Effects of Minor Components in Carbon Dioxide Capture Using Polymeric Gas Separation Membranes

The capture of carbon dioxide by membrane gas separation has been identified as one potential solution to reduce greenhouse gas emissions. In particular, the application of membranes to CO2 capture from both pre- and post-combustion strategies is of interest. For membrane technology to become commercially viable in CO2 capture, a number of factors need to be overcome, one being the role of minor components in the process on membrane performance. This review considers the effects of minor components in both pre- and post-combustion use of polymeric membranes for CO2 capture. In particular, gases such as SOx, NOx, CO, H2S, NH3, as well as condensable water and hydrocarbons are reviewed in terms of their permeability through polymeric membranes relative to CO2, as well as their plasticization and aging effects on membrane separation performance. A major conclusion of the review is that while many minor components can affect performance both through competitive sorption and plasticization, much remains unknown. This limits the selection process for membranes in this application.