Study on enhancement mechanism of NO absorption in K2FeO4 solution basing on mass transfer-reaction theory

Abstract

A study on enhancement mechanism of NO absorption using ferrate (VI) (K2FeO4) solution in a bubbling reactor basing on mass transfer-reaction kinetic theory was carried out for the first time. Influencing factors and mass transfer-reaction process of NO absorption were analyzed. The interrelation between mass transfer and chemical reaction was revealed. The key mass transfer and kinetic parameters were determined. The mass transfer-reaction kinetic rate equation (model) was also established. The results reveal that increasing K2FeO4 concentration, NO concentration and solution pH increases NO absorption rate, but increasing SO2 concentration reduces NO absorption rate. The total reaction is a pseudo-2.3 order reaction (CFeO42−≤0.2 mol/L) and a pseudo-1.26 order reaction (CFeO42−>0.2 mol/L). NO removal reaction is a rapid reaction, and NO absorption rate mainly depends on gas phase mass transfer coefficient, interfacial area and chemical reaction rate. The reactors with a large gas–liquid contact area will be more suitable for enhancing the absorption of NO in ferrate (VI) (K2FeO4) solution. The established NO absorption rate equation has a good agreement with the experimental values.