| The slurry bed hydrogenation process is a kind of heavy energy and light process which can be used to deal with all kinds of inferior oils such as high viscosity,high metal,high sulfur and nitrogen.In this paper,ferric,molybdenum and nickel salts were used as raw materials,and the stability of emulsion catalyst was used as the evaluation index.On this basis,the influences of dispersible oil type,emulsifier type and amount,stirring speed and active metal amount on the stability of emulsion catalyst were further investigated,the best stable catalyst formulation was optimized,the highly dispersed nano-emulsion catalyst was prepared,and the emulsion catalyst and its sulfide products were characterized.High pressure reactor was used to evaluate the catalytic performance of high dispersion emulsion catalyst and oil soluble iron nickel catalyst in three kinds of low quality heavy oil slurry bed hydrogenation reaction systems.Under the condition of high addition of emulsifier and high shear rate,ferric salt is easy to break and flocculate in the emulsion system.Because molybdenum salts are dissolved too low in water,most of them exist in solid state in emulsion catalyst,which affects the dispersive property of the catalyst and leads to excessively large particle size of the catalyst.Nickel salt B is difficult to be suspended in emulsion due to its low solubility and large solid particle size,which is unfavorable to the stability of catalyst system.Nickel salt A is an active metal salt which can maintain higher stability and smaller particle size of catalyst.With 400 N base oil as the catalyst dispersing oil,1.2wt % oil hydrophilic auxiliary D and0.8wt % hydrophilic auxiliary F as the compound emulsifier,nickel salt A as the active metal salt(added at A rate of 5wt % nickel content),and constant temperature shearing for A period of time at A certain shear rate,the highly dispersed nickel-based nano-emulsion catalyst can be prepared.The nickel based emulsion catalyst prepared has good oil solubility with an average particle size of 317.8 nm,which is in line with the category of nano emulsion.After sulfurization,the catalyst has an average particle size of 37 nm,and has good dispersion in heavy oil reaction system.The results of coal/heavy oil hydrogenation show that the larger the particle size of emulsion catalyst,the worse the catalytic effect.The catalytic activity of high dispersed nickel-based nano-emulsion catalysts was evaluated in three inferior heavy oil systems,which were prepared by MRAR,YLCTAR,and anhui lignite with the mixture of MRAR and FCCS.The results showed that the nickel-based emulsion catalyst and the oil-soluble iron-nickel catalyst also had higher hydrogenation activity,which could promote the hydrogenation of poor quality heavy oil in slurry bed.The second metal was introduced to investigate the synergistic effect of metals.It was found that the catalytic activity of oil soluble iron catalyst and nickel-based emulsion catalyst could be improved to some extent. |
