eesti teaduste
akadeemia kirjastus
SINCE 1984
Oil Shale cover
Oil Shale
ISSN 1736-7492 (Electronic)
ISSN 0208-189X (Print)
Impact Factor (2020): 0.934

Desulfurization, denitrogenation and deoxygenation of shale oil; pp. 137–154

Full article in PDF format | 10.3176/oil.2021.2.03

Zachariah Steven Baird, Heino Rang, Vahur Oja


Producing valuable transportation fuels from shale oil has long been a goal among the industries concerned, but to meet modern environmental regulations a significant upgrading is required involving removing heteroatoms from it. The quantity of sulfur, nitrogen and oxygen in shale oil is one of the major obstacles to its wider use. Unlike petroleum whose upgrading consists mainly in desulfurization, for shale oils denitrification and deoxygenation are also important. This review compiles and summarizes the extensive research that has been performed on removing sulfur, nitrogen and oxygen from shale oil. By far the most widely investigated method has been hydrotreatment, but the results of work done with other methods are also presented.


1. Smith, W. M., Lanum, T. C., Phillips, G. E. Hydrogenation of shale oil. Ind. Eng. Chem., 1952, 44, 586–589.

2. Lee, S. Oil Shale Technology. CRC Press, 1990.

3. Oja, V., Suuberg, E. M. Oil Shale Processing, Chemistry and Technology. In: Encyclopedia of Sustainable Science and Technology (Meyers, R. A., ed.). Springer-Verlag, New York, 2012, 7457–7491.

4. World Energy Council. World Energy Resources 2013 Survey. World Energy Council, London, 2013.

5. Bartis, J. T., LaTourrette, T., Dixon, L., Peterson, D. J., Cecchine, G. Oil Shale Development in the United States: Prospects and Policy Issues. Rand Corporation, 2005.

6. Oja, V. A breaf overview of motor fuels from shale oil of Kukersite. Oil Shale, 2006, 23(2), 160–163.

7. Luts, K. The Estonian Oil Shale Kukersite, its Chemistry, Technology and Analysis (Der estländische Brennschiefer-Kukersit, seine Chemie, Tehnologie und Analyse). K. Mattiesens Buchdruckerei Ant.-Ges., Tartu, Estonia, 1934.

8. Qian, H. Y., Tian, H. Y. A new scheme for upgrading Fushum shale oil. In: Proceedings of the International Conference on Oil Shale and Shale Oil, Beijing, China, 1988, 486–492.

9. Mapstone, G. E. Wartime shale oil production at Marangaroo, N.S.W. In: Proceedings of the Second Oil Shale and Cannel Coal Conference, Glasgow, 1950. The Institute of Petroleum, London, WI, USA, 1951, 489–499.

10. Egloff, G., Walter, J. F., Grote, H. W., Davis, R. F. Refining Australian and South African torbanite oils. In: Proceedings of the Second Oil Shale and Cannel Coal Conference, Glasgow, 1950. The Institute of Petroleum, London, WI, USA, 1951, 605–620.

11. Robertson, R. E. The refining of South African torbanite crude oil. In: Proceedings of the Second Oil Shale and Cannel Coal Conference, Glasgow, 1950. The Institute of Petroleum, London, WI, USA, 1951, 571–583.

12. Shale oil – Eesti Energia. n.d. (in Estonian).

13. Landau, M. V. Deep hydrotreating of middle distillates from crude and shale oils. Catal. Today, 1997, 36(4), 393–429.

14. Hüsse, J. Hydration and desulfurization of Estonian shale oil. Tehnika Ajakiri, 1930, 11, 162–165 (in Estonian).

15. Koern, T., Removal of sulfur from shale oil. Tehnika Ajakiri, 1930, 11, 166–168 (in Estonian).

16. Kogerman, P. N., Kopvillem, J. Hydrogenation of Estonian oil shale and shale oil. Journal of the Institution of Petroleum Technologists, 1932, 18(108), 833–845.

17. Low, G., Egelberg, R., Alkilde, O. Upgrading of Estonian shale oil to high quality Euro v diesel. International Oil Shale Symposium, Tallinn, Estonia, June 10–13, 2013, 28.

18. Rang, H., Kann, J., Oja, V. Advances in desulfurization research of liquid fuel. Oil Shale, 2006, 23(2), 164–176.

19. Srivastava, V. C. An evaluation of desulfurization technologies for sulfur removal from liquid fuels. RSC Adv., 2012, 2, 759–783.

20. Landau, M. V., Herskowitz, M., Givony, D., Laichter, S. Process and Catalysts for the Production of Motor Fuels from Shale Oils. WO1997019150 A1, 1997.

21. Lankford, J. D., Morris, J. Refining of Colorado shale oil. A review of work by the Bureau of Mines, U.S. Department of the Interior. In: Proceedings of the Second Oil Shale and Cannel Coal Conference, Glasgow, 1950. The Institute of Petroleum, London, WI, USA, 1951, 500–532.

22. Lille, Ü., Heinmaa, I., Pehk, T. Molecular model of Estonian kukersite kerogen evaluated by 13C MAS NMR spectra. Fuel, 2003, 82(7), 799–804.

23. Hruljova, J., Oja, V. Application of DSC to study the promoting effect of a small amount of high donor number solvent on the solvent swelling of kerogen with non-covalent cross-links in non-polar solvents. Fuel, 2015, 147, 230–235.

24. Hruljova, J., Savest, N., Oja, V., Suuberg, E. M. Kukersite oil shale kerogen solvent swelling in binary mixtures. Fuel, 2013, 105, 77–82.

25. Schmidt-Collerus, J. J., Prien, C. H. Investigation of the hydrocarbon structure of kerogen from oil shale of the Green River Formation. Am. Chem. Soc., Div. Fuel Chem., Prepr., 1974, 19(2), 100–108.

26. Robinson, W. E. Kerogen of the Green River Formation. In: Organic Geo-chemistry (Eglinton, G., Murphy, M. T. J., eds.). Springer Berlin Heidelberg, 1969, 619–637.

27. Urov, K., Sumberg, A. Characteristics of oil shales and shale-like rocks of known deposits and outcrops: monograph. Oil Shale, 1999, 16(3 SPECIAL). Estonian Acad. Publ., Tallinn, 1999.

28. Guo, S. H. The chemistry of shale oil and its refining. In: Coal, Oil Shale Natural Bitumen, Heavy Oil and Peat – Vol. II. Publishers Company Limited, 2009, 94–106.

29. Järvik, O., Oja, V. Molecular weight distributions and average molecular weights of pyrolysis oils from oil shales: Literature data and measurements by SEC and ASAP MS for oils from four different deposits. Energy Fuels, 2017, 31(1), 328–339.

30. Blokker, P., van Bergen, P., Pancost, R., Collinson, M. E., de Leeuw, J. W., Damste, J. S. S. The chemical structure of Gloeocapsomorpha priscamicrofossils: implications for their origin. Geochim. Cosmochim. Acta, 2001, 65(6), 885–900.

31. Siskin, M., Scouten, C. G., Rose, K. D., Aczel, T., Colgrove, S. G., Pabst, Jr., R. E. Detailed structural characterization of the organic material in Rundle Ramsay Crossing and Green River oil shales. In: Composition, Geochemistry and Conversion of Oil Shales (Snape, C., ed.). Springer Netherlands, 1995, 143–158.

32. Orendt, A. M., Pimienta, I. S. O., Badu, S. R., Solum, M. S., Pugmire, R. J., Facelli, J. C., Locke, D. R., Chapman, K. W., Chupas, P. J., Winans, R. E. Three-dimensional structure of the Siskin Green River oil shale kerogen model: A comparison between calculated and observed properties. Energy Fuels, 2013, 27(2), 702–710.

33. Baird, Z. S., Oja, V., Järvik, O. Distribution of hydroxyl groups in Kukersite shale oil: Quantitative determination using Fourier transform infrared (FT-IR) spectroscopy. Appl. Spectrosc., 2015, 69(5), 555–562.

34. Derenne, S., Largeau, C., Casadevall, E., Sinninghe Damsté, J. S., Tegelaar, E. W., de Leeuw, J. W. Characterization of Estonian Kukersite by spectroscopy and pyrolysis: Evidence for abundant alkyl phenolic moieties in an Ordovician, marine, type II/I kerogen. Org. Geochem., 1990, 16(4–6), 873–888.

35. Burnham, A. K., Happe, J. A. On the mechanism of kerogen pyrolysis. Fuel, 1984, 63(10), 1353–1356.

36. Speight, J. G. Crude Oil Assay Database. 2015.

37. Cady, W. E., Seelig, H. S. Composition of shale oil. Ind. Eng. Chem., 1952, 44(11), 2636–2641.

38. Andersson, J. T., Schmid, B. Polycyclic aromatic sulfur heterocycles IV. Determination of polycyclic aromatic compounds in a shale oil with the atomic emission detector. J. Chromatogr. A, 1995, 693(2), 325–338.

39. Zehua, Z., Kuangzong, Q., Tingfen, W., Yajie, Z. Preliminary study of hydrotreating of a high sulfur content shale. In: Proceedings of the International Conference on Oil Shale and Shale Oil, Beijing, China, 1988, 451–460.

40. Zelenin, N. I., Fainberg, V. S., Chernysheva, K. B. The Chemistry and Technology of Shale Oil. Chemistry Publishing House, Leningrad, 1968 (in Russian).

41. Dijkmans, T., Djokic, M. R., Van Geem, K. M., Marin, G. B. Comprehensive compositional analysis of sulfur and nitrogen containing compounds in shale oil using GC×GC – FID/SCD/NCD/TOF-MS. Fuel, 2015, 140, 398–406.

42. Al-Harahsheh, A., Al-Otoom, A. Y., Shawabkeh, R. A. Sulfur distribution in the oil fractions obtained by thermal cracking of Jordanian El-Lajjun oil shale. Energy, 2005, 30(15), 2784–2795.

43. Harvey, T. G., Matheson, T. W., Pratt, K. C., Stanborough, M. S. Catalyst performance in continuous hydrotreating of Rundle shale oil. Ind. Eng. Chem. Proc. Des. Dev., 1986, 25(2), 521–527.

44. Souza, G. L. M., Afonso, J. C., Schmal, M., Cardoso, J. N. Mild hydrocracking of an unstable feedstock in a three-phase fluidized-bed reactor: behavior of the process and of the chemical compounds. Ind. Eng. Chem. Res., 1992, 31, 2127–2133.

45. Holmes, S. A., Thompson, L. F. Nitrogen compound distributions in hydrotreated shale oil products from commercial-scale refining. Fuel, 1983, 62(6), 709–717.

46. Marecaux, P. P. Experiments on the integrated valorization of Severac shale oil. In: Proceedings of the Second Oil Shale and Cannel Coal Conference,Glasgow, 1950, Institute of Petroleum, London, WI, USA, 1951, 673–689 (in French).

47. Bunger, J. W. Shale Oil Value Enhancement Research. James W. Bunger and Associates, Inc., Salt Lake City, UT, USA, 2007.

48. Miknis, F. P., Robertson, R. E. Characterization of Doe Reference Oil Shales: Mahogany Zone, Parachute Creek Member, Green River Formation Oil Shale, and Clegg Creek Member, New Albany Shale. Western Research Inst., Laramie, WY (USA), 1987.

49. Lovell, P. F. Production of Utah Shale oils by the Paraho DH and Union ‘B’ retorting processes. In: Eleventh Oil Shale Symposium Proceedings (Gary, J. H., ed.). Colorado School of Mines Press, Golden, Colorado, 1978, 184–192.

50. Miknis, F. P. Characterization of DOE Reference Oil Shale: Tipton Member, Green River Formation Oil Shale from Wyoming. Western Research Institute, Laramie, WY, USA, 1988.

51. Hill, G. R., Dougan, P. The characteristics of a low temperature in situ shale oil. 96th Annual AIME Meeting, Los Angeles, Calif., Feb. 19–23, 1967.

52. Dinneen, G. U., Allbright, C. S., Ball, J. S. Comparison of Brazilian and Colorado shale oils. Ind. Eng. Chem. Chem. Eng. Data Series, 1957, 2(1), 91–95.

53. Mapstone, G. E. Some properties of crude shale oil and naphtha with a note on carbon disulfide in shale naphta. In: Proceedings of the Second Oil Shale and Cannel Coal Conference, Glasgow, 1950. The Institute of Petroleum, London, WI, USA, 1951, 662–672.

54. Elenurm, A., Oja, V., Tali, E., Tearo, E., Yanchilin, A. Thermal processing of Dictyonema Argillite and Kukersite oil shale: transformation and distribution of sulfur compounds in pilot-scale Galoter process. Oil Shale, 2008, 25(3), 328–334.

55. Oja, V., Elenurm, A., Rohtla, I., Tali, E., Tearo, E., Yanchilin, A. Comparison of oil shales from different deposits: Oil shale pyrolysis and co-pyrolysis with ash. Oil Shale, 2007, 24(2), 101–108.

56. Landau, M. V., Herskowitz, M., Givoni, D., Laichter, S., Yitzhaki, D. Medium-severity hydrotreating and hydrocracking of Israeli shale oil. 1. Novel catalyst systems. Fuel, 1996, 75(7), 858–866.

57. Landau, M. V., Herskowitz, M., Givoni, D., Laichter, S., Yitzhaki, D. Medium severity hydrotreating and hydrocracking of Israeli shale oil – II. Testing of novel catalyst systems in a trickle bed reactor. Fuel, 1998, 77(1–2), 3–13.

58. Landau, M. V., Herskowitz, M., Givoni, D., Laichter, S., Yitzhaki, D. Medium severity hydrotreating and hydrocracking of Israeli shale oil: III. Hydrocracking of hydrotreated shale oil and its atmospheric residue for full conversion to motor fuels. Fuel 1998, 77(14), 1589–1597.

59. Luik, H., Lindaru, E., Vink, N., Maripuu, L. Upgrading of Estonian shale oil distillation fractions. 1. Hydrogenation of the “diesel fraction”. Oil Shale, 1999, 16(2), 141–148.

60. Luik, H., Vink, N., Lindaru, E., Maripuu, L. Upgrading of Estonian shale oil distillation fractions. 2. The effect of time and hydrogen pressure on the yield and composition of “diesel fraction” hydrogenation products. Oil Shale, 1999, 16(3), 249–256.

61. Luik, H., Maripuu, L., Vink, N., Lindaru, E. Upgrading of Estonian shale oil distillation fractions. 3. Hydrogenation of light mazute. Oil Shale, 1999, 16(4), 331–336.

62. Luik, H., Maripuu, L., Vink, N., Lindaru, E. Upgrading of Estonian shale oil distillation fractions. 4. The effect of time and hydrogen pressure on the yield and composition of light mazute hydrogenation products. Oil Shale, 1999, 16(4), 337–342.

63. Luik, H., Vink, N., Lindaru, E., Maripuu, L. Upgrading of Estonian shale oil distillation fractions. 5. Hydrogenation of heavy mazute. Oil Shale, 2000, 17(1), 25–30.

64. Luik, H., Vink, N., Maripuu, L., Lindaru, E. Upgrading of Estonian shale oil distillation fractions. 6. The effect of time and temperature on the yield and composition of heavy mazute hydrogenation products. Oil Shale, 2000, 17(1), 31–36.

65. Luik, H., Luik, L., Johannes, I., Tiikma, L., Vink, N., Palu, V., Bitjukov, M., Tamvelius, H., Krasulina, J., Kruusement, K., Nechaev, I. Upgrading of Estonian shale oil heavy residuum bituminous fraction by catalytic hydroconversion. Fuel Process. Technol., 2014, 124, 115–122.

66. Harvey, T. G., Matheson, T. W., Pratt, K. C., Stanborough, M. S. Studies of the batch hydrotreatment of Rundle shale oil. Fuel, 1985, 64(7), 925–930.

67. Benyamna, A., Bennouna, C., Moreau, C., Geneste, P. Upgrading of distillate fractions of Timahdit Moroccan shale oil over a sulphided NiO-MoO3γ-Al2O3 catalyst. Fuel, 1991, 70(7), 845–848.

68. Yoshida, R., Miyazawa, M., Yoshida, T., Narita, H., Maekawa, Y. Chemical structure changes in Condor shale oil and catalytic activities during catalytic hydrotreatment. Fuel, 1996, 75(1), 99–102.

69. Curtin, D. J., Dearth, J. D., Everett, G. L., Grosboll, M. P., Myers, G. A. Arsenic and nitrogen removal during shale oil upgrading. Am. Chem. Soc., Div. Fuel Chem., Prepr., 1978, 23(4), 18–29.

70. Che, S. C., Madgavkar, A. Upgrading Shale Oil by a Combination Process. US4623444 A, 1986.

71. Madgavkar, A. Upgrading Shale Oil by a Combination Process. US4605489 A, 1986.

72. Kunesh, J. G. Hydrocracking and Hydrotreating Shale Oil in Multiple Catalytic Reactors. US4344840 A, 1982.

73. Hayashi, M., Kohno, F., Masuda, T., Shinoda, N., Shimada, T., Kaneko, M., Fujita, H., Ohmoto, S. Upgrading of shale oil by ebullated-bed reactor. In: Proceedings of the International Conference on Oil Shale and Shale Oil, Beijing, China, 1988, 478–485.

74. Hellwig, K. C., Feigelman, S., Alpert, S. B. Shale oil developments: Upgrading feeds by the H-Oil process. Chem. Eng. Prog., 1966, 62, 51–54.

75. Yu, H., Li, S., Jin, G. Catalytic hydrotreating of the diesel distillate from Fushun shale oil for the production of clean fuel. Energy Fuels, 2010, 24(8), 4419–4424.

76. Yu, H., Li, S., Jin, G. Hydrodesulfurization and hydrodenitrogenation of diesel distillate from Fushun shale oil. Oil Shale, 2010, 27(2), 126–134.

77. Chen, X., Shen, B., Sun, J., Wang, C., Shan, H., Yang, C., Li, C. Characterization and comparison of nitrogen compounds in hydrotreated and untreated shale oil by electrospray ionization (ESI) Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). Energy Fuels, 2012, 26(3), 1707–1714.

78. Chishti, H. M., Williams, P. T. Aromatic and hetero-aromatic compositional changes during catalytic hydrotreatment of shale oil. Fuel, 1999, 78(15), 1805–1815.

79. Chervenak, M. C., Johnson, C. A., Schuman, S. C. H-oil process treats wide range of oils. Petrol. Refiner, 1960, 39(10), 151–156.

80. Johnson, C. A., Ward, C., Moore, H. F., Hettinger, Jr. W. Combination Process for Upgrading Oil Products of Coal, Shale Oil and Crude Oil to Produce Jet Fuels, Diesel Fuels and Gasoline. US4409092 A, 1983.

81. Taylor, J. L., Hensley, A. L., Forgac, J. M., Tatterson, D. F. Oil Stabilization. US5059303 A, 1991.

82. Sullivan, R. F., Stangeland, B. E. Catalytic hydroprocessing of shale oil to produce distillate fuels. 174th Natl. Am. Chem. Soc. Symp., Chicago, 28 Aug. – 2 Sep., IL, USA, 1977.

83. Sullivan, R. F., Stangeland, B. E. Catalytic hydroprocessing of shale oil to produce distillate fuels. In: Refining of Synthetic Crudes, Adv. Chem., 179, American Chemical Society, 1979, 25–51.

84. Sullivan, R. F., Stangeland, B. E. Converting Green River shale oil to transportation fuels. In: 11th Oil Shale Symposium, Colorado School of Mines, 1978, 120–134.

85. Gorring, R. L., Smith, R. L. Upgrading Shale Oil. US4153540 A, 1979.

86. Thompson, L. F., Holmes, S. A. Effect of multistage hydroprocessing on aromatic and nitrogen compositions of shale oil. Fuel, 1985, 64(1), 9–14.

87. Zingarelli, J. A., Muradian, A., Stephenson, L. Upgrading of Stuart shale oil. Fuel, 1988, 67(10), 1408–1410.

88. Su, Z. S., Liu, P., Cai, L., Zhao, G. F. Hydrotreating of Fushun shale oil. Contemporary Chemical Industry, 2008, 37(3), 246–248 (in Chinese).

89. Williams, P. T., Chishti, H. M. Reaction of nitrogen and sulphur compounds during catalytic hydrotreatment of shale oil. Fuel, 2001, 80(7), 957–963.

90. Wasilk, N. J., Robinson, E. T. Commercial-scale refining of Paraho crude shale oil into military specification fuels. In: Oil Shale, Tar Sands, and Related Materials, ACS Sym. Ser., 163, 1981, 223–235.

91. Afonso, J. C., Schmal, M., Cardoso, J. N., Frety, R. Hydrotreatment of Irati shale oil: behavior of the aromatic fraction. Ind. Eng. Chem. Res., 1991, 30(9), 2133–2137.

92. Bludis, J. A., Lyzinski, D., McKinney, J. D., Sebulsky, R. T., Stauffer, H. C. Hydrodenitrogenation of Shale Oil Using Two Catalysts in Series Reactors. US4022682 A, 1977.

93. Lovell, P. F., Fryback, M. G., Reif, H. E., Schwedock, J. P. Maximize shale oil gasoline. Hydrocarb. Process., 1981, 60(5), 125–130.

94. Robinson, E. T. Refining of Paraho shale oil into military specification fuels. In: 108th AIME Annual Meething, New Orleans, Louisiana, 1979.

95. Hoog, H., Koome, J., Weeda, K. A. Hydrofining and cracking-hydrofining of Colorado shale oil. In: Proceedings of the Second Oil Shale and Cannel Coal Conference, Glasgow, 1950. The Institute of Petroleum, London, WI, USA, 1951, 562–570.

96. Laine, J., Trimm, D. L. Conversion of heavy oils into more desirable feedstocks. J. Chem. Technol. Biot., 1982, 32(7–12), 813–833.

97. Cawley, C. M. The properties of “diesel” oils prepared from low-temperature tar, cannel tar, and Kimmeridge shale tar. Fuel, 1944, 23, 19–22.

98. Cawley, C. M., Kingman, F. E. T. Hydrogenation of Kimmeridge shale tar. Fuel, 1944, 23, 4–8.

99. MacDougall, D., Cawley, C. M. Recovery and treatment of oil from shale from the Kimmeridge area, Dorset, England. In: Proceedings of the SecondOil Shale and Cannel Coal Conference, Glasgow, 1950. The Institute of Petroleum, London, WI, USA, 1951, 440–448.

100. Reed, H., Berg, C., Multer, H. Retorting and refining of shale oil, Union Oil Co. of California. In: Colorado Mining Association Conference, Denver, Colorado, 1949.

101. Enkhjargal, G., Enkhsaruul, B., Monkhoobor, D., Narangerel, J., Yoshikazu, S. Characterization and hydrotreatment of shale oils of Mongolian oil shales. Oil Shale, 2018, 35(2), 168–182.

102. Aljariri Alhesan, J. S., Marshall, M., Jackson, W. R., Cassidy, P. J., Chaffee, A. L. Catalytic hydropyrolysis of El-Lajjun and Julia Creek shale oils using flow-through and sealed autoclaves. J. Anal. Appl. Pyrol., 2019, 143, 104682.

103. Bej, S. K., Dalai, A. K., Adjaye, J. Kinetics of hydrodesulfurization of heavy gas oil derived from oil-sands bitumen. Petrol. Sci. Technol., 2002, 20(7–8), 867–877.

104. Tang, X., Li, S., Yue, C., He, J., Hou, J. Lumping kinetics of hydrodesulfurization and hydrodenitrogenation of the middle distillate from Chinese shale oil. Oil Shale, 2013, 30(4), 517–535.

105. Shamsi, A. Study of eastern and western oil shale mineral activity for hydrodesulfurization reactions. Ind. Eng. Chem. Res., 1990, 29(7), 1466–1470.

106. U.S. Energy Information Administration (EIA). Today in Energy. Coking is a refinery process that produces 19% of finished petroleum product exports, January 28, 2013.

107. Egloff, G., Walter, J. F., Grote, H. W., Davis, R. F. Cracking Colorado shale oils. In: Proceedings of the Second Oil Shale and Cannel Coal Conference, Glasgow, 1950. The Institute of Petroleum, London, WI, USA, 1951, 533–561.

108. Chi, Y., Li, S., Li, X. Study on shale oil diesel refining. Oil Shale, 2005, 22(3), 359–366.

109. Han, D. Y., Li, G. X., Cao, Z. B., Zhai, X. Y., Yuan, M. M. A Study on the denitrogenation of Fushun shale oil. Energ. Source. Part A, 2013, 35(7), 622–628.

110. Choi, H. W., Dines, M. B. Selective removal of nitrogen compounds from shale oil. Fuel, 1985, 64(1), 4–8.

111. Narangerel, J., Sugimoto, Y. Removal of nitrogen compounds before deep hydrotreatment of synthetic crude oils. J. Jpn. Petrol. Inst., 2008, 51(3), 165–173.

112. Rayner-Canham, G. W., Dickerhoof, D. W. Elucidation of the iron chloride-clay system for removal of nitrogen-containing compounds from petroleum and shale-oil distillates. Fuel, 1984, 63(10), 1472–1474.

113. VKG. Phenols and Phenol Products. n.d.

114. Zelenin, N. I., Vassiliev, M. L. Oil shale phenols and ways of their utilization. In: United Nations Symposium on the Development and Utilization of Oil Shale Resources, section 111, Tallinn, August 26 – September 4, 1968, Estonia, 1968.

115.  Maloletnev, A. S., Naumov, K. I., Shvedov, I. M., Mazneva, O. A. Shale hydrogenation. Solid Fuel Chem+., 2011, 45, 316–321.

116. Klesment, I., Nappa, L., Vink, N. Results of low-temperature destructive hydrogenation of Estonian kukersite kerogen concentrate. Khimiya Tverdogo Topliva, 1979, 33–39 (in Russian).

117. Tippin, R. B., Rex, R. C. Combined beneficiation and hydroretorting of oil shale. In: Symposium on Chemistry and Processing Supercritical Fluids, 1985, San Francisco, 237–246.

118. Krichko, A. Hydrogenation of oil shale and polymers. Oil Shale, 2000, 17(3), 271–285.

119. Abbasian, J., Rue, D. M., Lau, F. S. In-bed sulphur capture during pressurized fluidized-bed hydroretorting of Eastern oil shales. Fuel, 1991, 70(11), 1342–1346.

120. McCollum, J. D., Quick, L. M. Process for Recovering and Upgrading Hydrocarbons from Oil Shale and Tar Sands. US3948755 A, 1976.

121. McCollum, J. D., Quick, L. M. Process for Recovering and Upgrading Hydrocarbons from Oil Shale. US4151068 A, 1979.

122. Slater, W. L. Recovery of Oil from Oil Shale by Underground Hydrogenation. US3084919 A, 1963.

123. Forgac, J. M., Hoekstra, G. R. Pulsed in Situ Retorting in an Array of Oil Shale Retorts. US4552214 A, 1985.

124. Krasulina, J. Catalytic Hydrogenation of Liquids from Estonian Kukersite Oil Shale: Upgrading of liquid products from Estonian kukersite oil shale by catalytic hydrogenation. TUT Press, Tallinn, 2015.

125. Rembashevskii, A. G., Proskuryakov, V. A. Za Ekonomiyu Topliva, 1951, (12), 14.

126. Rollmann, L. D. Catalytic hydrogenation of model nitrogen, sulfur, and oxygen compounds. J. Catal., 1977, 46(3), 243–252.

127. McIlvried, H. G. Kinetics of the hydrodenitrification of pyridine. Ind. Eng. Chem. Proc. Des. Dev., 1971, 10(1), 125–130.

128. Katzer, J. R., Sivasubramanian, R. Process and catalyst needs for hydrodenitrogenation. Catal. Rev., 1979, 20(2), 155–208.

129. Girgis, M. J., Gates, B. C. Reactivities, reaction networks, and kinetics in high-pressure catalytic hydroprocessing. Ind. Eng. Chem. Res., 1991, 30(9), 2021–2058.

130. Benson, D. B. Catalytic hydrotreating of shale oil. [HF-activated Co molybdate was best of 12 catalysts]. Chem. Eng. Prog. (United States), 1966, 62(8), 61–67.


Back to Issue