Energy Efficient Solvents for CO2 Absorption from Flue Gas: Vapor Liquid Equilibrium and Pilot Plant Study

From solvent screening for new, amine based solvents for CO2 recovery from flue gas, two most promising solvent formulations, a 51 wt% New Solvent (NS) and a 26.7% AMP-11.9% HMDA mixture were selected and tested in an industrial pilot plant, mainly to identify the regeneration energy requirement. In the pilot plant tests CO2 absorption was done at 40 degrees C, 1.3 bar and regeneration at 120 degrees C, 2.0-2.2 bar, using both 5 and 10 vol% CO2 inlet concentration. At 90% CO2 recovery and optimized solvent circulation, the NS solvent was the most energy efficient, requiring only 2.48 and 2.26 MJ/kg CO2 for 5 and 10 vol% CO2 inlet concentration respectively, whereas the AMP-HMDA solvent required 3.62 and 3.41 MJ/kg CO2. Both solvents compare favorably to the 30wt% MEA reference measurements in the same pilot plant (4.80 resp. 4.33 MJ/kg CO2) showing the potential of these energy-efficient solvents. (C) 2013 The Authors. Published by Elsevier Ltd.