Preparation Of High-density Fuel By Co-hydrogenation Of Coal Oil Co-refining Light Oil And Washing Oil

In this thesis,a washing oil（WO）produced by the Coking Company of Masteel and a coal oil co-refining light oil（COLO）from Shaanxi Yanchang Petroleum（Group）Co.Ltd.,were used as raw materials.1-MN,the most abundant aromatic substance in WO,was used as a model compound.The catalyst with excellent catalytic hydrogenation activity and the optimum reaction conditions were screened out through experiments.Then,the two kinds of raw oils were subjected to separate catalytic hydrogenation separately and catalytic co-hydrogenation to obtain the relations between the synergistic effect and the mixing ratio of COLO and WO and the process conditions with the highest content of cycloalkanes in the co-hydrogenation products,therefore to explore the feasibility of preparing coal-based semi-synthetic high density fuel,The results suggest that:The hydrogenation activity of Ni-Mo,Co-Mo and Ni-W metal sulfide catalysts for 1-MN was significantly different,and the activity order of the three catalysts was Ni Mo S/γ-Al₂O₃>Co Mo S/γ-Al₂O₃>Ni WS/γ-Al₂O₃.By changing the preparation conditions of Ni-Mo catalyst and evaluating its catalytic hydrogenation performance for 1-MN,the optimal preparation conditions of Ni-Mo catalyst were selected as following:γ-Al₂O₃ as the carrier,Ni loading of 4.84 wt%,Ni-Mo molar ratio of 1:2,presulfidation after calcination in air.Ni Mo S/γ-Al₂O₃ catalyst was used to catalyze the hydrogenation of 1-MN under different reaction conditions.It was found that the activation energy of double ring saturation hydrogenation for 1-MN was high,and the high temperature was more beneficial for promoting the conversion of 1-MN to the target product methyl decahydronaphthalene.Adding solvent,prolonging reaction time and increasing the amount of catalyst might to increase the contact probability of catalyst,hydrogen and reactant three-phase,thus improving the hydrogenation performance of the catalyst.The optimum experimental conditions were as following:solvent ratio was 1:20,reaction temperature was 380°C,catalyst dosage was 0.2 g and reaction time was 5 h.Under this condition,the conversion rate of Ni Mo S/γ-Al₂O₃ to 1-MN was 86.2%,and the selectivity to methyldecahydronaphthalene was 21.0%using Ni Mo S/γ-Al₂O₃ as catalyst.Wo and COLO was separately hydrogenation and co-hydrogenation using Ni Mo S/γ-Al₂O₃ catalyst.It was found that the content of cycloalkanes in the co-hydrogenated product was much higher than the weighted theoretical value of the content of cycloalkanes from the single hydrogenation result of the two raw oils,and the content of polycyclic aromatic hydrocarbons was much lower than corresponding theoretical calculation value,indicating that there was a synergistic effect between COLO and WO in their co-hydrogenation process.The largest synergistic effect was taken place in the mixing ration of 66.5%WO in the mixed oil.When the reaction temperature was 380°C,the content of cycloalkanes was the highest（13.0%）and the content of polycyclic aromatic hydrocarbons was the lowest（7.2%）in the co-hydrogenation products of COLO（0.335 m L）and WO（0.665 m L）.The content of cycloalkanes in the co-hydrogenation products was further increased to 15.3%by adding 0.2 m L tetrahydronaphthalene as hydrogen donor.When the reaction temperature was 340°C,the content of cycloalkanes（8.4%）in the co-hydrogenation products of COLO（0.335 m L）and WO（0.665 m L）gave the largest increase（4.1%）compared with the theoretical value,suggesting that the synergistic effect between COLO and WO was the largest at this temperature.In the mean times,the content of cycloalkanes in the product increased to 10.4%after adding with 0.2 m L tetrahydronaphthalene.