Zero-Carbon Biofuels: An Optimized Two-Stage System for High Productivity Conversion of CO2 to Liquid Fuels
Technology Description:
The Massachusetts Institute of Technology (MIT) has demonstrated a two-stage system where acetate is produced from CO2 and H2 via acetogenic fermentation in the first stage and then fed to the yeast reactor for converting acetate to lipids or alkanes. MIT proposes to reduce or eliminate CO2 generation during lipid production by (1) engineering an oleaginous yeast with the enzymes necessary to generate reducing equivalents from hydrogen, formic acid, or methanol, and (2) installing a carbon-conserving non-oxidative glycolysis. The system’s commercial competitiveness is currently limited by the rate of CO2 fixation in the first stage. MIT recently showed that synergistic substrate co-feeding drastically enhances CO2 fixation rates and will explore additional co-substrate pairs to maximize acetate productivity.
Potential Impact:
The application of biology to sustainable uses of waste carbon resources for the generation of energy, intermediates, and final products---i.e., supplanting the “bioeconomy”—provides economic, environmental, social, and national security benefits and offers a promising means of carbon management.