Development of technology higher performance

This preview shows page 33 - 35 out of 53 pages.

development of technology, higher performance requirements and greater demands on electrical andelectronic equipment make their replacement ever more frequent. This situation leads to a continualincrease in the number of electronic and electrical devices in our garbage.The average composition of WEEE is shown in Figure 13. Approximately 30 wt. % of WEEE areplastics. Those plastics consist of a wide range of polymers such as acrylonitrile butadiene styrene,polypropylene, polystyrene, polycarbonate, styrene acrylonitrile, polyamide, high impact polystyrene,polyethylene terephthalate, polyethylene, polyvinyl chloride etc. [152]. Additionally, printed circuitboard is a major constituent of discarded electronic scraps and it accounts for circa 30% of the totalelectronic scrap generated. Due to the heterogeneous mix of organic material, metal and glass fibre,printed circuit board waste is particularly very problematic to recycle [154]. Printed circuit boards areone of the main parts of electrical and electronic equipment. They are classified as FR-4 or FR-2according to their use. The FR-4 type is composed of a multilayer of epoxy resin, fiberglass coatedwith a copper layer. The FR-2 type is a single layer of fiberglass or cellulose paper and phenoliccoated with the copper layer. The FR-4 type is used in small devices such as mobile phones and FR-2type is used in televisions and personal computers or other household appliances [155].Figure 13. The composition of WEEE[156]The pyrolysis of waste plastics from electric and electronic equipment and PCBs has beeninvestigated several times [152,154,157,158]. However, the studies usually cover thethermogravimetric and kinetic analysis. Information about the composition of products and theirpossible uses is limited.In 2015Muhammad et al.[152] investigated the pyrolysis of waste plastics from WEEE. Theyfocused on high impact polystyrene, which appears mainly in waste cathode ray tubes andacrylonitrile-butadiene-styrene from waste refrigerators. Both of them have high a bromine content,because of the high content of brominated flame retardant added to those plastics. More than 80 wt. %of oil was obtained in both cases. The oils ware dominated by single ring aromatic compounds withlower concentrations of polycyclic aromatic hydrocarbons (PAH). In oil from waste refrigeratorsPlastics30%Copper20%Iron8%Tin4%Nickel2%Lead2%Aluminum2%Others2%Refractoryoxides30%WEEE composition
about 50 wt. % was styrene; toluene and ethylbenzene were slightly more than 10 wt. %. However,pyrolysis of pure acrylonitrile-butadiene-styrene resulted in a lower styrene concentration and higherbenzene and toluene concentrations in the oil. A comparison of the pyrolysis of raw high impactpolystyrene and acrylonitrile-butadiene-styrene with the WEEE plastics results suggested that theWEEE plastics consisted mostly, but not exclusively, of plastics mentioned above.

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 53 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Fall
Professor
NoProfessor
Tags
The Land, Waste, Biodegradable waste, MSW, Pyrolysis

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture