Study On Diffusion And Hydrogenation Kinetics Of Vanadium Enriched Components In Vacuum Residue

With the world’s crude oil is becoming heavier and worse,and the environmental standards are becoming stricter,the efficient use of crude oil and product the clean oil productions have become major challenges facing the current petroleum processing industry,which have also promoted residue hydrogenation technology.However,the metal vanadium compounds in the residue oil will cause serious problems in transportation,refining or product production,so hydrodevanadium technology has also received much attention.Due to the complex structure of the residual oil and the large differences in the nature of the components,the current research on residual oil as a raw material cannot form a unified conclusion.However,there are few studies on separation and enrichment of residual oil.This article takes Venezuela vacuum residue as the research object.First,according to the principle of similar compatibility,the solvents of different polarities are used for solvent extraction and column chromatography to separate the vacuum residues to form porphyrin vanadium enriched components and "non-porphyrin" vanadium enriched components.The results of separation and enrichment show that after separation and enrichment,porphyrin vanadium accounts for 16.10 wt%of the total vanadium element.It can be seen that the "non-porphyrin" vanadium accounts for most of the metal vanadium elements.The concentration of the vanadium-rich porphyrin vanadium component is 5156.09 μg/g,which is 17.3 times that of the raw material,and it is mainly concentrated in substances with polarities between 2.74 to 3.40.Then,the hydrogenation reaction behavior of vacuum residue,its porphyrin vanadium and "non-porphyrin" vanadium enriched components was explored,and the hydrogenation kinetic data of the three raw materials was obtained.The results show that the raw material vacuum residue follows the second-order reaction kinetics,while the porphyrin vanadium-rich components and "non-porphyrin" vanadium-rich components follow the first-order reaction kinetics.The apparent activation energy of the three raw materials is:vacuum residue>"non-porphyrin" vanadium enriched component>porphyrin vanadium enriched component.Under the same reaction conditions,the reaction rate constant is:porphyrin vanadium enriched components>"non-porphyrin" vanadium enriched components>vacuum residue.It can be seen that the porphyrin vanadium enrichment component has the best hydrogenation performance.FT-ICR MS analysis of the three raw materials and hydrogenation products was carried out.The structure of CnHmN4V1O1 porphyrin compounds was found in the products of the vacuum residue and the porphyrin vanadium enrichment components."After vanadium-rich components were hydrogenated,only a small amount of products were detected under mild conditions,but the structure of CnHmN4V1O1 porphyrin compounds was not detected under harsh conditions.Finally,the effects of the three raw materials on hindered diffusion during the reaction are also explored.By changing the catalyst particle size,the intrinsic reaction kinetic data of the three raw materials was obtained,and the effect of temperature on the degree of hindered diffusion of the reactants in the catalyst was investigated.The experimental results show that as the temperature increases,the degree of hindered diffusion becomes more serious.