A Comparison of Post-combustion Capture Technologies for the NGCC

Abstract

Four different post-combustion capture technologies are compared for the same NGCC (electric efficiency 58.1% without CO2 capture). The technologies are aqueous amine, polymeric membranes, a low temperature sorbent and Ca-looping. The effect of 40% Exhaust Gas Recirculation (EGR) is compared for all technologies except Ca-looping. At 90% CO2 capture rate, polymeric membranes (as expected) give a very poor efficiency (34.9-46.2%). Ca-looping efficiency spans over a wide range, 45.6-53.1%, depending on process configuration and Ca-looping sorbent applied. The NGCC electric efficiency with aqueous amine capture (MEA or a Novel Generic Solvent) spans from 49.5-51.8%. The low temperature sorbent electric efficiency was found to be 50.8-52.3%. Aqueous amines, with their maturity, relative ease of process integration and potential for performance improvement when reducing reboiler approach, improving solvent performance and applying EGR appears to be a good option for CO2 capture from the NGCC. The performance of the low temperature sorbent appear interesting enough to merit further investigations. Polymeric membranes could be interesting to evaluate further when aiming for lower capture rates, whereas Ca-looping mainly should be of interest to develop further for base load NGCC applications.