A Sustainable Chemicals Manufacturing Paradigm Using CO2 and Renewable H2

The chemical industry must decarbonize to align with UN Sustainable Development Goals. A shift toward circular economiesmakes CO2 an attractive feedstock for producing chemicals, provided renewable H-2 is available through technologies such as supercritical water (scH(2)O) gasification. Furthermore, high carbon and energy efficiency is paramount to favorable techno-economics, which poses a challenge to chemo-catalysis. This study demonstrates continuous gas fermentation of CO2 and H-2 by the cell factory, Cupriavidus necator, to (R,R)-2,3-butanediol and isopropanol as case studies. Although a high carbon efficiency of 0.75 [(C-mol product)/(C-mol CO2)] is exemplified, the poor energy efficiency of biological CO2 fixation requires similar to 8 [(mol H-2)/(mol CO2)], which is techno-economically infeasible for producing commodity chemicals. Heat integration between exothermic gas fermentation and endothermic scH(2)O gasification overcomes this energy inefficiency. This study unlocks the promise of sustainable manufacturing using renewable feedstocks by combining the carbon efficiency of bio-catalysis with energy efficiency enforced through process engineering.