Modified nanometer ZSM-5 molecular sieve catalyst, preparation method and application thereof

Abstract

The invention relates to a kind of modifying nanometer ZSM-5 molecular-sieve catalyst and its manufacturing method, and it also can be used to produce para-xylene by base reaction with toluene and alkane methoxide. The catalyst uses the nanometer ZSM-5 molecular-sieve as the parent, and uses aluminium oxide, mixed rare earth and their community as the supporter respectively. The active component modifier, such as the oxidate loading La, Mg or Si, undergoes dipping, desiccating and roasting, and then as a result the catalyst can be acquired. In the reaction that toluene and alkane methoxide producing para-xylene, the catalyst has the advantages of the high selectivity, excellent activity and stability and so on.

Description

technical field [0001] The invention relates to a modified nano ZSM-5 molecular sieve catalyst used in the alkylation of toluene and methanol to produce p-xylene and a preparation method thereof. Background technique [0002] Alkylation of toluene and methanol to produce p-xylene technology: Chinese patent 94110202.5 uses magnesium-mixed rare earth modified ZSM-5 catalyst. The ZSM-5 molecular sieve synthesized with ammonia water as a template has a rare earth weight content of 10-40%, a MgO load of 1.7-4.0%, and the reaction conditions are: toluene, methanol molar ratio 2:1, temperature 465 ° C, toluene weight Airspeed is 2h -1 . Toluene conversion 16.0-17.9. The selectivity to p-xylene is 91.6-95.6%. The ZSM-5 molecular sieve synthesized by using ethylenediamine as a template is mixed with rare earth at a ratio of 80% and 20%, and loaded with 3% MgO to prepare a modified catalyst. The reaction conditions are: the molar ratio of toluene and methanol is 2, and the tempera...

AI Technical Summary

Problems solved by technology

Low selectivity of p-xylene