Pilot-scale CO2 capture in a cement plant with CESAR1: Leveraging absorber intercooling and cold-feed heat-integration to lower the SRD

Abstract

Reducing energy consumption within CO2 capture, and managing energy flow within the capture process remain challenges. This work presents a pilot-scale experimental campaign of amine-based CO2 capture from cement flue gas using the CESAR1 solvent, focusing on two heat-integration strategies: absorber intercooling and cold-feed. In addition, we present a composite-curve analysis of available heat, illustrating how the CO2 capture unit can be integrated with external heat integration. When using intercooling (IC), the performance of the absorber improved. The specific reboiler duty (SRD) decreased from 3.39 GJ/tCO2 (baseline) to 3.10 GJ/tCO2, corresponding to an energy reduction of 8.6%. Implementing a cold-feed (CF) bypass around the lean-rich heat exchanger (LRHX) did not reduce the SRD, but it lowered top-column temperatures and shifted cooling duty from the overhead condenser to the lean cooler, supporting improved solvent stability and more direct control of cooling demand. Combining intercooling and cold-feed enabled decoupled control of lean and rich solvent loadings, and achieved an SRD of 2.50 GJ/tCO2 at approximately 70% capture, or an energy reduction of 26.3%.