EFFECT OF RESIDENCE TIME ON PRODUCTS YIELD AND CHARACTERISTICS OF SHALE OIL AND GASES PRODUCED BY LOW-TEMPERATURE RETORTING OF DACHENGZI OIL SHALE; pp. 501–516Full article in PDF format | doi: 10.3176/oil.2013.4.04
Oil shale samples from Dachengzi mine located in Huadian city, Jilin province, China, were retorted in a stainless-steel cylindrical retort under argon atmosphere to determine the influence of residence time on the products yield and characteristics of shale oil and gases. It was found that the liquid yield increased with increasing residence time from 6 to 40 min, and then leveled off as the residence time further increased. The gases yield also increased with increasing residence time, while the shale char yield decreased. When prolonging the residence time from 6 to 60 min, the atomic H/C ratio of the derived shale oils decreased from 2.007 to 1.768, both the oxygen and sulfur content also decreased, while the nitrogen content slightly increased. It was also noticed that high boiling point oils were produced in the initial stage of the retorting process and low boiling point oils in its later stages. The shale oil obtained in 20 min had the lowest quantity of heavy fractions, 52.8 wt%, whilst the shale oils produced in 40 and 60 min showed similar boiling point distribution. The produced shale oils had similar atomic H/C ratio and lower heavy oil content compared to crude oils, and could be classified as sweet and high-nitrogen oil in terms of the classification method of crude oil. Extending the residence time decreased the aliphatics content and increased the aromatics content of the produced shale oil. When the residence time was 40 min, the derived oil contained the lowest amount of asphaltenes and the highest amount of non-hydrocarbons. Moreover, the produced gases contained maximum concentrations of C1–C4 gases (except propane) and had the lowest ethene/ethane ratio and the highest propene/propane and butene/butane ratios. The alkene/alkane gases ratio increased from 0.27 to 0.65 with increasing residence time from 6 to 60 min, which reflected the increasing secondary cracking reactions during a longer residence time.
1. BP Group. BP Statistical Review of World Energy June 2011 [R/OL]. http://www.bp.com/assets/bp_internet/globalbp/globalbp_uk_english/reports_and_publications/statistical_energy_review_2011/STAGING/local_assets/pdf/statistical_review_of_world_energy_full_report_2011.pdf.
2. IEA. World Energy Outlook 2010 Executive Summary. http:// www.worldenergyoutlook.org/ docs/weo2010/weo2010_es_english.pdf.
3. Na, J. G., Im, C. H., Chung, S. H., Lee, K. B. Effect of oil shale retorting temperature on shale oil yield and properties. Fuel, 2012, 95, 131–135.
4. El harfi, K., Mokhlisse, A., Ben Chanâa, M. Yields and composition of oil obtained by isothermal pyrolysis of the Moroccan (Tarfaya) oil shales with steam or nitrogen as carrier gas. J. Anal. Appl. Pyrol., 2000, 56(2), 207–218.
5. Dyni, J. R. Geology and resources of some world oil-shale deposits. Oil Shale, 2003, 20(3), 193–252.
6. Bauman, J. H., Deo, M. Simulation of a conceptualized combined pyrolysis, in situ combustion, and CO2 storage strategy for fuel production from Green River oil shale. Energ. Fuel., 2012, 26(3), 1731–1739.
7. 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.
8. Al-Ayed, O. S., Matouq, M., Anbar, Z., Khaleel, A. M., Abu-Nameh, E. Oil shale pyrolysis kinetics and variable activation energy principle. Appl. Energ., 2010, 87(4), 1269–1272.
9. Dung, N. V. Factors affecting product yields and oil quality during retorting of Stuart oil shale with recycled shale: a screening study. Fuel, 1995, 74(4), 623–627.
10. Dung, N. V. Yields and chemical characteristics of products from fluidized bed steam retorting of Condor and Stuart oil shales: effect of pyrolysis temperature. Fuel, 1990, 69(3), 368–376.
11. Solomon, P. R., Carangelo, R. M., Horn E. Effects of pyrolysis conditions on Israeli oil shale properties. Fuel, 1986, 65(5), 650–662.
12. Williams, P. T., Ahmad, N. Influence of process conditions on the pyrolysis of Pakistani oil shales. Fuel, 1999, 78(6), 653–662.
13. Han, X. X., Jiang, X. M., Cui, Z. G. Studies of the effect of retorting factors on the yield of shale oil for a new comprehensive utilization technology of oil shale. Appl. Energ., 2009, 86(11), 2381–2385.
14. Han, X. X., Jiang, X. M., Cui, Z. G., Liu, J. G., Yan, J. W. Effects of retorting factors on combustion properties of shale char. 3. Distribution of residual organic matters. J. Hazard. Mater., 2010, 175(1-3), 445–451.
15. Al-Harahsheh, A., Al-Ayed, O., Al-Harahsheh, M., Abu-El-Halawah, R. Heating rate effect on fractional yield and composition of oil retorted from El-lajjun oil shale. J. Anal. Appl. Pyrol., 2010, 89(2), 239–243.
16. Jaber, J. O., Probert, S. D., Williams, P. T. Evaluation of oil yield from Jordanian oil shales. Energy, 1999, 24(9), 761–781.
17. Nazzal, J. M. The influence of grain size on the products yield and shale oil composition from the Pyrolysis of Sultani oil shale. Energ. Convers. Manage., 2008, 49(11), 3278–3286.
18. Hurst, H. J., Levy, J. H., Patterson, J. H. Siderite decomposition in retorting atmospheres. Fuel, 1993, 72(6), 885–890.
19. Charlesworth, J. M. Oil shale pyrolysis. 1. Time and temperature dependence of product composition. Ind. Eng. Chem. Proc. Des. Dev., 1985, 24(4), 1117–1125.
20. Salhi, N., Bennouna, C., Bitar, H., Sergent, M., Luu, R. P. T. An experimental design to optimize pyrolysis conditions of Timahdit (Morocco) oil shale. Fuel, 1996, 75(5), 633–640.
21. 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.
22. Fassinou, W. F., Van De Steene, L., Toure, S., Volle, G., Girard, P. Pyrolysis of Pinus pinaster in a two-stage gasifier: Influence of processing parameters and thermal cracking of tar. Fuel Process. Technol., 2009, 90(1), 75–90.
23. Abnisa, F., Wan Daud, W. M. A., Husin, W. N. W., Sahu, J. N. Utilization possibilities of palm shell as a source of biomass energy in Malaysia by producing bio-oil in pyrolysis process. Biomass Bioenerg., 2011, 35(5), 1863–1872.
24. López, A., De Marco, I., Caballero, B. M., Laresgoiti, M. F., Adrados, A. Influence of time and temperature on pyrolysis of plastic wastes in a semi-batch reactor. Chem. Eng. J., 2011, 173(1), 62–71.
25. Nazzal, J. M. Influence of heating rate on the pyrolysis of Jordan oil shale. J. Anal. Appl. Pyrol., 2002, 62(2), 225–238.
26. Nazzal, J. M. The presence of polycyclic aromatic hydrocarbons (PAH) in oil obtained at pyrolysis of Jordan oil shale. Oil Shale, 2007, 24(3), 465–475.
27. Williams, P. T., Nazzal, J. M. Polycyclic aromatic compounds in shale oils: influence of process conditions. Environ. Technol., 1998, 19(8), 775–787.
28. Burnham, A. K. Chemistry of shale oil cracking. In Oil Shale, Tar Sands, and Related Materials (Stauffer, H. C., ed.). American Chemical Society Symposium Series, 1981, 163(Chap. 4), 39–60.
29. Lin, S. X. Petroleum Refining Engineering (Third Edition). Petroleum Industry Press, Beijing, 2000 (in Chinese).
30. Sun, Z. L. Evaluation and Analysis of Crude Oils. China Petrochemical Press, Beijing, 2005 (in Chinese).
31. Li, S. Q., Yao, Q., Chi, Y., Yan, J. H., Cen, K. F. Pilot-scale pyrolysis of scrap tires in a continuous rotary kiln reactor. Ind. Eng. Chem. Res., 2004, 43(17), 5133–5145.
32. Williams, P. F. V. Thermogravimetry and decomposition kinetics of British Kimmeridge Clay oil shale. Fuel, 1985, 64(4), 540–545.
34. Wallman, P. H., Tamm, P. W., Spars, B. G. Oil shale retorting kinetics. In Oil Shale, Tar Sand, and Related Materials (Stauffer, H. C., ed.). American Chemical Society Symposium Series, 1981, 163(Chap. 7), 93–113.
35. Trejo, F., Ancheyta, J., Centeno, G., Marroquín, G. Effect of hydrotreating conditions on Maya asphaltenes composition and structural parameters. Catal. Today, 2005, 109(1-4), 178–184.
36. Ancheyta, J., Centeno, G., Trejo, F., Marroquín, G. Changes in asphaltene properties during hydrotreating of heavy crudes. Energy Fuels, 2003, 17(5), 1233–1238.
Back to Issue