Oil Shale, 2007, Vol. 24, No. 3, pp. 535-546

 

FORMATION OF THERMOBITUMEN FROM OIL SHALE BY LOW-TEMPERATURE PYROLYSIS IN AN AUTOCLAVE

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L. TIIKMA, A. ZAIDENTSAL, M. TENSORER

 

This work presents a review of investigations concerning formation of thermo­bitumen (TB) and a systematic experimental study of thermo­bituminiza­tion of Baltic oil shale, Kukersite, in autoclaves. The bituminizing process was performed at different nominal temperatures (340-380 °C) and residence times (20 min–10 hours). Distribution of organic matter of the shale between thermobitumen, gas and insoluble in benzene solid residue was studied. Composition of thermobitumen depending on pyrolysis condi­tions was characterized. The pyrolysis process of kukersite in autoclaves consists of three stages: 1. Formation of TB and gas from kerogen until obtaining the maximum yield of TB. 2. Equilibrium of formation and thermal cleavage of TB molecules. The yield of TB is maximum and practically constant in this stage. The quantity of gas grows continously and that of organic solid residue is minimal. The lower is the temperature, the longer is the thermobituminization stage. 3. Destruction of obtained TB forming gas, coke and oil. The formed oil favors extraction of TB from solid residue, but a part of kerogen gets lost with coke. The duration of these stages depends on the nominal temperature being shorter at higher temperatures.

 

 

REFERENCES

1.   Urov, K., Sumberg, A. Characteristics of oil shales and shale-like rocks of known deposits and outcrops // Oil Shale. 1999. Vol. 16, No. 3. P. 1–64.

2.   Jefimov, V., Purre, T. Characteristics of kukersite oil shale, some regularities and features of its retorting // Oil Shale. 1993. Vol. 10, No. 4. P. 313–319.

3.   Klewer, H. W., Mauch, K. Über den estlandischen Ölschiefer “Kukersit”. – Halle, 1927.

4.   Kogerman, P., Luts, K., Hüsse, J. The chemistry of Estonian oil shale. – M.-L: Goshimizdat, 1934 [in Russian].

5.   Kogerman, P. N., Kopwillem, J. J. Hydrogenation of Estonian oil shale and shale oil // Inst. Petrol. Technol. 1932. Vol. 18, No. 108. P. 833–845.

6.   Luts, K. Der estländische Brennschiefer Kukersit, seine Chemie, Technologie and Analyse. – Reval, 1934.

7.   Lille, Ü., Heinmaa, I., Pehk, T. Molecular model of Estonian kukersite kerogen as evaluated by ¹³C MAS NMR spectroscopy // Fuel. 2003. Vol. 82, No. 7. P. 799–804.

8.   Aarna, A. Y. Isothermal destruction of Baltic oil shale // Transactions of Tallinn Polytechnic Institute. Series A. 1954. No. 57. P. 32–34 [in Russian].

9.   Karavayev, N. M., Wener, I. M. About thermobitum of Gdov oil shale // Trans­actions of the Institute of Goryuchih Iskopayemyh. Academy of Sciences of SSSR. 1950. Vol. 2. P. 285–295 [in Russian].

10.     Aarna, A. Y., Lippmaa, E. T. Thermal destruction of oil shale-kukersite // Transactions of Tallinn Polytechnic Institute. Series A. 1958. No. 97. P. 3–27 [in Russian].

11.     Kask, K. A. About bituminizing of kerogen of oil shale-kukersite. Report I // Transactions of Tallinn Polytechnic Institute. Series A. 1955. No. 63. P. 51–64 [in Russian].

12.     Kask, K. A. About bituminizing of kerogen of oil shale-kukersite. Report II // Transactions of Tallinn Polytechnic Institute. Series A. 1956. No. 73. P. 23–40 [in Russian].

13.     Aarna, A. Y. Dynamic of separation of volatile products at thermal destruc­tion of oil shale // Transactions of Tallinn Polytechnic Institute. Series A. 1955. No. 63. P. 65–81 [in Russian].

14.     Schulman, A. I. Investigation of bituminizing process of shale organic con­centrate. Thesis of PhD. Leningrad: VNIINeftehim, 1968 [in Russian].

15.    Fomina, A. S., Pobul, L. Y., Degteryova, Z. A. Origin of kerogen of Baltic oil shale and its chemical characteristics as raw material. – Tallinn: Acad. Sci. Estonian SSR, 1965 [in Russian].

16.     Kask, K. A., Mihkelson, V. J. The chemical composition of thermobitumen of kukersite oil shale // Transactions of Tallinn Polytechnic Institute. Series A. 1958. No. 97. P. 68–84 [in Russian].

17.     Aarna, A., Alev, M. Investigation of low-temperature destruction of kukersite shale by infrared spectroscopy // Transactions of Tallinn Polytechnic Institute. Series A. 1964. No. 210. P. 3–14 [in Russian].

18.     Broi-Karre, G., Proskuryakov, V. Investigation of low-temperature destruc­tion of Gdov oil shale concentrate by infrared spectroscopy // J. Appl. Chem. 1966. Vol. 39, No. 5. P. 1214–1216 [in Russian].

19.     Lille, Ü., Pehk, T., Purre, T., Bitter, L. Examination of the structure of heavy shale oil by means of NMR spectroscopy // Proc. Acad. Sci. ESSR. Chem. 1973. Vol. 22, No 1. P. 17–25 [in Russian with English summary].

20.     Miknis, F. P., Turner, T. F., Berdan, G. L., Conn, P. J. Formation of soluble products from thermal decomposition of Colorado and Kentucky oil shales // Energy & Fuels. 1987. Vol. 1, No. 6. P. 477–483.

21.     Sadeghi, K. M., Sadeghi, M-A., Wen Hui Wu, Teh Fu Yen. Fractionation of various heavy oils and bitumen for characterization based on polarity // Fuel. 1989. Vol. 68, No. 6. P. 782–787.

22.     Luik, H., Vink, N., Lindaru, E. Upgrading of Estonian shale oil. 1. Effect of hydrogenation on the chemical composition of kukersite retort oil // Oil Shale. 1996. Vol. 13, No. 1. P. 13–19.

23.     Kuningas, K., Urov, K., Rang, S., Eisen, O. On the sequence of formation of aliphatic hydrocarbons during the thermal decomposition of the kukersite-shale // Proc. Acad. Sci. ESSR. Chem. 1977. Vol. 26, No. 2. P. 152–154 [in Russian].