Plastic wastes Subject

The research on the liquefaction of waste polymers and the coprocessing of waste plastics with vacuum residue or coal has been a subject of study by many groups at universities and environmental agencies. A significant amount of effort and funds are being diverted to develop process technology in order to convert mixed plastics waste from municipal... 

Mixing carbon with microwave-transparent materials, particularly plastics, and subjecting the mix to microwave radiation, is a very efficient way to heat up such materials, increasing their bulk temperature to a point where pyrolysis occurs. In this chapter the main characteristics of a number of microwave pyrolysis processes, for plastics and other materials, have been introduced, showing that these processes combine the advantages of microwave heating with the commercial and environmental opportunities intrinsic to the pyrolysis of wastes. 

Already having this subject in mind as a common understanding in the plastic industries, respective plastic companies are conducting various studies for the collection and re-utilization of the plastic wastes. 

The plastic waste products are subject to photodegradation, which causes the plastic waste products to degrade into small toxic plastic polymers. In the course of time, the plastic polymers are broken down into smaller and smaller pieces. However, the polymers do not decompose into materials found in nature. These small... 

Hydrogenation technologies are not that widely used in waste management. It is usually a two-stage process where plastic waste is first subjected to mild cracking by low-temperature pyrolysis and the condensable product is reacted with hydrogen... 

Until recently 96% of all discarded electrical and electronic equipment in Europe was landfilled. This amounted to about 14 kg of equipment per inhabitant every year, and the practice is now to be banned. All post-consumer electrical and electronic products will have to be collected and subjected to specific disposal procedures. The WEEE Directive (2002/96/EC) (February 2003) requires the manufacturers of electrical and electronic equipment appliances to bear the cost of recovery and recycling. It is intended to ensure the recovery of 300,000 tonnes of electrical and electronic plastics waste material per year by 2006, the date by which each member state should be collecting 4 kg per inhabitant by separate collection procedures. 

Plastics waste recovery, with the exception of PET, from the waste stream is to be made compulsory. Plastics waste is subjected to a series of sensors that sort the type and colour further inspection ensures no PVC contamination. 

Plastics waste arises from everyday activities of human existence in residential areas or commercial and industrial centres. The entire generation of plastics waste is subject to value judgment, i.e., when industry or consumers decide to dispose of a plastic item. The critical factors to consider in making projections of future plastics waste quantities are ... 

Unlike the well researched subject of the stabilisation of PVC, only a few researchers have investigated the dehalogenation of plastic waste. The studies which have been performed [2] have come up with the following results ... 

Mixed plastics wastes from packaging refuse are recycled by different technologies depending on technological, economical and also subjective factors. In principle the main procedures of plastics recycling can be classified into the following groups ... 

Many fields of expertise are necessary for the understanding of problems involved in the value recovery from plastics waste, either as materials, chemicals or energy. For these reasons contributions are required from chemists, physicists, engineers as well as polymer and materials scientists. Due to the dimension of the subject, the participation of the environmental, legal and economic experts is also of paramount importance. 

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