Method for directly preparing p-xylene from synthetic gas and aromatic hydrocarbon

Patent metadata

Field	Value
Publication number	US-11225443-B2
Application number	US-201716763015-A
Country	US
Kind code	B2
Filing date	Nov 21, 2017
Priority date	Nov 15, 2017
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

A method for directly preparing p-xylene from synthetic gas and aromatic hydrocarbon. The method includes contacting the feedstock containing synthetic gas and aromatic hydrocarbon excluding p-xylene with the catalyst in the reaction zone under reaction conditions sufficient to convert at least part of the feedstock to obtain a reaction effluent containing p-xylene; and separating p-xylene from the reaction effluent, where the catalyst includes a highly dispersed metal oxide material confined by an inert carrier, an acidic molecular sieve, and optionally at least one of graphite powder and dispersant, where in the highly dispersed metal oxide material confined by the inert carrier, the inert carrier is at least one of silicon oxide and alumina, and the content of the metal oxide in terms of metal is less than or equal to 10% by mass calculated based on the weight of the highly dispersed metal oxide material confined by the inert carrier.

First claim

The invention claimed is:

1. A method for directly preparing p-xylene from synthetic gas and an aromatic hydrocarbon, comprising:
contacting a feedstock containing synthetic gas and an aromatic hydrocarbon excluding p-xylene with a catalyst in a reaction zone under reaction conditions sufficient to convert at least part of the feedstock to obtain a reaction effluent containing p-xylene; and
separating p-xylene from the reaction effluent,
wherein the catalyst comprises a metal oxide material confined by an inert carrier, an acidic molecular sieve, and at least one selected from graphite powder and dispersant;
wherein the inert carrier is at least one selected from silicon oxide and alumina;
wherein the content of the metal oxide material in terms of metal is less than or equal to 10% by mass calculated based on the weight of the metal oxide material confined by the inert carrier; and
wherein the acidic molecular sieve is a modified acidic molecular sieve selected from the group consisting of modified acidic ZSM-5 molecular sieve, modified acidic ZSM-11 molecular sieve and mixtures thereof.

2. The method according to claim 1 , further comprising at least one of:
the reaction zone comprises a fixed bed reactor, or multiple fixed bed reactors in series and/or parallel;
the reaction conditions comprise: a reaction temperature in a range of 300° C. to 450° C., a reaction pressure in a range of 0.5 MPa to 10.0 MPa, a molar ratio of hydrogen to carbon monoxide in the synthetic gas in a range of 1:9 to 9:1, a weight hourly space velocity of aromatic hydrocarbon in a range of 0.01 h −1 to 20 h −1 , and a volume hourly space velocity of synthetic gas in the standard state in a range of 1000 −1 to 20000 h −1 ;
the metal oxide material is an oxide of at least one of zinc, chromium, zirconium, copper, manganese, platinum and palladium;
the content of the metal oxide material in terms of metal in the metal oxide material confined by the inert carrier is less than or equal to 5% by weight calculated based on the weight of the metal oxide material confined by the inert carrier;
the particle size of the metal oxide material in the metal oxide material confined by the inert carrier is less than or equal to 100 nm;
the modified acidic molecular sieve is provided by modifying acidic ZSM-5 molecular sieve or acidic ZSM-11 molecular sieve, wherein the modification is one or more of modification by phosphorus, modification by boron, modification by silicon, modification by an alkaline earth metal, and modification by a rare earth metal;
the atomic ratio of silicon to aluminum (Si/AI) in the modified acidic ZSM-5 and ZSM-11 molecular sieves is 3 to 200;
the particle shape of the catalyst is spherical, bar-shaped, cylindrical, semi-cylindrical, prismatic, clover-shaped, ring-shaped, pellet-shaped, regular or irregular particle-shape or flake; and
the aromatic hydrocarbon excluding p-xylene is at least one aromatic hydrocarbon having the following general formula:

wherein, R 9 , R 10 , R 11 , R 12 , R 13 and R 14 are each independently selected from hydrogen, or a C 1 -C 10 hydrocarbyl.

3. The method according to claim 1 , wherein the catalyst comprises the metal oxide material confined by the inert carrier in an amount ranging from 10% to 90% by weight, the acidic molecular sieve in an amount ranging from 10% to 90% by weight, the graphite powder in an amount ranging from 0% to 10% by weight and the dispersant in an amount ranging from 0% to 40% by weight;
wherein the total content of the metal oxide material confined by the inert carrier and the acidic molecular sieve is in a range of 60% to 100% by weight; and
wherein the weight percentage is calculated based on the total weight of the catalyst.

4. The method according to claim 1 , wherein the catalyst comprises the metal oxide material confined by the inert carrier in an amount ranging from 20% to 80% by weight, the acidic molecular sieve in an amount ranging from 20% to 80% by weight, the graphite powder in an amount ranging from 0% to 5% by weight and the dispersant in an amount ranging from 0% to 30% by weight; and
wherein the weight percentage is calculated based on the total weight of the catalyst.

5. The method according to claim 1 , wherein the average particle size of the metal oxide material confined by the inert carrier is less than or equal to 5 mm, and the average particle size of the acidic molecular sieve particles is less than or equal to 5 mm.

6. The method according to claim 1 , wherein the catalyst is prepared by a method comprising the following steps:
(1) providing a metal oxide material confined by the inert carrier;
(2) providing a modified acidic molecular sieve;
(3) mixing the metal oxide material confined by the inert carrier obtained in step
(1) with the modified acidic molecular sieve obtained in step (2) and at least one selected from graphite powder and dispersant to obtain a mixture, and molding the mixture.

7. The method according to claim 6 , the method for preparing the catalyst further comprising at least one of the following features:
in step (1), the metal oxide material confined by the inert carrier is prepared by a precipitation-calcination method, or by a sol-gel method;
the modified acidic molecule is one selected from the group consisting of phosphorus-modified, boron-modified, silicon-modified, alkaline earth metal-modified and/or rare earth metal-modified ZSM-5 molecular sieve, and phosphorus-modified, boron-modified, silicon-modified, alkaline earth metal-modified and/or rare earth metal-modified ZSM-11 molecular sieve; and in step (3), the mixture is molded into catalyst particles by an extrusion method or a molding method.

8. The method according to claim 6 , wherein in step (1) of the method for preparing the catalyst, the metal oxide material confined by the inert carrier is provided by a method comprising the steps as follows:
formulating a mixed metal salt aqueous solution from a catalytically active metal salt and an aluminum salt;
contacting the mixed metal salt aqueous solution with a precipitant aqueous solution to co-precipitate the metal ions in the mixed metal salt aqueous solution;
aging the solution mixture; and
washing, drying and calcining the precipitate to obtain the metal oxide material confined by the inert carrier.

9. The method according to claim 8 , further comprising at least one of the following features:
the catalytically active metal salt and aluminum salt are one selected from hydrochloride, sulfate and nitrate;
the precipitant aqueous solution is one selected from sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, ammonia water, sodium hydroxide, potassium hydroxide and mixtures thereof;
the co-precipitation is carried out at a temperature in a range of 0° C. to 90° C.;
the pH value during the co-precipitation is in a range of 7.0 to 8.5;
the time for aging is not less than 1 hour; and
the calcination is carried out at a temperature in a range of 300° C. to 700° C.

10. The method according to claim 6 , wherein in step ( 1 ) of the method for preparing the catalyst, the metal oxide material confined by the inert carrier is provided by
a method comprising the steps:
adding an aqueous solution of a catalytically active metal salt and an aqueous solution of a precipitant together into siloxane-based compound, so that a co-precipitation and sol-gel reaction can be carried out, and then washing, drying and then calcining the obtained gel to prepare the metal oxide material confined by the

Assignees

• Dalian Inst Chem & Physics Cas

Inventors

• Ni Youming
• Zhu Wenliang
• Liu Zhongmin
• Liu Yong
• Chen Zhiyang
• Liu Hongchao
• Ma Xiangang
• Liu Shiping

Classifications

• B01J2235/15

  X-ray diffraction · CPC title

• C07C2/862 Primary

  the non-hydrocarbon contains only oxygen as hetero-atoms · CPC title

• B01J35/40

  characterised by dimensions, e.g. grain size (in a colloidal state B01J35/23; crystallite size B01J35/77) · CPC title

• C07C2529/40

  of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11 · CPC title

• B01J37/0009

  Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst · CPC title