Method for preparing modified pseudo-boehmite

Abstract

The invention discloses a method for preparing modified pseudo-boehmite. The method is characterized by comprising the following steps: (1) sequentially adding activated aluminum oxide, aluminum hydroxide and modifying agents into a proper amount of deionized water under the fully stirring condition, wherein the total amount of the activated aluminum oxide and aluminum hydroxide accounts for 5-20 mass percent of the deionized water, the modifying agent(s) is / are selected from one or more of boron, fluorine, silicon, phosphorus, magnesium, titanium, zinc and zirconium, and the total amount of the modifying agents accounts for 0.1-10 mass percent of the deionized water; (2) performing homogenizing and refining pretreatment on the obtained slurry, thereby obtaining the slurry of which the average particle size is 0.2-20 microns; (3) adding an alkali to regulate the pH value of the pretreated slurry system to 8-11, transferring the materials into a high pressure reactor to carry out a hydrothermal reaction, controlling the reaction temperature to 100-250 DEG C, wherein the reaction time is 1-48 hours; (4) performing solid-liquid separation on the obtained slurry after the reaction is ended, and washing, thereby obtaining a product filter cake in which the impurities are removed; and (5) drying, and grinding, thereby obtaining the pseudo-boehmite powder.

Description

Technical field: [0001] The invention belongs to the field of preparation of inorganic materials, and relates to a preparation method of modified pseudo-boehmite, in particular to a preparation method of hydrothermal reaction of activated alumina and aluminum hydroxide in the presence of auxiliary agents, with controllable pore structure and adjustable acidity. The pseudo-boehmite method. Background of the invention: [0002] With the increasingly inferior and heavy quality of petroleum resources, there are a large number of organometallic compounds and asphaltenes in raw oil, requiring various petroleum refining catalyst supports to have large enough pores for diffusion to prevent or slow down catalyst poisoning or deactivation At the same time, the catalyst support should maintain a large specific surface area, so that the active components can be better dispersed to ensure that the catalyst has high catalytic activity. At the same time, people's awareness of environmenta...

AI Technical Summary

Problems solved by technology

[0008] For the method of adding additives while forming gels, since the co-precipitation method requires different species to co-precipitate under certain conditions, the conditions for simultaneous precipitation of different substances may not be optimal for each species, resulting in the promotion of additives on alumina. can't give full play

Adding additives after gelling and adding additives during molding will easily lead to uneven distribution of additives and the inability to effectively exert the modification performance. At the same time, it is easy to have a high acid content on the surface of the carrier, which is used for hydrogenation of oil products. The process is prone to side reactions (such as cracking, etc.) and other problems

Images