SO2 interference on separation performance of amine-containing facilitated transport membranes for CO2 capture from flue gas.

Post-combustion carbon capture using membranes is a key approach to control CO 2 emissions from power plants using fossil fuels. The minor contaminants, such as SO 2 and O 2 , may influence the long-term membrane performance. With the presence of SO 2 in the feed gas, SO 2 could preferably react with amine carriers and hinder the permeation of CO 2 in the amine-containing facilitated transport membranes. Possible amine degradation and competitive reactions would reduce membrane performance with real flue gas. With SO 2 concentrations of 0.7–5 ppm, two amine-containing facilitated transport membranes were tested at 57 and 102 °C, respectively. Unstable membrane performance was observed at 102 °C for the membrane containing Lupamin® as fixed-site carrier and potassium glycinate (K-Gly) as mobile carrier in the presence of SO 2 . On the contrary, two membranes containing polyvinylamine (PVAm) as fixed-site carrier and amino acid salts as mobile carriers showed stable separation performance in the presence of 1–3 ppm SO 2 at 57 °C. Therefore, the operating temperature plays a significant role in the membrane stabilities in the presence of SO 2 . In addition, the infrared (IR) spectra of the membrane components exposed to SO 2 with respect to exposure time were collected. It was found that the amines reacted with SO 2 to form sulfite products irreversibly at 102 °C. The spectral results were consistent with the observed membrane separation performance. The stable membrane performances of the facilitated transport membranes at 57 °C with SO 2 at ppm levels indicate the applicability of the developed amine-containing membranes for use in CO 2 capture from real flue gas. [ABSTRACT FROM AUTHOR]