Biological photosynthesis is the origin of our liquid transportation fuels, from petroleum to corn ethanol. Biological photosynthesis has an efficiency of approximately 1% for the conversion of photons from sunlight to biomass1. Increasing the energy efficiency of biomass production (solar-to-biomass conversion) would allow for biomass, and biofuels, to be produced using less resources. Artificial photosynthesis seeks to overcome the limitations of biological photosynthesis, including low efficiency of solar energy capture and poor carbon dioxide reduction, and could provide an alternative route for biomass production. A two-step electrochemical process converts CO2 to acetate. Acetate is a soluble, two-carbon substrate that can serve as the sole carbon and energy source for the heterotrophic cultivation of algae, an oil-producing feedstock for the production of drop-in liquid fuels. Coupling this system of carbon fixation to photovoltaics offers an alternative, more energy efficient approach to biomass production for biofuels.
Hann, Elizabeth, "A Combined Electrochemical-Biological System for the Production of Liquid Fuel from CO2" (2022). Link Foundation Energy Fellowship Reports. 1.