Prepare And Study On The Oil-soluble Iron-nickel Composite Catalyst For Coal/Heavy Oil Hydrogenation Co-processing

The oil-soluble iron-nickel composite catalyst which was suitable for coal/heavy oil co-processing system was synthesized by using fatty acid salt,metal salt and disperse solvent as main raw materials.The synthesis conditions were optimized on the basis of the yield of catalyst precursor and metal recovery.Then the sulfide properties of oil-soluble iron-nickel catalyst precursor was studied.In the end,the activity of oil-soluble iron-nickel catalyst was evaluated in different coal/heavy oil hydrogenation co-processing systems with oil-soluble molybdenum as the reference catalyst.Based on the correlation analysis of solid residue（SEM、XRD、FT-IR）,the effect of oil-soluble iron-nickel catalyst on coal conversion was discussed.The fatty acid salt A and the solvent C were selected as the raw materials.The iron reagent and the nickel reagent were added according to the iron and nickel molar ratio 1:1,the amount of fatty acid salt A was over 20%according to the complete reaction of iron and nickel.The reaction time was 5h.That was the best synthesis condition of the oil-soluble iron-nickel catalyst precursor.The yield of the catalyst precursor was 68.14%,the iron recovery was 82.56%and the nickel recovery was 88.05%.The oil-soluble iron-nickel catalyst precursor had good oil solubility.Before the coal/heavy oil hydrogenation reaction temperature（400℃）,most of the catalyst precursor could be decomposed,which was favorable for vulcanization of metals.Much information could be obtained by XRD,TEM and XPS analysis.The sulfide degree of the oil-soluble iron-nickel catalyst precursor was improved with the increase of temperature.The sulfide of the iron-nickel mixed crystal existed,the sulfide particles of nickel slowly became smaller and highly dispersed,the degree of crystallization of iron sulfide was improved.At the temperature of 400℃,the oil-soluble iron-nickel catalyst precursor after sulfide formed iron sulfide,nickel sulfide and iron-nickel mixed crystal sulfide.The iron-nickel mixed crystal sulfide（Fe-Ni-S mixed crystal）had synergistic effect between the metals.Moreover,the sulfurized product of the oil-soluble iron-nickel catalyst precursor had low crystallinity,coarse surface and high dispersibility,which could provide a large contact area for hydrogenation reaction.The activity of the oil-soluble iron-nickel catalyst was evaluated in the coal/heavy oil hydrogenation co-processing system.The results showed that the oil-soluble iron-nickel catalyst had higher catalytic activity than the corresponding single metal catalyst under the same reaction conditions.In the different coal/heavy oil hydrogenation co-processing system,the catalytic effect of oil-soluble iron-nickel(500μg·g^-1)was similar to that of oil-soluble molybdenum(500μg·g^-1).The catalytic effect of oil-soluble iron-nickel(1000μg·g^-1)was better than that of oil-soluble molybdenum(500μg·g^-1).Based on the structure analysis of solid residue obtained by the different catalysts,the smaller the particle size of the solid residue was,the higher the degree of loosening was,the smaller the fragrance was,the more conversion of the corresponding coal was,which indicated the better reaction effect.