| It is the main route to increase fuel-efficient and economic benefit by improving light oil and industrial chemicals yields of inferior oil. The solvent deasphalting (SDA) process is an important methods to obtain light oil from heavy oil. However, the industrial operation is in a dilemma:the yield is low when the quality of deasphalting oil (DAO) can satisfy the feedstock catalytic cracking (FCC) standard; to increase the yield, the quality is impaired, thus, can not attain the FCC feedstock standard. In order to gain more DAO from vacuum residue (VR). Asphaltene, heavy metal and part of the sulfur and nitrogen compound in the product should be removed and ensure its quality is satisfied with the requirement of the secondary operation by the current SDA equipment and technical, there is an interesting prospect to develop coprocessing technology of oil-coal. The importance is prominent especially today when the oil price is continuing high and the pressure of environment protection keeping growing. Moreover, China is lack of oil, short of gas, but rich of coal.Firstly, VR SDA process blend with high temperature coal tar (CT) was investigated in this paper. The solubility of the VR in ethyl acetate and C4 sovent had been tested separately firstly. It shows the solubility of VR in the two solvents is sharply affected by temperature. The solubility increases linear with growth of temperature in ethyl acetate, while decreases in C4. In addition, the VR solubility can be affected by components of the C4 and the solubility paramater. The solubility equilibrium model of VR in mixed C4 is followed Flory-Huggins equation.Secondly, the property change of VR-CT blend had been investigated. By analyzing the property of the raw material and simulated distillation experiment, the compatibility of VR and CT was studied. There is equilibrium between solution and adsorption when the CT blend ratio is 5%. When the ratio increases, the main effort in the system is adsorption and the asphaltene is easy to subside and separate out. It has been revealed by the TBP distillation and delay coking experiments that, though there is positive effect on the VR product process by blending with CT, the liquid oil yield has been decreased, the equipment are easy to coking and short the operation cycle.Based on the results above, the effect on VR SDA process by blending with CT had been researched and compared with the process that blending with powdered coal, with ethyl acetate as solvent. The result shows that there is some improvement on the VR SDA process by blending with CT. In the optimized condition of extraction temperature 30℃and solvent ratio 6:1, the DAO yield has been increased by 2% when blended with 10% CT. Meanwhile, the removal rate of carbon residue kept unchanged, the total content of nickel and vanadium has a decrease of 5μg/g, with the sulfur content has a slight decrease and the nitrogen content stays invariable. With the same DAO yield, the contents of metal, sulfur and carbon residue in DAO obtained from VR that blended with 10% CT decreased obviously. And the property of DOA revealed that blending with CT is benefit for the deep cut of the VR. In the SDA process that VR is blended with 30% Beisu bituminous coal powdered coal (150～830μm) and pretreated in 250℃, the DAO yield has been enhanced by 3%. the removal rate of metal nickel and vanadium has increased by 7%. This technical process, however, has many disadvantages, such as, with difference to transpot the feedstock, the damage to the equipment, and need to reform the device.The SDA process of VR blending with CT was investigated in subcritical state with C4 hydrocarbon as solvent. Compared with VR without any blend, the DAO yield has been improved by 17% with a CT blend ratio of 10% under the same extract condition. The improvement is around 19% when the blend ratio is 20%. The nickel and vanadium content is declined from 3.41μg·g-1 to 2.69μg·g-1, and the asphaltene content is declined from 1.6 wt% to 0.7 wt%. But the metal removal rate is nearly the same. The property of the DAO with the same yield has been compared. When the CT blend ratio is low (<20 wt%), its removal rate of metal, sulfur and nitrogen has increased distinct, while the carbon residue removal rate remain unchangeable. The DAO molecular structure has been studied by various methods: infrared spectrum, nuclear magnetic resonance, ultraviolet spectrum, gel chromatograph, and mass spectra. The results exhibit a more straight-chain and side-chain paraffin content in the DAO, for the light component is easier to be extracted into it by blend with CT.The catalytic cracking property of the DAO was evaluated by fixed fluid catalytic cracking bed. DAO obtained from VR that blended with 10% CT showes a fine cracking property. The light oil yield has been promoted by 6%. And the properties of the gasoline and diesel fraction are close to that without any blend. Results of SDA process on Middle East mixed inferior VR reveales that when blend with 10% CT, the DAO yield is improved by 4% and property of the DAO is similar and coincide with the heavy oil catalytic cracking raw material standard for DAO. Meanwhile, the deoiled asphalt (DOA) can be used as feedstock for gasifying. These results reveales further that, by blending with CT, more light oil can be gained from inferior VR in the SDA-FCC combination process.The effect mechanism of SDA process when VR was blended with CT had been investigated, and it was exposited by the research results of rheological behavior, colloid structure and solubility parameter of raw material. Component and compatibility of the VR colloid system was altered when blend VR with CT. Its viscosity declined, the stability of the colloid got worse, and the solubility parameter decreased. The mass transfer efficiency of the solvent deasphalting process was improved. More components have been extracted into DAO. The yield and quality of DAO have both been promoted.
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