Process for producing fine grain ZSM-5 zeolite catalyst for methylbenzene selective dismutation

A zeolite catalyst, ZSM-5 technology, applied in physical/chemical process catalysts, molecular sieve catalysts, chemical instruments and methods, etc., can solve the problem of high toluene disproportionation activity

Inactive Publication Date: 2008-08-20
NANJING UNIV OF TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] In the selective disproportionation reaction of toluene, Wang Yue et al. (Journal of Petrochemical Universities, 2005, 18 (4): 20) synthesized a nanoscale ZSM-5 zeolite catalyst and found that its toluene disproportionation activity was higher than that of the micron scale, but it did not The catalyst was subjected to shaping and shape-selective modification; Wang et al. The acid properties and toluene disproportionation reaction performance of the ZSM-5 zeolite catalyst have not yet been shaped and shape-selectively modified, and the p-xylene selectivity is still at the thermodynamic equilibrium value

Method used

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  • Process for producing fine grain ZSM-5 zeolite catalyst for methylbenzene selective dismutation
  • Process for producing fine grain ZSM-5 zeolite catalyst for methylbenzene selective dismutation
  • Process for producing fine grain ZSM-5 zeolite catalyst for methylbenzene selective dismutation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Take 0.28mol (60g) of tetraethyl orthosilicate, add 5.6mol (100.8g) of deionized water to it, make it fully dissolved, then add 2g of concentrated sulfuric acid, adjust the pH of the solution to 1.0, then add aluminum sulfate 0.0068mol ( 4.5g), 0.027mol (7.2g) of tetrapropylammonium bromide, 0.5g of ZSM-5 zeolite seed crystal, stirred at 20°C for 6h and then added 0.0125mol (0.5g) of NaOH solid to adjust the pH of the crystallization solution =10, stirred evenly, packaged in a high-pressure hydrothermal kettle, and statically crystallized at 180°C for 15 hours. The obtained product was washed, filtered (centrifuged?), dried, and roasted to obtain ZSM-5 zeolite raw powder. attached figure 1The XRD pattern of the small-grain sample obtained in this case and the standard ZSM-5 zeolite molecular sieve is given. Referring to the standard spectrum, it can be seen that the synthesized sample is a ZSM-5 molecular sieve. Accompanying drawing 2 shows the SEM image of the sample ...

Embodiment 2

[0024] Take 0.28mol (43g) of methyl orthosilicate, add 10mol (180g) of deionized water to it, make it fully dissolved, then add concentrated nitric acid to adjust the pH value of the solution to 3.0, then add 0.0035mol (2.32g) of aluminum sulfate, 0.054mol (14.2g) of tetrapropylammonium bromide, 0.3g of ZSM-5 zeolite seed crystal, stirred at 60°C for 24 hours and fully hydrolyzed, then added NaOH solid, adjusted the pH of the crystallization solution to 11, stirred evenly, and packaged in high-pressure water Hot kettle, static crystallization at 200°C for 10 hours, the obtained product was washed, filtered, dried, and roasted to obtain ZSM-5 zeolite raw powder. XRD and SEM results showed that the synthesized zeolite was ZSM-5 with a crystal grain size of <500nm. 5 zeolites.

Embodiment 3

[0026] Take 0.28mol (60g) of tetraethyl orthosilicate, add 8.4mol (151.2g) of deionized water to it, make it fully dissolved, then add concentrated hydrochloric acid to adjust the pH value of the solution to 2.0, then add aluminum sulfate 0.0186mol (12.4 g), 0.084mol (22.3g) of tetrapropylammonium bromide, after fully hydrolyzed by stirring at 90°C for 3 hours, add 0.0125mol (0.5g) of NaOH solid, adjust the pH of the crystallization solution to 10, stir evenly, and pack it into high-pressure water Heat the kettle, statically crystallize at 170°C for 15 hours, and the obtained product is washed, filtered, dried and calcined to obtain the original ZSM-5 zeolite powder. XRD and SEM results show that the ZSM-5 zeolite grain size is <500nm.

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Abstract

The invention relates to method for preparing toluene selective disproportionate catalyst using small crystallite ZSM-5 zeolite, which comprises the steps as follows: mixing molecular weight siloxane and aluminum salt for hydrolysis reaction for 1 to 24 hours under acid conditions with the presence of a template; adjusting the pH value of the mixture using inorganic base; performing hydrothermal crystallization for 10 to 24 hours at 160 to 200 DEG C; preparing small crystallite ZSM-5 zeolite with the crystalline grain of 100 to 500nm; forming the small crystallite zeolite using adhesive; preparing hydrogenous zeolite through ion exchange; adopting tetraethyl orthosilicate chemical liquidoid silica deposition for modification, so as to obtain a shape selective catalyst with high activity, high selectivity to xylene and low side reaction. The catalyst has the advantages of simple reparation technology, low cost, high reactivity, and wide application prospect.

Description

technical field [0001] The invention belongs to the field of catalytic materials and catalyst synthesis, and in particular relates to a method for synthesizing a small-grain ZSM-5 zeolite catalytic material with a low silicon-aluminum ratio, and a method for preparing a toluene disproportionation catalyst using it as a raw material. Background technique [0002] The ZSM-5 zeolite molecular sieve (USP 3702886) invented by Mobil Petroleum Company of the United States has become a very important shape-selective catalytic material with its unique pore structure and good catalytic performance. It has been used in toluene disproportionation, isomerization, alkylation, etc. It has been widely used in petrochemical process. The grain size of the traditional hydrothermally synthesized ZSM-5 zeolite is generally 1-10 μm. Compared with the traditional micron-sized zeolite molecular sieve, the small grain ZSM-5 zeolite has a high external area and a short pore structure. With its uniqu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J29/40B01J35/02C07C15/02
Inventor 王军任晓乾陆由东吴雅静
Owner NANJING UNIV OF TECH
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