SMALL INCINERATION PLANT FOR PLASTIC WASTE AND OTHER ORGANIC MATERIALS
THE WASTE PROCESSING PLANT
With the aid of the newly developed thermal waste material utilisation plant, organic waste materials such as wood, plastics, harvest residues and forest waste can be incinerated and subsequently converted into superheated steam or electrical energy.
The resulting flue gases are purified and the required process water is treated or recycled.
THE PROBLEM
In 2019, approximately 350 million tons of plastic waste were generated worldwide. Of this, less than 25% was recycled or thermally used. The remainder was disposed of in the environment, where it is particularly harmful to the maritime life.
Due to the many advantages plastic has over other packaging materials, it cannot be assumed that the amount of plastic waste generated worldwide will decrease. With the exception of urban conurbations, most used plastics end up scattered and decentralised in the environment, so that conventional large-scale incineration plants cannot be operated economically in rural areas.
THE SOLUTION
The newly developed thermal waste processing plant was specially developed for the utilisation of organic waste materials such as wood, plastics and harvest residues.
Depending on the plant configuration, a wide variety of organic residues and types of plastics can be treated. If an appropriate flue gas cleaning system is used, polyvinyl chloride (PVC) can also be processed in the incineration plant.
In addition, harvest residues and forest waste can also be used, among other things, bagasse, coconut husks, dried fruit waste, etc. Depending on the type of plant, the electrical plant output varies between 100 kWel. and 3 MWel.
By using an absorption chiller, the unused waste heat can be converted into process cooling.
Process principle of the thermal waste utilisation plant for steam or electrical power generation presented in a highly simplified form
As this diagram shows, the waste utilisation plant is divided into four functional groups:
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Funktional group I:
Residual material storage for plastic waste, wood and residual materials from agriculture and forestry as well as residual material preparation with shredder and optional pelletisation
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Funktional group II:
Combustion plant for superheated steam generation
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Funktional group III:
Steam engine or steam turbine with generator for electrical power generation including cooling water system
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Funktional group IV:
Exhaust gas and process water purification plant
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Optional:
Use of an absorption refrigeration system with which unused waste heat can be converted into process refrigeration.
With the help of the waste utilisation plant, the use of fossil energy sources such as coal, crude oil and natural gas can be avoided. By abandoning the use of fossil energy sources, the desired sustainable climate targets can be supported.
Optionally, the unused thermal energy can be used for cooling buildings or for technical processes with the aid of an absorption refrigeration system.
In contrast to finite fossil resources, organic residues form a virtually inexhaustible reservoir of high-quality fuels with high energetic potential.
The waste utilisation plant is variable in terms of its electrical output. According to this fact, it can be adapted to municipalities or energy parks of different sizes.
The pre-sorted organic residues have a much higher calorific value than conventional household waste and are therefore particularly suitable for decentralised energy generation in the form of electricity, heating and process steam.
When the organic residues are incinerated, the process is controlled in such a way that strict environmental requirements are met. The minimum temperature in the combustion chamber is 850 ºC, which completely destroys potential pollutants such as dioxins and furans.
On request, possible nitrogen oxides can be converted into environmentally neutral nitrogen (N2) and water (H2O) by adding urea. A multi-stage exhaust gas purification system reduces dust, heavy metals and other pollutants to a minimum. Remaining slag can be recycled and used, for example, in road construction and landfill construction.
The waste water generated during exhaust gas cleaning is treated in a multi-stage cleaning process to such an extent that it can be reused as process water.
The conversion of organic waste materials produces valuable electrical power and thermal energy without the need to use expensive fossil fuels, see Technical Description "Conversion of Organic Waste Materials into Electric Power".
