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CN-121975074-A - Method for preparing m-cresol and m-cresol formaldehyde resin by using crude phenol refining residues

CN121975074ACN 121975074 ACN121975074 ACN 121975074ACN-121975074-A

Abstract

The invention discloses a method for preparing m-cresol and m-cresol formaldehyde resin by using crude phenol refining residues. The invention adopts an acidic silicon aluminum oxide solid catalyst and a zirconium phosphate system, removes longer alkyl groups such as ethyl groups on aromatic rings in a 3, 4-methyl ethyl phenol mixture, simultaneously retains methyl groups, converts phenol containing longer alkyl groups into simple cresol, phenol and the like, obtains phenol, m-cresol, 2,3, 5-trimethylphenol through reduced pressure rectification treatment, further reacts mixed phenol obtained through rectification with aldehydes to obtain modified m-cresol formaldehyde resin products such as p-cresol, 2,3, 5-trimethylphenol and the like, converts complex raw materials into simple products with definite targets through a cracking reaction, removes sulfur and nitrogen impurities in most raw materials by utilizing the acidic environment of the cracking process, omits additional refining steps, and improves the grade of all subsequent products. The invention breaks through the limitation of traditional rectification, simplifies the difficulty of physical separation by chemical means, combines phenol and phenolic resin, and improves the added value of the product.

Inventors

  • YAN CHUNPING
  • WANG JING
  • SUN HUIQING
  • ZHAO YUAN
  • MENG DECHANG
  • QIN LIYING
  • ZHAO JIAWEI
  • SHI ZHIJIE
  • HAN XUE
  • Kong Bihua
  • CHEN YIMING

Assignees

  • 煤炭科学技术研究院有限公司

Dates

Publication Date
20260505
Application Date
20260206

Claims (8)

  1. 1. A method for preparing m-cresol and m-cresol formaldehyde resin by using crude phenol refining residues, which is characterized by comprising the following steps: (1) Rectifying and separating the crude phenol refining residues to obtain a 3, 4-methyl ethyl phenol mixture; (2) Carrying out cracking and transposition reaction on the 3, 4-methyl ethyl phenol mixture, the acidic silicon aluminum oxide solid catalyst and zirconium phosphate at 300-400 ℃, cooling after the reaction is finished, discharging ethylene generated in the reaction, filtering to obtain a cracking reaction product, and carrying out preliminary rectification on the cracking reaction product to obtain mixed phenol; (3) Carrying out reduced pressure rectification treatment on the mixed phenol and sulfuric acid obtained by rectification in the step (2) to obtain a m-cresol product, a phenol product and a2, 3, 5-trimethylphenol product; (4) Adding aldehydes into the mixed phenol to react, heating and distilling to remove free phenol, rectifying the free phenol to obtain 99.9 percent of p-cresol, and heating and decompressing and dehydrating the material with the free phenol removed to obtain the m-cresol formaldehyde resin.
  2. 2. The method of claim 1, wherein the step (1) comprises adding crude phenol refining residues into a reaction kettle, heating to 110-150 ℃, dropwise adding concentrated sulfuric acid with a concentration of more than or equal to 95wt%, rectifying the materials under reduced pressure after the treatment, refluxing and dehydrating, and obtaining a 3, 4-methyl ethyl phenol mixture at the top of a rectifying tower.
  3. 3. The method according to claim 2, wherein the crude phenol refining residue is residue after crude phenol is distilled to phenol, cresol and xylenol, and the residue distillation range is not less than 225 ℃; And/or the 3, 4-methyl ethyl phenol mixture comprises 80-98 wt% of 3, 4-methyl ethyl phenol/m-p-tertiary butyl phenol, 1-10 wt% of 3-methyl-5-ethyl phenol, 1-10 wt% of 2,3, 5-trimethyl phenol, 0-1 wt% of m-p-isopropyl phenol, 0-1 wt% of m-p-propyl phenol and 0-10 wt% of other components; And/or the addition amount of the concentrated sulfuric acid is 0.1-0.5wt% of the crude phenol refining residues; And/or the condition of reduced pressure rectification is 150-300 of theoretical plates of a theoretical plate of a rectifying tower, the vacuum degree is-0.085 to-0.095 MPa, and the reflux ratio is 15-30:1.
  4. 4. The method according to claim 3, wherein in the step (2), the mass ratio of the 3, 4-methyl ethyl phenol mixture, the acidic silicon aluminum oxide solid catalyst and the zirconium phosphate is 100:5-30:0.05-5; and/or the acidic silicon aluminum oxide solid catalyst comprises silicon dioxide and acidic aluminum oxide, wherein the mass ratio of the silicon dioxide to the acidic aluminum oxide is 1:0.01-100; And/or the time of the cracking and transposition reaction is 5-10 h, and the reaction pressure is 1.8-6.0 MPa; And/or, the cleavage reaction product comprises p-cresol, m-cresol, 2,3, 5-trimethylphenol, and phenol; And/or the condition of preliminary rectification of the cracking reaction product is that the theoretical plate is 20-100, the vacuum degree is-0.080 to-0.090 MPa, and the reflux ratio is 0.5-5:1; and/or, the mixed phenol obtained by preliminary rectification of the cracking reaction product comprises phenol, m-cresol, 2,3, 5-tricresyl.
  5. 5. The method of claim 1, wherein the vacuum degree of the vacuum rectification treatment in the step (3) is-0.080 to-0.090 MPa, the reflux ratio is 5-15:1, and the theoretical plate is 100-200.
  6. 6. The method according to claim 6, wherein the content of the phenol product in the step (3) is not less than 99.5wt%, and the content of the sulfur-containing compound and the nitrogen-containing compound is not more than 10ppm; And/or the content of the m-cresol product is more than or equal to 99.5 weight percent, and the content of the sulfur-containing compound and the nitrogen-containing compound is less than or equal to 10ppm; And/or the content of the 2,3, 5-trimethylphenol product is more than or equal to 99.5 weight percent, and the content of the sulfur-containing compound and the nitrogen-containing compound is less than or equal to 10ppm.
  7. 7. The method of claim 1, wherein the step (4) comprises mixing the mixed phenol and the catalyst, heating to 80-100 ℃ to react with aldehydes, adding for 3-6 hours, preserving heat for 3-10 hours to sample and analyze, ending the reaction when the m-cresol content is less than or equal to 0.1%, heating and distilling, standing and layering distilled phenol water by using a liquid separation device, returning a water layer into a kettle to separate a phenol-containing oil layer, continuously distilling to 110-120 ℃ to dehydrate when the distilled water is clear and transparent, extracting the distilled water layer once by using a water-insoluble solvent, standing and layering, merging the oil layer and the phenol-containing oil layer, adding dilute sulfuric acid with the concentration of 20-50% and water for one time, adding sulfuric acid with the concentration of 95-100% into an organic layer to rectify to obtain a solvent, and performing reduced pressure rectification to obtain a p-cresol product; And heating, decompressing and dehydrating the material after the free phenol is distilled off, heating to 190-200 ℃, heating for 2-3 hours, then preserving heat for 1-2 hours, breaking vacuum by using nitrogen, and discharging the material to a stainless steel material tray while the material is hot under the protection of nitrogen to obtain the 2,3, 5-trimethylol modified m-cresol formaldehyde resin product.
  8. 8. The method of claim 7, wherein the catalyst comprises one or more of oxalic acid, formic acid, phosphoric acid, hydrochloric acid, benzoic acid, and benzenesulfonic acid; And/or the catalyst is used in an amount of 0.1-5wt% of the mass of the mixed phenol; and/or the aldehyde comprises one or more of paraformaldehyde, formaldehyde and acetaldehyde; And/or the using amount of the aldehydes is 0.5-0.9 of the molar amount of the mixed phenols; And/or the water-insoluble solvent comprises one of benzene, chlorinated hydrocarbon, chlorinated benzene, ether, ketone and ester; and/or the dosage of the water-insoluble solvent is 0.1-1 times of the mass of the distilled water layer material; and/or the vacuum degree of the reduced pressure rectification treatment is-0.080 to-0.090 MPa, the reflux ratio is 5-10:1, and the theoretical plate is 100-200; and/or the content of the p-cresol product is more than or equal to 99.9 weight percent, and the content of the sulfur-containing compound and the nitrogen-containing compound is less than or equal to 0.1ppm.

Description

Method for preparing m-cresol and m-cresol formaldehyde resin by using crude phenol refining residues Technical Field The invention relates to the technical field of coalification product separation and organic synthesis, in particular to a method for preparing m-cresol and m-cresol formaldehyde resin by using crude phenol refining residues. Background The crude phenol rectification residue has a low price of 1000-2000 yuan/ton and can only be used as firing oil, and many phenol substances such as m-p-isopropyl phenol, m-p-propyl phenol, 3-methyl-5-ethyl phenol, 2,3, 5-tricresyl, 2, 3-methyl ethyl phenol, 3, 4-methyl ethyl phenol, m-p-tert-butyl phenol and the like are not utilized, and 3, 4-methyl ethyl phenol has similar boiling points with m-p-propyl phenol, 3-methyl-5-ethyl phenol, 2,3, 5-tricresyl, m-p-tert-butyl phenol and the like, and high-purity 3, 4-methyl ethyl phenol cannot be obtained through rectification separation, but 3, 4-methyl ethyl phenol fraction can be enriched. The 3, 4-methyl ethyl phenol fraction contains a small amount of m-p-isopropyl/propyl phenol, a certain amount of m-p-tert-butyl phenol, 2,3, 5-trimethylphenol, 3-methyl-5-ethyl phenol and other impurities, the method of catalytically removing ethyl, propyl and tert-butyl by a high-temperature fixed bed can be considered to obtain a mixture of m-cresol, 2,3, 5-trimethylphenol and phenol, then the mixture of m-cresol with very low sulfur-nitrogen impurity content (m-cresol, 2,3, 5-trimethylphenol and phenol) is distilled to obtain mixed m-cresol with very low sulfur-nitrogen impurity content, the mixed m-cresol can be treated by two methods, namely, the method is considered to respectively consider that the reactivity of 2,3, 5-trimethylphenol, m-cresol, phenol, p-cresol and formaldehyde is 2.02, 2.88, 1, 0.31,2,3,5-trimethylphenol, and m-cresol, the heat resistance, the dimensional stability, the optical performance and the electrical performance of the phenolic resin can be obviously improved, the flexibility of the phenolic resin can be increased, the material processing performance is good, the m-cresol reaction is slow, the m-cresol can be directly mixed with the m-cresol under the conditions of very low in the m-cresol impurity content, and the m-cresol has very high thermal stability, and the 3.99% of the m-cresol is produced by the method, and the optical m-cresol has very poor thermal stability, and the 3.99% of the m-cresol is compared with the optical m-cresol. Disclosure of Invention The present invention aims to solve at least one of the technical problems in the related art to some extent. The invention provides a method for preparing m-cresol and m-cresol formaldehyde resin by using crude phenol refining residues. In a first aspect, the present invention provides a method for preparing m-cresol, m-cresol formaldehyde resin from crude phenol refining residues, comprising the steps of: (1) Rectifying and separating the crude phenol refining residues to obtain a 3, 4-methyl ethyl phenol mixture; (2) Carrying out cracking and transposition reaction on the 3, 4-methyl ethyl phenol mixture, the acidic silicon aluminum oxide solid catalyst and zirconium phosphate at 300-400 ℃, cooling after the reaction is finished, discharging ethylene generated in the reaction, filtering to obtain a cracking reaction product, and carrying out preliminary rectification on the cracking reaction product to obtain mixed phenol; (3) Carrying out reduced pressure rectification treatment on the mixed phenol and sulfuric acid obtained by rectification in the step (2) to obtain a m-cresol product, a phenol product and a2, 3, 5-trimethylphenol product; (4) Adding aldehydes into the mixed phenol to react, heating and distilling to remove free phenol, rectifying the free phenol to obtain 99.9 percent of p-cresol, and heating and decompressing and dehydrating the material with the free phenol removed to obtain the m-cresol formaldehyde resin. Further, the step (1) comprises the steps of adding crude phenol refined residues into a reaction kettle, heating to 110-150 ℃, dropwise adding concentrated sulfuric acid with the concentration of more than or equal to 95wt%, rectifying the materials under reduced pressure after the treatment, refluxing and dehydrating, and obtaining a 3, 4-methyl ethyl phenol mixture at the top of a rectifying tower. Further, the crude phenol refining residues are residues obtained after crude phenol is distilled to phenol, cresol and xylenol, and the distillation range of the residues is more than or equal to 225 ℃. Further, the 3, 4-methyl ethyl phenol mixture comprises 80-98 wt% of 3, 4-methyl ethyl phenol/m-p-tert-butyl phenol, 1-10 wt% of 3-methyl-5-ethyl phenol, 1-10 wt% of 2,3, 5-trimethyl phenol, 0-1 wt% of m-p-isopropyl phenol, 0-1 wt% of m-p-propyl phenol and 0-10 wt% of other components. Further, the addition amount of the concentrated sulfuric acid is 0.1-0.5wt% of the crude phenol refining residues. Further, the