Analysis of Carbon Capture Potential and Economic Viability of Post-Combustion CO2 Capture from Cement Plants in Sokoto State

Nigeria's cement manufacturing sector is the second largest industrial source of carbon dioxide emissions nationally, and cement plants in Sokoto State, North West Nigeria, present an opportunity to evaluate post-combustion capture as part of Nigeria's Nationally Determined Contribution commitments under the Paris Agreement. This study analyses the technical performance and economic viability of amine scrubbing post-combustion carbon capture retrofitted to a cement kiln flue gas stream in Sokoto State. Flue gas characterisation data from the target cement kiln were used to model a monoethanolamine-based absorption-regeneration system in Aspen Plus at two capture rates of 50% and 90% CO2 removal. Process simulation yielded energy demands, CO2 capture rates, solvent circulation rates, and regeneration duty for each scenario. Capital and operating costs were estimated using the IEAGHG cost methodology adjusted for Nigerian engineering and construction cost factors. The simulation predicted a specific reboiler duty of 3.8 GJ per tonne of CO2 captured at 90% capture efficiency. Levelised cost of capture was estimated at 78 USD per tonne of CO2 at 50% capture and 94 USD per tonne at 90% capture. Sensitivity analysis indicated that a carbon price of 45 USD per tonne would be required for economic viability under a government-supported carbon credit scheme. The study establishes the policy and investment framework requirements for cement sector carbon capture and storage in Nigeria. Keywords: carbon capture, post-combustion, cement plant, Sokoto State, amine scrubbing