A hybrid membrane-absorption process for carbon dioxide capture: Effect of different alkanolamine on energy consumption

Abstract

Amine and membrane based process are commonly used to treat acid gases such as carbon dioxide and hydrogen sulfide. Carbon dioxide adversely affect the environment therefore, its utilization and storage are critical. In this work, a simplistic approach of single stage membrane unit combine with amine absorption processes with different commercial amines were investigated. Increase in CO2 concentration in the feed gas, results in substantial increase in the thermal energy consumption of the stripper reboiler, where using hybrid amine-membrane setup can effectively reduce energy consumed in reboiler. Both amine absorption process and membrane process are simulated using Aspen HYSYS V10. Since, membrane is not available in Aspen HYSYS V10 unit operation package, it is programmed and added as custom user operation. Moreover, a new acid/ amine based fluid package builds in combination of Peng-Robinson equation of state for vapor phase and electrolyte non-random two liquid based activity model for liquid phase were used in this study. Furthermore, energy consumption in CO2 capture using different alkanolamine such as N-methyldiethanolamine (MDEA), monethanolamine (MEA), deithanolamine (DEA), piperazine (PZ), triethanolamine (TEA) are also studied. As membrane unit help in CO2 reduction in feed to amine absorption process in hybrid amine-membrane setup. This significantly reduces the energy requirement as compared to the conventional standalone alkanolamine process. In comparison with various amines used in amine absorption process, MEA offers the lowest total energy consumed, whereas, MDEA considered to be the highest in terms of energy consumption.