Study On The Characteristics Of Shale Oil Under Dewaxing Conditions Before And After Dry Distillation Of Oil Shale

As an important unconventional energy source,shale oil is recognized as an alternative energy source for petroleum due to its abundant reserves,and its development and utilization have attracted more and more attention.However,because shale oil contains a large amount of shale wax,it has high density,poor fluidity,and inconvenient transportation and storage,which severely restricts the large-scale development and utilization of shale oil.In current industrial production,the process of shale oil processing and production of refined oil must go through a dewaxing process.The method is to directly remove shale wax from shale oil,which is complicated and difficult to achieve.The waxy component comes from the shale wax in the oil shale,so this topic proposes to dewax the oil shale before retorting to reduce the shale wax in the shale oil after retorting.This project uses two methods:oil shale dewaxing and shale oil dewaxing to achieve the purpose of removing shale wax in shale oil.The design test compares and analyzes the results of oil shale dewaxing and shale oil dewaxing.The influence of shale oil properties provides new ideas and data support for shale oil dewaxing process.The effects of dewaxing on the fuel characteristics and physical properties of oil shale are studied through experiments such as aluminum retort test,industrial analysis test,element analysis test,calorific value measurement,scanning electron microscopy test and specific surface area analysis of oil shale before and after dewaxing.The research results show that after oil shale dewaxing,the oil content decreases,the semi-coke yield decreases,and the non-condensable gas yield increases,and the mixed solvent dewaxing has a greater impact on the fuel characteristics of the oil shale than the single solvent dewaxing;The volatile content of the oil shale after waxing decreases,the moisture content decreases,and the ash content increases;the content of C,H,N,and S elements in the oil shale after dewaxing all decrease to a certain extent;the oil shale after dewaxing the calorific value is reduced to a certain extent;the oil shale pre-dewaxing increases the specific surface area and improves the pore structure,and the effect of mixed solvent dewaxing on the contrast surface area and pore structure is more significant;after dewaxing,the surface of the oil shale becomes roughly broken,uneven structure,cracks and micropores increased,and mixed solvent dewaxing has a deeper transformation and damage to oil shale.By comparing and analyzing the density,viscosity,freezing point,pour point and calorific value of shale oil obtained by different dewaxing methods and original shale oil,the influence of different dewaxing methods on the properties of shale oil is studied.The experimental results show that both pre-dewaxing and shale oil dewaxing methods can significantly reduce the density,viscosity,freezing point and pour point of shale oil,indicating that both dewaxing methods can change the properties of the oil.Good,and the effect of shale oil dewaxing is the best,and the effect of xylene dewaxing of oil shale is the worst.Oil shale pre-dewaxing and shale oil dewaxing have little effect on the calorific value of shale oil.The calorific value of shale oil is slightly reduced after dewaxing.The pre-dewaxing of oil shale makes dry distillation refining shale oil.Increased heat generation.Through GC-MS test of shale oil<300℃fraction,FT-IR test and liquid phase NMR test of shale oil>300℃fraction,the effects of two dewaxing methods on shale oil compound composition,functional group distribution and molecular The influence of structural parameters.Through the GC-MS test,it is found that due to the removal of shale wax,the content of alkane in the fraction of shale oil<300℃is significantly reduced,and the content of alkane is lower after the mixed solvent dewaxing,indicating that the shale wax removed from the oil shale is alkane compound Mainly;through the analysis of FT-IR spectrogram,it is found that dewaxing can shorten the average length of the fatty chain in the fraction of shale oil>300℃and increase the degree of isomerization.Among them,the fatty chain of the dewaxed oil of shale oil>300℃The average length is the shortest and the degree of isomerization is the highest;the influence of the two dewaxing methods on the molecular structure parameters of the shale oil fraction>300℃is studied by ¹H NMR and ¹³C NMR experiments,and it is found that different dewaxing methods have the effect of shortening the average length of aliphatic chains.Influence:shale oil dewaxing>mixed solvent predewaxing>single solvent xylene predewaxing.Through experimental research,this article found that dewaxing before dry distillation of oil shale can reduce the waxy components in shale oil to a certain extent,thereby improving the properties of shale oil,and the effect of mixed solvent dewaxing is better than single solvent dewaxing,but not as good as shale oil dewaxing.The microscopic mechanism of oil shale dewaxing and shale oil dewaxing to improve the oil properties of shale oil is that organic solvents remove long-chain alkane compounds,resulting in shortened aliphatic chain length and branching of fatty chains in shale oil the degree is elevated.