Nitrogen and sulphur chemistry in pressurised flue gas systems: A comparison of modelling and experiments

► In pressurised flue gas systems NOx and SOx is absorbed in the water to form acids. ► The absorption of NOx and SOx could control emissions but could also damage process equipment. ► The absorption process is governed by the gas-phase oxidation of NO into NO2, whose reaction rate increases with pressure. ► The absorption of SO2 is enhanced by liquid-phase reactions between HNO2 and H2SO3 that increases the formation of H2SO4. ► Small amount of N2O may be formed in the liquid-phase reactions between HNO2 and H2SO3.