Evaluation of an Industrial Absorption Process for Carbon Capture Using K2CO3 Promoted by Boric Acid

Hot potassium carbonate (HPC) process aims to remove the CO2 present on synthesis gas. This removal is done in an absorption process, where takes place the reaction of CO2 with a K2CO3 solution. This reaction is slow and H3BO3 can be used to increase the rate of reaction. The rate-based model is the most suitable way to model the process. This approach uses different correlations to calculate important mass transfer and hydraulic parameters, such as: mass transfer coefficient, interfacial area, and liquid holdup. This paper aims to evaluate the performance of many correlations to represent the HPC process. An automatic procedure was developed to test a high number of equations, using MATLAB and Aspen Plus software. The best set of correlations was found after a comparison with industrial data. Correlations with errors less than 10% for the entire evaluated operating conditions were calculated for mass transfer coefficient and the interfacial area, as well as for liquid holdup.热碳酸钾（Hot Potassium Carbonate, HPC）工艺的核心目标为脱除合成气中的二氧化碳。该脱除流程采用吸收工艺实现，过程中二氧化碳会与碳酸钾（K₂CO₃）溶液发生反应。此反应速率较为缓慢，可通过添加硼酸（H₃BO₃）提升反应速率。速率基模型（Rate-based Model）是模拟该工艺的最优选择，该方法依托多种关联式计算传质系数、相界面积与持液量等关键传质及水力参数。本文旨在评估多组关联式对HPC工艺的表征效果，开发了一套自动化测试流程，结合MATLAB与Aspen Plus软件对大量方程开展测试。通过与工业实测数据对比，最终筛选得到最优关联式组合。在全部评估的操作工况下，传质系数、相界面积及持液量的关联计算误差均低于10%。