Catalyst for producing paraxylene by co-conversion of methanol and/or dimethyl ether and C4 liquefied gas, method for preparing the same and method for using the same

Patent metadata

Field	Value
Publication number	US-9968922-B2
Application number	US-201214366209-A
Country	US
Kind code	B2
Filing date	Apr 26, 2012
Priority date	Dec 19, 2011
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

This application provides a catalyst for producing paraxylene by co-conversion of methanol and/or dimethyl ether and C 4 liquefied gas, and preparation and application thereof. The catalyst is an aromatization molecular sieve catalyst with a shape-selective function co-modified by bimetal and siloxane compound. Methanol and/or dimethyl ether and C 4 liquefied gas are fed in reactor together, wherein aromatization reaction occurring on a modified shape-selective molecular sieve catalyst. The yield of aromatics is effectively improved, in which paraxylene is the main product. In products obtained by co-conversion of methanol and/or dimethyl ether and C 4 liquefied gas, the yield of aromatics is greater than 70 wt %, and the content of paraxylene in aromatics is greater than 80 wt %, and the selectivity of paraxylene in xylene is greater than 99 wt %.

First claim

The invention claimed is:

1. A process for producing paraxylene by co-conversion of methanol and/or dimethyl ether and C 4 liquefied gas, comprising the steps as follows:
passing a gas mixture containing methanol and/or dimethyl ether and C 4 liquefied gas through a reactor comprising an aromatization molecular sieve catalyst with a shape-selective function to produce paraxylene by aromatization reaction;
wherein said aromatization reaction is carried out at a temperature from 400° C. to 550° C., a pressure from atmospheric pressure to 2 MPa and a weight hourly space velocity of said gas mixture from 1 h −1 to 10 h −1 ;
wherein said aromatization molecular sieve catalyst comprises HZSM-5 and/or HZSM-11 zeolite molecular sieve co-modified by bimetal and a siloxane compound;
wherein said bimetal are zinc and gallium;
wherein said siloxane compound has the structural formula

wherein, R 1 , R 2 , R 3 and R 4 are independently selected from C 1 -C 10 alkyl group, and wherein a loading amount of said zinc is 0.5-8 wt % of a total weight of said catalyst, a loading amount of said gallium is 0.5-8 wt % of the total weight of said catalyst, and a loading amount of said siloxane compound, which is based on silicon oxide, is 0.5-10 wt % of the total weight of said catalyst;
wherein the process comprises the following step to prepare said aromatization molecular sieve catalyst:
(a) impregnating a molecular sieve comprising HZSM-5 and/or HZSM-11 in a solution containing at least one soluble salt of one of zinc or gallium, which is then filtered, dried and calcined to obtain a metal-modified molecular sieve;
(b) impregnating said metal-modified molecular sieve obtained from step (a) in a solution containing at least one soluble salt of the other of zinc or gallium, which is then filtered, dried and calcined to obtain a bimetal-modified molecular sieve; and
(c) impregnating said bimetal-modified molecular sieve obtained from step (b) in a siloxane compound, which is then filtered, dried and calcined to obtain said aromatization molecular sieve catalyst.

2. The process according to claim 1 , wherein said siloxane compound is tetraethoxysilane.

3. The process according to claim 1 , wherein said process is conducted in a fixed bed or a fluidized bed reactor.

Assignees

• Xu Lei
• Liu Zhongmin
• Yu Zhengxi
• Dalian Inst Chem & Physics Cas

Inventors

• Xu Lei
• Liu Zhongmin
• Yu Zhengxi

Classifications

• C07C15/08

  Xylenes · CPC title

• B01J2229/186

  not in framework positions · CPC title

• B01J2231/005

  General concepts, e.g. reviews, relating to methods of using catalyst systems, the concept being defined by a common method or theory, e.g. microwave heating or multiple stereoselectivity · CPC title

• B01J31/0275

  also containing elements or functional groups covered by B01J31/0201 - B01J31/0269 · CPC title

• B01J29/40 Primary

  of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively · CPC title