Kinetic characterization of solvents for CO2 capture under partial oxy-combustion conditions

Abstract

Partial oxy-combustion is proposed as a new carbon capture concept based on the use of oxygen-enriched air as an oxidizer instead of air during the combustion stage followed by a CO2 chemical absorption. This novel approach has showed potential advantages compared with other CCS technologies that may lead to a further reductions of the energy penalties related to the CO2 separation process. In this work, a lab-scale apparatus operating under semi-batch conditions was used for the kinetic evaluation of potassium carbonate (K2CO3), aminoethylpiperazine (AEP) and methyldiethanolamine (MDEA) and monoethanolamine (MEA). Four experiments were set for each solvent where the flue gas composition varied from 15%v/v (post-combustion) to 60%v/v. In general, the use of a more CO2 concentrated flue gas enhanced the CO2 absorption process and the kinetic was significantly improved under partial oxy-combustion conditions. The CO2 loading also increased in the presence of a more CO2 concentrated flue gas for each solvent tested. Those results strengthened partial oxy-combustion as a potential CCS approach in comparison with more mature technologies such as post-combustion and oxy-combustion.