Process optimization of high purity CO2 compression and purification system from oxygen-rich combustion flue gas

• Published in: International journal of greenhouse gas control Vol. 135; p. 104146
• Main Authors: Ma, Lijin, Du, Yawei, Guo, Xiaojun, Zhou, Wuao, Deng, Huining, Zhang, Shaofeng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2024
• Subjects: CO2 capture; CO2 purification; Genetic algorithm; Oxygen-rich combustion; Sensitivity analysis; Sensitivity analysis; CO2 capture; Genetic algorithm; Oxygen-rich combustion; CO2 purification
• ISSN: 1750-5836; 1878-0148
• DOI: 10.1016/j.ijggc.2024.104146

•CO2 compression and purification process with high level of impurities is established.•Proposed model is validated with a similar experiment from reference.•One tower with sideline extraction and heat coupling are used to improve process performance.•Methanol is introduced as hydrate inhibitor for icing protection.•Sensitivity analysis is performed with key parameters. The CO2 compression and purification units (CO2CPU) is an effective process to capture CO2 from oxygen-rich combustion flue gas. However, the quality of CO2 products needs to be improved for high-value-added utilization. In this study, the CO2CPU with high concentration of impurities (SOX, NOX, H2O) was optimized by Aspen Plus and Matlab with genetic algorithm. The model is validated with similar experiment from reference. The results showed that under the compressor pressure of 30 bar and condensation temperature of −36 °C, the liquid CO2 product with a high purity of 99.9991 % with the total cost of 26.98 $/tCO2 could be obtained. Sensitivity analysis was utilized to investigate the influences of key parameters on the system performance, including the number of plates of towers, pressure, reflux ratio, and gasification fraction. The required cooling capacity and performance of compressor are closely related to the ambient temperature. One impurities removal tower with sideline extraction was used to further improve the process performance. Energy consumption and total cost are reduced by 140.55 kW and 0.23 $/t CO2, respectively. Methanol is introduced as the hydrate inhibitor for icing protection. Despite the additional three towers, the total cost is reduced by 1.86 % with heat coupling. [Display omitted]