This is a repository copy of Fast pyrolysis of halogenated plastics recovered from waste computers.

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1 This is a repository copy of Fast pyrolysis of halogenated plastics recovered from waste computers. White Rose Research Online URL for this paper: Article: Hall, William and Williams, Paul (2006) Fast pyrolysis of halogenated plastics recovered from waste computers. Energy and Fuels, 20 (4). pp ISSN Reuse See Attached Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by ing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. eprints@whiterose.ac.uk

2 The final, definitive version of this article has been published in Energy and Fuels, vol 20 (4), 2006, American Chemical Society, Fast Pyrolysis of Halogenated Plastics Recovered from Waste Computers William J. Hall and Paul T. Williams Energy and Resources Research Institute, University of Leeds, Leeds, UK LS2 9JT Contact: William Hall ( ABSTRACT The disposal of waste computers is an issue that is gaining increasing interest around the world. In this paper, results from the fast pyrolysis in a fluidized bed reactor of three different waste computer monitor casings composed of mainly acrylonitrile-butadiene-styrene (ABS) copolymer and two different waste computer body casings composed of mostly poly(vinyl chloride) (PVC) type polymers are presented. Preliminary characterization of the waste plastics was investigated using coupled thermogravimetric analysis-fourier transform infrared spectrometry (TGA-FT-IR). The results showed that the plastics decomposed in two stages. For the ABS-containing monitor casings, aromatic and aliphatic material were released in the first and second stages. The PVCcontaining computer body casing samples showed a first-stage evolution of HCl and a second stage evolution of aromatic and aliphatic material and further HCl. In addition, each of the five plastics was fast-pyrolyzed in a laboratory-scale fluidized bed reactor at 500 C. The fluidized bed pyrolysis led to the conversion of most of the plastics to pyrolysis oil, although the two PVC computer body cases produced large quantities of HCl. The pyrolysis oils were characterized by GC-MS and it was found that they were chemically very heterogeneous and contained a wide range of aliphatic, aromatic, halogenated, oxygenated, and nitrogenated compounds. TABLES AND FIGURES Table 1. Characteristics of the waste plastics Waste Plastic Sample Country of Origin Date Main Material Abbreviation Computer Monitor Back Cover Computer Monitor Back Cover Computer Monitor Back Cover Taiwan 1994 ABS Co-polymer MO1 Indonesia 1995 ABS Co-polymer MO2 Taiwan 1991 ABS Co-polymer MO3 Computer Body Casing PVC CT1 Computer Body Casing PVC CT2

3 Table 2 Elemental composition of the waste plastic computer body and monitor cases Element MO1 (wt%) MO2 (wt%) MO3 (wt%) CT1 (wt%) CT2 (wt%) N C H S O Br Cl Ca Fe Sb Ti Table 3. Total mass balance, bromine, and chlorine balances from the fluidised bed pyrolysis of the waste plastics Product MO1 MO2 MO3 CT1 CT2 Mass (%) Bromine (%) Chlorine (%) Char Oil Gas Char Oil Gas Char Oil Gas

4 Table 4. Composition of the pyrolysis gases derived from the fluidised bed pyrolysis of waste plastics Gas MO1 (Vol %) MO2 (Vol %) MO3 (Vol %) CT1 (Vol %) CT2 (Vol %) Hydrogen Carbon monoxide Carbon dioxide N/D N/D N/D N/D N/D Methane Ethene Ethane Propene Propane Butene + butadiene HBr + Br HCl + Cl Butane

5 Table 5 Components identified by GC-MS in the pyrolysis oil of MO1 RT (min) SI (%) CAS Name Concentration Peak # (%) GC-FID only acrylonitrile 2.7 GC-FID only benzene 21.9 GC-FID only toluene Ethylbenzene Styrene Cumene α-methylstyrene Phenol (1-Methoxyethyl)benzene Propenylbenzene Methylstyrene α-methyleneglutaronitrile Undecane Benzyl nitrile alpha-methyl-benzeneacetonitrile Naphthalene trans-3-phenylpropenonitrile Dodecene < Isopropylphenol Methylnaphthalene Benzenebutanenitrile Cyclopropanecarbonitrile Pentadecene Methyldiphenyl Naphthalenecarbonitrile Bibenzyl Dodecyl trichloroacetate ,3-Diphenylpropane Naphthaleneacetonitrile ,2-Diphenylethene ,4-Diphenyl-4-methyl-1-pentene ,3-Diphenyl-1-butene ,4-Diphenyl-4-methyl-2(E)-pentene Hexadecanenitrile ,3-Diphenyl-3-methylcyclopropene Methyl hexadecanoate Naphthalene, 2-phenyl (2H-Benzotriazol-2-yl)-5-methylphenol Methyl octadecanoate phenyl-1(3-phenyl-3butenyl)cyclopropane unknown Benzene, 1,1'-(1,1,2,2-tetramethyl-1,2- ethanediyl)bis ,4-Diphenyl-4-methyl-1-pentene ,4-Diphenyl-4-methyl-1-pentene ,3-Dimethyl-2,3-diphenylbutane 0.4 TOTAL 78.8

6 Table 6 Components identified by GC-MS in the pyrolysis oil of MO2 RT (min) SI (%) CAS Name Concentration (%) Peak # GC-FID only acrylonitrile 3.0 GC-FID only benzene 20.5 GC-FID only toluene chlorobenzene Ethylbenzene Styrene Α-Methylstyrene (1-methoxyethyl)Benzene propenylbenzene Methyleneglutaronitrile Undecane Benzyl nitrile Naphthalene trans-3-phenylpropenonitrile Tridecene Isoquinoline methylnaphthalene Benzenebutanenitrile Pentadecene Naphthalenecarbonitrile Bibenzyl Naphthalenecarbonitrile α-methyl benzyl ether ,3-Diphenylpropane Naphthaleneacetonitrile (E)-Stilbene (l-erythro-2,3-diphenyl)-2-butanol ,3-Diphenyl-1-butene ,4-Diphenyl-4-methyl-1-pentene ,3-Diphenyl-1-butene ,2-Dihydro-3-phenylnaphthalene ,4-Diphenyl-4-methyl-2(E)-pentene Bis-(2-methylbenzyl)-methylenisonitril Phenylnaphthalene H-Cyclopenta[l]phenanthrene, 2,3-dihydro ,2-Propanediol, 3-benzyloxy-1,2 diacetyl Methyl octadecanoate m-terphenyl Cyclopropane, 1-phenyl-1(3-phenyl-3- butenyl) unknown Oxazolidinone, 4-phenyl-5-p-tolyl-, trans ,3-Diphenyl-1-butene Propene, 3-(2-cyclopentenyl)-2-methyl-1,1- diphenyl TOTAL 86.9

7 Table 7 Components identified by GC-MS in the pyrolysis oil of MO3 RT (min) SI (%) CAS Name Concentration (%) Peak # GC-FID only acrylonitrile 0.6 GC-FID only benzene 1.5 GC-FID only Toluene Ethylbenzene Styrene Cumene Phenol cyclopropylbenzene butylbenzene < Acetophenone ,5-dimethyloctane < cis-2-phenyl-2-butene < methyl-2-(2-propenyl)Benzene < Benzyl nitrile ,4-Dihydronaphthalene α-methylbenzeneacetonitrile Naphthalene trans-3-phenylpropenonitrile (1-Methylethyl)phenol Phenyl-1-cyclopropanecarbonitrile methylNaphthalene, Benzenebutanenitrile Phenylcyclopropanecarbonitrile (1,3-dimethyl-3-butenyl)Benzene Bicyclo[4.2.0]octa-1,3,5-triene, 7-(3- butenyl) Methylbiphenyl < ,3-Diphenylpropane Naphthaleneacetonitrile (E)-Stilbene Phenylcyclopropyl)benzene ,3-Diphenyl-1-butene ,4-Diphenyl-4-methyl-1-pentene ,3-Diphenyl-1-butene ,4-Diphenyl-4-methyl-2(E)-pentene Methyl-3,4-dihydroisoquinoline Methyl hexadecanoate ,1'-[oxybis(methylene)]bis[4-ethylBenzene (2-chloropropyl)Benzene Methyl octadecanoate Cyclopropane, 1-phenyl-1(3-phenyl-3- butenyl) Docosane unknown ,3-Dimethyl-2,3-diphenylbutane ,4-Diphenyl-4-methyl-1-pentene TOTAL 61.7

8 Table 8 Components identified by GC-MS in the pyrolysis oil of CT1 RT (min) SI (%) CAS Name Concentration (%) Peak # GC-FID only benzene 20.3 GC-FID only toluene chlorobenzene Ethylbenzene Styrene α-methylstyrene (1-methoxyethyl)Benzene chloro-2,3-dihydro-1H-Indene < (1-chloroethyl)benzene (1-methoxy-1-methylethyl)benzene Benzyl nitrile ,4-Dihydronaphthalene Naphthalene Dodecene < Benzenebutanenitrile methylnaphthalene Benzenebutanenitrile (1,3-dimethyl-3-butenyl)benzene Biphenyl Tetradecene Methylbiphenyl < Pentadecane Bibenzyl < Fluorene Chloro-acetic acid hexadecyl ester ,3-Diphenylpropane (3-Phenylbutyl)benzene Heptadecane (E)-Stilbene Methyl tetradecanoate ,3-Dimethyl-2,3-diphenylbutane ,4-Diphenyl-4-methyl-1-pentene ,3-Diphenyl-1-butene Oxazolidinone, 4-phenyl-5-p-tolyl-, trans ,4-Diphenyl-4-methyl-2(E)-pentene Methyl-3,4-dihydroisoquinoline Hexadecanenitrile Methyl hexadecanoate methyl heptadecanoate Octadecenoic acid, methyl ester Methyl octadecanoate unknown Butyl hexadecanoate Propene, 3-(2-cyclopentenyl)-2-methyl- 1,1-diphenyl ,3-Diphenyl-1-butene TOTAL 58.3

9 Table 9 Components identified by GC-MS in the pyrolysis oil of CT2 RT (min) SI (%) CAS # Name Concentration (%) Peak # GC-FID only benzene 0.1 GC-FID only toluene chlorobenzene Ethylbenzene < Styrene Ethyl-1-hexanol Indene (1-methoxy-1-methylethyl)benzene Undecane ,3-dihydro-4-methyl-1H-Indene Ethylstyrene Methylindene ,4-Dihydronaphthalene Naphthalene methylnaphthalene Benzenebutanenitrile Biphenyl ethylnaphthalene < Pentadecene Methyl dodecanoate Fluorene Pentadecene Methylbiphenyl ,3-Diphenylpropane Methylfluorene (E)-Stilbene Methyl tetradecanoate Anthracene Methyl pentadecanoate Methylanthracene Methyl hexadecanoate methyl heptadecanoate Octadecenoic acid, methyl ester Methyl octadecanoate phenyl-1(3-phenyl-3-butenyl)cyclopropane dl-2-ethylhexyl chloroformate ,6,,15,19,23-Hexamethyl-2,6,,14,18,22- Tetracosahexaene TOTAL 25.6

10 Water Pump Alkali Pump Furnace Exhaust Feed Hopper Agitator TC TC Gas sample point N 2 TC TC N 2 Distributor Gas pre-heater TC Water Cooled CO 2 Acetone Cooled Water Reservoir Alkali Reservoir Fluidised Condensers Scrubber Bed Reactor Units Figure 1. Schematic diagram of the fluidised bed pyrolysis reactor. Mass loss (%) Temperature ( C) Time (seconds) CT1 CT2 MO1 MO2 MO3 CT1 MO1 MO3 CT1 MO2 Temp. Figure 2. Thermogravimetric analysis of the five different plastics at a heating rate of 50 C min -1 to a final temperature of 500 C. 0

11 A Absorbance B Absorbance Wavenumbers (cm-1) 00 Figure 3. Fourier transform infra-red analysis of the evolved products derived from computer body casing sample CT1 at a thermogravimetric analysis temperature of 330 C (A) and 485 C (B) A Absorbance B Absorbance Wavenumbers (cm-1) 00 Figure 4. Fourier transform infra-red analysis of the evolved products derived from computer monitor casing sample MO1 at a thermogravimetric analysis temperature of 380 C (A) and 485 C (B).

12 Responce Time (min) Figure 5. Total ion chromatogram from the gas chromatography-mass spectrometric analysis of the pyrolysis oil derived from the fluidised bed pyrolysis of computer monitor sample MO1 at 500 C Responce Time (mins) Figure 6. Total ion chromatogram from the gas chromatography-mass spectrometric analysis of the pyrolysis oil derived from the fluidised bed pyrolysis of computer monitor sample MO2 at 500 C.

13 Responce Time (mins) Figure 7. Total ion chromatogram from the gas chromatography-mass spectrometric analysis of the pyrolysis oil derived from the fluidised bed pyrolysis of computer monitor sample MO3 at 500 C Responce Time (min) Figure 8. Total ion chromatogram from the gas chromatography-mass spectrometric analysis of the pyrolysis oil derived from the fluidised bed pyrolysis of computer body sample CT1 at 500 C.

14 Responce Time (min) Figure 9. Total ion chromatogram from the gas chromatography-mass spectrometric analysis of the pyrolysis oil derived from the fluidised bed pyrolysis of computer body sample CT2 at 500 C %Transmittance Wavenumbers (cm-1) 00 Figure. Fourier transform infra-red analysis of the pyrolysis oil derived from computer monitor sample MO1 pyrolysed at 500 C in the fluidised bed reactor.

15 %Transmittance Wavenumbers (cm-1) 00 Figure 11. Fourier transform infra-red analysis of the pyrolysis oil derived from computer monitor sample MO2 pyrolysed at 500 C in the fluidised bed reactor %Transmittance Wavenumbers (cm-1) 00 Figure 12. Fourier transform infra-red analysis of the pyrolysis oil derived from computer monitor sample MO3 pyrolysed at 500 C in the fluidised bed reactor.

16 %Transmittance Wavenumbers (cm-1) 00 Figure 13. Fourier transform infra-red analysis of the pyrolysis oil derived from computer body sample CT1 pyrolysed at 500 C in the fluidised bed reactor %Transmittance Wavenumbers (cm-1) 00 Figure 14. Fourier transform infra-red analysis of the pyrolysis oil derived from computer body sample CT2 pyrolysed at 500 C in the fluidised bed reactor.