Study On Reaction Characteristics Of Residue Blending With Tail Oil From Co-Processing Of Coal And Heavy Oil

Because of China’s characteristics energy reserves which is rich coal,meager oil and less gas,the development and research of coal/heavy oil co-refining technology is of strategic significance for the rationalization of my country’s energy structure and solving the oil product gap.However,the tail oil from co-hydrogenation processing of coal and heavy oil reactions(COVR)is of high yield and the properties are poor,which is difficult to be further processed and utilized.In this paper,the chemical composition and properties of COVR were investigated,and the phase composition,morphology and content of the metallic compounds of toluene insoluble substance(COVR-Ti)separated from COVR were investigated in detail by means of XRD and XPS;the hydrothermal reaction behavior of Venezuelan atmospheric residue(MRAR)mixed with a certain proportion of COVR was investigated in a autoclave.The properties of asphaltene and toluene insoluble in MRAR system were investigated by XRD,XPS,FT-IR,HNMR and other methods;the toluene soluble compounds(COVR-Ts)in COVR were separated and mixed with MRAR,and Mo,Ni and Fe dispersed catalysts were added.The reaction performance of Mo-Ni and Fe-Ni catalysts with metal compounds in COVR as catalysts was investigated.The results showed that there were more organic hydrocarbon compounds in COVR,which had better hydrocracking potential,and the colloid and aromatic content were higher.COVR had high colloidal and aromatic content.The organic components of COVR-TI were mainly aromatic compounds,and the metallic compounds were mainly iron,nickel and molybdenum sulfides,which may have the catalytic activity of dispersed catalysts.When COVR and MRAR were blended in the absence of external catalyst,the yield of light oil,tail oil conversion rate asphaltene conversion were high.High reaction temperature will reduce the pitch of the product asphaltene aromatic sheets,increase the stacking height and the number of stacked layers,and increase the aromatic carbon content.Prolonging the reaction time was conducive to the conversion of asphaltene molecules,but it will cause the condensation and aggregation of asphaltenes.Therefore,the optimum technological conditions of blending reaction were as follows: the mixing ratio of COVR and MRAR is 1:1,the reaction temperature was 440℃,and the reaction time was 60 min.Under these conditions,the content of aromatic carbon in the asphaltene in the reaction products was low,the number of accumulation of aromatic lamellae was small,the size of toluene insoluble in the product was small,the dispersion degree was high,and there was a rough surface structure.Therefore,although the content of toluene insoluble in the reaction system was high,it was not easy to deposit in the bottom of the reactor.COVR-TS and MRAR were blended,and Fe-Ni and Mo-Ni catalysts were added,and the light oil yield,tail oil conversion and asphaltine conversion of the products were similar to those of COVR-MRAR reaction system,indicating that the metal compounds in COVR-TI had the ability to substitute catalysts for the blending system.Fe-Ni,Mo-Ni catalysts and metal compounds in Co VR-TI can shorten the side chains of asphaltenes in the blending system,reduce the degree of branched chains,and make it difficult to cross link polymerization.Meanwhile,it can improve the dispersion of toluene insoluble substances in the products,and inhibit the formation of coke to a certain extent.