Kinetics of NOx Absorption into (NH4)2SO3 Solution in an Ammonia-Based Wet Flue Gas Desulfurization Process

The mass transfer and kinetics of NOx absorption into (NH4)(2)SO3 solution, the main compound of an ammonia-based wet flue gas desulfurization process, have been investigated in a double-stirred reactor Under the experimental conditions, the gas-liquid reaction between NOx and the (NH4)(2)SO3 solution without O-2 coexisting is controlled mainly by the gas film because the (NH4)(2)SO3 concentration is higher than 0 05 mol/L In this case, the absorption rate of NOx is found to be zero-order with respect to the (NH4)(2)SO3 concentration The inlet partial pressure and the oxidation degree (Phi = NO2/NOx) have an apparent effect on the absorption rate of NOx. In this research, a simplified mathematical calculated model is applied to the simulation of the absorption process The experimental results demonstrate that the orders of the reaction with respect to the concentration of NOx (NO2* or NO*) in the gas phase and the reaction rate constants of NOx (NO2* or NO*) with (NH4)(2)SO3 are all a function of the oxidation degree A kinetic equation for total NOx absorption as a function of the oxidation degree can be obtained, and the calculated value fits the experimental data well