2024-11-15 ワシントン大学セントルイス校
＜関連情報＞
- https://source.washu.edu/2024/11/researchers-create-novel-electro-biodiesel-more-efficient-cleaner-than-alternatives/
- https://www.cell.com/joule/abstract/S2542-4351(24)00434-3
微生物と電極触媒の共同設計でパワーアップした電気バイオディーゼル Electro-biodiesel empowered by co-design of microorganism and electrocatalysis
Kainan Chen∙ Peng Zhang∙ Yayun Chen∙ … ∙ Sisi Xiang∙ Susie Y. Da∙ Joshua S. Yuan
Joule Published:October 31, 2024
DOI:https://doi.org/10.1016/j.joule.2024.10.001
Graphical abstract
Context & scale
Long-range heavy-duty vehicles and industries such as mining, shipping, and construction heavily rely on energy-dense diesel fuels, which cannot be defossilized by electric vehicles. Biofuels can fill the gap, yet biodiesel productivity is limited by low photosynthesis efficiency. It is unrealistic to defossilize diesel consumption by a large percentage with biodiesel, considering the substantial land usage. Similarly, the fundamental limit in human civilization lies in the efficient utilization of renewable energy to produce sufficient fuels, chemicals, materials, and food with limited natural resources. Herein, we developed a new electro-biodiesel concept to manufacture diesel from CO2 by integrating electrocatalytic CO2 reduction reaction (CO2RR) to produce biocompatible C2+ intermediates, with subsequent microbial conversion of these intermediates into lipids as biodiesel feedstock. This new concept can be broadly applied to the circular economy for manufacturing emission-negative fuels, chemicals, materials, and food ingredients at a much higher efficiency than photosynthesis and lower carbon emissions than petrochemicals. We have systemically addressed the challenges in electro-biomanufacturing by identifying the metabolic and biochemical limits of C2 utilization and overcame these limits by balancing the reducing equivalent and enhancing ATP production. Furthermore, we have revealed co-substrate effects for ethanol and acetate and designed catalysts to produce an optimal ratio of acetate and ethanol to achieve higher bioconversion efficiency. The synergistic microbial and catalyst design empowered electro-biodiesel to achieve 4.5% solar-to-molecule efficiency for converting CO2 into lipid, which is much more efficient than biodiesel and other competing platforms. Techno-economic and life cycle analyses revealed competitive minimal selling prices, substantial carbon emissions, and substantially less land use compared with current biodiesels. The electro-bioconversion of CO2 could alleviate the biodiesel feedstock shortage and transform the renewable fuel industry. The new concept can be broadly applied to chemical, material, and fuel manufacturing to create a circular carbon economy for mitigating global climate change.
Highlights
•Electro-biodiesel with 4.5% solar-to-molecule energy efficiency and 1/45 biodiesel land use
•Co-design of microbes and catalysts to improve electron-to-molecule efficiency from CO2
•Discover and overcome metabolic and bioenergetic limits of C2 intermediates bioconversion
•Electro-biodiesel platform with competitive economics and substantial carbon reduction
Summary
Efficient and sustainable energy production is essential for climate change mitigation, yet current approaches like biofuels or electro-fuels have limitations in efficiency and product profile. We advanced a new electro-biodiesel route via integrating electrocatalysis and bioconversion to produce lipids from CO2 for biodiesel. We first revealed bioenergetic and metabolic limits in C2+ intermediate utilization through simulations and metabolomics, guiding the synthetic biology design to achieve reductant balance, more ATP production, efficient lipid conversion, and higher lipid yield. Furthermore, we discovered specific ratios of ethanol and acetate to achieve co-substrate synergy, empowering bimetallic catalyst design to improve bioconversion efficiency. The microbial and catalyst co-design achieved a solar-energy-to-molecule conversion efficiency of 4.5% for CO2-to-lipid conversion. Electro-biodiesel leverages the high efficiency of electrocatalysis and longer-carbon-chain products from microbial lipid synthesis, overcoming the limitations for both electrocatalysis and bioconversion. Electro-biodiesel achieved 45 times less land usage than soybean biodiesel, competitive economics, and substantial carbon emission reduction.
