Research of the thermal decomposition mechanism and pyrolysis pathways from macromonomer to small molecule of waste printed circuit board

Gao, Ruitong; Zhan, Lu; Guo, Jie; Xu, Zhenming

doi:10.1016/j.jhazmat.2019.121234

Cited by 68 publications

(36 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…, which leads to a possible mixing ratio for the two main constituents of tar detected by TD-GC/MS: 0.5 part by mole of dodecanol (C 12 H 26 O) and 2 parts by mole of phenol (C 6 H 6 O). This high phenol content in tar is in accordance with the investigation of bisphenol A pyrolysis by Gao et al (Gao et al (2020)). They concluded that all pathways led to the formation of phenol.…”

Section: Analysis Of Data From Central-point Experiments At 450°csupporting

confidence: 89%

“…The most developed industrial application is the pyrolysis of biomass, which generates useful products such as bio-oil, syngas and bio-char (Demirbaş and Arin, 2002;Wu et al, 2014). More specifically, many on-going research works are focused on the elimination of epoxy resin by pyrolysis as an option in the view of metal recovery from printed circuit board (Gao et al, 2020). This application has strong similarities with our problematic, where the mold resin tightly covers the material (Chen et al, 2018;Gurgul et al, 2018;Liu et al, 2018;Niu et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Application of pyrolysis to remove hydrogen from an organic nuclear waste

Duan

Fiquet

Ablitzer

et al. 2021

Journal of Hazardous Materials

View full text Add to dashboard Cite

The work deals with the removal by slow pyrolysis of epoxy resin from samples of spent nuclear fuel embedded in this polymer. Beyond the nuclear field, epoxy resin removal by pyrolysis is a typical issue for the recovery of metals in electronic waste. The main objective is to find the optimal conditions to remove hydrogen in the residual solid waste, in order to avoid hydrogen production by radiolysis during storage and so to prevent any risk of overpressure and explosion. The condensable pyrolysis products (tar-water mixture) and the char were characterised and quantified by elemental analyses, while the permanent gases were quantified by gas chromatography. A data reconciliation method was applied to adjust the values of raw measurements in order to complete the mass balances for both C, H, O and N elements and pyrolysis products. After studying the impact of temperature on the pyrolysis balance, experiments on a pilot furnace were conducted at 450°C, in the frame of a parametric study of the heating rate, argon gas flow rate, resin mass and plateau time. At fixed temperature, we show that the plateau time is the only significant parameter for minimizing the residual hydrogen content in the char.

show abstract

Section: Analysis Of Data From Central-point Experiments At 450°csupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Application of pyrolysis to remove hydrogen from an organic nuclear waste

Duan

Fiquet

Ablitzer

et al. 2021

Journal of Hazardous Materials

View full text Add to dashboard Cite

show abstract

“…According to the chemical bond theory, the chemical bond will be broken when the energy provided by the reaction system is greater than the energy of the bond . Therefore, weak bonds in the WEP would be destroyed first, such as C 6 H 5 O-CH 2 and C–N bonds, the bond strengths of which were 268 and 305 kJ/mol, respectively. , Some stronger bonds like C–C bond with a bond strength of 332 kJ/mol would be broken with further milling, destroying the crosslinking structure of the WEP. After these bonds were broken, a large number of free radicals would be generated, and those free radicals could react with water and oxygen in the air or other radicals to produce some new alkanes, alcohols, and other substances .…”

Section: Resultsmentioning

confidence: 99%

Novel Application of Mechanochemistry in Waste Epoxy Recycling via Solid-State Shear Milling

Kang

Yang

Bai

et al. 2021

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

Epoxy resin is one of the most popular thermosetting resins and has been widely used in many fields for its excellent performance. However, the stable crosslinking structure of waste epoxy (WEP) caused poor interfacial compatibility, which makes it very difficult to be recycled. This paper reported a novel method for recycling the waste epoxy through partial de-crosslinking and recrosslinking processes via solid-state shear milling (S3M). The waste epoxy was effectively pulverized into an ultrafine powder about 17 μm and the crosslinking density decreased from 3.43 × 10 −3 to 2.69 × 10 −3 mol/mL. The C−N, C−C, and C−O−C bonds in the WEP were broken by the mechanochemical action and many hydroxyl and amino groups were formed on the surface of the WEP powder, which could react with the epoxy and curing agent to form the new crosslinking network. The interface strength between the WEP powder and epoxy (EP) resin matrix was improved greatly and there were no voids that could be observed by scanning electron microscopy (SEM) after the re-crosslinking process. The maximum tensile strength, flexural strength, and non-notched impact strength of WEP/EP composites reached up to 42.2 MPa, 73.2 MPa, and 8.8 kJ/ m 2 , which means 62, 41, and 109% enhancement, respectively. This low-cost, high-efficiency, and environmentally friendly method shows great potential for value-added recycling of thermosetting resins.

show abstract

“…Studies have shown that liquid products from WPCB pyrolysis could be a valuable source of chemicals or energy as it contained products such as phenols and bisphenol A etc. (Quan et al 2010;Gao et al 2020). Fig.…”

Section: Screening Of Co-pyrolysis Reagent By Liquid Yieldmentioning

confidence: 99%

Co-pyrolysis of waste printed circuit boards with iron compounds for Br-fixing and material recovery

Chen

Shu

et al. 2021

Environ Sci Pollut Res

View full text Add to dashboard Cite

Waste printed circuit board was co-pyrolyzed with iron oxides and iron salts.Solid, liquid and gaseous products were collected and characterized. Co-pyrolysis with FeCl2, FeCl3 or FeSO4 was able to increase the yield of liquid product which was rich in phenol and its homologues. Also, the addition of co-pyrolysis reagents reduced the release of brominated organics to liquid as Br was either fixed as FeBr3 in solids or released as HBr. In particular, FeCl2 showed the best ability to reduce the release of Brcontaining organics to liquid compared with FeCl3 and FeSO4. Solid residuals were rich in iron oxides, glass fibers and charred organics with surface areas of 20.6-26.5 m 2 /g. CO2 together with a small amount of CH4 and H2 were detected in the gaseous products. Overall, co-pyrolysis could improve the quantity and quality of liquid oil which could be reused as chemical or energy sources. Pyrolysis of waste printed circuit board was promising as a method for recycling.

show abstract

Research of the thermal decomposition mechanism and pyrolysis pathways from macromonomer to small molecule of waste printed circuit board

Cited by 68 publications

References 47 publications

Application of pyrolysis to remove hydrogen from an organic nuclear waste

Application of pyrolysis to remove hydrogen from an organic nuclear waste

Novel Application of Mechanochemistry in Waste Epoxy Recycling via Solid-State Shear Milling

Co-pyrolysis of waste printed circuit boards with iron compounds for Br-fixing and material recovery

Contact Info

Product

Resources

About