Techno-economic Analysis of Carbon Capture at an Aluminum Production Plant – Comparison of Post-combustion Capture Using MEA and Ammonia

Paper in proceeding, 2014

Two absorbents, ammonia and MEA, have been evaluated for post-combustion capture of carbon dioxide at an aluminum manufacturing plant with respect to technical and economic performance. Process simulations combined with advanced thermodynamic models are used to model the process performance. A detailed economical estimation has been made for both ammonia and MEA-based post combustion capture as a function of flue gas CO2 concentration. The two processes have been compared with respect to the specific capture cost (€/tCO2 captured). The results show that the ammonia-based process is the most cost efficient at high flue gas CO2 concentrations (7-10%) with a cost of 74-82 €/tCO2 and the MEA-based process is the most cost efficient option at low flue gas CO2 concentrations (3-4%) with a cost of 93-97 €/tCO2. A heat integration analysis reveals that up to 50% of the heat requirement can be covered with excess heat from the aluminum manufacturing plant, which potentially could reduce the capture cost with 10-15 €/tCO2.