Computational fluid dynamics simulation on oxy-fuel combustion performance of a multiple-burner furnace firing coking dry gas

•Oxy-fuel combustion characteristics of coking dry gas were investigated.•The varying oxygen content causes great differences in CO2 and H2O content.•The rise in O2 purity and excess oxygen ratio conduce to the enrichment of CO2.•The CO2 content rises by 14% as the dehydration efficiency increases to 0.95. In heat production and power generation utilizing carbon-based fuels, oxy-fuel combustion is regarded as a potential method for carbon capture and sequestration. However, few studies, if any, have been performed on the impacts of exhaust dehydration efficiency and oxygen purity on the parameters of oxy-fuel combustion. In the current study, based on the experimental data, the oxy-fuel combustion characteristics of coking dry gas (CDG) in a gas-fired furnace were investigated using the computational fluid dynamics approach. The simulation results illustrate that the CO2 concentration in the flue gas could rise by nearly 14% as the dehydration efficiency increases from 0.60 to 0.95. The contents of CO2 elevate with the oxygen purity, while H2O and N2 show an opposite trend. Within the scope of the present study, an O2 content of 32% and an excess oxygen ratio of 1.1 are recommended given the combustion performance and economic issue. Due to the impacts of combustion performance, cost of ASU, CO2 enrichment, and so on, the selection of oxygen purity needs to be considered comprehensively. The content of N2 declines with the increase of the dehydration efficiency, which benefits the enrichment of CO2. The present work contributes to the clean and efficient utilization of combustible exhaust gas and provides further knowledge on green and low-carbon development.