Method for preparing o-cresol

A technology for o-cresol and phenol, applied in the field of preparing o-cresol, can solve the problem of low selectivity of o-cresol, and achieve the effects of long service life, high selectivity and simple process

Active Publication Date: 2009-08-26
HUNAN XINLING CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In the existing industrial synthesis method of o-cresol, the main deficiency is: the selectivity of o-cresol is not high, and more by-products such as 2,6

Method used

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  • Method for preparing o-cresol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Catalyst preparation: Weigh Fe(NO 3 ) 3 9H 2 O 404g, Mg(NO 3 ) 2 ·6H 2 O 51.2g and Ce(NO 3 ) 3 ·6H 2 O 2.17g was mixed and dissolved in 800mL ethanol, and then it was slowly mixed with 28% concentrated ammonia water 700mL containing 4g PEG in a co-current manner under normal temperature ultrasonic conditions, and the ultrasonic wave was continued for 30min after the addition, and then the precipitate was filtered. Wash and dry at 120°C for 6h. The obtained solid is then roasted at 450°C for 8 hours, and finally the solid is ground into fine particles, and then crushed into small particles of 10 to 20 meshes after tableting. The obtained basic metal oxide catalyst is Fe 1 Mg 0.2 Ce 0.05 / o.

[0026] The above-mentioned catalyst was packed in a Φ7mm stainless steel reaction tube, the catalyst loading amount was 5g, the reaction mixture was metered in with an advection pump, and the temperature was controlled by a temperature control device. Feed space velocity...

Embodiment 2

[0031] Catalyst is the same as embodiment 1, reaction mixture phenol: xylenol: methyl alcohol: water=34: 10: 38: 18 (wt%), carrier gas helium flow rate is 40mL / min, changes feeding space velocity, other conditions are implemented with Example 1, after 12 hours of reaction, sampling was carried out for chromatographic analysis. There were no impurities such as p-cresol and anisole, and the selectivity of o-cresol was more than 95.2%. The results are shown in Table 2.

[0032] Table 2 changes the result of feed space velocity synthesis o-cresol

[0033]

Embodiment 3

[0035] The catalyst is the same as in Example 1, and the catalyst is filled with 40mL and weighs 36.5g. The reaction tube is a Φ16×1200mm stainless steel tube. Reaction mixture phenol:xylenol:methanol:water=34:10:38:18 (wt%), space velocity 1.2h -1 , atmospheric pressure, carrier gas N 2 The flow rate was 120mL / min, and the reaction was carried out continuously for 500h (excluding regeneration). The results are shown in Table 3. The average conversion rate of phenol was 33.4%, and the selectivity of o-cresol was 96.0%.

[0036] Table 3 Catalyst Activity Stability Investigation Results

[0037]

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Abstract

The invention discloses a method for preparing o-cresol, comprising the following steps: uniformly mixing phenol, 2, 6-dimethyl phenol and methanol with water by a mass ratio 34: (5-20): (33-46): (28-41), and then pumping the mixture into a reaction tube containing alkylate catalyst, introducing inert supporting gas to the reaction tube, and obtaining the o-cresol after condensating and recycling the reaction product. The reaction conditions comprise normal atmosphere, reaction temperature of 280 to 450 DEG C, and the airspeed of incoming stock of 0.8-1.8h. The method has advantages of simple technical process, high selectivity of o-cresol, relatively low selectivity of 2, 6-dimethyl phenol, no generation of by-products such as meta-cresol, p-cresol and anisole and long service life of the catalyst.

Description

technical field [0001] The present invention relates to a method for preparing o-cresol, in particular to a method for preparing o-cresol by increasing the equilibrium concentration of 2,6-xylenol in the system by using basic metal oxides as catalysts and using phenol and methanol as raw materials . Background technique [0002] O-cresol, also known as o-cresol, is a colorless crystal with a strong phenol smell, slightly soluble in water, soluble in ethanol, ether, chloroform and hot water, and is mainly used for synthetic resins, pesticides, medicines, dyes, and antioxidants Raw materials for agents, etc. At present, the synthesis of o-cresol generally adopts the phenol-methanol vapor phase alkylation process. Due to the high catalytic selectivity of metal oxides for the ortho-alkylation of phenol, metal oxides are mostly used as catalysts for the synthesis of o-cresol. However, when metal oxides are used as catalysts, there is a thermodynamic equilibrium relationship be...

Claims

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Application Information

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IPC IPC(8): C07C39/07C07C37/11B01J23/745B01J23/83
CPCY02P20/52
Inventor 黄华佘喜春衷晟徐斌谢琼玉胡莲佑
Owner HUNAN XINLING CHEM CO LTD
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