Bench Scale Carbon Dioxide Recovery from the Flue Gas by Monoethanolamine

Abstract

A bench scale unit (2 m3N/h) for removing CO2 from flue gas was operated. Based on a chemical absorption/regeneration process with aqueous monoethanolamine (MEA) solution, we have evaluated the energy requirement for regeneration and degree of CO2 removal as a function of reboiler temperature, MEA concentration, CO2 concentration in the flue gas and ratio of the flow rate of liquid and flue gas. For verification of the experimental results from the bench scale CO2 capture unit, we have also calculated the regeneration energy by the summation of the reaction enthalpy of CO2, the sensible heat and the heat of vaporization of MEA solution and have compared these results with those of bench scale tests. It was observed that the regeneration energy using a 30 wt% MEA solution was 4.29 GJ/ton CO2 (experiment) and 4.55 GJ/ton CO2 (estimation), respectively. Also, the degree of CO2 removal increases with an increase in reboiler temperature and ratio of the flow rate of liquid and flue gas, while CO2 regeneration energy decreases with an increase in MEA concentration and CO2 concentration in the flue gas.