CO_2 capture from fossil-fuelled power plants using facilitated transportmembrane technology

摘要

The application of a highly selective fixed site carrier PVAm membrane to capture CO_2 has been investigated for four different power plant scenarios. These scenarios are 1) recovery from a NGCC flue gas, 2) recovery in an integrated membrane unit where the partial pressure of CO_2 is higher, 3) recovery from an IGCC flue gas and 4) recovery in an integrated IGCC process with CO shift. Feed compression, permeate vacuum and the use of a sweep gas on the permeate side were investigated. It was seen that the partial pressure of the CO_2 in the target stream was critical to the performance of the membrane separation. Both flue gas options required feed compression, sweep and vacuum on the permeate to achieve greater than 60 vol% purity of the recovered CO_2. Membrane area requirements were large. The two integrated scenarios, however, achieved purities greater than 90 vol% at 80% recovery and with energy requirements lower than that for typical amine absorption.