Study On Properties And Pyrolysis Of Xinjiang Oil Sand And Its Fractions

With the growing demand for energy in the world,oil resources are becoming less and less.oil sand is an unconventional oil resource and its reserves is very rich.It is due to high economic value and energy strategic significance that oil sand attracts more and more people's attention.At present,China's oil sand mining and separation technology are still relatively difficult to achieve the large-scale industrial production of oil bitumen.In this paper,Xinjiang oil sand was chosen as the main research object,Indonesia and Inner Mongolia oil sands as a supplement.The properties and the pyrolysis characteristics of Xinjiang oil sand were studied.The extraction ability of three solvents(toluene,chloroform and petroleum ether)to oil sand was investigated,and the properties of oil sand bitumen obtained by different solvent extraction were analyzed.Systematic study was performed on the wettability of oil sands from the composition of mineral oil,the organic matter on the surface of minerals,the particle size and the contact angle.Further stuty was about the change of Zeta potential of sediment and asphalt surface in Xinjiang oil sand under different conditions.Finally,The thermal analysis of Xinjiang oil sands,three Xinjiang oil sands bitumen and sediment were studied.The pyrolysis kinetic parameters of Xinjiang oil sands were calculated by CR method.The results showed that using chloroform extraction can more accurately determine the oil content in oil sands and evaluate the grade of oil sands better.The oil content of Xinjiang oil sands measured by chloroform is 13.40%,which belongs to oil sand rich ore.Three kinds of oil sand bitumen were extracted from three different solvents including Toluene,chloroform and petroleum ether,and the three solvent extraction capacity was obtained: chloroform> toluene> petroleum ether.In the extraction process,chloroform showed a stronger extraction ability of the colloid and asphaltene,which hetero atom content and the molecular weight was bigger.However,petroleum ether could hardly extract asphaltene from oil sand.The solid mineral composition of the Xinjiang oil sand similar to the Inner Mongolia oil sand,contains mainly both quartz and feldspar.The Xinjiang oil sand sediment had large particle size.Using XPS analysis,the insoluble organic matter in the sediment of Xinjiang oil sand was found to be mainly composed of carbonyl carbon and organic matter.And these organic matter will have an important influence on the wettability of oil sands.The contact angle of sediment water contact in Xinjiang oil sand is less than 90°.It belongs to hydrophilic oil sand,but its hydrophilicity is smaller than Inner Mongolia oil sand.In this study,the type and concentration of electrolyte,pH value and surfactant can affect the surface electrification of oil sand asphalt and sediment.The change of Zeta potential was analyzed by using ion surface group and double layer theory.The pyrolysis process of Xinjiang oil sands was divided into three stages,and the second stage is the main oil production stage of oil sand asphalt.The activation energy of volatile section of light oil is less than that of heavy oil cracking by CR method.Asphalt with high asphaltene content has high coke formation rate and highest thermal stability.