The study of nickel effect on the hydrothermal dechlorination of PVC

Zhao, Peitao; Li, Zhaozhi; Tian, Li; Yan, Weijie; Ge, Shifu

doi:10.1016/j.jclepro.2017.03.101

Cited by 103 publications

(41 citation statements)

References 30 publications

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“…1700 cm À1 ) and C-OH (1150 cm À1 ) can be observed. 22,23 In addition, the stretching vibrations of C^N (2210 cm À1 ), C-N (1100 cm À1 ) was also detected. The IR vibration signals from the C]C-H and C]C in the precursors affirmed the proposed chemical reaction mechanism, as shown in Scheme 1.…”

Section: Morphologies and Propertiesmentioning

confidence: 95%

Highly efficient solar seawater desalination with environmentally friendly hierarchical porous carbons derived from halogen-containing polymers

et al. 2019

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Desalination of seawater using solar energy is a promising solution to the global freshwater shortage.Ultrahigh surface area (up to 1740 m 2 g À1 ) hierarchical porous carbons (HPC) have been prepared by the carbonization of precursors derived from the room temperature dehalogenation of low cost, widely available polyvinyl chloride (PVC) with simple, low cost, environmentally friendly processes. The broad hierarchical pores (from 2 nm to 20 mm) facilitate and ensure fast water and vapor transportation. Flexible photothermal steam generation devices were successfully fabricated with these hierarchical porous carbons on hydrophilic ultrathin (200 mm) paper. An evaporation rate record of 7.87 kg m À2 h À1 and high energy conversion of 95.8% have been obtained under the concentrated solar intensity of 5 kW m À2 . Our research leads to a new approach to converting halogenated plastics into environmentally friendly and useful porous carbon materials by simple, low-cost processes. It establishes and validates the concept of creating a sustainable and economic pathway to simultaneously recycle halogenated polymers, harvest solar energy and produce clean freshwater.

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Section: Morphologies and Propertiesmentioning

confidence: 95%

Highly efficient solar seawater desalination with environmentally friendly hierarchical porous carbons derived from halogen-containing polymers

et al. 2019

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“…The main problems of catalytic dechlorination are the catalyst poisoning, high operation temperature (400-1000 ºC), non-uniform heat transfer, low yields obtained and excessive formation of char and gas (Wang and Zhang, 2012). HTD has become an effective and environmentally friendly method for the chlorine removal of PVC waste (Kubátová et al, 2002;Poerschmann et al, 2015;Soler et al, 2018;Xiu et al, 2014;Yao and Ma, 2017;Zhao et al, 2018Zhao et al, , 2017 because it presents simple and fast reaction rates, and homogeneous reactions without limitations of mass transfer occur, which give rise to excellent process efficiency (Soler et al, 2017). Poerschmann et al (2015) subjected PVC to subcritical water treatment at different temperatures (180-260 ºC) and they observed that dechlorination increased with the increase of process temperature.…”

Section: Introductionmentioning

confidence: 99%

“…Yao and Ma (2017) also observed a decrease of the chlorine content in the residue and an increase of the carbon and hydrogen content as the dechlorination temperature increased due to reactions of elimination and substitution. In order to improve the dechlorination efficiency of the HTD process applied to PVC waste, some catalysts (Lv et al, 2009;Zhao et al, 2017) and alkaline additives (Yoshioka et al, 2008;Zhao et al, 2018) were used. Zhao et al (2018) investigated the effect of different alkaline additives in the HTD of PVC, which was performed in subcritical Ni 2+ -containing water at 220 ºC.…”

Section: Introductionmentioning

confidence: 99%

Dechlorination of polyvinyl chloride electric wires by hydrothermal treatment using K2CO3 in subcritical water

et al. 2020

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Polyvinyl chloride (PVC) waste generation has significantly increased in recent years and their disposal is considered a major environmental concern. Removal techniques of chlorine from PVC waste are being studied to minimize a negative environmental impact. In this work, the use of K2CO3 as an alkaline additive to improve the dechlorination efficiency (DE) in the hydrothermal degradation of PVC wires was studied. Different experiments were carried out varying both temperature (175 ºC, 200 ºC, 225 ºC, 235 ºC and 250 ºC) and K2CO3 concentration (0.025 M, 0.050 M and 0.125 M), using a solid/liquid ratio of 1:5 in order to determine the evolution of the dechlorination efficiency with time. About 4.66, 21.1, 24.4, 45.7 and 92.6 wt. % of chlorine in PVC wire was removed during hydrothermal dechlorination (HTD) with an additive/chlorine ratio of 1:25 (K2CO3 solution of 0.050 M) at 175, 200, 225, 235 and 250 ºC, respectively. Optimal additive/chlorine ratio decreased to 1:50 (K2CO3 solution of 0.025 M) at 250 ºC, obtaining a dechlorination degree of 99.1% after 4 hours without the need of metallic catalysts. Concerning the solid phase behavior during dechlorination, a linear correlation between the DE reached and the weight loss of PVC was found including every experiment performed in this work.

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“…Hydrothermal treatment with subcritical or supercritical water have become an effective and promising techniques to remove the chlorine contained in PVC-containing wastes [13] because these process present simple and fast reaction rates, and homogeneous reactions without limitations of mass transfer occur in these processes. However, subcritical water treatment presents advantages over supercritical water treatment, in addition to requiring lower temperatures and pressures, dechlorination reactions may be enhanced [14].…”

Section: Introductionmentioning

confidence: 99%

Application of Subcritical Water to Dechlorinate Polyvinyl Chloride Electric Wires

2018

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Polyvinyl chloride (PVC) electric wires were subjected to dechlorination in subcritical water at three different temperatures in a high-pressure reactor. About 2.09, 73.08, and 95.96 wt % of chlorine in PVC wires was removed during dechlorination at 200 °C, 250 °C, and 300 °C, respectively. The solid residues were analyzed and characterized by thermogravimetry, at three different heating rates (5 °C, 10 °C, and 20 °C/min) in inert and oxidizing atmosphere. With the purpose of studying the emission of chlorinated pollutants, pyrolysis experiments at 850 °C were also performed in a laboratory-scale reactor with the dechlorinated materials, as well as with the original PVC electric wire. Polycyclic aromatic hydrocarbons (PAH) formation increased, but chlorobenzenes (ClBz) and chlorophenols (ClPh) formation decreased as the temperature of dechlorination increased; naphthalene was the most abundant PAH and monochlorobenzene and monochlorinated phenols (3-+4-) were the most abundant chlorinated compounds.

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The study of nickel effect on the hydrothermal dechlorination of PVC

Cited by 103 publications

References 30 publications

Highly efficient solar seawater desalination with environmentally friendly hierarchical porous carbons derived from halogen-containing polymers

Highly efficient solar seawater desalination with environmentally friendly hierarchical porous carbons derived from halogen-containing polymers

Dechlorination of polyvinyl chloride electric wires by hydrothermal treatment using K2CO3 in subcritical water

Application of Subcritical Water to Dechlorinate Polyvinyl Chloride Electric Wires

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