Analysis of Adsorbent-Based Warm CO2 Capture Technology for Integrated Gasification Combined Cycle (IGCC) Power Plants

Integrated gasification combined cycle with CO2 capture and sequestration (IGCC-CCS) emerges as a promising method for reducing emission of greenhouse gases from coal without reducing efficiency significantly. However, the high capital costs of these plants have limited their deployment. The current solvent-based low-temperature CO2 capture process is energy and capital intensive contributing to the problem. Warm CO2 capture has been predicted to be a key enabling technology for IGCC-CCS. Here, we assessed the applicability of CO2 removal technology to IGCC via a warm pressure swing adsorption (PSA) process based on our newly invented sorbent, which has good cyclic sorption-desorption performance at an elevated temperature. A 16-step warm PSA process was simulated using Aspen Adsorption based on the real sorbent properties. We used the model to fully explore the intercorrelation between hydrogen recovery, CO2 capture percentage, regeneration pressure of sorbent, and steam requirement. Their trade-off effects on IGCC efficiency were investigated by integrating the PSA process into the plant-wide IGCC simulation using Aspen Plus. On the basis of our analysis, IGCC-warm PSA using our new sorbent can produce similar thermal efficiencies to IGCC-cold Selexol. In order to achieve this, warm PSA needs a narrow range of process parameters to have a good balance between the hydrogen loss, steam consumption and work requirement for CO2 compression. This paper provides a rigorous analysis framework for assessing the feasibility of warm CO2 capture by sorbents in an IGCC system.