Method for making hydrofining catalyst

Abstract

The invention discloses a method for making a hydrofining catalyst. According to the method, a nickel and aluminum deposit is prepared through adopting a positive addition method; a tungsten, molybdenum and aluminum deposit is prepared through adopting a parallel-flow method; the two deposits are mixed; an obtained first mixture is aged, and then urea is added into the first mixture while the hydrothermal treatment is carried out; afterwards, an obtained second mixture is soaked by using a solution containing an organic compound, and then the soaked second mixture is made into the catalyst through molding and the like. According to the catalyst prepared by the method, the content of epiphase active metal is high; the active-site density is high; the active metal is more uniformly dispersed; the coordination and the cooperation among active metal are good; the utilization rate of the active metal is high; meanwhile, the pore structures of the catalyst are reasonable; the mechanism strength is high; the hydrofining catalyst is particularly suitably applied to the ultra-deep hydrodesulfurization and hydrodenitrification reactions of a diesel fraction, and has higher hydrodesulfurization and denitrification activity.

Description

technical field [0001] The present invention relates to a preparation method of a hydrotreating catalyst, in particular to a preparation method of a highly active bulk phase hydrotreating catalyst. Background technique [0002] Currently in the world, crude oil is becoming heavier and inferior, coupled with the continuous development of the world economy and the increasingly stringent environmental regulations, it is necessary to produce a large amount of light and clean fuels. The development and use of ultra-low sulfur or even sulfur-free gasoline and diesel is the trend of clean fuel development in the world today. Using traditional hydrodesulfurization catalysts, by increasing the reaction severity, such as increasing the reaction temperature, hydrogen partial pressure or reducing the reaction space velocity, deep desulfurization or even ultra-deep desulfurization of diesel can also be achieved. Variation and catalyst life are shortened, while reduced space velocity mea...

AI Technical Summary

Problems solved by technology

[0010] The bulk phase hydrogenation catalyst disclosed by CN102049265A adds ammonium bicarbonate during the coprecipitation process, and the bulk phase hydrogenation catalyst disclosed by CN102451703A adds carbon dioxide during the coprecipitation process to generate carbonate or bicarbonate. It releases a certain amount of gas during the roasting process. Under the impact of the gas, the pore volume and specific surface area of ​​the catalyst are increased, so that more metal active sites are exposed on the surface of the catalyst, but this method will cause some pores to collapse. , the pore distribution is dispersed, the mechanical strength is reduced, and the active metal is locally aggregated, and the exposed metal active sites are limited

The co-precipitation method adopted above will make the distribution of different hydrogenation active metals difficult to control, thereby affecting the distribution of different hydrogenation active metals and reducing the interaction between active metals. At the same time, the content of surface active metals in the catalyst is relatively low. Small and low active center density, which ultimately affects the ultra-deep hydrodesulfurization performance of the catalyst