Optimization Of Synthesis Method Of Coal/Heavy Oil Hydrogenation Catalyst And Its Application

Due to the excellent dispersibility and high catalytic activity,oil-soluble catalysts have good application prospects in coal/heavy oil hydro-refining.Laboratory studies have developed a type of iron-nickel bimetallic catalyst with high activity and low cost for this kind of reaction system,but its low synthesis efficiency limits its industrial usage.Therefore,this paper aims to enlarge the reaction volume and the solvent ratio of the catalyst.The amplification synthesis effect and the vulcanization performance of the synthesized catalyst were investigated.The catalytic effect in different reaction systems,which provided the necessary research basis for the subsequent amplification synthesis test of the catalyst,was conducted too.In this thesis,the synthetic raw materials prepared by the catalyst were optimized under the reaction conditions of the 250 ml flask.Suitable factors such as metal salt,catalyst,and solvent were selected.On this basis,the reaction volume amplified catalyst was investigated under two different volumes namely 2L and 10 L synthesis reactors.The effect of yield,metal content and oil solubility studies were subsequently followed by the effect of the solvent ratio amplification to further improve the synthesis efficiency of the catalyst.The vulcanization experiments were carried out on the post-synthesized series catalysts with the application of various analytical methods to study the phase composition changes and micro-morphological changes of the vulcanized products.Finally,the catalysts under different amplification conditions were applied to the coal/heavy oil hydrogenation co-refining system for catalyst evaluation experiments,and the solid residue after the reaction was analyzed and characterized.It was noted that with the amplification of the synthesis volume and the solvent ratio,the yield of the catalyst precursor increased with a decrease in the metal recovery rate.Each series of catalyst precursors exhibited good oil solubility.The amplification of the reaction volume and the increase of the solvent ratio are not conducive for the vulcanization process of the catalyst,increasing the sulfide particle size,reducing the effective element content and the number of surface active sites,which may inhibit the catalytic performance of the synthesized catalyst.It is found that for the coal/FCCS system,as the catalyst reaction volume and the solvent ratio are amplified,the reaction effect decreases to a certain extent,and the effect of the catalyst reaction volume amplification shows a greater negative effect.For the coal/MRAR/FCCS system,it was found that the catalyst reaction volume and the dissolution ratio of the solvent did not have much influence,and the amplification of the solvent ratio showed a slight positive effect.The analysis results of the solid residue after the reaction showed that the content of aromatic carbon in the solid residue decreased with the amplification factor of the catalyst,while the content of fat carbon increased,which was mainly reflected in the increase of oxygen-carbon content.The comparison of SEM images showed that after the solution ratio was amplified,although the conversion rate did not change much,the particle size of the solid residue increased and the dispersion type decreased after the reaction,it is indicated that the amplification of the solvent ratio during the synthesis of the catalyst has a slight negative effect on the dispersibility of the product after the reaction.