Life cycle assessment of amine-based versus ammonia-based post combustion CO2 capture in coal-fired power plants

Considering two sets of subcritical and supercritical 500 MW coal fired power plants with and without CO2 capture unit, a comparative, cradle-to-gate life cycle assessment was performed to evaluate the environmental impact of CO2 capture through amine-based and ammonia-based absorption from the flue gasses. The aqueous solutions of monoethanolamine (MEA) was considered as the amine solvent. The effects of MEA concentration of 20, 30, and 40 wt% and CO2 capture efficiency on the environmental impact of different categories were investigated. The methods of IPCC 2013 GWP 100a, AWARE V1.02, ReCiPe 2016 Midpoint (H) V1.03, and TRACI 2.1 V1.05, were considered for this LCA. In terms of global warming, adding a CO2 capture unit presented significant benefits for the environment. However, for other impact categories such as water footprint, ozone depletion, ionizing radiation, marine eutrophication, smog and fossil fuel depletion the plants with CO2 capture unit showed higher impact compared to the plants without a CO2 capture unit. In terms of carbon and water footprints MEA-based CO2 capture unit presents better performance compare to the ammonia-based.

Automated summary

A comparative life cycle assessment was conducted on subcritical and supercritical coal fired power plants with and without CO2 capture unit. The results showed that adding a CO2 capture unit had significant benefits for global warming but had negative impact on other environmental categories. MEA-based capture unit performed better than ammonia-based.