Conversion of an Oil/Gas-Fired Industrial Boiler to Fire Hogged Fuel

The rising costs of oil and gas make waste wood an attractive fuel for industrial boilers. However, the boiler modifications necessary to fire wood are substantial. Emissions of pollutants, particularly particulate matter, must also be considered, including their effects on boiler operation and compliance with emissions regulations. This paper discusses the conversion of an oil/gas-fired industrial boiler to fire wood in a metropolitan area with stringent emission control regulations. Several alternatives were evaluated, including direct suspension firing, fluidized bed combustion, gasification and a two-stage gasifier/burner. The two-stage gasifier/burner was selected as the most desirable for this application. A field test of a 45 x 10^ Btu/hr two-stage gasifier/burner was conducted to evaluate efficiency, operability and emissions. The test results showed that the unit could achieve emissions less than the regulated levels in the metropolitan area. Modification of the boiler is now in progress.