Assessing the techno-economic performance of membrane-based carbon capture and storage in South African coal-fired power plants

South Africa relies heavily on coal for electricity generation, making its power sector a major contributor to carbon dioxide emissions. Carbon capture and storage (CCS) technologies have been proposed as pathways to mitigate carbon dioxide emissions and environmental impacts. This study presents a techno-economic evaluation of a membrane-based carbon dioxide capture system tailored for a South African coal-fired power plant. This study presents a techno-economic evaluation of a membrane-based carbon dioxide capture from a South African coal-fired power plant. The work involves firstly simulating a supercritical coal power plant with a capacity to produce a gross power of 804 MW. Coal characteristics and local ambient conditions in a specified region of South Africa are considered. The resulting flue gas composition and state are determined from the simulation. In a second stage, a membrane system is proposed for carbon capture from the power plant flue gas. To optimise the process, a superstructure-based model is applied. The capture efficiency is set at 90% whilst the product stream consists of 95% carbon dioxide. The cost of the membrane process, transport and storage and ultimately the cost of electricity, is determined. The study shows that an optimal membrane-based carbon capture and storage system in South Africa would result in an additional 10.6% efficiency penalty. The cost of electricity would increase by 131.9% to 152.5 US$/MWh.