Corrosion and Deposits From Combustion of Solid Waste—Part IV: Combined Firing of Refuse and Coal

Abstract

Combined firing of processed municipal refuse with coal has been investigated in a stoker-fired boiler. The refuse preparation consisted of shredding, magnetic separation of metals, and air classification. The nature of the deposits and the extent of corrosion of simulated boiler tube surfaces was determined by inserting probes into the boiler. For amounts of refuse up to 35 percent on a heating value basis, the corrosion rate of carbon steels was reduced substantially below that found from previous measurements for refuse alone, and below that calculated on the basis of dilution by the coal. The temperature of the boiler flue gases also was found to be an important factor in corrosion. The emissions of sulfur oxides from high sulfur coal were reduced by the action of the alkaline components of the refuse.