Preparation method of wear-resistant large-pore-volume microspherical silica carrier

Abstract

The invention provides a preparation method of a wear-resistant large-pore-volume microspherical silica carrier. The preparation method comprises the steps: roasting precipitated silica powder or white carbon black with the specific surface area of 250-600 m<2> / g at the temperature of 730-760 DEG C, and making the specific surface area reduced to 100-220 m<2> / g; adding water to the precipitated silica powder or white carbon black, adding an acid, adjusting the pH to 2-3, grinding and dispersing until the diameters of micro particles are all 1 [mu]m or less, adding the roasted silica powder, grinding and dispersing until the average diameter of micro particles is 2-5 [mu]m, adding an activated carbon emulsion, mixing evenly, carrying out spray granulation, roasting at the temperature of 650-720 DEG C, and thus obtaining the microspherical carrier with the average diameter of 50-250 [mu]m, the specific surface area of 80-200 m<2> / g, the pore volume of 0.7-1.1 ml / g, and the average pore diameter of 20-40 nm. The prepared microspherical silica carrier has the advantages of wear resistance and impact resistance, and is suitable for preparation of 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

Images