Optimization of industrial intercooled post-combustion CO2 absorber by applying rate- base model and response surface methodology (RSM)

The most important challenge in the post-combustion CO2 capture process is energy consumption. Using intercooled absorption columns increases absorption rate and decreases the energy needed for solvent regeneration. In this study, the optimum conditions for the usage of intercoolers (height and duty) have been investigated. First of all, the accuracy of rate-base model was validated to predict industrial unit in four different situations. The results showed that CO2 absorption percentage and temperature along the height of the absorption column were predicted precisely with average error of 1.38% and 3.85%, respectively. The second part of this article is dedicated to the optimization to maximize CO2 absorption and minimize total cooling duty by applying response surface methodology (RSM). The statistical analysis showed that the optimum heights for intercoolers I and II were found to be 2 and 5 m, respectively. The energy consumption of intercoolers I and II in optimum conditions were -496 and -809.28 kW respectively. By applying intercoolers’ optimum conditions in the model, the CO2 absorption percentage and energy consumption were obtained at 87.29 and −3890 kW, respectively. Hence, by decreasing the intercoolers’ height in the absorption column and using intercoolers in the optimum heat duty, with constant packing height, the CO2 absorption increased by 3.3%.