Study on the chemical absorption main heat exchanger and process modification for 150kt/y CCS demonstration project

In this paper, the heat transfer exchanger with higher heat transfer coefficient and process modification of a 150 kt/y chemical absorption CCS demonstration project is introduced. The fully welded plate heat exchanger and tubular falling film reboiler is first employed in commercial carbon capture system for reducing the system investment. The cold lean/rich solution temperature difference of the lean/rich solution heat exchanger can reduce to 5 K due to the high heat transfer coefficient of fully welded plate heat exchanger. The falling film reboiler process could improve the gas/liquid separation efficicency. The inter-cooling process is set on the bottom structured packing section for increasing the rich CO₂ loading in the carbon absorber. The modified rich split and lean vapor compression process are applied to this project. The stripper diameter of the top section can reduce to 2.4–3.2 m, which could improve the heat transfer coefficient of the top section in the stripper. The optimal rich solution split ratio is about 12.5% of the total rich solution which out from the absorber. The solution regeneration duty saving is about 0.6 GJ/t CO₂ when the flash pressure choose as 0.7 bar.