For biorefineries to displace fossil fuels, a sustainable feedstock for microbial growth must be identified. As agricultural production of sugars has a limited capacity, it cannot completely replace fossil fuels without severely undermining food security and decreasing biodiversity. In order to fully displace fossil fuels we need to utilize resources that are (almost) unlimited and that are independent of agricultural or forestry land use.
eForFuel developed an industrial biotechnology solution that uses electricity, water and microorganisms to convert CO2 into hydrocarbon fuels, thus providing a sustainable replacement of energy stored in fossil carbons. We used the advantages of different disciplines to establish an efficient process: carbon dioxide activation via reduction to formic acid is performed via electrochemical means while production of hydrocarbons is carried out in genetically engineered formatotrophic microbes.
eForFuel addresseed multiple challenges previously limiting the success of novel fuel technologies. We decoupled production from agricultural resources, instead relying on widely available resources, such as water, (renewable) electricity, and concentrated waste CO2 originating for example from the gas outflow of the steel industry. As a mediator between the electrochemical apparatus and microbial growth we use formic acid, which, unlike hydrogen and carbon monoxide, is fully soluble, easily stored and safe to handle. We focused on the production of two products, gaseous propane and isobutene. Both can be easily separated from the microbial culture, reducing production cost and increasing energy efficiency. Furthermore, the products can be easily integrated into existing fuel facilities: propane as component of Liquefied Petroleum Gas (LPG), and isobutene for production of the superb fuel substitute isooctane.
eForFuel was a truly interdisciplinary consortium, bringing together experts from a wide spectrum of fields, including electrochemistry, material science, enzymology, biochemistry, microbiology, chemical engineering, industrial biotechnology, environmental science, and sociology. By focusing on integrated sustainability, eForFuel set the stage for a future environmentally, economically, and societally sustainable value chain to produce renewable chemicals and fuels.
The main results achieved in eForFuel were:
• optimized structure and composition for both cathode and anode in the CO2 electrolyser;
• optimized electrolysis with regard to Energetic and Faraday Efficiencies, Current Densities and Electrode Lifetime;
• optimise growth of E. coli on formate via one of the formate assimilation pathways;
• proof of concept of production of isobutene in a formatotrophic E. coli strain;
• construction of a prototype of the electrobioreactor (EBR), with detailed architecture of hardware control and software;
• an integrated Life Cycle Assessment (LCA);
• a public perception survey in several European countries, indicating a positive attitude towards eForFuel telated goals and technologies;
• a series of video clips for the general public.
For more details on the results, publications etc. please visit: www.eforfuel.eu