Economic evaluation for four different solid sorbent processes with heat integration for energy-efficient CO2 capture based on PEI-silica sorbent

An amine-functionalized solid sorbent-based process with heat integration is considered an energy-efficient method for large-scale CO2 capture. Herein, we propose a techno-economic analysis (TEA) of four different solid sorbent processes for post-combustion CO2 capture with internal heat integration as an alternative to the conventional amine scrubbing process. Our proposed processes are fluidized bed adsorption, fixed bed adsorption, moving bed adsorption, and rapid thermal swing adsorption and involve continuous adsorption, heating, desorption, and cooling. In addition, the four processes use an amine-functionalized solid sorbent, SiO2/0.37 EB-PEI, which was transformed into powder, pellet, and hollow fiber to reflect the characteristics of each process. The proposed processes enable internal heat integration by recovering sensible heat from the cooling process and further enhance the CO2 cyclic capacity of amine-functionalized solid sorbents with high CO2 recovery by performing adsorption heat removal. Most importantly, our TEA based on rigorous mathematical modeling revealed that the CO2 capture cost of the four solid sorbent-based processes was approximately 48.1–75.2 $/t-CO2, with a 45%–58% sensible heat recovery. Such a low CO2 capture cost is comparable to that of the most mature amine-based absorption process (62.8 $/t-CO2), owing to a combination of internal heat integration and enhanced CO2 cyclic capacity. The results support the feasibility of four solid sorbent-based processes for post-combustion CO2 capture.