DESCRIPTION OF WASTE TO ENERGY (WTE) PROCESS
WtE is a form of energy recovery. It consists on generating energy in the form of electricity or heat by using waste as oil source. As indicated by its name, WtE process contains two aspects: Waste and Energy and to describe this process one has to treat each one of these aspects.
WHAT DOES MUNICIPAL SOLID WASTE MEAN? Municipal Solid Waste (MSW), commonly known as trash or garbage, refers to common household waste, as well as office and retail wastes for which the collection is performed by the Municipality within a given area. MSW includes wastes such as durable goods (tires, furniture, ..); nondurable goods (newspapers, plastic plates/cups, ..); containers and packaging (milk cartons, plastic wrap, ..); and other kind of waste (yard waste, food, ..), but excludes industrial, agricultural hazardous, and construction wastes,..
WHAT DOES WASTE TO ENERGY (WTE) MEAN?
Waste-to-energy (WtE) is the process of creating energy in the form of electricity or heat from waste source. WtE is a form of energy recovery.
Most WtE processes produce electricity directly through combustion, or produce a combustible fuel commodity, such as methane, methanol, ethanol or synthetic fuels.
WtE plants, also called MSW power plants, are designed to dispose of MSW and to produce electricity and/or heat as a byproduct of the incinerator operation. Electricity can be produced by burning MSW as a fuel.
There are currently two main WtE facility designs: Mass Burn is the most common WtE technology, in which MSW is combusted directly in much the same way as fossil fuels are used in other direct combustion technologies. Burning MSW converts water to steam to drive a turbine connected to an electricity generator. Refuse-derived fuel (RDF) facilities process the MSW prior to direct combustion. The level of pre-combustion processing varies among facilities, but generally involves shredding of the MSW and removal of metals and other bulky items. The shredded MSW is then used as fuel in the same manner as at mass burn plants. There are also a number of other new and emerging technologies that are able to produce energy from waste and other fuels without direct combustion. These technologies are classified as follows: Thermal technologies: Gasification (produces combustible gas, hydrogen, synthetic fuels) Thermal depolymerization (produces synthetic crude oil, which can be further refined) Pyrolysis (produces combustible tar/bio oil 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)