Cost and environmentally efficient design of an absorption-based post-combustion carbon capture unit for industry applications

Carbon capture and storage technologies are currently considered promising solutions to mitigate CO2 emissions of hard-to-abate industries. Among those, the cement industry accounts alone for around 6–7 % of the global anthropogenic CO2 emissions and necessitates the integration of carbon capture and storage to substantially reduce its CO2 emissions. This work focused on the design and analysis of a cost-efficient and low-emitting cement plant integrated with an absorption-based Post-Combustion Carbon Capture (PCCC) system using an aqueous water-amine solution. An innovative system layout is presented to minimize CO2 emissions and energy consumption. Furthermore, the sizing of the absorber and stripper of the PCCC unit was performed to minimize the cost of the avoided CO2. The environmental and economic performances of the overall process are evaluated under different boundary conditions, encompassing both gate-to-gate and cradle-to-gate perspectives. A reduction of the CO2 emissions of around 66–87 % was obtained, depending on the fuel used to produce the steam needed in the PCCC unit and the analysis boundary considered. The primary energy consumption per avoided CO2 was estimated at 5.5–7.3 MJ/kgCO2. The specific cost per avoided CO2 also varies with the fuel choice and the analysis boundary. Through the optimal sizing of the PCCC unit, costs of 56–57 €/tCO2 were obtained for the integration of carbon capture in the plant. When a cradle-to-gate boundary is considered, costs for CO2 transportation and storage need to be accounted for, and costs of equivalent avoided CO2 ranging from 74.5 €/tCO2 to 124 €/tCO2 are estimated, depending on the transportation and storage scenario considered.