Preparation Of Micro-foam And Its Application To The Dispersion Of Catalyst For Slurry Phase Hydroprocessing

There are some problems in the dispersion of catalysts for slurry-bed hydroprocessing, so it is necessary to develop a new dispersion technology. Because of the special structure and nature of microfoam which includes colloidal liquid aphron(referred to as CLA) and colloidal gas aphron(referred to as CGA), it is of a great potential in this aspect.At the first of this experiment, the prescription to prepare microfoam was determined according to the need to disperse the catalysts for slurry-bed hydroprocessing, optimization analysis of conditions to prepare microfoam was then carried on, structure and stability of it was also discussed by optical microscopy, dynamic light scattering and so on. Liao-he and Venezuela residual oil were taken as base oil to study on the dispersion condition of catalysts in the form of microfoam, microscope observation and autoclave reaction were used to evaluate the dispersion state.In this experiment, aimming at problems of the dispersion of water-soluble catalysts for slurry phase hydroprocessing, foam system is filtered and optimization analysis of conditions to prepare CGA was then carried on under pure water, single and mixed metal ion catalyst solution, mainly seeing about the impact of frother concentration, the type and concentration of metal ions, temperature, stirring rate and stirring time. Solution of catalysts is used as solvent with foaming agent as solute to prepare CGA. The results showed that under the conditions: 3min stirring time and 9000rpm stirring rate,pH=2~3, the output and half-life of CGA made of combination of SDS(1.1g/L) and CTAB (3.4g/L) is 1150ml and 2140s; CGA shows a shape with a transparent multi-layer spherical under the optical microscope; and its diameter concentrated in 10~100μm tested by dynamic light scattering instrument. The formation of liquid crystal in the system can help to improve the stability of CGA.The prescription to prepare CLA was determined according to the experiential ratio of oil-soluble and water-soluble catalysts.When PVR is 2, the products presented as brown emulsion and can be stored for up to three months, and no obvious phase separation occurs, which is very stable. It shows a shape of regular polyhedron or spherical under the optical microscope; the diameter of CLA concentrated between 1~3μm tested by dynamic light scattering instrument. The formation of liquid crystal in the system can help to improve the stability of CLA.It is observed by optical microscopy that the effect of catalyst material dispersed to base oil in form of micro-foam is better than traditional forms. The result of autoclave reaction showed that compared to traditional dispersion technology, slurry-bed hydro-processing coke yield of Liao-he residual oil dispersed by CGA reduced from 1.25% to 0.98%, coke yield of Venezuela residual oil reduced from 1.31% to 1.06%, coke yield of Liao-he residual oil dispersed by CGA reduced from 2.39% to 1.67%, coke yield of Venezuela residual oil reduced from 2.78% to 2.05%; with yield of light oil increased to some extent.