Physical and Chemical Resistance of Elastomers in Aqueous Monoethanolamine (MEA) and CO2-Loaded MEA Solutions during Postcombustion Carbon Dioxide Capture Processes

Abstract

The resistance of raw EPDM, natural rubber, isobutylene isoprene, and styrene butadiene to amines in terms of mass and chemical changes was studied using aqueous solutions of 3–7 M MEA with 0–0.5 mol CO2/mol MEA each for 30 days at 40 °C. The results showed that SBR and NR had poor chemical resistance leading to formation of amides on their surfaces and resulting in high mass change. In contrast, EPDM and IIR had insignificant mass and chemical structure changes. Commercial EPDM and IIR were then benchmarked against PTFE, using aqueous 5 M MEA and with 0.5 mol CO2/mol MEA at 40 and 120 °C each for 30 days. Resistance was measured in terms of mass, hardness, and tensile strength changes. The results showed that PTFE was compatible with the solution at both temperatures. For EPDM and IIR at 40 °C, the changes in mass, hardness, and tensile strength were negligible while at 120 °C, these changes were very significant, implying that PTFE can be used in any part of the process while EPDM and IIR can only be us...