Experimental analysis of CO/H2 syngas with NOx and SOx reactions in pressurized oxy-fuel combustion

A pressurized oxy-fuel combustion system is a technology for carbon capture and storage with a low efficiency penalty. In this study, the characteristics of combustion, heat transfer, and NOx/SOx emissions at various pressures were investigated using a lab-scale pressurized oxy-fuel combustion system. A gaseous fuel, composed of CO and H-2 , and pure oxygen were considered. The internal flue gas recirculation was induced by the inner wall to control the high oxy-flame temperature. The total heat recovery rate determined using the water jacket is 3% higher at 10 barg compared with atmospheric conditions, although the combustion temperature is lower. The heat flow rate increased by a higher H2O fraction in flue gas because the emissivity of H2O is higher than that of CO2. Under the condition of low H2O in flue gas, NOx and SOx simultaneously decreased, by approximately 50% and 63% at 10 barg, respectively. The concentrations of NOx and SOx with a higher H2O contents condition in flue gas decreased by 87% and 93% respectively at 10 barg, compared with atmospheric conditions. The effects of H radicals and the H2O fraction on the NOx and SOx oxidation and decrease were identified. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This study investigated the combustion characteristics and NOx/SOx emissions at different pressures using a lab-scale pressurized oxy-fuel combustion system. Higher pressure resulted in increased heat recovery rate, lower combustion temperature, and higher heat flow rate with higher H2O content in flue gas. NOx and SOx emissions decreased under low H2O conditions in flue gas, and significantly decreased under high H2O conditions at 10 barg. The study identified the effects of H radicals and H2O fraction on the oxidation and decrease of NOx and SOx.