Methanol to aromatic catalyst containing two molecular sieves and preparation method

Abstract

The invention relates to a methanol to aromatic catalyst containing two molecular sieves and a preparation method. The methanol to aromatic catalyst comprises, based on the weight of the catalyst, 40 wt%-85 wt% of the total content of a zinc-aluminium compound modified ZSM-5 molecular sieve and a nickel modified Y-shaped molecular sieve, 0.5 wt%-5.0 wt% of rare earth oxide and the balance aluminium oxide binder, wherein the ratio of the weight content of the zinc-aluminium compound modified ZSM-5 molecular sieve to the modified Y-shaped molecular sieve is 9:1-1:1. The invention further discloses a method for preparing the catalyst. The methanol to aromatic catalyst is used in a methanol to aromatic process, has high light weight aromatic yield and is low in dry gas and liquefied gas productivity. The wastage rate of zinc oxide active components of the catalyst is low, and the stability is high.

Description

technical field [0001] The invention relates to the technical field of chemical catalysis for the production of aromatics, in particular to a catalyst for producing aromatics from methanol containing two molecular sieves and a preparation method. Background technique [0002] Aromatic hydrocarbons refer to hydrocarbons containing benzene rings, which are important basic raw materials in the petrochemical industry. Among them, BTX is called a first-class basic organic raw material, and is widely used in synthetic fibers, synthetic resins, synthetic rubbers and various fine chemical products. At present, aromatics mainly come from petroleum-based catalytic reforming of naphtha to produce oil and steam cracking of naphtha, and a small part comes from coal tar. As my country's dependence on foreign oil becomes higher and higher, the petroleum-based aromatics production technology may be limited. my country has abundant coal resources, so the development of coal-based methanol-t...

AI Technical Summary

Problems solved by technology

The catalyst has high reactivity, but the selectivity of heavy aromatics is still high

In addition, due to the high activity of the catalyst, the yield of by-products such as dry gas and liquefied gas is high

[0009] At present, the molecular sieve carrier of methanol-to-aromatics catalyst is mainly ZSM-5 molecular sieve. Due to the limitation of molecular sieve channels, the selectivity of heavy aromatics in aromatics products can be as high as 20% to 40%, which seriously affects the yield of BTX light aromatics and reduces Economics of Methanol to Aromatics

In addition, the metal active components of the catalyst, such as zinc oxide and gallium oxide, are often loaded by equal-volume impregnation. The large amount of water generated during the reaction of methanol to aromatics will lead to the loss of active components, and the stability of the catalyst is poor.

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