Hot Water Extraction And Pyrolysis Of Zhalaiteqi Oil Sands

Oil sand, which can be called tar sand, is a sedimentary rock containing bitumen (solid or semi-solid phase) or other heavy oil, sand, water, mineral matter and clays. Zhalaiteqi oil sand of Inner Mongolia is much like black molasses, and its maximum oil content reaches to 10-13%, which is high enough in such a oil shortage age. However, the oil sand study in China is just in the primary stage, it is of great significance to select a feasible oil recovery technology for the future industrialization.Hot water extraction with aliki and fixed-bed pyrolysis of Zhalaiteqi oil sand are investigated. In the hot water extraction experiment, the effect of temperature, alkali concentration and the ratio of water to oil sand on the extraction yield have been studied. In the pyrolysis experiment, temperature, time, flow rate of carrier gas and pressure are identified as parameters for oil recovery in both nitrogen and hydrogen atmosphere, oil yield is especially investigated with those parameters varies. In addition, the hot water extraction-derived oil, pyrolysis-derived oil, gas and char are analyzed contrastively as well.The result of hot water extraction shows a maximum oil recovery of 94.85% for No.2 oil sand and 85.71% for No.6 oil sand on the condition of 90°C, 0.3% alkali concentration, 1:1 ratio of water to oil sand, as the extraction time is 90min and 60min respectively. However, the performance of No.6 oil sand in the hot water extraction process is not very well.The fixed-bed pyrolysis result shows higher oil yields under atmospheric pressure in N2 atmosphere. The preferable temperature is 540℃ for No.2 oil sand and 560℃ for No.6 oil sand, The maximum oil yield of No.2 oil sand is 12.55%, and 7.18% of No.6 oil sand. In H2 atmosphere, 460℃ is the preferable temperature. The oil yield is higher than that of pyrolysis in N2 atmosphere. The maximum oil yield of No.2 oil sand is 11.51% and 9.13% in H2 and N2 atmosphere, and for No.6 oil sand, 5.80% is the maximum oil yield in H2 atmosphere, 4.38% in N2 atmosphere.The hot water extraction-derived oil has not been changed much compared to the original oil sand oil, but the pyrolysis-derived oil has been improved especially for No.2 oil sand, as the saturates and aromatics increased, resin decreased and no asphaltene detected. High oil yield can be obtained from No.2 oil sand by both the hot water extraction with alkali and fixed-bed pyrolysis, and the pyrolysis-derived oil is better than the extraction-derived oil. As for No.6 oil sand, the oil yield is a little lower, with large amount of fine clays in theextracted oil which can not be easily removed, therefore, hot water extraction is not suitable for No.6 oil sand.