Energetic–Environmental–Economic Assessment of Integrated Different Carbon Capture and Compression Processes for High CO₂ Concentration Gas

Abstract

In this work, a novel energetic–environmental–economic assessment methodology for different processes integrating carbon capture and compression was proposed. It was found that for acquiring high-pressure liquid CO2 products, the pressurized desorption (PD) process is better than conventional atmospheric desorption. Based on this, quantitative and comprehensive evaluation and comparison between PD and cryogenic distillation (CD) processes of CO2 concentrations ranging from 50 to 90% were analyzed. The results indicated that the PD process is more energy-intensive than the CD process due to the high regeneration heat. Meanwhile, the green degree analysis results showed that the CD process exhibits an environmental superiority over the PD process when the CO2 concentration exceeds 50%. According to the cost analysis, the CD process presents an almost exponential drop in the total capture cost (TCC) as the CO2 content increases, but the PD process is insensitive. Moreover, we developed a TCC model, taking the feed gas composition and flow rates as variables. It can be seen that as the flow rates of the feed gas are less than 1800 kmol/h, the PD process is more cost-effective than the CD process over a wide range below 73.02% CO2 composition, providing a quantitative method to guide the optimal process selection and design.