We cannot identify one single configuration to be the optimum always for all situations, as it depends on many parameters like energy and material costs, interest rate, plant complexity, etc. With the assumption and estimated parameters in this study we find that vapor recompression configuration is the best configuration because it has the lowest total capture cost and CO2 avoided cost. In addition, the plant complexity does not increase very much compared to the benchmark. The split-stream configuration with cooling of semi-lean amine is the second best. However, this configuration increases the investment cost and plant complexity significantly.
The effect of heat integration between the compression section and the stripper is also considered. We can reduce heat requirement by heat integration, but since the inlet temperature to the compressors become higher, the compression efficiency will decrease and compression work will increase. In addition, the capital cost and the complexity of the plant will increase. Because of the higher inlet temperature the water content of produced CO2 is higher and consequently the corrosion problems is more serious in pipes and equipment for compression and injection section.