Investigation into Optimal CO₂ Concentration for CO₂ Capture from Aluminium Production

Capture of CO₂ from aluminum production has been simulated using Aspen Plus and Aspen Hysys. The technology used for aluminum production is the Hall-Héroult and the current cell design necessitates that large amounts of false air is supplied to the cells. This results in a CO₂ concentration in the process gas at around 1 vol%, which is considered uneconomical for CO₂ capture. Therefore, the aim of this investigation is to evaluate the CO₂ capture from aluminum production when the process gas CO₂ concentration is increased to 4, 7 and 10 vol%. Generic MEA based CO₂ capture models have been built-up in Aspen Plus and Aspen Hysys. Based on the results from the simulations with the current assumptions, the overall recommendation is to increase the CO₂ concentration to 4 vol%.