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

Composition of gas from pyrolysis of Estonian oil shale with various sweep gases; pp. 215–227

Full article in PDF format | 10.3176/oil.2021.3.03

Sepehr Mozaffari, Oliver Järvik, Zachariah Steven Baird


Studying the evolution of gas during the decomposition process of oil shale provides information about the changes of its composition, as well as an understanding of the mechanism of the pyrolysis process. Earlier mainly the COatmosphere was used to observe the effect of the sweep gas on the production of pyrolysis products. In the current study, the Fischer assay method was used to analyze the pyrolysis of Estonian kukersite oil shale with CO2, CO2/steam, N2 and N2/steam sweep gases. The gaseous products were collected offline using a sample bag. Gas chromatography (GC) was performed to investigate the evolution of C1–C3gases, H2, CO2 and CO. Subsequently, the results from each test were analyzed and compared. It was shown that in comparison with N2, pyrolysis in CO2increased the production of alkanes and hydrocarbon (HC) gases. Also, the generation of CH4 and CO gases was enhanced with CO2, while the concentration of H2 in the pyrolysis gas did not significantly change with either environment. The tests carried out in the presence of steam showed that unlike the N2 atmosphere, CO2/steam decreased the production of total hydrocarbons, H2, CO2 and CO.


1. Wang, S., Liu, J., Jiang, X. Han, X., Tong, J. Effect of heating rate on products yield and characteristics of non-condensable gases and shale oil obtained by retorting Dachengzi oil shale. Oil Shale, 2013, 30(1), 27–47.

2. Wang, S., Jiang, X., Han, X., Tong, J. Effect of residence time on products yield and characteristics of shale oil and gases produced by low-temperature retorting of Dachengzi oil shale. Oil Shale, 2013, 30(4), 501–516.

3. Baird, Z. S., Uusi-Kyyny, P., Järvik, O., Oja, V., Alopaeus, V. Temperature and pressure dependence of density of a shale oil and derived thermodynamic properties. Ind. Eng. Chem. Res., 2018, 57(14), 5128–5135.

4. Ristic, N. D., Djokic, M. R., Konist, A., Van Geem, K. M., Marin, G. B. Quantitative compositional analysis of Estonian shale oil using comprehensive two dimensional gas chromatography. Fuel Process. Technol., 2017, 167, 241–249.

5. Mozaffari, P., Järvik, O., Baird, Z. S. Vapor pressures of phenolic compounds found in pyrolysis oil. J. Chem. Eng. Data, 2020, 65(11), 5559–5566.

6. Mozaffari, P., Baird, Z. S., Listak, M., Oja, V. Vapor pressures of narrow gasoline fractions of oil from industrial retorting of Kukersite oil shale. Oil Shale, 2020, 37(4), 288–303.

7. Coburn, T. T. Eastern oil shale retorting: Gas evolution during pyrolysis of northeastern Kentucky shales. Energ. Source., 1983, 7(2), 121–150.

8. Campbell, J. H., Koskinas, G. J., Gallegos, G., Gregg, M. Gas evolution during oil shale pyrolysis. 1. Nonisothermal rate measurements. Fuel, 1980, 59(10), 718–726.

9. Williams, P. T., Nazzal, J. M. Polycyclic aromatic compounds in shale oils: Influence of process conditions. Environ. Technol. (United Kingdom), 1998, 19(8), 775–787.

10. Wang, S., Jiang, X., Han, X., Tong, J. Effect of retorting temperature on product yield and characteristics of non-condensable gases and shale oil obtained by retorting Huadian oil shales. Fuel Process. Technol., 2014, 121, 9–15.

11. Williams, P. T., Ahmad, N. Influence of process conditions on the pyrolysis of Pakistani oil shales. Fuel, 1999, 78(6), 653–662.

12. Nazzal, J. M. Gas evolution from the pyrolysis of Jordan oil shale in a fixed-bed reactor. J. Therm. Anal. Calorim., 2001, 65(3), 847–857.

13. Williams, P. T., Nazzal, J. M. Polycyclic aromatic compounds in oils derived from the fluidised bed pyrolysis of oil shale. J. Anal. Appl. Pyrol., 1995, 35(2), 181–197.

14. Huss, E. B., Burnham, A. K. Gas evolution during pyrolysis of various Colorado oil shales. Fuel, 1982, 61(12), 1188–1196.

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