Study of Physical and Chemical Resistance of Elastomers in Aqueous MEA and MEA+CO2 Solutions during the Carbon Dioxide Absorption Process

Abstract

Abstract A study was conducted to evaluate the resistance of raw EPDM, natural rubber (NR), isobutylene isoprene rubber (IIR) and styrene butadiene rubber (SBR) to amines in terms of mass and chemical changes in an amine-based CO 2 capture environment made up of aqueous solutions of 3–7 M MEA with 0–0.5 mol CO 2 /mol MEA. The test for each condition lasted 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. The performance of commercial EPDM and IIR were then further studied and compared against PTFE, using aqueous 5 M MEA and with 0.5 mol CO 2 /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. The implication is that PTFE can be used in any part of the process while EPDM and IIR can only be used in low-temperature sections.