Unlock instant, AI-driven research and patent intelligence for your innovation.

A kind of method that uses solid catalyst to carry out isopropyltoluene isomerization

A technology of isopropyltoluene and solid catalysts, which is applied in the direction of catalysts, molecular sieve catalysts, carbon compound catalysts, etc., can solve the problems of small pore size, harsh operating environment, and restrictions on the application of solid catalysts, and achieve convenient separation, simple post-processing, and overall Effect of High Atom Utilization

Active Publication Date: 2022-07-05
ZHEJIANG NHU CO LTD +1
View PDF0 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

AlCl 3 There are big problems in the use process: 1. AlCl 3 It will hydrolyze to produce HCl, the operating environment is harsh, and the equipment is severely corroded; 2. It will produce a large amount of aluminum-containing wastewater
This is because the molecular diameters of the three isomers of isopropyltoluene are different, and the molecular diameters of the middle and o-isopropyltoluene are relatively large, which are difficult to be adsorbed by conventional solid catalysts, and the isomerization reaction of isopropyltoluene requires Carried out at a certain acidity, which further limits the application of solid catalysts in this reaction
[0008] For example, solid phosphoric acid has weak acidity and low isomerization activity, so it can only be used as a catalyst for toluene alkylation; ZSM-5 and SAPO-11 molecular sieves have small pore sizes, and their ability to adsorb m- and o-isopropyltoluene is very weak, so isomerization Low activity; β-type molecular sieve has weak acidity and low isomerization activity

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A kind of method that uses solid catalyst to carry out isopropyltoluene isomerization
  • A kind of method that uses solid catalyst to carry out isopropyltoluene isomerization

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Example 1 (HY molecular sieve)

[0027] Add 56g HY molecular sieve (SiO 2 / Al 2 O 3 = 5.3). The raw material is a mixture of o- and m-cymene added with toluene, wherein the mass fractions of m-cymene, o-cymene and toluene are respectively: 37%, 3% and 60%, and the feed flow rate is 1.63mL / min, converted to mass airspeed of 1.5h -1 . The reaction temperature was 340° C. and the pressure was 0.1 MPa. The compositions of the components in the obtained isomerization reaction solution were shown in Table 1. The product intermediate / para / ortho=64.1 / 30.4 / 5.4, the isomer distribution is close to thermodynamic equilibrium, the ortho- and meta-isopropyltoluene is converted to para-isopropyltoluene to the greatest extent, and the single-pass yield of para-isopropyltoluene is 18.3 %.

[0028] Yield of p-cymene in one pass = mass of p-cymene in the product / (mass of intermediate cymene in the raw material + mass of o-cymene in the raw material)*100%.

Embodiment 2

[0029] Example 2 (HY molecular sieve)

[0030] Add 56g HY molecular sieve (SiO 2 / Al 2 O 3 = 9.7). The raw material is a mixture of o- and m-cymene added with toluene, wherein the mass fractions of m-cymene, o-cymene and toluene are respectively: 37%, 3% and 60%, and the feed flow rate is 1.63mL / min, converted to mass airspeed of 1.5h -1 . The reaction temperature was 340° C. and the pressure was 0.1 MPa. The compositions of the components in the obtained isomerization reaction solution were shown in Table 1. The product intermediate / para / ortho=64.5 / 29.7 / 5.8, the isomer distribution is also basically close to the thermodynamic equilibrium, the ortho and meta cumene are converted to para-cumene to the greatest extent, and the ratio of silicon to aluminum ratio is increased. The activity decreased slightly, but the decomposition of cumene slowed down, and the single-pass yield increased slightly, and the single-pass yield of p-cymene was 20.5%.

Embodiment 3

[0031] Example 3 (HY molecular sieve)

[0032] Add 56g HY molecular sieve (SiO 2 / Al 2 O 3 = 14.2). The raw material is a mixture of o- and m-cymene added with toluene, wherein the mass fractions of m-cymene, o-cymene and toluene are respectively: 37%, 3% and 60%, and the feed flow rate is 1.63mL / min, converted to mass airspeed of 1.5h -1 . The reaction temperature was 340° C. and the pressure was 0.1 MPa. The compositions of the components in the obtained isomerization reaction solution were shown in Table 1. The intermediate / para / ortho=72.3 / 21.4 / 6.3 of the product, with the further increase of the silicon-alumina ratio, the activity is further weakened, and the thermodynamic equilibrium is not reached, but the decomposition of the raw material is also reduced, and the single-pass yield of p-Cumene is 15.2%.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a method for isomerizing cumene by using a solid catalyst. The reaction solution comprising p-isopropyltoluene, the solid catalyst is HY molecular sieve. The method can efficiently isomerize o-cymene and meta-cymene into p-cymene, the composition distribution of the isomerized product is close to the thermodynamic equilibrium state, and the used catalyst is convenient for separation and recovery.

Description

technical field [0001] The invention belongs to the field of synthesis of perfume intermediates, relates to a method for synthesizing cymene, in particular to a method for isomerizing cumene by using a solid catalyst. Background technique [0002] P-Cymen, also known as cymene, is an important intermediate in organic synthesis and is widely used in the pharmaceutical and fragrance industries. Downstream can be used to produce p-cresol, p-isopropyl benzoic acid, musk tuna and powder sandalwood musk. [0003] There are two main production routes of p-Cumene: 1. It is prepared from natural products; 2. It is prepared by chemical synthesis with toluene and propylene as raw materials. The natural route mainly uses turpentine as the raw material. The production cost of this process is high and the output is low, which cannot meet the dosage requirements of downstream products. The chemical synthesis route has low cost and high atom utilization, which can reach 100% in theory. ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C07C5/27C07C15/02B01J29/08
CPCC07C5/2737B01J29/084C07C2529/08C07C15/02Y02P20/52
Inventor 向炜丁瑜周志杰张志鹏刘效先于明
Owner ZHEJIANG NHU CO LTD