Modified ZSM-5 catalyst for alkylation reactions, preparation method and applications thereof, and p-xylene preparation method

An alkylation reaction, ZSM-5 technology, applied in the field of modified ZSM-5 catalyst and its preparation, the preparation of p-xylene, can solve the problems of low product selectivity, reducing the activity of molecular sieve, blocking the original pores and the like, achieve high yield

An alkylation reaction, ZSM-5 technology, applied in the field of modified ZSM-5 catalyst and its preparation, the preparation of p-xylene, can solve the problems of low product selectivity, reducing the activity of molecular sieve, blocking the original pores and the like, achieve high yield

CN107930677AActive Publication Date: 2018-04-20CHNA ENERGY INVESTMENT CORP LTD +1
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  • Modified ZSM-5 catalyst for alkylation reactions, preparation method and applications thereof, and p-xylene preparation method
  • Modified ZSM-5 catalyst for alkylation reactions, preparation method and applications thereof, and p-xylene preparation method
  • Modified ZSM-5 catalyst for alkylation reactions, preparation method and applications thereof, and p-xylene preparation method

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Experimental program
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Effect test

preparation example Construction

[0033] The present invention further provides the preparation method of above-mentioned modified ZSM-5 catalyst, wherein, this method comprises:

[0034] (1) In an aqueous solvent, and in the presence of a template, carry out hydrothermal synthesis crystallization of ZSM-5 molecular sieve and silicon source;

[0035] (2) performing solid-liquid separation on the crystallized product, and roasting the obtained solid phase,

[0036] Wherein, the ZSM-5 molecular sieve provides the inner core of the ZSM-5 molecular sieve, and the silicon source provides the SiO required for the all-silicon molecular sieve shell. 2 ; Relative to 100 parts by weight of ZSM-5 molecular sieve as the inner core, the amount of the template agent used to form the shell of the all-silicon molecular sieve is 5-30 parts by weight; the amount of silicon source is 5-30 parts by weight.

[0037] According to the present invention, the crystallization reaction in step (1) can make the outer surface of the ZSM-...

Embodiment approach

[0045] According to one embodiment of the present invention, the roasting process includes: rising from 10-30°C to a roasting temperature of 500-700°C at a heating rate of 1-20°C / min (preferably 5-10°C / min), and keeping the temperature 1-24h (preferably 4-6h).

[0046] The present invention further provides a kind of preparation method of p-xylene, wherein, the method comprises:

[0047] In the presence of an alkylation catalyst, the toluene, methanol and hydrogen are subjected to an alkylation reaction, wherein the alkylation catalyst is the modified ZSM-5 catalyst used in the alkylation reaction of the present invention.

[0048] Wherein, the alkylation reaction is a conventional alkylation reaction process in the art, for example, the temperature of the alkylation reaction is 400-500°C. Usually, the process includes that the mixed gas of toluene, methanol and hydrogen flows through the alkylation catalyst at a certain flow rate, and the alkylation reaction is completed und...

Embodiment 1

[0058] This example is used to illustrate the modified ZSM-5 catalyst of the present invention and its preparation method.

[0059] (1) 10g of HZSM-5 (Si / Al (molar ratio) = 250, with a shape of 10μm*2μm plate-like structure, purchased from Nankai University Catalyst Co., Ltd.), 1.4g of ethyl orthosilicate, 0.8g of TPAOH (The quality is the quality of TPAOH, the same below; and TPAOH is provided as a 25% by weight aqueous solution) mixed with 112g of water, and hydrothermally synthesized and crystallized at 170°C in a rotary self-pressure crystallization kettle for 24h;

[0060] (2) Filter the crystallized sample in step (1) and wash it with deionized water to neutrality, and then dry it in an oven at 120°C for 2 hours; place the dried solid in a muffle furnace, Raise from room temperature (about 25°C) to 550°C at a heating rate of 5°C / min, then roast at a constant temperature of 550°C for 5 hours, and naturally cool to room temperature to obtain the modified ZSM-5 catalyst Z1;...

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Abstract

The invention discloses a modified ZSM-5 catalyst for alkylation reactions, a preparation method and applications thereof, and a p-xylene preparation method. The modified ZSM-5 catalyst comprises a ZSM-5 molecular sieve core and an all-silicon molecular sieve shell formed on the outer surface of the core, wherein the pore channels of the shell are communicated to the pore channels of the core so as not to cover the pore channels of the ZSM-5 molecular sieve core by the all-silicon molecular sieve shell, the all-silicon molecular sieve shell has shape-selective effects on alkylation reactions and does not have reaction activity, a molar ratio of Si to Al in the ZSM-5 molecular sieve core is 100-500:1, and the all-silicon molecular sieve shell is formed by reducing the concentrations of a silicon source and a template agent through epitaxial growth. According to the present invention, the catalyst can operate at a high toluene concentration and high space velocity to obtain the high yield of p-xylene, and is suitable for large-scale production and industrial scale application.

Description

technical field [0001] The invention relates to the field of alkylation catalysts, in particular to a modified ZSM-5 catalyst used in an alkylation reaction, a preparation method and application thereof, and a preparation method of p-xylene. Background technique [0002] P-xylene (p-xylene, PX) is an important chemical raw material commonly used in industry, and most of p-xylene is used to produce terephthalic acid, which is then used to produce chemical products such as polyester fiber. The demand for p-xylene has been growing rapidly in recent years. In 2015, the domestic demand for PX was 24 million tons, while the national production capacity was only about 11 million tons. In recent years, the import volume has exceeded 50%. Although new PX projects have been put into production all over the country in recent years, the annual gap is still more than 5 million tons. [0003] At present, there are three production processes of p-xylene worldwide, disproportionation of to...

Claims

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Application Information

Patent Timeline
20 Apr 2018
Publication
CN107930677A
IPC
B01J29/40; C07C2/86; C07C15/08
CPC
B01J29/005; B01J29/40; C07C2/864; C07C2529/40; C07C15/08; Y02P20/52
Inventors
王传付; 朱豫飞