Viability of the Cocapture of CO₂ and Impurities from Oxy-Fuel Combustion and Other Processes in Carbon Capture and Storage Technology

The feasibility of cocapturing CO₂ with SO₂, CO, and (O₂ or NO) from unpurified flue gas produced by oxy-fuel combustion and other processes was assessed by determining the influence of the simultaneous presence of these impurities on selected carbon capture and storage (CCS) operational parameters. These parameters were calculated based on experimental results obtained under CCS conditions. The density, vapor-liquid equilibrium, and speed of sound of [CO₂ + 3.0038 mol % O₂ + 0.09035 mol % SO₂ + 0.17032 mol % CO] and [CO₂ + 0.1410 mol % NO + 0.09100 mol % SO₂ + 0.17002 mol % CO] mixtures were experimentally determined at temperatures between 263 and 373 K and pressures of up to 30 MPa for density and 190 MPa for speed of sound. Joule-Thomson coefficients and isentropic compressibilities of the mixtures were calculated from our experimental results. Using experimental and calculated data, we assessed the predictive capability of the EOS-CG, GERG-2008, and PC-SAFT equations of state. The simultaneous presence of the investigated impurities at the studied concentrations adversely affects the transport and storage steps in CCS; however, the behavior of the NO-containing mixture is very similar to that of pure CO₂. The implications of the chemical effects of the impurities were overlooked.