The PEC_Flow project aimed to validate original device architectures for the direct photoelectrochemical (PEC) conversion of CO2 and H2O, both in terms of technology and business attractiveness. We have tested four different approaches for PEC CO2 reduction: (i) direct PEC reduction (photocathode), (ii) direct PEC oxidation (photoanode), (iii) PEC reduction and oxidation (photocathode+photoanode tandem), (iv) buried light absorber + EC. In all cases we focused on membrane separated, zero-gap cells, where humidified CO2 was used as input. Based on our results and literature analysis, detailed studies were carried out with the type (ii) and (iv) cells, while an electrolyzer cell (EC) coupled with a photovoltaic (PV) cell was also studied as the baseline. In addition to the validation experiments, technoeconomic analysis and preliminary life cycle analysis were also carried out for these selected technologies. We have analyzed the intellectual property landscape, and performed a market analysis (including stakeholder- and competitor analysis). We concluded that for C1 products (CO and HCOOH), the PV+EC system is the most competitive, while for C2+ products PEC methods can be promising on a longer term. The use of concentrated sunlight and alternative anode processes are also future opportunities. Based on all the above, we outlined a development strategy, in the form of a preliminary business concept, which paves the road for future activities, ultimately leading to commercialization of the PV+EC technology in the near future.This approach will open the opportunity to use industrial exhaust fume directly as feedstock for the generation of valuable chemicals, which will play a key role in turning the chemical industry onto a more sustainable path.
