NOx removal by selective noncatalytic reduction with urea solution in a fluidized bed reactor

Abstract

A fluidized bed reactor has been developed to overcome the plugging problem of urea injection by employing a sparger rather than nozzles in the SNCR process for simultaneous removal of SO2 and NOx. In a developed fluidized bed reactor, the optimum temperature to remove NOx is shifted to lower values, the reaction temperature window is widened with the presence of CO in flue gas, and NO conversion is higher than that in a flow reactor. The optimum amount of urea injection in the reactor is found to be above 1.2 based on the normalized stoichiometric molar ratio (NSR) with respect to NO conversion. In the simultaneous removal of SO2/NO, conversions of SO2 and NO reach 80–90%, nearly the same values for the individual removal of SO2 and NO above 850 ‡C.