Co-processing is the use of waste as raw material, or as a source of energy, or both to replace natural mineral resources (material recycling) and fossil fuels such as coal, petroleum and gas (energy recovery) in industrial processes, mainly in energy intensive industries (EII) such as cement, lime, steel, glass, and power generation. Waste materials used for Co-processing are referred to as alternative fuels and raw materials (AFR).
Co-processing contributes to the industrial competitiveness, is a complementary technology to concepts such as cleaner production or recycling and should be considered as a treatment alternative within an integrated waste management concept. Some EII offer co-processing as a sustainable waste management service. It is usually more cost effective to adapt existing facilities of EII than building new waste treatment capacities thereby reducing waste management cost to society.
The waste management hierarchy shows that Co-processing is a recovery activity which should be considered after waste prevention and recycling. Co-processing ranks higher in this hierarchy in comparison to disposal activities such as secured landfill or incineration.