Impurity impacts on the purification process in oxy-fuel combustion based CO 2 capture and storage system

Abstract

Based on the requirements of CO 2 transportation and storage, non-condensable gases, such as O 2, N 2 and Ar should be removed from the CO 2-stream captured from an oxy-fuel combustion process. For a purification process, impurities have great impacts on the design, operation and optimization through their impacts on the thermodynamic properties of CO 2-streams. Study results show that the increments of impurities will make the energy consumption of purification increase; and make CO 2 purity of separation product and CO 2 recovery rate decrease. In addition, under the same operating conditions, energy consumptions have different sensitivities to the variation of the impurity mole fraction of feed fluids. The isothermal compression work is more sensitive to the variation of SO 2; while the isentropic compression work is more sensitive to the variation of Ar. In the flash system, the energy consumption of condensation in is more sensitive to the variation of Ar; but in the distillation system, the energy consumption of condensation is more sensitive to the variation of SO 2, and CO 2 purity of separation is more sensitive to the variation of SO 2.