New concepts and advanced designs of PEcats, a TPER with an innovative approach involving 4 simultaneous processes. Expected results: Single TPER units and their enabling materials, The integration of TPER units and evaluation of potential impact vs. fossil-fuel based routes, demonstration of technical and economic feasibility, Evalutation of GHG emissions regarding commercial manufacturing by LCA, Assessment of increase of industrial competitiveness of the chemicals industry and Estimation of environmental and social benefits.
At TRL3, the system achieved a sunlight-to-chemical energy conversion efficiency of 4.6%, demonstrating stable syngas production. Integration of perovskite photovoltaic cells achieved a solar-to-fuel efficiency of 4–4.5%, with potential improvements identified in photoanode materials and light-harvesting techniques.
The project validates the technical feasibility of solar-driven CO2 reduction and suggests pathways for improvement through better reactor design and cost reductions. Economic viability could be enhanced by savings from rising CO2 tax allowances and lower electrode production costs, but long-term electrocatalyst stability remains a key challenge. The SunCoChem project continues to show promise for advancing PEC-based renewable chemical production technologies.
The TRL3 prototype demonstrated significant progress in system stability, maintaining stable syngas production for 200 hours with a CO:H2 ratio of ~4:1 under optimal conditions. The Cu2O/SnO2-based GDE achieved high Faradaic efficiency (CO ~85%) while mitigating challenges like GDE flooding through optimized pressure and flow rates. Integration with perovskite photovoltaic cells enabled a solar-to-fuel efficiency of 4–4.5%, showcasing scalability.
Operando characterization using EXAFS and X-ray fluorescence at BESSY-II provided insights into the catalyst’s elemental composition and oxidation state changes, aiding in material and operational optimization. Future integration of complementary techniques will further enhance performance and advance CO2 electrolysis technology toward industrial readiness, with a clear pathway to achieving long-term stability and economic feasibility.
The SunCoChem technology offers a sustainable alternative to fossil-fuel-based chemical production, particularly for oxo-products, with potential to become competitive after further improvements. Current challenges include low current density limitations of photocatalysts, leading to larger reactors and higher costs (CAPEX and OPEX). Transitioning to a PV+EC system could reduce syngas production costs by 70–75%.
The technology shows potential energy savings compared to traditional methods. At larger scales, energy consumption could be reduced by 11%, improving energy neutrality and lowering production costs, such as a 0.15 €/kg reduction for Limoxal.
From an environmental perspective, the project demonstrates reduced CO2 emissions and energy consumption. CO2 reductions of up to 50% are achieved for valeraldehyde and glycolic acid, and up to 90% for glycolic acid via electrochemical methods. Energy efficiency improvements are around 36% for valeraldehyde and 66% for glycolic acid. Limoxal shows lower reductions but follows a downward trend.
Future improvements could focus on optimizing reaction inputs or selecting materials with lower environmental impact, enhancing both energy efficiency and CO2 emission reductions.
