What is waste to energy?

Reduction in the volume and mass of solid waste is a crucial issue especially in the light of limited availability of final disposal sites in many parts of the world. Millions of tonnes of waste are generated each year with the vast majority disposed of in open fields or burnt.

The term “waste-to-energy” has traditionally referred to the practice of incineration of garbage. Today, a new generation of waste-to-energy technologies is emerging which hold the potential to create renewable energy from waste matter, including municipal solid waste, industrial waste, agricultural waste, and industrial byproducts.

Waste feedstocks can include municipal solid waste (MSW); agricultural waste, such as crop silage and livestock manure; industrial waste from manufacturer, lumber mills, or other facilities. Advanced waste-to-energy technologies can be used to produce biogas (methane and carbon dioxide), syngas (hydrogen and carbon monoxide), liquid biofuels (ethanol, biodiesel and advanced biofuel), or pure hydrogen; these fuels can then be converted into electricity.

A host of technologies are available for realizing the energy potential of wastes, ranging from very simple systems for disposing of dry waste to more complex technologies capable of dealing with large amounts of industrial waste. Conversion routes for wastes are generally thermo-chemical or bio-chemical, but may also include chemical and physical. The last generation innovative technologies, besides recovery of substantial energy, can lead to a substantial reduction in the overall waste quantities requiring final disposal, which can be better managed for safe disposal in a controlled manner while meeting the pollution control standards.