The high content of heteroatoms and trace metals makes it difficult to upgrade poor-quality oils (PQO). The co-pyrolysis or co-hydrogenation of coal tar (CT)/vacuum residue (VR) is a new approach for the efficient utilization of PQO. The products of CT/VR co-pyrolysis and co-hydrogenation were characterized by RV, TG-FTIR, and GC × GC-TOF. Co-pyrolysis reduces the reaction harshness by lowering the activation energy of pyrolysis. Co-pyrolysis changes the reaction paths of oxygen-containing free radicals by promoting the generation of oxygen-containing organic compounds and inhibiting coke generation by increasing the pyrolysis spillover of unsaturated hydrocarbons. Co-hydrogenation increased the gasoline and diesel yields while reducing coke production. The saturates, aromatics, resins, and asphaltenes of CT and VR experienced a significant increase in the gasoline and diesel fractions after hydrogenation. The gasoline and diesel content enhancement in the four-component hydrogenation products of CT increased with increasing polarity, whereas the opposite trend was observed for the four-component hydrogenation of VR. There was a clear synergistic effect between the aromatics of CT and VR in terms of hydrogenation saturation, while the synergistic effect of the aromatics was somewhat weaker. The saturates and resins had an inhibitory effect on each other.
This study investigates the synergistic effect during the co-hydrogenation process of coal tar and biomass oil through experiments. By conducting hydrogenation experiments on model compounds of coal tar (naphthalene, tetrahydronaphthalene, decalin, and 9,10-phenanthrene) and waste soybean oil, it was found that partially saturated and fully saturated polycyclic aromatic hydrocarbons release active hydrogen atoms due to dehydrogenation at high temperatures. These active hydrogen atoms can promote the hydrogenation conversion of fatty acids derived from triglycerides in waste soybean oil during the co-hydrogenation process with coal tar. Through co-hydrogenation experiments of coal tar and waste soybean oil, it was discovered that when coal tar was first hydrogenated under conditions of temperature of 360 °C, pressure of 8 MPa, and LHSV (liquid hourly space velocity) of 0.4 h −1 , and then mixed with waste soybean oil (at a concentration of 30 g/100 mL) for hydrogenation under the conditions of temperature of 360 °C, pressure of 8 MPa, and LHSV of 0.4 h −1 , the deoxygenation conversion rate of fatty acids in the soybean oil is 94.5%. The hydrogenation deoxygenation conversion rate of the product in this process was 87.5% higher than that of individual fatty acids. This study indicates that the co-hydrogenation of hydrogenated coal tar and bio-oil promotes the deoxygenation conversion of bio-oil.
危险品化学品经营许可证（带存储）