Evaluation of the Performance of Various Amine Based Solvents in an Optimized Multipurpose Technology Development Pilot Plant

Abstract

Abstract The overall goal of this work was to show experimentally using a CO 2 capture plant of reasonable capacity the contributions of plant and solvent optimization to minimizing the steam requirement. Experimental studies were conducted in an optimized CO 2 capture pilot plant to evaluate the performance of RS-1 solvent and 5 molar aqueous MEA. The first objective was to test a highly improved plant configuration that can minimize both the amine circulation rate and the steam requirements below the values reported in the literature for a desired CO 2 recovery. The second objective was to show the superior performance of RS-1 relative to 5 molar MEA. Both these strategies were aimed at reducing the steam requirement without increasing the size or complexity of the CO 2 capture plant. The pilot plant used for the tests was the highly optimized multi-purpose technology development plant at the International Test Center for CO 2 capture which processes 186 Nm 3 /h of flue gas to produce CO 2 with a nominal capacity of 1 tonne per day. This plant has 12-inch ID for the absorber and stripper columns. The inlet flue gas temperature was 40 ∘ C while the CO 2 concentrations in the flue gas were 4 and 8% based on exhaust gases obtained respectively from a natural gas turbine-natural gas boiler combination, and a natural gas boiler. The results show that for flue gas containing 4 and 8% CO 2 for a 90% recovery or absorber efficiency, the steam duties using our optimized plant configuration were respectively 2.03 and 1.43 kg steam/kg CO 2 for MEA as compared to industry and literature values based on conventional plant configuration in the range of 1.9 to 2.5 kg steam/kg CO 2 depending on the CO 2 concentration in the flue gas. When RS-1 solvent was used, the steam duties using the optimized plant configuration were respectively 1.74 and 1.35 kg steam/kg CO 2 which showed improvements over the corresponding performance of 5 molar MEA. It was interesting to observe that with a completely modified and optimized process configuration, the heat duty using RS-1 was 1 kg steam/kg CO 2 . These results show that in order to minimize steam requirements in a post combustion CO 2 capture amine plant, there is the need to optimize both the plant process configuration and the solvent.