The incineration of waste is an hygienic method of reducing its volume and weight which also reduces its potential to pollute. Not all wastes are suitable for combustion. Residues from incineration processes must still be landfilled, as must the non-combustible portion of the waste stream, so incineration alone cannot provide a disposal solution. Generating electricity or producing hot water or steam as a by-product of the incineration process has the dual advantages of displacing energy generated from finite fossil fuels and improving the economics of waste incineration, which is the most capital-intensive waste disposal option.
Incineration offers virtually a ten-fold reduction of the volume of waste to be disposed. However, capital and operating costs associated with incineration are extremely high and air pollution can result from emissions unless appropriate pollution control equipment is used.
In many countries incineration combined with energy production is more common than disposal in landfills and recycling. Japan incinerates 72% of its municipal solid waste, Belgium 25%, France 50%, Switzerland 59%, Denmark 90%, France 42% and Germany 36% (2002). In 1990, there were 135 mass burn plants in the USA, with another 53 under construction. Collectively they process 13% of the nation's municipal solid waste.