Evaluation of elastomer suitability for CCUS: Chemical compatibility and rapid gas decompression in supercritical CO2

Abstract

AbstractThe equipment of carbon capture, utilization, and sequestration (CCUS) infrastructure demands a range of elastomers fully compatible with CO2 phases. In this paper, the typical oilfield elastomers, perfluoroelastomer (FFKM), fluoroelastomer (FKM), tetrafluoroethylene propylene elastomer (FEPM), and hydrogenated nitrile butadiene rubber (HNBR), were studied for their chemical compatibility and rapid gas decompression (RGD) in 100% supercritical carbon dioxide (sCO2). At a given test condition, all selected oilfield compounds passed the ISO 23936‐2 acceptance compatibility criteria after 28‐day aging at 100 C and 34.5 MPa in sCO2. After aging, the elongations at break of the FFKM and FEPM compounds increased; tensile strength for FEPM decreased. In contrast to FFKM and FEPM, FKM and HNBR exhibited both lower elongations at break and lower tensile strengths. The moduli of the various elastomers consistently decreased after the sCO2 aging. The RGD testing revealed that all compounds were capable of passing the RGD ISO 23936‐2 criteria. Complementary material analyses by Fourier transform infrared spectroscopy and differential scanning calorimetry along with surface morphology analyses were also conducted to gain additional insight into the suitability of the selected elastomers for sCO2 service.