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%.