The world energy mix has been confronted with significant challenges since the international circumstances became increasingly complicated. Oil shale is a typical alternative resource to traditional oil, therefore, it is of great significance to re-evaluate its exploitation and utilization status and research trend under the new background. Through the bibliometric analysis of 944 articles on oil shale published between 2012 and 2022 collected from the Web of Science (WoS) database, this research has carried out a review on the global publication and research trend in oil shale relevant studies. It then investigated and compared the research characteristics in three major countries that carry out oil shale related research, to identify the opportunities of oil shale development in different nations under the restriction of diversified factors. The results show that during the last ten years, research on oil shale has experienced a continuous growth in publication quantity and greatly contributed to the oil shale development with the production of highest cited studies. As for the regional characteristics, Estonia focuses on the comprehensive utilization of oil shale and stands out in its engagement in the environment protection, while China and the United States are still accumulating the applied technological research and fundamental science knowledge and conservatively develop the utilization of oil shale. Although different regions have developed different research priorities and strategies due to the differentiated resource reserve, technical condition and environmental pressure, the environment-friendly and efficient utilization of oil shale resource will be the future emphasis of the oil shale development.
1. Al-Ayed, O. S., Hajarat, R. A. Shale oil: Its present role in the world energy mix. Glob. J. Energy Technol. Res. Updates, 2018, 5(1), 11‒18.
https://doi.org/10.15377/2409-5818.2018.05.2
2. Liu, Z. J., Meng, Q. T., Dong, Q. S., Zhu, J. W., Guo, W., Ye, S. Q., Liu, R., Jia, J. L. Characteristics and resource potential of oil shale in China. Oil Shale, 2017, 34(1), 15‒41.
https://doi.org/10.3176/oil.2017.1.02
3. Dyni, J. R. Geology and resources of some world oil-shale deposits. Oil Shale, 2003, 20(3), 193‒252.
https://doi.org/10.3176/oil.2003.3.02
4. Russell, P. L. Oil Shales of the World, Their Origin, Occurrence, and Exploitation. Pergamon Press, Beijing, 1990, 1‒20.
5. Talumaa, R. Oil shale power prevails in Estonia. Oil Shale, 2005, 22(2S), 93‒94.
https://doi.org/10.3176/oil.2005.2S.01
6. Jiang, S., Xu, Z. Y., Feng, Y. L., Zhang, J. C., Cai, D. S., Chen, L., Wu, Y., Zhou, D. S., Bao, S. J., Long, S. X. Geologic characteristics of hydrocarbon-bearing marine, transitional and lacustrine shales in China. J. Asian Earth Sci., 2016, 115, 404‒418.
https://doi.org/10.1016/j.jseaes.2015.10.016
7. Han, X. X., Kulaots, I., Jiang, X. M., Suuberg, E. M. Review of oil shale semicoke and its combustion utilization. Fuel, 2014, 126, 143‒161.
https://doi.org/10.1016/j.fuel.2014.02.045
8. Brendow, K. Global oil shale issues and perspectives. Oil Shale, 2003, 20(1), 81‒92.
https://doi.org/10.3176/oil.2003.1.09
9. Guo, H. F., Yang, Y. D., Wang, K. K., Pei, Y. S., Wu, Q. C., Liu, Y. Y. Strengthening the applicability of self-heating retorting process to oil shale via co-retorting. Fuel, 2015, 143(3), 1‒8.
https://doi.org/10.1016/j.fuel.2014.11.009
10. Gavrilova, O., Vilu, R., Vallner, L. A life cycle environmental impact assessment of oil shale produced and consumed in Estonia. Resour. Conserv. Recycl., 2011, 55(2), 232‒245.
https://doi.org/10.1016/j.resconrec.2010.09.013
11. Jiang, X. M., Han, X. X., Cui, Z. G. Progress and recent utilization trends in combustion of Chinese oil shale. Prog. Energy Combust. Sci., 2007, 33(6), 552‒579.
https://doi.org/10.1016/j.pecs.2006.06.002
12. Xu, Y., Sun, P., Yao, S., Liu, Z., Tian, X., Li, F., Zhang, J. Progress in exploration, development and utilization of oil shale in China. Oil Shale, 2019, 36(2), 285‒304.
https://doi.org/10.3176/oil.2019.2.03
13. York, R. Do alternative energy sources displace fossil fuels? Nat. Climate Change, 2012, 2(6), 441‒443.
https://doi.org/10.1038/nclimate1451
14. Lackner, K. S. Comparative impacts of fossil fuels and alternative energy sources. In: Carbon Capture: Sequestration and Storage (Hester, R. E., Harrison, R. M., eds.), Issues in Environmental Science and Technology. Royal Society of Chemistry, UK, 2009, 1‒40.
https://doi.org/10.1039/9781847559715-00001
15. Alpern, B., Lemos de Sousa, M. J. Documented international enquiry on solid sedimentary fossil fuels; coal: definitions, classifications, reserves-resources, and energy potential. Int. J. Coal Geol., 2002, 50(1‒4), 3‒41.
https://doi.org/10.1016/S0166-5162(02)00112-X
16. Pakulska, T. Green energy in central and eastern European (CEE) countries: New challenges on the path to sustainable development. Energies, 2021, 14(4), 884.
https://doi.org/10.3390/en14040884
17. Alaloul, W. S., Al Salaheen, M., Malkawi, A. B., Alzubi, K., Al-Sabaeei, A. M., Musarat, M. A. Utilizing of oil shale ash as a construction material: A systematic review. Constr. Build. Mater., 2021, 299(9), 123844.
https://doi.org/10.1016/j.conbuildmat.2021.123844
18. Kang, Z. Q., Zhao, Y. S., Yang, D. Review of oil shale in-situ conversion technology. Appl. Energy, 2020, 269(7), 115121.
https://doi.org/10.1016/j.apenergy.2020.115121
19. Avvaru, B., Venkateswaran, N., Uppara, P., Iyengar, S. B., Katti, S. S. Current knowledge and potential applications of cavitation technologies for the petroleum industry. Ultrason. Sonochem., 2018, 42(4), 493‒507.
https://doi.org/10.1016/j.ultsonch.2017.12.010
20. Pan, Y., Zhang, X. M., Liu, S. H., Yang, S. C., Ren, N. A Review on Technologies for Oil Shale Surface Retort. J. Chem. Soc. Pak., 2012, 34(6), 1331–1338.
21. Aarna, I. Developments in production of synthetic fuels out of Estonian oil shale. Energy Environ., 2011, 22(5S), 541‒552.
https://doi.org/10.1260/0958-305X.22.5.541
22. Tiwari, P., Deo, M., Lin, C. L., Miller, J. D. Characterization of oil shale pore structure before and after pyrolysis by using X‒ray micro CT. Fuel, 2013, 107, 547‒554.
https://doi.org/10.1016/j.fuel.2013.01.006
23. Jiang, X. M., Han, X. X., Cui, Z. G. New technology for the comprehensive utilization of Chinese oil shale resources. Energy, 2007, 32(5), 727‒777.
https://doi.org/10.1016/j.energy.2006.05.001
24. Petersen, H. I., Rosenberg, P., Nytoft, H. P. Oxygen groups in coals and alginite-rich kerogen revisited. Int. J. Coal Geol., 2008, 74(2), 93‒113.
https://doi.org/10.1016/j.coal.2007.11.007
25. Yan, J. W., Jiang, X. M., Han, X. X., Liu, J. G. A TG‒FTIR investigation to the catalytic effect of mineral matrix in oil shale on the pyrolysis and combustion of kerogen. Fuel, 2013, 104, 307‒317.
https://doi.org/10.1016/j.fuel.2012.10.024
26. Qian, T. T., Li, J. H., Ma, H. W., Yang, J. The preparation of a green shape-stabilized composite phase change material of polyethylene glycol/SiO2 with enhanced thermal performance based on oil shale ash via temperature-assisted sol‒gel method. Sol. Energy Mater. Sol. Cells, 2015, 132, 29‒39.
https://doi.org/10.1016/j.solmat.2014.08.017
27. Saif, T., Lin, Q. Y., Butcher, A. R., Bijeljic, B., Blunt, M. J. Multi-scale multi-dimensional microstructure imaging of oil shale pyrolysis using X-ray micro-tomography, automated ultra-high resolution SEM, MAPS Mineralogy and FIB-SEM. Appl. Energy, 2017, 202, 628‒647.
https://doi.org/10.1016/j.apenergy.2017.05.039
28. Shawabkeh, R., Al-Harahsheh, A., Hami, M., Khlaifat, A. Conversion of oil shale ash into zeolite for cadmium and lead removal from wastewater. Fuel, 2004, 83(7‒8), 981‒985.
https://doi.org/10.1016/j.fuel.2003.10.009
29. Williams, P. T., Ahmad, N. Investigation of oil-shale pyrolysis processing conditions using thermogravimetric analysis. Appl. Energy, 2000, 66(2), 113‒133.
https://doi.org/10.1016/S0306-2619(99)00038-0
30. Jaber, J. O., Probert, S. D. Non-isothermal thermogravimetry and decomposition kinetics of two Jordanian oil shales under different processing conditions. Fuel Process. Technol., 2000, 63(1), 57‒70.
https://doi.org/10.1016/S0378-3820(99)00064-8
31. Sun, L., Tuo, J. C., Zhang, M. F., Wu, C. J., Wang, Z. X., Zheng, Y. W. Formation and development of the pore structure in Chang 7 member oil-shale from Ordos Basin during organic matter evolution induced by hydrous pyrolysis. Fuel, 2015, 158, 549‒557.
https://doi.org/10.1016/j.fuel.2015.05.061
32. Cui, G. D., Niu, Z., Zhao, D. F., Kong, Y. L., Feng, B. High-temperature hydrothermal resource exploration and development: Comparison with oil & gas resource. Gondwana Res., 2022, in press.
https://doi.org/10.1016/j.gr.2022.09.015
33. Kalm, V. The research published in Oil Shale: How it looks in bibliometric indicators. Oil Shale, 2011, 28(4), 467‒468.
https://doi.org/10.3176/oil.2011.4.01
34. Lauk, K. Bibliometrical analysis of research published in Oil Shale. Oil Shale, 2016, 33(3), 290‒297.
https://doi.org/10.3176/oil.2016.3.07
35. Tanavsuu-Milkeviciene, K., Sarg, J. F., Bartov, Y. Depositional cycles and sequen—ces in an organic-rich lake basin: Eocene Green River formation, Lake Uinta, Colorado and Utah, U.S.A. J. Sediment. Res., 2017, 87(3), 210‒229.
https://doi.org/10.2110/jsr.2017.11
36. Yefimov, V. Oil shale processing in Estonia and Russia. Oil Shale, 2000, 17(4), 367‒385.
https://doi.org/10.3176/oil.2000.4.08
37. Lund, H., Hvelplund, F., Ingermann, K., Kask, Ü. Estonian energy system – Proposals for the implementation of a cogeneration strategy. Energy Policy, 2000, 28(10), 729‒736.
https://doi.org/10.1016/S0301-4215(00)00048-3
38. Raukas, A., Punning, J.-M. Environmental problems in the Estonian oil shale industry. Energy Environ. Sci., 2009, 2(7), 723‒728.
https://doi.org/10.1039/b819315k
39. Yan, F., Song, Y. Properties estimation of main oil shale in China. Energ. Source Part A. 2009, 31(4), 372‒376.
https://doi.org/10.1080/15567030701530347
40. Zhao, D., Guo, Y., Wang, G., Guan, X., Zhou, X., Liu, J. Fractal analysis and classification of pore structures of high-rank coal in Qinshui Basin, China. Energies, 2022, 15(18), 6766.
https://doi.org/10.3390/en15186766
41. Wang, H., Ma, F., Tong, X., Liu, Z., Zhang, X., Wu, Z., Li, D., Wang, B., Xie, Y., Yang, L. Assessment of global unconventional oil and gas resources. Pet. Explor. Dev., 2016, 43(6), 925‒940.
https://doi.org/10.1016/S1876-3804(16)30111-2
42. Zhao, D., Yin, S., Guo, Y., Ren, C., Wang, R., Ding, W., Liu, J. Investigation of pore structure characteristics of marine organic-rich shales using low-pressure N2 adsorption experiments and fractal theory. Interpretation ‒ A Journal of Subsurface Characterization, 2019, 7(3), 671‒685.
https://doi.org/10.1190/INT-2018-0191.1
43. Lin, B., Xu, B. How does fossil energy abundance affect China´s economic growth and CO2 emissions? Sci. Total Environ., 2020, 719(2), 137503.
https://doi.org/10.1016/j.scitotenv.2020.137503
