WASTE TYPES MUNICIPAL SOLID WASTE

INCINERATION

The incineration of MSW essentially involves combustion of waste leading to volume reduction and recovery of heat to produce steam that in turn produces power through steam turbines basically, it is a furnace for burning waste and converts MSW into ash, gaseous and particulate emissions and heat energy. The efficiency of the technology is linked to the waste characteristics and their properties such as moisture content and calorific values. When the waste is dry, it may not need any auxiliary fuel except for start-up but when it is rich in inert and moisture content, supplementary fuel may be needed to sustain combustion, adversely affecting net energy recovery. The combustion process involves essentially, drying, volatilization, and ignition and desirably, elimination of odors, and combustion of unburned furnace gases and carbon suspended in the gases. It requires high temperature of the order of 800-1000oC and sufficient air and mixing of gas stream. The minimum temperature for burning carbonaceous wastes to avoid release of smoke and prevent emissions of dioxins and furans is 850oC. In order to ensure proper breakdown of organic toxins, this temperature should be maintained at least for 2 minutes. For steam generation and energy recovery, the combustion temperature should be 1400oC. This will also ensure degradation of all organic compounds. Depending on the nature of wastes and the operating characteristics of combustion reactor, the gaseous products derived from the combustion of MSW may include carbon dioxide (CO2), water (H2O, flue gas), oxygen (O2), nitrogen oxides (NOx), sulphur dioxide (SO2) and small amounts of hydrogen chloride, mercury, lead, arsenic, cadmium, dioxins and furans, and organic compounds. The combustion residues include bottom ash, fly ash and non-combusted organic and inorganic materials. Modern incinerators include pollution mitigation equipment such as flue gas cleaning and in such versions, sludge from scrubber and waste water adds to the contaminants in lieu of polluted emissions. There are various types of incinerator plant design: moving grate, fixed grate, rotary-kiln, fluidized bed. The typical incineration plant for municipal solid waste is a moving grate incinerator.

Waste Incineration plants are composed of several units that have specific tasks, and together they recover the energetic content of Municipal Solid Waste.

The units are:

  • Waste bunkar : Holds the waste and is the part where the plant operator can pick up, sort the waste and feed the incinerator using a crank.
  • Feeding Unit : Pre-dries the waste and feeds the incinerator.
  • Furnace : Incinerates the waste and destroys the organic component at temperatures above 800 degrees Celsius; ash and metals are recovered.
  • Boiler : Utilizes the heat from the burning waste to superheat the water pipes.
  • Energy Genration : The superheated steam is piped to a turbine generator to generate electricity.
  • Flue Gas Cleaning : Remove solid and gaseous pollutants from the gas before releasing through the stack

 

Reports and Research Paper 

World Bank Technical Paper 462 – Municipal solid waste incineration (requirement for successful project)
http://books.google.co.in/books

Urban Solid Waste Management: Waste Reduction in Developing Nations 

http://www.cee.mtu.edu/sustainable_engineering/resources/technical/Waste_reduction_and_incineration_FINAL.pdf 

Development of Municipal Solid Waste Incineration Waste_Portal2/Technologies
http://www.seas.columbia.edu/earth/wtert/sofos/Li_Development%20of%20MSW%20technology%20in%20China.pdf


Municipal Solid Waste Incineration-A decision maker Guide 
http://www.eawag.ch/organisation/abteilungen/sandec/publikationen/publications_swm/downloads_swm/incineration-dmg.pdf

 

Links for incineration

 

Pdf's for incineration

 

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National Solid Waste Association of India (NSWAI) is the only leading professional non-profit organisation in the fields of Solid Waste Management of India.