Bio-based products from solar energy and carbon dioxide

Producing bio-based products directly from CO2 and solar energy is a desirable alternative to the conventional biorefining that relies on biomass feedstocks. The production paradigm is based on an artificial photosynthetic system that converts sunlight to electricity and H2 via water electrolysis. An autotrophic H2-oxidizing bacterium fixes CO2 in dark conditions. The assimilated CO2 is stored in bacterial cells as polyhydroxybutyrate (PHB), from which a range of products can be derived. Compared with natural photosynthesis of a fast-growing cyanobacterium, the artificial photosynthetic system has much higher energy efficiency and productivity of bio-based products. The new technology looks promising because of possible cost reduction in feedstock, equipment, and operation.