A preliminary study on the co-hydrogenation process of coal tar and bio-oil

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 degrees 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 degrees 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.