Preparation method capable of increasing macropore volume of silicon dioxide carrier

Abstract

The invention provides a preparation method capable of increasing the macropore volume of a silicon dioxide carrier. The preparation method comprises steps as follows: components comprising, in parts by mass, 100 parts of silicon dioxide powder with the specific surface area of 60 m<2>/g-250 m<2>/g and 10-30 parts of macromolecule ultrafine powder which basically doesn't have any residues after firing and basically doesn't absorb water to be swollen are sufficiently and uniformly mixed; 80-100 parts of a polymer aqueous solution with certain viscosity and with the mass concentration being 0.1%-0.5% is added, the mixture is sufficiently and uniformly mixed, 40-70 parts of silica sol with the concentration being 20%-30% is added, and the mixture is sufficiently and uniformly mixed and placed in an airtight manner; the average diameter of particles of the silica sol ranges from 10 nm to 30 nm, and the polymer basically doesn't have any residues after calcination and is selected from one of polyacrylamide, cellulose and modified starch; the mixture is kneaded and extruded to form strips, the extruded strips are dried and calcined at the temperature of 600 DEG C-670 DEG C for 2-4 hours, and the silicon dioxide carrier is obtained. According to the silicon dioxide carrier, the volume of macropores with the diameters larger than 100nm is higher than 0.10-0.35ml/g, the silicon dioxide carrier has higher mechanical strength, and the side pressure strength is higher than 150 N/cm.

Description

technical field [0001] The invention relates to a preparation method of a catalyst carrier, in particular to a preparation method for increasing the macropore volume of a silica carrier. Background technique [0002] Silica carrier is a common catalyst carrier. Its acid resistance and water resistance are better than commonly used high-temperature alumina such as α-alumina carrier, and it shows better performance in some reaction processes. For example, in the process of selective oxidation of hydrogen sulfide to elemental sulfur, catalysts made of silica carrier-supported active components have slower reaction performance degradation and generally have longer lifespan. Moreover, the Claus of silica carrier The reaction activity is much lower than that of high-temperature alumina, and the selectivity of the prepared catalyst to oxidize hydrogen sulfide to elemental sulfur can be higher than 95%, which is higher than about 90% of the catalyst prepared by loading the same acti...

AI Technical Summary

Problems solved by technology

[0003] A common problem with silica supports is that there are few macropores. In some applications, the internal diffusion resistance of some components in the reaction system is relatively large, or the macropores are not enough. It is hoped to increase the macropores.

[0005] Mechanical strength is an important indicator of catalysts. For most industrial processes, if the strength is lower than 100N / cm, there will be more disadvantages, such as fragility and easy pulverization, which will cause further problems such as increased bed pressure drop, bias flow, etc., thereby reducing the processing capacity and shortening the service life of the catalyst

[0006] In recent years, some manufacturers have also used silica sol as a binder, mixed with silica powder, kneaded, extruded (addition of water, cellulose, sage powder, etc.), and then dried and roasted at about 650 ° C to prepare The silica carrier is used to improve the mechanical strength of the carrier, but there is basically no research on how to increase the macropore volume by adding more pore-forming agents under the premise of ensuring the mechanical strength.