Waste incineration with energy recovery

Waste incineration with energy recovery, usually named Waste-to-Energy (WtE) is a widely applied technique in developed countries - especially in the European Union, Japan, and the USA. WtE plants process the Municipal Solid Waste (MSW) and similar wastes that remains after waste prevention, re-use and recycling.  WtE plants treat waste hygienically, reduce its volume by about 90%, and enable the recovery of energy contained in the waste through the generation of electricity and /or thermal energy (steam or hot water). The electricity is fed into the power grid to supply the end-users; depending on local infrastructure, the hot water can be used for District Energy network to heat (or cool) homes, hospitals, offices etc.; and the steam can be used by nearby industries for their production processes.

The choice of WtE needs to be developed within an integrated waste management approach and a clear framework for emissions control, to ensure adequate installation design, operation and quality control, in order to deliver the desired environmental performance [5] [13] (see, for example, the requirements laid down in the Industrial Emissions Directive of the European Union, under the section "Other resources").

Because many local governments have mandates for residential MSW collection/management but not necessarily for management of waste from other sources (including hazardous waste), this Solution purposefully focus on WtE of non-hazardous waste. It considers that separate collection of hazardous waste should take place upstream, since getting the equipment in place to treat hazardous waste would increase the capital and operational costs of the facilities [6], although technologies for the safe incineration of hazardous waste are available.

Motivation / Relevance

The proper implementation of WtE, under an adequate waste management and emissions control framework, although entails higher costs presents significant advantages when compared to landfilling. WtE avoids the loss of land use, substitutes fossil fuels through energy recovery from waste, allows recovery of valuable metals, and avoids production of landfill leachates, soil and groundwater contamination methane release into the atmosphere and waste of land.

The energy produced from the waste can help replace fossil fuels, such as gas, oil, hard coal and lignite, avoiding the greenhouse gas (GHG) emissions derived from their combustion. For example in Europe about 78 million tonnes of household and similar waste that remains after waste prevention, re-use and recycling, were treated in Waste-to-Energy plants in 2011. From this waste, 31 TWh of electricity and 78 TWh of heat  can be generated and, depending on the type of source, between 8 and 42 million tonnes of fossil fuels (gas, oil, hard coal and lignite) can be substituted annually, which would emit 21 - 42 million tonnes of CO2.[24]

The energy generated by WtE plants that treat MSW and similar waste is recognized as partly renewable (typically with a share of 50% [8][15] in Europe, depending on the biogenic content of the waste input), and contributes to the targets of producing more renewable energy.

This solution is particularly suitable for large cities lacking wide areas to place landfill sites, since it contributes greatly to waste volume reduction.

Main impacts

  • Reduce the consumption of fossil fuels for energy purposes
  • Contribution to energy independence through production of local, reliable and partly renewable energy
  • Avoided land-use conversion for landfill waste disposal (extended useful-life of the sanitary landfills which integrate the Municipal Solid Waste management system)
  • Creation of a long-term waste sorting and treatment strategy as requirement
  • Climate change mitigation

Benefits and Co-Benefits

  • Pollutant sink - pollutants are destroyed and/or captured to provide for an overall reduction in the environmental impact that might otherwise arise from the waste
  • Hygienic waste treatment that destroys germs and bacteria
  • Significant waste volume reduction
  • Recovery of energy for heat and electricity production
  • Revenue for local governments by selling electricity to the national grid [5] and heat to industry/district heating networks;
  • Creation of jobs for construction, operation and maintenance
  • Reduction of methane emissions from MSW landfilling
  • Avoided land use consumption for MSW landfilling
  • Metal recovery from bottom ash, for recycling
  • Production of alternative aggregates for road construction and similar civil works from bottom ash