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Identification of Synthesized Pitch Derived from Pyrolyzed Fuel Oil (PFO) by Pressure

석유계 잔사유(PFO)의 피치 합성 시 압력조건에 따른 피치 특성 변화

  • Seo, Sang Wan (Carbon Industry Frontier Research Center, Korea Research Institute of Chemical Technology (KRICT)) ;
  • Kim, Ji Hong (Carbon Industry Frontier Research Center, Korea Research Institute of Chemical Technology (KRICT)) ;
  • Lee, Young-Seak (Department of applied chemical engineering, Chungnam National University) ;
  • Im, Ji Sun (Carbon Industry Frontier Research Center, Korea Research Institute of Chemical Technology (KRICT))
  • 서상완 (한국화학연구원(KRICT) 탄소산업선도연구단) ;
  • 김지홍 (한국화학연구원(KRICT) 탄소산업선도연구단) ;
  • 이영석 (충남대학교 응용화학공학부) ;
  • 임지선 (한국화학연구원(KRICT) 탄소산업선도연구단)
  • Received : 2018.07.05
  • Accepted : 2018.07.24
  • Published : 2018.12.10

Abstract

In this study, effects of the reaction pressure were studied for petroleum-based pitch synthesis. A two-stage reaction process was performed based on different reaction pressure conditions. Each stage experiments for the two-stage reaction were consecutively carried out. The first stage was consisted of three different pressure conditions; high (10 bar), normal and low (0.1 bar). And the second stage was carried out at the normal and low (0.1 bar) pressure. The pitch synthesis was realized at $400^{\circ}C$ for 2 h. Thermal properties and molecular weight distributions of each samples were investigated by analyzing the softening point and MALDI-TOF data. Volatilized components during the pith synthesis were measured by GC-SIMDIS. In case of the first-step reaction with the high pressure condition, the low molecular weight component participated to the pitch formation more effectively and the pitch with the low softening point was obtained. However, for the case of the first-step with the low pressure, the low molecular weight component was vent outside and the partial coke formation occurred. Eventually, pitch properties such as the softening point and yield were controlled effectively by changing the pressure in the pitch synthesis reaction.

본 연구에서는 석유계 잔사유를 원료로 피치 합성반응 중 압력변수에 의한 영향을 고찰하였다. 압력변수를 달리하여 두 단으로 나누어 반응을 진행하였다. 실험은 두 단을 연속적으로 진행하였고, 첫 번째 단에 가압, 상압, 감압으로 열처리를 진행하였고, 두 번째 단은 상압과 감압으로 실험하였다. 합성 온도는 $400^{\circ}C$, 합성 시간은 총 2 h으로 피치 합성을 진행하였다. 각 조건에 의해 제조된 피치의 열적 특성과 분자량 분포는 연화점 측정과 MALDI-TOF 분석을 통해 고찰하였다. 또한, GC-SIMDIS를 이용해 피치 합성 반응 중 휘발된 액상 성분에 대한 특성을 고찰하였다. 첫 번째 단에서 가압 조건을 이용한 경우, 저비점 물질들이 상대적으로 다른 두 조건보다 많이 피치 합성 반응에 참여하였으며, 저비점 물질들의 반응참여 효과로 낮은 연화점을 갖는 피치를 얻을 수 있었다. 반대로 첫 번째 단에서 감압 조건을 사용한 경우, 저비점 물질들이 효과적으로 휘발되어 반응기 외부로 빠져나가 낮은 피치 수율을 얻었고, 일부 코크스화가 진행된 결과를 얻을 수 있었다. 압력 공정변수를 제어하여 피치의 수율 및 연화점 등 물성을 효과적으로 조절할 수 있는 공정변수를 도출하였다.

Keywords

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Figure 1. Scheme illustration of the reactor system for synthesis of pitch at various pressure conditions.

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Figure 2. Optical microscopy images of the prepared pitch.

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Figure 3. TGA curve of prepared pitch.

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Figure 4. DTG curve of prepared pitch.

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Figure 5. Weight loss rate of prepared pitch for temperature range.

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Figure 6. GC-SIMDIS curve of distillated materials.

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Figure 7 Molecular weight distribution of prepared pitch.

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Figure 8. Molecular weight segment divided by the pseudocomponent.

Table 1. Comprehensive Information of Reaction Condition

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Table 2. Softening Point & Yield of the Prepared Pitch

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References

  1. J. R. Kershaw and K. J. T. Black, Structural characterization of coal-tar and petroleum pitches, Energy Fuels, 7, 420-425 (1993). https://doi.org/10.1021/ef00039a014
  2. L. F. King and W. D. Robertson, A comparison of coal tar and petroleum pitches as electrode binders, Fuel, 47, 197-212 (1968).
  3. R. H Wombles and M. D. Kiser, Developing coal tar/petroleum pitches, In: A. Tomsett and J. Johnson (eds), Essential Readings in Light Metals. Springer, 4, 246-250 (2016).
  4. B. J. Kim, T. Kotegawa, Y. Eom, J. An, I. P. Hong, O. Kato, K. Nakabayashi, J. Miyawaki, B. C. Kim, and I. Mochida, Enhancing the tensile strength of isotropic pitch-based carbon fibers by improving the stabilization and carbonization properties of precursor pitch, Carbon, 99, 649-657 (2016). https://doi.org/10.1016/j.carbon.2015.12.082
  5. A. Charatte, D. Kocaefe, J. L. Saint-Romain, and P. Couderc, Comparison of carious pitches for impregnation in carbon electrodes, Carbon, 29, 1015-1024 (1991). https://doi.org/10.1016/0008-6223(91)90181-H
  6. I. Mochida, Y. Korai, C. H. Ku, F. Watanabe, and Y. Sakai, Chemistry of synthesis, structure, preparation and application of aromatic-derived mesophase pitch, Carbon, 38, 305-328 (2000). https://doi.org/10.1016/S0008-6223(99)00176-1
  7. B. C. Bai, J. G. Kim, J. H. Kim, C. W. Lee, Y. S. Lee, and J. S. Im, Blending effect of pyrolyzed fuel oil and coal tar in pitch production for artificial graphite, Carbon Lett., 25, 75-83 (2018).
  8. J. G .Kim, J. H. Kim, B. J. Song, Y. P. Jeon, C. W. Lee, Y. S. Lee, and J. S. Im, Characterization of pitch derived from pyrolyzed fuel oil using TCL-FID and MALDI-TOF, Fuel, 167, 25-30 (2016). https://doi.org/10.1016/j.fuel.2015.11.050
  9. J. G. Kim, J. H. Kim, B. J. Song, C. W. Lee, and J. S. Im, Synthesis and its characterization of pitch from pyrolyzed fuel oil (PFO), J. Ind. Eng. Chem., 36, 293-297 (2016). https://doi.org/10.1016/j.jiec.2016.02.014
  10. J. G. Kim, J. H. Kim, B. J. Song, C. W. Lee, Y. S. Lee, and J. S. Im, Empirical approach to determine molecular weight distribution using MALDI-TOF analysis of petroleum-based heavy oil, Fuel, 186, 20-23 (2016). https://doi.org/10.1016/j.fuel.2016.08.052
  11. J. G. Kim, J. H. Kim, C. W. Lee, K. B. Lee, and J. S. Im, Effect of added mesophase pitch during the pitch synthesis reaction of PFO, Carbon Lett., 23, 48-54 (2017).
  12. R. Santamaria-Ramirez, E. Romero-Palazon, C, Gomez-de-Salazar, F. Rodriguez-reinoso, S. Martinez-Saez, M. Martinez-Esacandell, and H. Marsh, Influence of pressure variations on the formation and development of mesophase in a petroleum residue, Carbon, 37, 445-455 (1999). https://doi.org/10.1016/S0008-6223(98)00211-5
  13. Y. D. Park and I. Mochida, A two-stage preparation of mesophase pitch from the vacuum pesidue of FCC decant oil, Carbon, 27, 925-929 (1989). https://doi.org/10.1016/0008-6223(89)90043-2
  14. R. Moriyama, J. Hayashi, K. Suzuki, T. Hiroshima, and T. Chiba, Analysis and modeling of mesophase sphere generation, growth and coalescence upon heating of a coal tar pitch, Carbon, 40, 53-64 (2002). https://doi.org/10.1016/S0008-6223(01)00070-7
  15. J. D. Brooks and G. H. Taylor, The formation of graphitizing carbons from the liquid phase, Carbon, 3, 185-186 (1965). https://doi.org/10.1016/0008-6223(65)90047-3
  16. C. Blanco, R. Santamaria, J. Bermejo, and R. Menedez, Separation and characterization of the isotropic phase and co-existing mesophase in thermally treated coal-tar pitches, Carbon, 38, 1169-1176 (2000). https://doi.org/10.1016/S0008-6223(99)00243-2
  17. H. Shui, Y. Feng, B. Shen, and J. Gao, Kinetics of mesophase transformation of coal tar pitch, Fuel Process. Technol., 55, 153-160 (1998). https://doi.org/10.1016/S0378-3820(98)00038-1
  18. R. Garcia, J. L. Crespo, S. C. Martin, C. E. Snape, and S. R. Moinelo, Development of mesophase from a low-temperature coal tar pitch, Energy Fuels, 17, 291-301 (2003). https://doi.org/10.1021/ef020109n
  19. A. Dang, H. Li, T. Li, T. Zhao, C. Xiong, Q. Zhuang, Y. Shang, X. Chen, and X. Ji, Preparation and pyrolysis behavior of modified coal tar pitch as C/C composites matrix precursor, J. Anal. Appl. Pyrolysis, 119, 18-23 (2016). https://doi.org/10.1016/j.jaap.2016.04.002
  20. I. Mochida, K. Maeda, and K. Takeshita, Structure of anisotropic spheres obtained in the course of needle coke formation, Carbon, 15, 17-23 (1977). https://doi.org/10.1016/0008-6223(77)90069-0
  21. M. Legin-Kolar, Optical and crystallographic structure of pitch cokes, Carbon, 30, 613-618 (1992). https://doi.org/10.1016/0008-6223(92)90180-5
  22. H. Yang and R. Luo, Effect of coal tar pitch modified by sulfur as a binder on the mechanical and tribological properties of bronze-impregnated carbon-matrix composites, Mater. Sci. Eng. A, 528, 2929-2935 (2011). https://doi.org/10.1016/j.msea.2011.01.004