The impact of capture rate on membrane-based CO₂ capture: A techno-economic and environmental evaluation

Reducing CO₂ emissions is required to achieve carbon-neutrality, and membrane-based carbon capture has gained attention with the potential to mitigate CO₂ emissions. Numerous studies have considered the design of membrane-based capture with respect to economic and environmental objectives. However, in most studies a fixed 90 % capture rate has been used. A small number of studies have considered the impact of varying the capture rate on the economics of membrane-based CO₂ capture, but the influence of this crucial parameter has not been considered with respect to the environmental impacts of membrane-based capture. In this study the trade-off relationship between economics and environmental impact of the membrane-based capture process are investigated with a varying capture rate between 60 and 99 %. The cost-optimal CO₂ capture rate of the membrane-based capture process is identified by imposing carbon tax on the CO₂-eq emissions. For the base case considered, reducing the capture rate from 90 % to 60 % is shown to reduce capture costs by 12.1 % while increasing the emissions by 171.9 % per ton CO₂ captured.