Effect of the impurities O2 or NO present in non-purified flue gas from oxy-fuel combustion processes for carbon capture and storage technology

Abstract

CO2/impurities cocapture in CCS technology allows reducing the purification costs and avoiding the emission of pollutants into the atmosphere. The viability of the transport by pipeline and the geological storage of the non-purified flue gas from oxy-fuel combustion of biomass and other processes, keeping the impurities O2 or NO in the stream along with CO2, is assessed considering thermodynamic and hydraulic aspects. For this, we experimentally determined, under CCS conditions, the density, vapor-liquid equilibrium, and speed of sound of three CO2 + O2 and CO2 + NO mixtures as binary models of the gas, and we calculated their Joule-Thomson coefficients from the experimental data. Additionally, we compared the values calculated for the determined properties using the equations of state EOS-CG, GERG-2008 and PC-SAFT to our results of CO2 + O2, validating all three equations for this system. For the CO2 + NO mixtures, only PC-SAFT could be applied, which was also validated using the parameters obtained in this work. Finally, we calculated several selected CCS parameters from our data and concluded that both O2 and NO have negative effects on the transport and storage steps of this technology, which are negligible in the case of NO with the investigated concentrations.