Techno-economic assessment and exergy analysis of iron and steel plant coupled MEA-CO2 capture process

Abstract

In the interest of mitigating global warming and climate change, the steel industry urgently needs to take measures to reduce CO2 emissions. In the context, this study is to evaluate the application value and feasibility through the techno-economic assessment and exergy analysis of the iron and steel industry coupled MEA-CO2 capture process. The integrated process, successfully implemented in Aspen Plus v12®. Considering the influence of heat integration and capture scale, scenarios 1–4 are designed: 1. Full-flow carbon capture, using outsourced steam; 2. Full-flow carbon capture with heat recovery and outsourced steam mixed use; 3. Partial-flow carbon capture only using surplus steam; 4.100,000 tons of CO2/year of capture scale, using outsourced steam. The process can achieve an effective gas capture rate of 90% and a CO2 product purity of 98.3%. The maximum annual CO2 emission reduction is about 7.65 million tons in scenarios 1 and 2. Compared with scenario 1, the CO2 capture cost of scenario 3 decreased by 22.1%, 29.0%, 23.9% and 21.2%, while that of scenario 4 increased by 44.1%, 39.5%, 25.3% and 18.0%. Through exergy analysis, the total exergy efficiency is calculated to be 38.04%, and the components that need attention and improvement in the process are diagnosed. TTAShis provides a reference for the performance analysis and application feasibility of the coupling process of CO2 capture and waste heat utilization from steel plant.