Energy Recovery by Incineration

In some countries, notably Japan, incineration is the major method of disposing of combustible waste products from domestic sources. Japan has over 5000 incinerators and most municipalities have their own installations. Until recently, there appeared to be little public protest about this disposal technique in Japan but recent reports have caused some concern about the environmental safety of incineration in heavily populated areas of Japan. Dioxin levels in the air are three times higher than in the USA and in some European countries. Perhaps more significantly, infant mortality rates are 40-70% higher downwind of Japanese incinerators than elsewhere and there is concern about the increase in dioxins in human milk. 

On ecological grounds it is also important that the heat produced by incineration of waste polymers (Table 4.3) should be used for the generation of power. It is increasingly evident that this should be carried out locally to reduce transport costs. Both heat and power should also be 

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The decomposition of waste polymer by means of chemical substances or heat and the decomposition products are monomers or mixture of compounds [25]. In chemical recycling, monomers are produced as a result of depolymerization or other secondary valuable materials are produced by partial degradation. Energy recovery by incineration is a successful way to decrease the volume of organic materials. 

The recycling of plastics waste is eonsidered with respect to energy recovery through incineration. It is claimed that burning solid municipal waste could produce nearly 10% of Europe s domestic electricity and heat and conserve resources by replacing, for example, over half of current coal imports to Western Europe. The potential for power from waste plastics and examples of energy from waste in action are described. 

In the former West Germany, energy recovery from incineration reduces the cost of waste disposal by 20% - 40%, in Sweden all municipal waste incinerators recover energy (ISWA, 1991), and in 1991, 137 incinerators in the USA (where approximately one sixth of municipal waste is incinerated) recovered energy. 

This paper introduces the Twin-Interchanging Fluidised Bed Incinerator (TIF) from EBARA Corp. of Japan, and describes a combustion test carried out by the company in collaboration with the Plastic Waste Management Institute, on waste plastic separated from municipal refuse, verifying the level of non-polluting combustion and high-efliciency energy recovery. The results of the test are presented, with considerations and conclusions. JAPAN... 

Both pyrolysis and gasification convert carbonaceous materials into energy-rich fuels by heating the feedstock under controlled conditions. Whereas incineration fully converts the input material into energy and ash, these processes deliberately limit the conversion so that combustion does not take place directly. Instead, they convert the material into valuable intermediates that can be further processed for materials recycling or energy recovery. 

By taking this approach, the benefits from recovering solvent versus incineration can be evaluated with greater confidence. Over time, robust models can be developed which show the life cycle energy and economic benefits of recovery versus incineration and provide an understanding of where the transition point for the process comes. 

The amount and rate of plastic waste and resource recovery is shown in Table 26.2 [5], Total plastic waste discharged reached 9900 000 t in 2002. The amount of municipal solid waste exceeded that of industrial waste in 2001 and the difference between them tends to increase. Although the amount of feedstock recycling reached 450 000 t in 2002, it still accounts for only 8.9% of municipal solid waste (MSW). Large amounts of waste plastics are treated by incineration with or without energy recovery both in MSW and industrial waste. 

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