Cardo polyimide membranes for CO2 capture from flue gases

Abstract

This chapter discusses that cardo polyimide hollow fiber membranes were developed as an alternative to existing commercial amine absorption for CO2 capture from flue gases. To investigate the relationship between chemical structures and CO2 separation properties, various cardo polyimides were synthesized to measure CO2 separation properties and some chemical structure was found to give remarkable properties both in CO2 permeation and selectivity. An economic analysis was carried out for CO2 separation using the hollow fiber membrane followed by a liquefaction process. In the cost breakdown of CO2 separation with membrane, the electricity consumption of the vacuum pump, which induce a pressure difference between a feed side and a permeate side of a membrane, contributed 50% or more of the total cost. For further cost reduction, an application of membrane system to pressurized gas streams similar to CO2 removal from natural gas might be a promising way of reducing the cost of CO2 separation.