separation units to remove co-produced CO2, resulting in high operational costs and energy consumption. Here, we introduce wollastonite as a dual-function agent to simultaneously enhance H2 yield and capture CO2. An optimal dosage of 10 g/L was identified, which shortened the lag phase from 23.13 to 12.38 h and increased the hydrogen yield from 158.11 ± 3.44 mL/g glucose-consumed to 210.75 ± 15.87 mL/g glucose-consumed. Mechanistically, wollastonite buffered the system pH, steering metabolic flux away from lactate towards acetate synthesis by enriching Clostridium and suppressing Lactobacillus. Wollastonite also enabled in-situ CO2 sequestration by precipitating it as CaCO3. However, maximal CO2 capture was achieved at a higher dosage (≥15 g/L), which passively reached the required neutral pH but compromised the hydrogen yield. This created a conflict with the optimal 10 g/L dosage for hydrogenesis. To prioritize the primary goal of green hydrogen production, a two-stage strategy was developed. This approach first uses the optimal 10 g/L dosage for maximal fermentation, followed by a post-fermentation pH adjustment from 6.54 ± 0.18 to 7.0 to induce carbonation. The optimized process successfully sequestered 0.49 ± 0.05 of CO2 per liter of medium, thereby increasing the H2 content in the final biogas to a high of 58.2 ± 1.1%. Finally, a life cycle assessment (LCA) validated the environmental superiority of this strategy, confirming a significantly lower Global Warming Potential (GWP) for the entire process. This work thus provides a proof-of-concept for a pragmatic strategy that co-optimizes hydrogen production and carbon capture in a single, sustainable biorefinery process.

生物化学工学
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