Study On The Characteristics Of Slurry-phase Hydrocracking Reaction For Venezuela’s Heavy Oil

Venezuela residue was treated by slurry-phase hydrocracking in the presence of oil-soluble catalyst. It was inferred that the optimum conditions of slurry-phase hydrocracking were shown as following: reaction temperature at about 430℃, concentration of catalyst at 200μg·g-1, reaction initial pressure of hydrogen at 9MPa. Conversion rate and born of coke increased significantly as the temperature increased, the hydrogen pressure increasing of the reaction greatly inhibited the born of coke.Adding SDBS or wax oil can change the colloidal stability of residue system. After hydrogenation reaction, the result showed that: with SDBS ratio increasing, the coke particle dispersion of the reaction product and the coke content of liquid phase increased correspondingly while the coke content of wall phase and total amount of coke fell slightly. The circulation of wax oil could destroy the colloidal stability of residue system. The smaller of the wax oil, the better of the system colloid stability. When the proportion of residual and wax oil was 3:1, the coke particle reunion was the most serious and the reaction system had the largest born of coke.After the reaction of different initial pressure, the distribution of SARS, the average molecular structure of asphaltenes and AR of the product were measured. The study found that, as the initial pressure increasing, the content of saturates and resins increased, the content of aromatics and asphaltenes decreased, the conversion of saturates gradually decline, the conversion of aromatics, resins, asphaltenes increased gradually. After the reaction, the naphthenic carbon rate of asphaltenes was less, alkyl carbon rate relatively increased, the condensation index of asphaltenes decreased more than raw material. As the initial pressure increasing, the number of total carbon, aromatic carbon and naphthenic carbon as well as alkyl carbon showed the tendency of decreasing. Through the calculation of AR average molecular structure, the study showed that as initial pressure of hydrogen increased, aromatic carbon rate of the product AR gradually declined, while naphthenic carbon rate and alkyl carbon rate gradually increased. The number of total rings, aromatic ring and naphthenic rings were diminishing. After the reaction, the condensation index of AR increased.The calculation of vapor-liquid equilibrium of the hydrogen system showed that, under high temperature and pressure, the bigger of the components molecular weight, the smaller of the vapor-liquid equilibrium. Under different reaction pressure, the vapor-liquid equilibrium of each component declined gradually with the increase of the initial pressure. The heavier of fractions, and the closer of K value. At different reaction temperature, with increasing reaction temperature, the K value of H2、CH4、C2H6 decreased gradually, the heavier gas increased gradually such as C3H8、C3H6、C4H10、C5H12, etc. and the vapor-liquid equilibrium constant of each fraction increased.