Silicon-containing aluminium hydroxide and prep. thereof

Abstract

The present invention relates to basic material for catalyst. The present invention prepares aluminum hydroxide via CO2 process, in which cheap siliceous compound is introduced while preparing aluminum hydroxide, partial siliceous compound is added in forming colloid, and the residual siliceous compound is added after finishing forming colloid and before aging. The siliceous aluminum hydroxide thus prepared has excellent surface acid property, proper pore structure and mutual solubility. The siliceous aluminum hydroxide of the present invention may be used for various catalyst carriers, especially those for heavy oil hydrogenation or conversion.

Description

technical field [0001] The invention relates to a silicon-containing aluminum hydroxide and a preparation method thereof, in particular to a silicon-containing aluminum oxide with strong protonic acid on the product surface after roasting, a preparation method thereof, and a silicon-containing aluminum hydroxide directly obtained by the method. The method of the invention belongs to the technical field of catalytic base materials, in particular to the technical field of catalyst base materials used in petroleum processing, especially heavy oil hydrotreating or conversion processes. Background technique [0002] Generally, in the preparation process of catalysts used in petroleum refining, alumina or γ-Al containing a small amount of one or more other elements such as Si, P, Ti, B, Mg, F, etc. are usually used 2 o 3 as the carrier. In the preparation process of this kind of alumina, the above elements can be introduced into the system at different st...

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Problems solved by technology

However, the content of amorphous silica-alumina-silicon is often high, the peptization is poor, and it is difficult to form the carrier or catalyst. In the process of carrier or catalyst preparation, a part of amorphous silica-alumina has to be mixed with the selected alumina, which will cause It brings more troubles to the catalyst preparation process, and the scope of application of amorphous silica-alumina is limited, and its pore structure and surface acid properties are often not suitable for the hydrotreating and hydroconversion process of heavy oil and residual oil

[0003] CN1110304A discloses a method for preparing macroporous alumina containing silicon and phosphorus. In the preparation process of this alumina, silicon and phosphorus are added by step-by-step colloidal method, so that most of silicon and phosphorus can be dispersed On the surface of alumina, but this alumina has large pores and poor peptization. In the process of catalyst or carrier preparation, only a part of alumina containing silicon and phosphorus is mixed, and the rest is made of alumina with better peptization. It is beneficial to molding; at the same time, it contains low silica content, only 1w% to 4w%, and contains more phosphorus, which will make the acidity of the surface of the carrier weak, and can be used to prepare hydrorefining catalysts, but it is not suitable for Preparation of heavy oil hydroconversion catalysts or other catalysts that require conversion performance; the gelling process uses AlCl 3 As the raw material, use ammonia water to neutralize the glue, which will make the cost higher and a large amount of pollutants will be discharged

Its molding process is complicated and the yield is low. At the same time, its preparation process determines that the acidity of the carrier is weak. The purpose of adding silicon is only to adjust the pore properties of the carrier, thermal stability and to facilitate the formation of the carrier.