Life cycle assessment and costing of indoor VOC removal via electro-absorption and in situ electrochemical regeneration of activated carbon.

This study evaluates the sustainability performance of a novel indoor air purification system that integrates electro-absorption within situ electrochemical regeneration of activated carbon (AC), specifically designed for benzene removal. Two configurations were compared: (1) indirect treatment using purifiers with electrochemically regenerated AC and (2) direct treatment using electrochemical cells that combine adsorption, electro-absorption, and in situ AC regeneration. A comprehensive Life Cycle Assessment (LCA) was conducted, encompassing human toxicity, global warming potential, freshwater ecotoxicity, resource use, and a Life Cycle Costing (LCCA). These systems reduced cancer-related human toxicity impacts by 90-93%, offering a substantially safer alternative to untreated indoor air or conventional ventilation approaches. The integrated system (Case 2) consistently achieved the lowest environmental burdens, showing around 30% reductions across all evaluated categories. The impacts obtained were 3.9·10-7 CFC11 eq for ozone depletion, 2 L of water consumption, 52.1 PAF·m3·day in freshwater ecotoxicity, and 26.8 g CO₂ eq for global warming per m3 of treated air. Using renewable energy decreased toxicity impacts by over 70% compared to conventional grids, and up to 97.5% compared to untreated air. On-site AC regeneration reduced material use by up to 87% and environmental footprint by 73%. The monetized cost analysis confirmed the economic viability of the system, with values as low as € 0.11-0.13 per m3 of treated air, supporting this technology as a competitive and sustainable solution for indoor VOC mitigation.