Preparation and characterization of high softening point and homogeneous isotropic pitches produced from distilled ethylene tar by a novel bromination method

GE Chuan-zhang; SUN Zhen-long; YANG Hai-xiao; LONG Dong-hui; QIAO Wen-ming; LING Li-cheng

doi:10.1016/S1872-5805(18)60327-0

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GE Chuan-zhang, SUN Zhen-long, YANG Hai-xiao, LONG Dong-hui, QIAO Wen-ming, LING Li-cheng. Preparation and characterization of high softening point and homogeneous isotropic pitches produced from distilled ethylene tar by a novel bromination method. New Carbon Mater., 2018, 33(1): 71-81. doi: 10.1016/S1872-5805(18)60327-0

Citation:

GE Chuan-zhang, SUN Zhen-long, YANG Hai-xiao, LONG Dong-hui, QIAO Wen-ming, LING Li-cheng. Preparation and characterization of high softening point and homogeneous isotropic pitches produced from distilled ethylene tar by a novel bromination method. New Carbon Mater., 2018, 33(1): 71-81. doi: 10.1016/S1872-5805(18)60327-0

Citation:

GE Chuan-zhang, SUN Zhen-long, YANG Hai-xiao, LONG Dong-hui, QIAO Wen-ming, LING Li-cheng. Preparation and characterization of high softening point and homogeneous isotropic pitches produced from distilled ethylene tar by a novel bromination method. New Carbon Mater., 2018, 33(1): 71-81. doi: 10.1016/S1872-5805(18)60327-0

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Preparation and characterization of high softening point and homogeneous isotropic pitches produced from distilled ethylene tar by a novel bromination method

doi: 10.1016/S1872-5805(18)60327-0

1.
State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China;
2.
Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China

Funds: National Natural Science Foundation of China (U1303291, 51272077).

Received Date: 2017-07-06
Accepted Date: 2018-02-11
Rev Recd Date: 2017-10-12
Publish Date: 2018-02-28

Abstract

Abstract

Homogeneous isotropic pitches with high softening points were prepared from vacuum-distilled heavy residue ethylene tar (ET-HR) by a two-step method of bromination and subsequent dehydrobromination/polycondensation. The ET-HR was first brominated at 30 or 200℃, and then heat-treated at 350℃ to enable the dehydrobromination/polycondensation reactions. GC/MS and LDI TOF/MS spectra indicated that the ET-HR was mainly composed of compounds containing 3-to 6-ring aromatic species with a considerable aliphatic chain content. Compared with thermal condensation alone, such a two-step method increased the softening point of the pitches from 152 to 264℃ with a yield in the range of 62 wt.%-67 wt.% and a coking value in the range of 57 wt.%-77 wt.%, depending on the bromination temperature and the bromine content. Structural characterization of the as-prepared pitches by elemental analysis, 1H NMR, FT-IR and LDI-TOF/MS showed increased aromatization and polymerization of the precursor during the dehydrobromination/polycondensation. All the homogeneous isotropic pitches showed an ability to transform into an anisotropic texture after coking at 800℃.
- Ethylene tar,
- Distillation,
- Bromination,
- Dehydrobromination,
- Properties

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References

Maeda T, Zeng S M, Tokumitsu K, et al. Preparation of isotropic pitch precursors for general purpose carbon fibers (GPCF) by air blowing-I. Preparation of spinnable isotropic pitch precursor from coal tar by air blowing[J]. Carbon, 1993, 31(3):407-412.

Chen C, Kennel E B, Stiller A H, et al. Carbon foam derived from various precursors[J]. Carbon, 2006, 44(8):1535-1543.

Carlson R K, Ferritto J J. Manufacture of high density, high strength isotropic graphite[P]. United States Patent, 1980, 4226900.

Mabuchi A, Tokumitsu K, Fujimoto H, et al. Charge-discharge characteristics of the mesocarbon miocrobeads heat-treated at different temperatures[J]. Journal of the Electrochemical Society, 1995, 142(4):1041-1046.

Manocha L M, Patel M, Manocha S M, et al. Carbon/carbon composites with heat-treated pitches:I. Effect of treatment in air on the physical characteristics of coal tar pitches and the carbon matrix derived therefrom[J]. Carbon, 2001, 39(5):663-671.

Menéndez R, Granda M, Fernández J J, et al. Influence of pitch air-blowing and thermal treatment on the microstructure and mechanical properties of carbon/carbon composites[J]. Journal of Microscopy, 1997, 185(2):145-156.

Suzuki M. Activated carbon fiber:Fundamentals and applications[J]. Carbon, 1994, 32(4):577-586.

Mora E, Blanco C, Prada V, et al. A study of pitch-based precursors for general purpose carbon fibers[J]. Carbon, 2002, 40(14):2719-2725.

Blanco C, Santamaria R, Bermejo J, et al. A comparative study of air-blown and thermally treated coal-tar pitches[J]. Carbon, 2000, 38(4):517-523.

Yu B, Wang C, Chen M, et al. Two-step chemical conversion of coal tar pitch to isotropic spinnable pitch[J]. Fuel Processing Technology, 2012, 104:155-159.

Lewis I C. Thermal polymerization of aromatic hydrocarbons[J]. Carbon, 1980, 18(3):191-196.

Mendez A, Bermejo J, Blanco C, et al. Structural characterization of high-softening-point pitches by oxidation with RuO₄[J]. Energy & Fuels, 2001, 15(1):128-134.

Yang K S, Choi Y O, Kim Y M, et al. Preparations of carbon fibers from precursor pitches synthesized with coal tar or petroleum residue oil[J]. Fibers and Polymers, 2000, 1(2):97-102.

Zeng S M, Maeda T, Tokumitsu K, et al. Preparation of isotropic pitch precursors for general purpose carbon fibers (GPCF) by air blowing-Ⅱ. Air blowing of coal tar, hydrogenated coal tar, and petroleum pitches[J]. Carbon, 1993, 31(3):413-419.

Blanco C, Santamaria R, Bermejo J, et al. Separation and characterization of the isotropic phase and co-existing mesophase in thermally treated coal-tar pitches[J]. Carbon, 2000, 38(8):1169-1176.

Cheng X, Zha Q, Zhong J, et al. Needle coke formation derived from co-carbonization of ethylene tar pitch and polystyrene[J]. Fuel, 2009, 88(11):2188-2192.

Mochida I, Fei Y Q, Korai Y. A study of the carbonization of ethylene tar pitch and needle coke formation[J]. Fuel, 1990, 69(6):667-671.

Andersen S I, Jensen J O, Speight J G. X-ray diffraction of subfractions of petroleum asphaltenes[J]. Energy & Fuels, 2005, 19(6):2371-2377.

Shirokoff J W, Siddiqui M N, Ali M F. Characterization of the structure of Saudi crude asphaltenes by X-ray diffraction[J]. Energy & Fuels, 1997, 11(3):561-565.

Kim B J, Kil H, Watanabe N, et al. Preparation of novel isotropic pitch with high softening point and solvent solubility for pitch-based electrospun carbon nanofiber[J]. Current Organic Chemistry, 2013, 17(13):1463-1468.

Blanksby S J, Ellison G B. Bond dissociation energies of organic molecules[J]. Accounts of Chemical Research, 2003, 36(4):255-263.

Ge C, Yang H, Miyawaki J, et al. Synthesis and characterization of high-softening-point methylene-bridged pitches by visible light irradiation assisted free-radical bromination[J]. Carbon, 2015, 95:780-788.

Kumar S, Srivastava M. Catalyzing mesophase formation by transition metals[J]. Journal of Analytical and Applied Pyrolysis, 2015, 112:192-200.

Kershaw J R, Black K J T, Jaeger H K, et al. A comparison of mesophase formation under sparging and vacuum[J]. Carbon, 1995, 33(5):633-643.

Guillén M D, Díaz C, Blanco C G. Characterization of coal tar pitches with different softening points by ¹H NMR:role of the different kinds of protons in the thermal process[J]. Fuel Processing Technology, 1998, 58(1):1-15.

Guillen M D, Iglesias M J, Dominguez A, et al. Semi-quantitative FT-IR analysis of a coal tar pitch and its extracts and residues in several organic solvents[J]. Energy & Fuels, 1992, 6(4):518-525.

Yen T F, Erdman J G, Pollack S S. Investigation of the structure of petroleum asphaltenes by X-ray diffraction[J]. Analytical Chemistry, 1961, 33(11):1587-1594.

Obara T, Yokono T, Miyazawa K, Sanada Y. Carbonization behavior of hydrogenated ethylene tar pitch[J]. Carbon, 1981, 19(4):263-267.

Fanjul F, Granda M, Santamaría R, et al. The influence of processing temperature on the structure and properties of mesophase-based polygranular graphites[J]. Journal of Materials Science, 2004, 39(4):1213-1220.

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