ABSTRACT
This chapter discusses characteristics of the co-products and sludge, design of the systems that feed the streams into the boilers, environmental factors, and cost savings associated with the process. Whereas the coal-fired incineration of residue required no additional natural gas usage, the gas-fired option required gas consumption for the pilot flame and pre-heatup for each startup. The incineration of liquid flammable wastes and biological sludge in coal-fired boilers has been successfully demonstrated as a method of disposal at Monsanto's Nitro, West Virginia, plant. From a safety standpoint, burning residue in the gas-fired boilers increased the chance of a flameout which could cause an explosion or a smoke and/or chemical emission. The advantage of the recovered heat value was outweighed by the disadvantage of high cost, having another system to man and operate, and the potential for refractory, slagging, and salt caking problems.
