Preparation method of modified ZSM-5 zeolite toluene disproportionation catalyst by soda treatment

A technology of toluene disproportionation and ZSM-5 is applied in the field of preparation of ZSM-5 molecular sieve modified catalyst, which can solve the problems of decreasing conversion rate and aggravating the degree of side reactions, and achieve the effect of mild treatment conditions and simple steps.

Inactive Publication Date: 2009-03-11
NANJING UNIV OF TECH
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  • Abstract
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Problems solved by technology

[0015] The purpose of the present invention is to improve the problems in the prior art that the conversion rate is greatly reduced and the degree of side reactions is aggravated due to the modification of the catalyst, and a method for preparing an alkali-treated modified ZSM-5 zeolite toluene disproportionation catalyst is proposed , the prepared catalyst can effectively improve the activity of toluene disproportionation reaction and reduce side reactions

Method used

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  • Preparation method of modified ZSM-5 zeolite toluene disproportionation catalyst by soda treatment
  • Preparation method of modified ZSM-5 zeolite toluene disproportionation catalyst by soda treatment
  • Preparation method of modified ZSM-5 zeolite toluene disproportionation catalyst by soda treatment

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Embodiment 1

[0032] Mix 30g HZSM-5 zeolite molecular sieve raw powder (manufactured by Catalyst Factory of Nankai University, the molar ratio of silicon oxide to aluminum oxide is 38) with 25g silica sol, 1.2g squash powder, mix evenly, extrude and form, and make the binder Strip catalyst solid particles with a content of 20%. The above catalyst is exchanged for ammonium ion in ammonium chloride solution (the weight ratio of ammonium chloride to solid is 1:1), then washed, centrifuged, dried and roasted. The catalyst was pickled in 0.5mol / L oxalic acid solution, the solid-to-liquid ratio was 1:5, then washed, filtered, and dried, and chemical liquid phase deposition was performed twice with cyclohexane solution of tetraethyl orthosilicate, modified for 5 hours, The deposition temperature is 45°C, dried at 120°C for 6 hours, heated at 1°C / min to 550°C for 4 hours and calcined to obtain the final catalyst A.

[0033] The toluene disproportionation reaction was carried out on a high-pressure...

Embodiment 2

[0045] Mix 30g of HZSM-5 zeolite molecular sieve raw powder (manufactured by Nankai University Catalyst Factory, the molar ratio of silicon oxide to aluminum oxide is 38) and 0.2mol / L sodium hydroxide solution to form a suspension, the solid-to-liquid ratio is 1:10, Stir at 65°C for 0.5h, filter, wash, dry in an oven at 100-120°C for 2-5h, heat up to 550°C at 2°C / min in a muffle furnace, and bake at this temperature for 3-5h.

[0046] The powder thus obtained was subjected to ammonium exchange, extruded, dried, calcined and then exchanged, pickled and deposited according to a binder content of 20%, to obtain catalyst sample B.

Embodiment 3

[0048] 30g HZSM-5 zeolite molecular sieve raw powder (manufactured by Catalyst Factory of Nankai University, the molar ratio of silicon oxide to aluminum oxide is 38) was added to 25g silica sol, and 1.2g kale powder was formed (binder content 20%). The formed solid is dried and roasted.

[0049] Take 5 g of the above solid in 0.05 mol / L sodium hydroxide solution and shake at a constant speed for 2 h at 45 °C with a solid-to-liquid ratio of 1:10. Then wash, dry and roast. The obtained solid was exchanged with ammonium 6 times, washed with acid, and deposited twice. After deposition, a bar-shaped alkali-treated catalyst sample C was obtained.

[0050] Get 2 grams of above-mentioned catalysts to carry out toluene disproportionation reaction.

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Abstract

The invention relates to a preparation method of a modified ZSM-5 zeolite toluene disproportionation catalyst which is treated by alkali. The zeolite powder which takes ZSM-5 as active components is added in a caking agent to be formed, and then the formed zeolite is treated by 0.01-0.4mol/L of alkali solution at the temperature of 25-75 DEG C and is exchanged into hydrogen type zeolite; after being washed by organic acid and dried by the catalyst, the hydrogen type zeolite is modified by chemical liquid deposition with cyclohexane solution of ethyl orthosilicate, dried and calcined to obtain the catalyst. The obtained catalyst is especially used for preparing benzene and paraxylene by shape selection and disproportionation of toluene, thus obviously improving the transformation ratio of the toluene, and after the catalyst is used in the toluene disproportionation, the transformation ratio of the toluene is increased by 6-10% and secondary reaction is reduced.

Description

technical field [0001] The invention relates to a preparation method of a ZSM-5 molecular sieve modified catalyst and its application in toluene disproportionation reaction, in particular to a preparation method of an alkali-treated modified ZSM-5 zeolite toluene disproportionation catalyst. Background technique [0002] Toluene disproportionation is an important reaction process in the petrochemical industry. It can convert toluene into benzene and xylene with higher value. Among them, xylene has three isomers, and p-xylene (PX) with the highest value accounts for 24%. Therefore, someone proposed a new process of shape-selective disproportionation, so that the reaction system can selectively generate p-xylene. [0003] P-xylene is the main raw material for the production of purified terephthalic acid in the polyester industry, and its demand has been growing at a high rate. Industrial use of reformed gasoline, pyrolysis gasoline, toluene, C 9 Aromatic hydrocarbons and mix...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J29/40C07C6/12C07C15/02
CPCY02P20/52
Inventor 王军任晓乾顾海威陈德民
Owner NANJING UNIV OF TECH
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