From lab to industry: Screening carbon materials for enhanced plasma-based CO2 conversion and evaluating economic feasibility

Plasma-based CO 2 conversion with post-plasma carbon bed offers a promising pathway to sustainable CO production, yet carbonaceous material durability and economic feasibility require further study. This work evaluates two activated carbons (ACs), two biochars and one pyrolytic carbon (PC) on a gliding arc plasmatron (GAP). One biochar performs the best with 54 ± 2 vol% CO, 37 ± 2% CO 2 conversion and energy cost (EC) of 3.8 ± 0.2 kWh kg CO −1 (0.76 ± 0.04 MJ mol −1 ; or 0.46–0.6 MJ mol −1 based on plasma power) at 5 L min −1 , despite low surface area and limited durability. The ACs provide a balance between reactivity and stability, while PC demonstrates structural robustness, enhancing durability and CO molar production yield (MPY), despite lower CO concentration and high EC. Pilot scale validation on a multi-reactor GAP (MRGAP) for one AC demonstrates scalability, achieving 68 ± 3 vol% CO, 52 ± 3% CO 2 conversion and EC of 1.8 ± 0.2 kWh kg CO −1 (0.37 ± 0.07 MJ mol −1 ; or 0.22–0.3 MJ mol −1 based on plasma power) at 50 L min −1 . A techno-economic assessment (TEA) based on the levelised production cost of CO (LPC CO ) confirms a carbon bed greatly reducing costs below market benchmarks. When comparing OPEX projections against competing technologies, such as reverse water-gas shift (rWGS) and solid oxide electrolysis (SOEC), our plasma-based process with post-plasma carbon bed emerges as the most cost-competitive option. This work bridges lab and pilot scale insights, underscoring the critical role of carbon material selection in balancing efficiency, longevity, and cost. • Comparing activated carbon, biochar and pyrolytic carbon in a post-plasma carbon bed • 7-fold improvement in CO yield and 9-fold in energy cost, vs without carbon bed • Activated carbon shows best balance of performance efficiency and material durability. • Pilot scale validation achieves 69 vol% CO and energy cost of 1.8 kWh kg CO −1 . • Simplified TEA reveals carbon cost as the main economic factor.