Results of the fibec test program at Canadian forces base St. Hubert

Abstract

As part of the national management plan for NOx control, Environment Canada has drafted emissions regulations for industrial boilers, based on best available technology economically achievable. National Defence Canada, as a major boiler owner, has undertaken to demonstrate low-NO x burners in two plants. One is fuelled by natural gas with No. 2 fuel oil backup and one is fuelled by Bunker "C" oil with No. 2 oil backup. This report describes the results of combustion tests on the first demonstration - a boiler at CFB St. Hubert which has been retrofitted with a dual-fuel (natural gas and No. 2 fuel oil) burner employing flue gas recirculation (FGR). Tests were conducted with both fuels with and without flue gas recirculation over the load range of the boiler. Both efficiency and emissions were measured. It was found that FGR reduces NO x b y 50% when firing natural gas, and 20 to 25% when firing No. 2 fuel oil. With natural gas , NO x e missions were within the limits of the draft regulations with FGR but exceeded limits without FGR. With No. 2 oil, NO x e missions were within the draft regulations only at low loads; below 40 % Maximum Capacity Rating (MCR) with FGR, below 30% MCR without FGR. CO emissions were well below the limit for both fuels, but SO2 emissions were several times the limit when firing No. 2 fuel oil.