Flue gas recirculation as a means of improving the solid waste incineration process

The burning of municipal waste as a means of waste removal has been carried out on a commercial scale in Western Europe for more than a hundred years. The development of incineration processes designed to utilize the energy contained in the waste was slow, but has gained considerable impetus in recent times because of current shortages of energy.

The following objectives are particularly important as regards the improvement and further development of waste incineration facilities: raising the level of energy efficiency; reducing harmful emissions; and increasing plant reliability essentially through the reduction of corrosion problems. It should be examined whether flue gas recirculation represents a suitable means for optimizing waste incineration. This involves ascertaining how flue gas recirculation, i.e. the return of a part of the flow of flue gases from the boiler outlet back into the combustion chamber, affects the energy balance of the entire process, the formation of harmful material, and the degree of damage caused by corrosion and erosion.

This first article reviews general recirculation experiences to date and their special application to municipal waste incineration. It also shows the possible effects of flue gas recirculation on waste incineration but without detailed data. Data will be published later.