Life Cycle Assessment of Solar-Driven Post-Combustion Carbon Capture Systems: The Way Forward to Slash the Energy Penalty

Abstract

Post-combustion carbon capture (PCC) technique has been extensively investigated over the past two decades to mitigate the effects of greenhouse gas (GHG) emissions. Nowadays, integrating solar energy with a PCC retrofit has become an active area of research due to its potential to slash the energy penalty on power plants. The economic aspects of both solar-assisted PCC (SA-PCC) and solar-powered PCC (SP-PCC) counterparts have already been studied in literature. Therefore, this paper aims at analysing and comparing the environmental footprints of SA-PCC and SP-PCC systems throughout their life cycle using the ReCiPe 2016 method. A cradle-to-grave framework is employed to specify the life cycle inventories in OpenLCA software for capturing one carbon capture unit (tonne of CO2) over the project’s lifespan. Results showed that SP-PCC significantly reduces environmental burdens (>10%) in various midpoint categories compared to SA-PCC counterpart. Furthermore, the endpoint assessment of SA-PCC revealed that particulate matter formation, global warming, land use, and mineral scarcity have substantial damaging impacts on the endpoint areas of protection, accounting for 37.29%, 49.48%, 76.18%, and 13.49% of the total impact, respectively. As a result, they are classified as critical impact categories that should receive priority attention for improvements. Further categorization of critical categories showed that the key difference between the examined systems lies in the contributions of nitrate salts and mono-ethanolamine (MEA) production. Furthermore, MEA contributions in SP-PCC are considerably lower than those of nitrate salts in SA-PCC across the critical categories. This demonstrates the superiority of SP-PCC over the SA-PCC in mitigating the environmental burdens when incorporating solar energy in carbon capture process