Method for preparing wear-resisting large-pore-volume micro-spherical silicon dioxide carrier

Abstract

The invention provides a method for preparing a wear-resisting large-pore-volume micro-spherical silicon dioxide carrier. The method comprises the steps that precipitation method silicon dioxide powder or white carbon black with the specific surface area of 250-600 m<2> / g is calcined at the temperature of 730 DEG C to 760 DEG C, the specific surface area of the precipitation method silicon dioxide powder or white carbon black is reduced to 100-220 m<2> / g, and water is added for even mixing; grinding and dispersing are carried out till the average diameter of microparticles ranges from 2 micrometers to 5 micrometers, activated carbon emulsion and a white carbon black emulsus glue solution are added for even mixing, and spray granulation is carried out; pelleted powder is calcined at the temperature of 650 DEG C to 720 DEG C, the micro-spherical silicon dioxide carrier with the average diameter of 50-250 micrometers is prepared, the specific surface area ranges from 60 m<2> / g to 120 m<2> / g, the pore volume ranges from 0.7 ml / g to 1.1 ml / g, and the average pore diameter ranges from 35 nm to 50 nm. High mechanical strength, wear resistance and impact resistance are achieved, and the carrier is suitable for further loading active components and preparing a catalyst for a fluidized bed.

Description

technical field [0001] The invention belongs to the field of catalysts, and relates to a method for preparing a microspherical silica carrier, in particular to a method for preparing a wear-resistant microspherical silica carrier with a large pore volume. Background technique [0002] In addition to having a suitable pore structure, the catalyst should also have high mechanical strength and wear resistance, especially in the fluidized bed, between catalyst particles, between catalyst particles and the inner wall of the reactor, between catalyst particles and the solid phase in the fluidized bed There will be frequent friction and collision between the reaction raw materials or products, and the formed broken particles will expand the fluidized bed layer, and the formed finer powder, such as the part below 10-15um, is easy to blow off the fluidized bed, basically Scrapped. [0003] Preparing the carrier first, and then impregnating the active component is the most commonly u...

AI Technical Summary

Problems solved by technology

[0004] However, preparing a microspherical silica carrier with suitable pore structure, mechanical strength and wear resistance is a technical problem in this field, because silica raw materials such as precipitated silica and fumed silica are usually sintered The performance is poor; using silica sol as a binder can improve the mechanical strength and wear resistance of the silica carrier, but the effect is limited. Even after recrystallization treatment such as hydrothermal treatment, the wear resistance of the carrier cannot be greatly improved

Using alumina, calcium oxide, kaolin, etc. as a binder can also improve the mechanical strength and wear resistance, but under acidic conditions, the acid-resistant components contained in the binder will be eroded, making the mechanical strength and wear resistance of the carrier Abrasiveness will gradually decrease