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 H-2 via water electrolysis. An autotrophic H-2-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.