Selective strategy for solid sorbent replacement in CCS

Abstract

An innovative method for sorbent replacement in the looping of a generic solid sorbent for post-combustion carbon capture and sequestration (CCS) is introduced. First, the standard replacement method is revisited with some original results presented. A new strategy is then modeled, aimed at selectively replacing the material as it degrades. This method exploits the density difference, after adsorption, between relatively fresh, CO2-laden sorbent and relatively degraded material, with small residual adsorption capacity. The model is then applied to values of degradation rate within the experimental range available in scientific literature for silica-supported amines (SSA). The selective removal strategy ideally allows a saving of 37% of the sorbent with respect to the standard, undifferentiated replacement considered in first place, while keeping the same adsorptive capacity of the system.