FGD system retrofit of the Dalhousie Station Units 1&2, an Orimulsion conversion

The Dalhousie Thermal Station is an electric generating station owned and operated by New Brunswick Power. The station consists of two boiler units, Unit 1 having a capacity of 100 MW and Unit 2 having a capacity of 215 MW. Both units were converted to burn Orimulsion{trademark} due to the economics of the fuel. Unit 1 returned to service in August, 1994, while Unit 2 returned to service in September, 1994 burning the new fuel. In order to comply with Canadian National Government through Environment Canada emissions standards, New Brunswick Power decided to install a flue gas desulfurization (FGD) system consisting of a single 315 MW absorber module utilizing limestone forced oxidation (LSFO) technology. The unit is designed to generate a marketable grade gypsum product. This paper describes Orimulsion{trademark} and the modifications required to convert the Dalhousie station to Orimulsion{trademark} firing. The FGD system is described and the philosophy used to ensure high reliability in the system is discussed. Commissioning and operational performance results are also presented.