Pilot Plant Studies of the CO₂ Capture Performance of Aqueous MEA and Mixed MEA/MDEA Solvents at the University of Regina CO₂ Capture Technology Development Plant and the Boundary Dam CO₂ Capture Demonstration Plant

Evaluations of the benefits of using a mixed MEA/MDEA solvent for CO 2 capture in terms of the heat requirement for solvent regeneration, lean and rich loadings, CO 2 production, and solvent stability were performed by comparing the performance of aqueous 5 kmol/m 3 MEA with that of an aqueous 4:1 molar ratio MEA/MDEA blend of 5 kmol/m 3 total amine concentration as a function of the operating time. The tests were performed using two pilot CO 2 capture plants of the International Test Centre for CO 2 Capture (ITC), which provided two different sources and compositions of flue gas. The University of Regina CO 2 plant (UR unit) processes flue gas from the combustion of natural gas while the Boundary Dam CO 2 plant (BD unit) processes flue gas from a coal-fired electric power station. The results show that a huge heat-duty reduction can be achieved by using a mixed MEA/MDEA solution instead of a single MEA solution in an industrial environment of a CO 2 capture plant. However, this benefit is dependent on whether the chemical stability of the solvent can be maintained.