Next-generation membranes could separate out 95% of the CO2 in a flue gas, into a 95% pure permeate, for a cost of $20/ton and an energy penalty below 10%, which greatly exceeds the best amines. This 15-page note lays out ten key questions, to help decision makers de-risk next-generation CCS membranes. The technology is early-stage. Companies are also noted.