Study on Porous Structure and Fractal Characteristics of Oil Shale and Semicoke

Abstract:

In order to find the change rule of porous structure of oil shale during pyrolysis, the Huadian oil shale samples were heated to final temperature of 300°C400°C500°C600°C700°C. The pore structure and pore size distribution of oil shale and produced semi-cokes were measured by N2 isothermal adsorption/desorption method. The fractal characteristics and other parameters of porous structures were then analyzed in detail. The results indicate that the pores in oil shale were open at one direction while the pores in semi-cokes could be observed from two or even four directions. The pore sizes of semi-cokes were mostly between 3-5 nm; and the pore volume increased at a quickest rate when pyrolysis temperature increased from 400 to 600 °C. Oil shale and its semi-cokes all showed obvious fractal characteristics, whereas oil shale and the semi-coke from 600 °C gave the lowest fractal dimensions; this means that the matrix of oil shale tended to keep its original skeleton structure and the pore structure of semi-cokes from high temperatures became regular after devolatilization during the pyrolysis.

• Periodical: Advanced Materials Research (Volume 868)
• Pages: 276-281
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.868.276
• Online since: December 2013
• Authors: Li Mei Zhao*, Jie Liang, Lu Xin Qian
• Keywords: Fractal Characteristics, Oil Shale, Porous Structure, Pyrolysis, Semicoke

References

[1] Qian J．L．，Wang J．Q．World oil shale retorting technologies．International Conference on Oil Shale，Paper No．rtos A-118，Natural Resoures Authority，Amman-Jordan，Nov．(2006).

[2] Song Weina，Dong Yongli，Zhou Guojiang，et al．Reaearch summarization of structure-constitute and application of oil shale[J]．Journal of Heilongjiang Hydraulic Engineering，2010, 37（3）70-73. In chinese.

[3] Sun Baizhong，Zhou Mingzheng，Liu Hongpeng，et al．Study on surface characteristics of oil shale during fluidized combustion[J]．Journal of Power Engineering，2008, 28（2）：250-254. In chinese.

[4] Sun Baizhong，Wang Qing，Li Shaohua，et al．Analysis of specific Area and porous structure of oil shale and semi-coke[J]．Journal of Power Engineering，2008, 28（2）：163-167. In chinese.

[5] X．X．Han, X．M．Jiang，L．J．Yu，et al．change of Pore Structure of Oil Shale Particles during Combustion．Part 1．Evolution Mechanism[J]．Energy and Fuels，2006，20：2 408-2412.

[6] X．X．Han, X．M．Jiang，Z．G．Cui．Change of Pore Structure of Oil Shale Particles during Combustion．2 Pore Structure of Oil Shale Ash[J]．Energy and Fuels，2008，22: 972-975.

DOI: 10.1021/ef700645x

[7] Han Xiangxin，Jiang Xiumin，Cui Zhigang，et al．Evolution of pore structure of oil shale particles during combustion[J] ．Proceeding of the CSEE，2007, 27（2）：27-30. In chinese.

[8] J H de Boer．The shape of capillaries[A]．Everett D H, Stone F S．The structure and Properties of Porous Materials[C]．London: Butterworth, (1958).

[9] Chen Ping，Tang Xiuyi．The research on the adsorption of nitrogen in low temperature and micro-pore properties in coal[J]．Journal of China Coal Socienty，2001, 26（5）：552-556. In chinese.

[10] Kang Zhiqin．The Pyrolysis characteristics and in-situ hot drive simulation research that exploit oil-gas of oil shale[D]．Taiyuan，Taiyuan University of Technology，2008. In chinese.

[11] Angulo R F, A lvaradov and Gonzalez H. Fractal dimensions from mercury in trusion capillary tests[R]. SPE 23695, (1992).

DOI: 10.2118/23695-ms

[12] Thampaon A H. Katz A J, Krohn C E, the microgeometry and transportproperties of sandtones[J]. Advances in physic, 1987, 36(5): 625-631.

[13] Li Dayong，Zang Shibin，Ren Xiaojuan et al．Study on pore structure of low permeability Reservoirs with fractal theory[J]．Liaoning Chemical Industry，2010, 39（7）：723-726. In chinese.

[14] Li Liuren，Zhao Yanyan，Li Zhongxing，et al．Fractal characteristics of mocropore structure of porous media and the meaning of fractal coefficient[J]．Journal of the University of Petroleum，China，2004, 28（3）：105-108. In chinese.

[15] Tong Hongshu，Hu Baolin．Research on the fractal characteristics of pore of coal reservoirs tested with cryogenic nitrogen adsorption in the ordos basin[J]．Coal Technology，2004, 23（7）：1-3. In chinese.