Permeation of Ternary Mixture Containing H2S, CO2 and CH4 in Aquivion® Perfluorosulfonic Acid (PFSA) Ionomer Membranes

Abstract

Aquivion® E87-12S Perfluorosulfonated acid ionomer material (PFSA) has been studied as a membrane technology for natural gas sweetening from CO2, H2S due to its interesting chemical and mechanical stability and good separation performance for polar compounds in humid environments. In the present work, permeation of the H2S/CO2/CH4 ternary mixture in this short-side PFSA chain was investigated at pressures up to 10 bar, temperatures up to 50 °C, and in a range of relative humidity (RH) from 20% to 90%. The results obtained confirm the strong dependence of Aquivion® on water activity and temperature, and its ability to separate gases based on their water solubility without substantial differences between pure and mixed gas experiments. Indeed, even when tested in ternary mixture, the permeation behavior remains similar to that observed for pure components and binary mixtures. In particular, the permeability of H2S is higher than that of CO2 and methane CH4, reaching values of 500 Barrer at 50 °C and 80% RH, against 450 and 23 Barrer for the other two gases respectively. Additionally, when tested at higher pressures of up to 10 bar under humid conditions, the membrane properties remained largely unchanged, thus confirming the overall stability and durability of Aquivion® E87-12S in acid environments.

Parametrical Assessment of Polyacrylamide Polymer Membrane Used for CO2 Post-Combustion Capture

“…The minor components, such as H 2 S and SO 2 , have an effect on membrane materials which has been addressed by Luis et al [60]; the authors declared that these compounds may influence the material of plasticization and aging, which limits the membrane process performance and reduces its lifetime. However, five years is the efficient working period for the membrane material, and reparations must be considered after that duration [61,62]. CHEMCAD model 8.1 is the simulation platform harnessed to investigate all the operations in the present paper.…”

“…SPECCA, in MJ/kg, for the membrane was calculated as the next formulation[61]:SPECCA = 3600 × E fine,NO capture − E fine,With Capture E fine,No capture × C No capture − E fine,With capture × C With capture CO 2 removed presents the quantity of carbon dioxide removed through the capture process, in t/kWh. In another way, CO 2 avoided price (CO 2,AP ), in EUR/t, is determined respecting the CFPP price with and without carbon-capture technologies and CO 2 released for both cases, Equation (10) below shows that relation [65]: CO 2,AP = LCOE with capture − LCOE No capture C No capture − C with capture…”