In this paper an installation containing a negative corona discharge (DC) reactor, a pulse corona discharge reactor and a combined electron beam (EB) and microwave induced plasma reactor is presented. SO2 is removed up to 42% through spontaneous reaction with ammonia without EB or microwave irradiation at the temperature below 70 degrees C. Considering the values of the removal efficiencies of 98% for SO2 and 80% for NOx applying separate EB irradiation with a dose of 40 kGy, when the simultaneous EB and microwave irradiation is applied, the required absorbed dose is about two times smaller. The SO2 removal efficiency of simultaneous DC or positive discharge and microwave discharge is higher than separate corona discharge, pulse and microwave discharge. Also, the applied voltage level at which the removal efficiency reaches the maximum value is less than that for the separate application of corona discharge or pulse discharge. The NOx removal efficiency of DC or pulse discharge suffers little change by additional use of the microwave energy. Based on this research and the results obtained by a pilot project built in collaboration with Electrostatica Bucharest, a project for an installation involving simultaneous SO2 and NOx removal by irradiation with accelerated EBs and microwaves, has been proposed for Thermo-Power Plant CET-West-Bucharest of 550 MW. (c) 2007 Elsevier Ltd. All rights reserved.