Waste to energy uses trash as a fuel for power generation. Gasification converts any carbon-containing material into a synthesis gas (syngas). The syngas is a combustible gas mixture, sometimes known as ‘producer gas’, typically contains carbon monoxide, hydrogen, nitrogen, carbon dioxide and methane. The syngas has a relatively low calorific value, ranging from 100 to 300 BTU/SCF. The syngas can be used as a fuel to generate electricity or steam. Alternatively, it can be used as a basic chemical building block for a large number of applications in the petrochemical and refining industries. The overall thermal efficiency of gasification process is more than 75%. Gasification can accommodate a wide variety of gaseous, liquid, and solid feed stocks and it has been widely used in commercial applications for more than 50 years in the production of fuels and chemicals. Conventional fuels such as coal and oil, as well as low- or negative-value materials and wastes such as petroleum coke, heavy refinery residuals, secondary oil-bearing refinery materials, municipal sewage sludge, hydrocarbon contaminated soils, and chlorinated hydrocarbon byproducts have all been used successfully in gasification operations.
The chemical reactions in gasification process take place in the presence of steam in an oxygen-lean,reducing atmosphere. The ratio of oxygen molecules to carbon molecules is far less than one in the gasification reactor.
A portion of the fuel undergoes partial oxidation by precisely controlling the amount of oxygen fed to the gasifier. The heat released in the first reaction provides the necessary energy for the other gasification reaction to proceed very rapidly. In the Turn W2E™ system, gasification temperatures and pressures within the refractory-lined reactor typically range from 800 Deg C to 1200 Deg C and near atmospheric pressure to few inches of water respectively.