Supplementary information files for A strategy for CO2 capture and utilization towards methanol production at industrial scale: an integrated highly efficient process based on multi-criteria assessment

© the Authors CC-BY 4.0Supplementary files for article A strategy for CO2 capture and utilization towards methanol production at industrial scale: an integrated highly efficient process based on multi-criteria assessmentCO2 capture and utilization are an effective solution to the problem of CO2 emissions, and a combination of ammonia-based CO2 capture and its use for methanol production is a highly feasible strategy. However, the uses of conventional technologies have resulted in a high demand for energy, with limited use of hydrogen. To address these problems, an innovative strategy is proposed and demonstrated in this study that enhances the conventional design, i.e., to use ammonia-based CO2 capture with double tower absorption and solvent split, along with wet hydrogen for methanol production at industrial scale. The process is further improved through a multi-criteria assessment that considered the CO2 capture rate, NH3 loss rate, CO2 conversion rate, and energy saving factors, in which the latter is based on two components, namely the reboiler duty and the condenser duty. Moreover, an exergy analysis method is used to optimize the improved process, and a highly efficient integrated process is finally established. It has been found that the use of a double-tower absorption process ensures high rates of CO2 capture and low rates of NH3 loss. Additionally, adjusting the molar ratio of H2 to CO2 leads to an impressive 8% increase in the CO2 conversion rate, reaching 25%. In terms of energy savings, the average reboiler duty was reduced from 13.39 to 11.85 MJ/kgCO2, i.e., by 11.50%; while the condenser duty was reduced by 11.36%; both contributed to the overall energy savings. In the I-ACCMP process, the total exergy loss is 437.24 kW, of which the exergy loss of the heat exchangers accounts for 16%, and the desorption tower (DES) accounts for 48%. After optimization, the exergy loss of the heat exchangers decreases from 70.02 kW to 40.45 kW, the exergy loss of the DES decreases from 209.29 kW to 180.91 kW, and the reboiler duty is reduced from 10.60 MJ/kgCO2 to 7.71 MJ/kgCO2. The total exergy loss decreases from 437.24 kW to 372.68 kW, which is a reduction by 14.8%.

© 作者 CC-BY 4.0 辅助文件，用于文章《一种针对工业规模甲醇生产的二氧化碳捕获与利用策略：基于多标准评估的集成高效工艺》：二氧化碳捕获与利用是解决二氧化碳排放问题之有效途径，结合以氨为基础的二氧化碳捕获及其在甲醇生产中的应用，构成了一种高度可行的策略。然而，传统技术的应用导致能源需求高昂，氢能利用率有限。本研究提出并演示了一种创新策略，以提升传统设计，即采用基于氨的二氧化碳捕获技术，配合双塔吸收和溶剂分解，以及湿氢在工业规模甲醇生产中的应用。通过考虑二氧化碳捕获率、氨损失率、二氧化碳转化率和节能因素（后者基于再沸器负荷和冷凝器负荷两个组成部分）的多标准评估，进一步优化了该工艺。此外，运用热力学分析的方法对改进工艺进行优化，最终建立了一个高效集成的工艺流程。研究发现，采用双塔吸收工艺确保了高二氧化碳捕获率和低氨损失率。此外，调整氢气与二氧化碳的摩尔比，使得二氧化碳转化率提高了令人瞩目的8%，达到25%。在节能方面，平均再沸器负荷从13.39降低至11.85兆焦每千克二氧化碳，即降低了11.50%；而冷凝器负荷降低了11.36%；两者共同贡献了整体的节能效果。在I-ACCMP过程中，总熵变损失为437.24千瓦，其中热交换器的熵变损失占16%，解吸塔（DES）占48%。经过优化，热交换器的熵变损失从70.02千瓦降至40.45千瓦，DES的熵变损失从209.29千瓦降至180.91千瓦，再沸器负荷从10.60兆焦每千克二氧化碳降至7.71兆焦每千克二氧化碳。总熵变损失从437.24千瓦降至372.68千瓦，减少了14.8%。