A Comparative Study on CO 2 Capture Efficiency Using Single and Blended Solvent

Absorption of CO 2 from flue gas using solvents has been considered an effective process although its commercial implication still requires rigorous study. In this work, detailed process flowsheets of monoethanolamine (MEA), diethanolamine (DEA), and chilled ammonia solvent systems were developed in Aspen Plus to determine the maximum CO 2 capture efficiency by varying process parameters. The effects of several process parameters, such as absorber stages, temperature, regeneration duty of the solvent, and blended solvents, were evaluated through sensitivity analyses. The results showed that 15 stages and 30 °C temperature in the absorber column resulted in the maximum CO 2 capture efficiency using alkanolamine (MEA and DEA) solvent, but a lower temperature (5 °C) was needed for the maximum CO 2 capture efficiency using chilled ammonia. Moreover, DEA had a 10% higher CO 2 absorption capacity and 38% lower regeneration duty compared to MEA. CO 2 capture with chilled ammonia needed the highest solvent flow rate and regeneration duty. In the case of blended solvent, DEA with 5% of other solvent such as methyl diethanolamine (MDEA), 2-amino-2-methyl-1-propanol (AMP), and piperazine (PZ) showed the highest CO 2 capture efficiency with minimum solvent loss.