Silica granules prepared on basis of pyrolysis and preparation method and app {} lication thereof

Abstract

The invention relates to silica granules prepared on basis of pyrolysis and a preparation method and application thereof. Particularly, the invention relates to silica granule prepared on basis of pyrolysis, which has the following physicochemical property data: average granule diameter: 10-120 mu m; BET specific surface area: 40-400m2/g; pore volume: 0.5-2.5 ml/g; pore distribution: in the whole pore volume, the content of pore of which the pore diameter is smaller than 5 nm is less than 5%, and the balance mesopore and macropore compacted density: 220-1000g/l. The granularity is within the granularity range which is more than granularity distributed D10 value measured according to volume, and the numerical value content of granules containing tucks or sealed internal gaps is smaller than 35%. The granules are prepared with the following method: silica and one or a plurality of accessory ingredients are dispersed in liquid, preferably water; then, the dispersoid is atomized and dried; and if necessary, the granule is performed with heat treatment and/ or silanization. The granule can serve as a catalyst carrier.

Description

technical field [0001] The present invention relates to particles of pyrogenically prepared silica, a process for their preparation and their use as catalyst supports. Background technique [0002] from SiCl by high temperature or flame hydrolysis 4 Preparation of fumed silica or silicon dioxide is known (Ullmanns der technischen Chemie, [Ullmanns Encyclopaedia of Industrial Chemistry], 4th edition, volume 21, page 464 (1982)). [0003] Fumed silica is distinguished by its very fine division, high specific surface area (BET), very high purity, spherical particle shape and lack of pores. Due to these properties, pyrogenically prepared silicas are increasingly finding value as catalyst supports (Dr. Koth et al., Chem. Ing. Techn. 52, 628 (1980)). For such applications, pyrogenically prepared silicas are shaped by mechanical methods, such as tablet presses. [0004] It is also a known technique to shape pyrogenically prepared silicas into spray particles by spray drying. ...

AI Technical Summary

Problems solved by technology

This also leads to voids and distortions in the polymer, which reduce the bulk density (and thus the throughput of the polymerization plant) or possible inclusion of monomers, which adversely affects further processing

These defects lead to increased attrition and thus increased catalyst loss when used as a support for other fluidized bed catalysts

Images