Study On Coal/Oil Co-Processing With Mo-Based Catalyst

Coal/oil co-processing not only reduces the operation difficulty,but also improves the utilization rate of heavy oil processing.In the field of coal/oil co-processing,up to now,Fe-based catalyst is the most widely used,but Mo-based catalysts have higher activity and higher selectivity for C-C,C-H and C-O bonds in coal,so the application prospect is broader.In addition,it is of guiding significance to explore the liquefaction rule of maceral concentrates in coal/oil co-processing system for expanding the selection range of coal species.This thesis designed and prepared unsupported Mo-based catalysts were,and the effects of different preparation methods on the physical and chemical properties of Mo-based catalysts were studied.Using Liangshuijing coal and FCC oil slurry as raw materials,the catalytic performance of the catalyst in coal/oil co-processing reaction was investigated.Besides,different maceral concentrates of Liangshuijing coal were used as experimental coals to study the liquefaction rule of coal maceral concentrates in coal/oil co-processing reaction over Mo-based and Fe-based catalyst systems.The main research results were as follows:（1）Three kinds of NiMo catalysts were prepared:Ammonium nickelmolybdate（NM）was prepared,and NMO and NMH catalyst which were modified by stirring and hydrothermal methods respectively in CTAB.Through characterization analyses,it was found that the specific surface area and pore volume of the catalysts were greatly increased by the two modification methods.Hydrothermal modification formed New HMoO₃·H₂O species,obtained smaller size and better dispersion（Ni）MoS₂grains after vulcanization,The coating of CTAB was also beneficial to increase the lipophilicity of NMH catalyst.Over NMH catalyst,the coal conversion rate is the highest,reaching 60.40%.The effect of HDS,HDN and liquid products’upgrading was also better than that of NMO and NM catalyst obviously.（2）Three kinds of sulfided Mo-based catalysts were prepared:Ammonium tetrathiomolybdate（ATTM catalyst）and the C-ATTM and CP-ATTM catalyst were prepared by using CTAB and CTAB&PVP system respectively.Through the characterization analyses of thermal decomposition MoS₂of catalysts,it was found that the introduction of organic ligands by modified not only greatly increased the specific surface area and pore volume of MoS₂,but also got smaller size and layers of MoS₂grains.In addition,the composite system of CTAB&PVP can make the smaller micelle,which is beneficial to reduce the particle size of CP-ATTM catalyst,and further increase the specific surface area and pore volume.Over the CP-ATTM catalyst,the coal conversion rate is the highest,reaching 77.12%,and it also shows better catalytic activity in the upgrading of liquid products.（3）The differences in structure and composition of different maceral concentrates（Rich inertinite coal,Raw coal and Rich vitrinite coal）in Liangshuijing coal were analyzed by characterization.Reached the liquefaction rule of coal maceral concentrates by carrying out coal/oil co-processing reaction in different catalyst system:In the Mo-based catalyst（CP-ATTM）system,the order of coal conversion was Rich vitrinite>Raw coal>Rich inertinite coal,with the increase of vitrinite content in coal,the conversion rate of coal increased greatly.Compared with Rich inertinite coal,the coal conversion rate of Rich vitrinite coal increased from 69.51%to 90.00%,and hydrogen consumption was reduced at the same time.In the Fe-based catalyst（FC-OA）system,mineral content in coal has a great influence on coal/oil co-processing reaction results.The quality of liquid products from the co-processing of different coal macerals concentrates with heavy oil was compared and analyzed.It was found that with the increase of vitrinite content in coal samples,the lightening effect of liquid products was improved.