Movable bed catalyst for alkylation of toluene and methanol to produce paraxylene and low-carbon olefin

Abstract

The invention provides a catalyst used for preparing para-xylene and low-carbon olefin fluidized bed by selective methylation of toluene with methanol, which is obtained by the modification of zeolite molecular sieve by metal, nonmetal or / and rare earth metal, mixing, spraying, drying and forming of amorphous adhesive containing silicon or aluminium and the zeolite molecular sieve, and decoration of surface acidity and porous structure by siloxane-based compounds, wherein, the content of the alkaline earth metal is 0.1-8wt percent of the total weight of the catalyst, the content of the nonmetal is 0.1-8wt percent of the total weight of the catalyst, the content of the rare earth metal is 0.1-5wt percent of the total weight of the catalyst, and the loading of the Si decorated by the siloxane-based compound is 0.1-10wt percent of the total weight of the catalyst; the catalyst is used for the reaction of preparing para-xylene and low-carbon olefin fluidized bed by selective methylation of toluene with methanol; in the products, the selectivity of the para-xylene in the xylene isomers is more than 99 percent and the selectivity of the ethane and propylene in the composition C1-C5 is more than 90 percent.

Description

technical field [0001] The invention relates to a fluidized-bed catalyst for producing p-xylene and low-carbon olefins by alkylation of toluene and methanol with high selectivity. It is characterized in that the toluene methanol can simultaneously carry out the alkylation reaction and methanol cracking reaction on the catalyst to generate p-xylene, ethylene and propylene with high selectivity. Background technique [0002] Paraxylene and ethylene are two basic raw materials for the synthesis of polyester (PET). At present, p-xylene production mainly uses toluene, C 9 Aromatic hydrocarbons and mixed xylenes are used as raw materials, and are produced through disproportionation, isomerization, adsorption separation or cryogenic separation. Since the p-xylene content in its products is thermodynamically controlled, p-xylene is at C 8 Mixed aromatics only account for about 20%. In the process, the amount of material circulation is large, the equipment is huge, and the operati...

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Problems solved by technology

[0005] On the other hand, the alkylation of toluene with methanol to p-xylene and the reaction of methanol to light olefins using ZSM-5 molecular sieve as catalysts both use fixed-bed reactions. Due to the deactivation of the catalyst due to reaction carbon deposition, the fixed-bed reactions must be switched frequently regeneration, complex operation

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