Techno-economic and environmental evaluation of CO2 mineralization technology based on bench-scale experiments

摘要

This work presents a techno-economic & environmental analysis of a CO2 mineralization process, intended to examine its potential for CO2 reduction and economic feasibility. The CO2 mineralization technology of this study is composed of the CO2 carbonation process and the brine electrolysis process, producing various chemical compounds such as sodium bicarbonate, hydrogen, and chlorine. Notably, the CO2 mineralization process is able to utilize flue gas with a low concentration of CO2 that has not been subjected to CO2 capture processes. For the technical feasibility analysis of the CO2 mineralization process examined in the study, performance evaluation is conducted for a bench-scale CO2 mineralization test unit (2 kg/day CO2 utilization capacity), yielding sodium bicarbonate of over 97% purity. It is also estimated that the CO2 utilization process of this study produces 0.65 tons of CO2 emissions per ton of sodium bicarbonate produced, which indicates a 2.09 ton CO2 reduction compared to the conventional processes which produce 2.74 tons of CO2 emissions for the same amount of sodium bicarbonate production. With these results as a basis, an economic evaluation is conducted for a commercial-scale CO2 utilization plant (sodium bicarbonate production capacity: approximately 5000 tons/year) which utilizes CO2 in flue gas produced from thermal power plants. The evaluation supports the economic feasibility of the process with a benefit/cost ratio (B/C ratio) of 1.12 and internal rate of return (IRR) of 10.4%.