A kind of forming method of sapo-34 molecular sieve catalyst

Abstract

The invention relates to a forming method of a SAPO-34 molecular sieve catalyst. The method comprises the following steps: performing ultrasonic / colloid mill coupling treatment on a SAPO-34 molecularsieve, a silicon-aluminum material, a binding material, water and a pore-forming material, adjusting the pH of slurry to be 2 to 7 by using an acid or alkali pH regulator, performing spray drying on the homogeneous slurry, roasting the obtained semi-finished product under the oxygen-containing atmosphere, cooling after roasting, and preparing a finished product SAPO-34 molecular sieve catalyst, wherein the silicon-aluminum material is selected from one or more of micro-silicon powder, diatomite, kaolin and bauxite; the binding material is silicon sol or aluminum sol; and the pore-forming material is selected from one or more of lignin powder, cellulose powder, starch, graphite and sesbania cannabina powder. The industrial byproduct micro-silicon powder serves as the silicon-aluminum material, the rich and cheap cellulose or lignin material serves as the pore-forming material, the high-forming-rate, wear-resistant and porous SAPO-34 catalyst is prepared, and the larger range requirements of MTO are met.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and in particular relates to a molding method of a SAPO-34 molecular sieve catalyst. Background technique [0002] In 1984, United Carbide Corporation (UCC) developed a series of silicoaluminophosphate molecular sieves, known as the third generation molecular sieves. It is the introduction of Si element into AlPO 4 In the framework of the molecular sieve, AlPO is broken 4 The charge balance of the original system, the molecular sieve framework is electronegative, resulting in B acid centers and exchangeable cations. Most of the silicoaluminophosphate series molecular sieves have methanol-to-olefins (MTO) reactivity, such as SAPO-11, SAPO-17, SAPO-18, SAPO-34, SAPO-35, SAPO-46 and SAPO-56. Of particular concern is SAPO-34 molecular sieve, which has a small pore size (0.43-0.50nm), moderate acidity, strong hydrothermal stability and other qualities, suitable for MTO reaction, methanol conversi...

AI Technical Summary

Problems solved by technology

[0008] According to the relevant information on the molding of SAPO-34 molecular sieve catalyst, the carrier used for molding is mainly kaolin at present, and the slurry is obtained through repeated rubber grinding for a long time. and molding rate, at the same time, a large amount of catalyst active components prepared by this process are wrapped in microspheres, resulting in a large number of active centers that cannot perform catalytic activity, resulting in waste of catalyst raw materials, and increasing the time for reactants to reach catalyst active centers The distance increases the diffusion resistance in the reaction process and reduces the selectivity of the target product, especially for a large amount of exothermic chemical reaction like MTO, if the reaction heat inside the microspheres is not removed in time, it will cause serious carbon deposition, which will lead to catalyst inactivation of

[0009] Based on the lack of pores in the existing SAPO-34 catalyst, low utilization rate of active components, easy deactivation, low abrasion strength, and time-consuming molding process, the present invention aims to explore the use of low-cost industrial by-products in the existing technology. Silica fume is used as the carrier, rich and cheap cellulose or lignin is used as the pore-forming material, and the strategy of coupling ultrasound and rubber mill is used to develop SAPO-34 catalyst with simple process and better performance, which can meet the large-scale application of MTO. Has great practical application value and prospect