Valorization of Printed Circuit Boards from Waste Electrical and Electronic Equipment by Pyrolysis

Williams, Paul T.

doi:10.1007/s12649-009-9003-0

Cited by 61 publications

(19 citation statements)

References 68 publications

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“…biphenyl and triphenylene), as well as methylated benzofurans and naphthalenes. The emitted phenol compound had the highest yield in the PCBs pyrolysis (Williams, 2010) because it is present in the epoxy resin.…”

Section: (Figure 4)mentioning

confidence: 99%

Emissions of brominated compounds and polycyclic aromatic hydrocarbons during pyrolysis of E-waste debrominated in subcritical water

2017

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Degradation of brominated flame retardants present in printed circuit boards (PCBs) was tested using subcritical water in a high pressure reactor. Debromination experiments were carried out in a batch stirred reactor at three different temperatures (225 ºC, 250 ºC and 275 ºC) keeping a solid to liquid (S/L) ratio of PCB:water=1:5 during 180 min. Results indicated that debromination efficiency was increased with temperature (18.5 to 63.6% of bromine present in the original PCB was removed).Thermal decomposition of the debrominated materials was studied and compared with that of the original PCB. Thermogravimetric analyses were performed at three different heating rates (5, 10 and 20 K min -1 ), studying both the pyrolysis (inert atmosphere) and combustion (in air). Pyrolysis runs of the debrominated materials were also performed in a quartz horizontal laboratory furnace at 850 ºC, in order to study the emission of pollutants. More than 99% of the bromine was emitted in the form of HBr and Br 2 . Emissions of polycyclic aromatic hydrocarbons (PAHs) and bromophenols (BrPhs) decreased with the increase in the treatment temperature; naphthalene (10800 -18300 mg kg -1 original sample) and monobrominated phenols (12.8 -16.9 mg kg -1 original sample) were the most abundant compounds.

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Section: (Figure 4)mentioning

confidence: 99%

Emissions of brominated compounds and polycyclic aromatic hydrocarbons during pyrolysis of E-waste debrominated in subcritical water

2017

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“…Williams [16] in a recent review paper reported the use of pyrolysis for the treatment of wastes from electronic printed circuit boards as a recovery method for useful products such as metals, liquid and gaseous products as well as glass fibres. He also stated that the circuit boards contain significant concentrations of bromine in the form of bromine containing flame retardants, which also appears in the liquid fraction in the form of brominated organic compounds, a property which could possibly affect the the potential end uses of the produced oil.…”

Section: Chemical and Thermo-chemical Recycling Methodsmentioning

confidence: 99%

Chemical and Thermochemical Recycling of Polymers from Waste Electrical and Electronic Equipment

Achilias¹,

Antonakou²

2015

Recycling Materials Based on Environmentally Friendly Techniques

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The production of electric and electronic equipment (EEE), including personal computers, compact disks, TV sets, refrigerators, washing machines, toasters and many other daily-life items, is one of the fastest growing areas of manufacturing industry today. The rapid development in the EEE technology combined with a short life cycle and a variety of uses, at least for most of the products, poses a significant issue as far as their disposal is concerned. This has resulted in a continuous increase of Waste Electric and Electronic Equipment (WEEE) with some representative numbers: in the EU only, 9.5 million tones have been disposed in 2008 and this is expected to increase to 12.3 million tones in 2020 [1, 2]. While there is no generally accepted definition of electronic waste in most cases electronic waste consists of electronic products that were used for data processing, telecommunications, or entertainment in private households and businesses and are now considered obsolete, broken, or unrepairable (Figure 1). Despite its common classification as a waste, disposed electronics are a considerable category of secondary resource due to their significant suitability for direct reuse and material recycling. In view of the environmental problem involved in the management of WEEE, many countries and organizations have drafted national legislation to improve the reuse, recycling and other forms of recovery of such wastes so as to reduce disposal. The EU in an attempt to deal with the necessity of a meaningful recycling system and at the same time to preserve oil and fossil fuel resources has introduced 2002/96/EC directive [2], which demands 70-80% of WEEEs to be recovered in the form of energy and/or materials [2]. The directive aims at the minimization of the percentage of the solid wastes which will be landfilled or incinerated the full conversion of all waste streams (including plastics) through thermal or mechanic treatment by 2020.

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“…About 2 to 5% Sb is usually used in Pb-Sn-Sb alloys [6]. Antimony, found predominantly in printed circuit boards, is known to be toxic and highly volatile [9].…”

Section: Antimonymentioning

confidence: 99%

Environmental Impact of Processing Electronic Waste – Key Issues and Challenges

Cayumil¹,

Khanna²,

Rajarao³

et al. 2016

E-Waste in Transition - From Pollution to Resource

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Extensive utilization of electric and electronic equipment in a wide range of applications has resulted in the generation of huge volumes of electronic waste e-waste globally.Highly complex e-waste can contain metals, polymers and ceramics along with several hazardous and toxic constituents. There are presently no standard approaches for handling, dismantling, and the processing of e-waste to recover valuable resources. Inappropriate and unsafe practices produce additional hazardous compounds and highly toxic emissions as well. This chapter presents an overview of the environmental impact of processing e-waste with specific focus on toxic elements present initially in a variety of e-waste as well as hazardous compounds generated during e-waste processing. Hazardous constituents/ and contaminants were classified in three categories primary contaminants, secondary contaminants, and tertiary contaminants. Primary contaminants represent hazardous substances present initially within various types of e-waste these include heavy metals such as lead, mercury, nickel and cadmium, flame retardants presents in polymers etc. Secondary contaminants such as spent acids, volatile/toxic compounds, PAHs are the byproducts or waste residues produced after inappropriate processing of e-waste and the tertiary contaminants include leftover reagents or compounds used during processing. A detailed report is presented on the environmental impact of processing e-waste and the detrimental impact on soil contamination, vegetation degradation, water and air quality along with implications for human health. Challenges and opportunities associated with appropriate e-waste management are also discussed.

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Valorization of Printed Circuit Boards from Waste Electrical and Electronic Equipment by Pyrolysis

Cited by 61 publications

References 68 publications

Emissions of brominated compounds and polycyclic aromatic hydrocarbons during pyrolysis of E-waste debrominated in subcritical water

Emissions of brominated compounds and polycyclic aromatic hydrocarbons during pyrolysis of E-waste debrominated in subcritical water

Chemical and Thermochemical Recycling of Polymers from Waste Electrical and Electronic Equipment

Environmental Impact of Processing Electronic Waste – Key Issues and Challenges

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