Companies are continually searching for fuels less expensive
than coal, fuel oil, and gas. Natural sources such as manufacturing
and agricultural waste are inexpensive. Waste materials currently
being used as fuels include pulp mill liquor, sawdust, food processing
waste, municipal garbage, coal wash water coffee grounds,
cardboard, hog fuel (wet bark from plywood operations), and
bagasse (sugar cane after the liquid has been extracted). Using
industrial wastes as fuels can simplify the disposal process as well
as providing an inexpensive source of heat. Still, there are some
problems associated with burning any new fuel. The technology
for dealing with coal, gas, or fuel oil is well-known. Using a new
fuel, however, raises the following questions [1,48].