Heat (Thermal) Treatment as a means of Waste Treatment and Disposal
(September 2005 update)
An Introduction to Heat Treatment
Although the adoption of any of the heat treatment process may be seen by some as "just another form of incineration by another name", heat treatment technologies are looking progressively more attractive due to the ability of some to potentially produce energy products which may in the future be targeted to specifically displace or replace premium fossil fuels.
There can be no question but that bio-waste combustion when referred to in all possible process incarnations can be both a minimum greenhouse gas (GHG) emissions option, and a substantially air pollution free choice, when systems are installed in accordance with the EU WID (Waste Incineration Directive).
Definitions
- Combustion: This process uses the waste biomass directly to generate thermal energy, which can in turn be used to provide process heat, space heat, or can be used in a boiler system with a turbine to drive a power cycle to generate electricity. Combined heat and power units will deliver both useful heat and electricity and achieve a high degree of conversion efficiency. Examples of combustion type processes are Mass Burn , Fluidised Bed and Co-incineration.
- Pyrolysis: This process produces a bio-oil liquid from which chemical products can be extracted, or which can be used as a transportation fuel or as a fuel for stationary engines. (More...)
- Gasification: This process partially combusts biomass to produce a mixture of gases often referred to as syngas. This syngas can in turn be refined to yield hydrogen, converted into methanol, converted into various other chemical products, or it can be used to displace or replace fossil fuels to generate power in an engine, turbine, or boiler. (More...)
- Autoclaving: A sterilisation process which by the heating of waste, usually with steam and under pressure, substantially eliminates disease vectors. In the context of heat treatment in the presence of plastic wastes in MSW, autoclaving reduces volume, and breaks down the structure of MSW, making it more readily treated by a subsequent processes.
Scope of Heat (Thermal) Treatment Technologies
To provide an excellent graphical introduction we can do no better than to add a flow diagram showing how the process options interrelate.
This diagram is taken from the report , "IDENTIFYING ENVIRONMENTALLY PREFERABLE USES FOR BIOMASS RESOURCES, STAGE 1 REPORT: Identification of Feedstock-to-Product Threads, Prepared for: Natural Resources Canada, Commission for Environmental Co-operation, National Research Council of Canada. The full report can be downloaded here.
Heat (thermal) treatment technologies discussed on this web site are: Mass Burn , Fluidised Bed ,Co-incineration, Pyrolysis, and Gasification.
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