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An installation where controlled combustion occurs under optimal conditions, that is, with a minimum temperature of 850 °C, a minimum 2 seconds permanence and oxygen turbulence of over 6 %. The waste is thus turned into slag, ashes and gases, with the minimum possible pollutant production and a significant reduction in the volume of the waste. Steam is produced with the heat of the process, which drives a turbine and generates electricity.
The municipal waste energy evaluation plants in service in Catalonia are municipal facilities with strict controls and regulations to ensure an operation that supposes no risk to the environment or people’s health. |
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Gases |
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The gases produced in the process are mainly carbon dioxide (CO2), water, nitrogen and the surplus oxygen used in the combustion. The rest of the gases (chlorine, hydrogen chloride, sulphur and nitrogen oxides and organic compounds) and the burnt particles are eliminated in the gas purification system in order to comply with environmental regulations, which guarantees that the process causes the least possible impact on the environment. |
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Decree 80/2002 |
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Slag |
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They account for between 20 and 25 % of the weight of the waste. They are the waste remaining in the kiln, such as ceramics, earth, glass, metal objects, etc. The scrap in the slag is recovered for evaluation, and may be between 1 and 3 % in weight of the burnt waste. The rest of the slag is evaluated when it can be used as filling material. Its evaluation is regulated by the Order of 15th February 1996. |
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Order of 15th February 1996 |
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Ash and purification solids |
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They account for between 2 and 6 % (ash) and 4-5 % (purification solids) of the weight of the waste. This is the waste formed by all fine powdery materials resulting from the thermal process of a kiln and which are gathered in heat reuse, gas cleaning and particle precipitator systems and are formed mainly by inorganic salts. They are hazardous wastes and must be placed in a controlled landfill. |
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Order of 15th February 1996 |
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