Waste to energy or energy from waste

Waste to energy or energy from waste is the process of generating energy in the form of electricity and/or heat from the incineration of waste. WtE is a form of energy recovery. Most WtE processes produce electricity and/or heat directly through combustion, or produce a combustible fuel commodity, such as methanemethanolethanol or synthetic fuels.

There are a number of other new and emerging technologies that are able to produce energy from waste and other fuels without direct combustion. Many of these technologies have the potential to produce more electric power from the same amount of fuel than would be possible by direct combustion. This is mainly due to the separation of corrosive components (ash) from the converted fuel, thereby allowing higher combustion temperatures in e.g. boilers, gas turbines, internal combustion engines, fuel cells. Some are able to efficiently convert the energy into liquid or gaseous fuels:

Thermal technologies:

  • Gasification (produces combustible gas, hydrogen, synthetic fuels)
  • Thermal depolymerization (produces synthetic crude oil, which can be further refined)
  • Pyrolysis (produces combustible tar/biooil and chars)
  • Plasma arc gasification or plasma gasification process (PGP) (produces rich syngas including hydrogen and carbon monoxide usable for fuel cells or generating electricity to drive the plasma arch, usable vitrified silicate and metal ingots, salt and sulphur)
  • Non-thermal technologies:
  • Anaerobic digestion (Biogas rich in methane)
  • Fermentation production (examples are ethanol, lactic acid, hydrogen)
  • Mechanical biological treatment (MBT)
  1. MBT + Anaerobic digestion
  2. MBT to Refuse derived fuel

 

Reference

http://en.wikipedia.org/wiki/Waste-to-energy
http://www.sciencechannel.com/tv-shows/how-do-they-do-it