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CN-121974784-A - Method for preparing alkylphenol by alkylating phenol and isopropanol

CN121974784ACN 121974784 ACN121974784 ACN 121974784ACN-121974784-A

Abstract

The invention relates to the technical field of biomass energy chemical industry, in particular to a method for preparing alkylphenol by alkylating phenol and isopropanol. The method comprises the following steps of 1, calcining and preprocessing an H-Beta molecular sieve to obtain a preprocessed molecular sieve, 2, filling the preprocessed molecular sieve into a fixed bed reactor, discharging air, preheating to 200-350 ℃,3, dissolving phenol into isopropanol to obtain a mixed raw material, and 4, pumping the mixed raw material into the fixed bed reactor to contact with the preprocessed molecular sieve, and carrying out alkylation reaction under the conditions of the temperature of 200-350 ℃, the hydrogen pressure of 0.1-1.5 MPa and the mass airspeed of 2-5H ‑1 to obtain alkylphenol. The invention can efficiently prepare the precursor (isopropyl substituted phenol) of liquid fuel such as aromatic hydrocarbon, naphthene, alkyl cyclohexanol and the like, and has remarkable industrial application value.

Inventors

  • LI BINGSHUO
  • WANG HAONAN
  • YANG TIANHUA
  • LI RUNDONG

Assignees

  • 沈阳航空航天大学

Dates

Publication Date
20260505
Application Date
20260128

Claims (9)

  1. 1. A process for the preparation of alkylphenols by alkylation of phenol with isopropanol, comprising the steps of: step 1, calcining and preprocessing an H-Beta molecular sieve to obtain a preprocessed molecular sieve; step 2, filling the pretreated molecular sieve into a fixed bed reactor, discharging air, and preheating to 200-350 ℃; step 3, dissolving phenol in isopropanol to obtain a mixed raw material; And 4, pumping the mixed raw materials into a fixed bed reactor to contact with the pretreated molecular sieve, and carrying out alkylation reaction under the conditions of 200-350 ℃ of temperature, 0.1-1.5 MPa of hydrogen pressure and 2-5h -1 of mass airspeed to obtain alkylphenol.
  2. 2. The method for preparing alkylphenol by alkylating phenol and isopropanol according to claim 1, wherein the H-Beta molecular sieve has a silicon-aluminum ratio of 10-20.
  3. 3. The method for preparing alkylphenol by alkylating phenol with isopropyl alcohol according to claim 1, wherein in the step 1, the condition of the calcination pretreatment is set such that the temperature is raised to 400 ℃ at a temperature rising rate of 10 ℃ per minute and the calcination is performed for 100 minutes.
  4. 4. The process for producing alkylphenols according to claim 1, wherein in step 2, the air in the fixed bed reactor is purged by introducing nitrogen.
  5. 5. The method for preparing alkylphenol by alkylating phenol with isopropanol according to claim 4, wherein the flow rate of nitrogen is 100mL/min.
  6. 6. The method for preparing alkylphenol by alkylating phenol and isopropanol according to claim 1, wherein in the step 3, the molar ratio of phenol to isopropanol is 1:1-5.
  7. 7. The method for preparing alkylphenol by alkylating phenol and isopropanol according to any one of claims 1 to 6 is characterized in that the conversion of alkylphenol into polyisopropylphenol or monoisopropylphenol is realized by adjusting the molar ratio of phenol to isopropanol and the reaction temperature, hydrogen pressure and mass space velocity.
  8. 8. The method for preparing alkylphenol capable of directionally controlling product distribution according to claim 7, wherein when the target product is polyisopropylphenol, the molar ratio of phenol to isopropanol is 1:3-5, the reaction temperature is 300 ℃, the hydrogen pressure is 1.0 MPa, and the mass space velocity is 2-3 h -1 ; the polyisopropylphenol includes 2-isopropylphenol and 3-isopropylphenol.
  9. 9. The method for preparing alkylphenol capable of directionally controlling product distribution according to claim 7, wherein when the target product is mainly mono-isopropyl phenol, the molar ratio of phenol to isopropyl alcohol is 1:1, the reaction temperature is 300 ℃, the hydrogen pressure is 0.5MPa, and the mass space velocity is 4h -1 ; The mono-isopropyl phenol includes 2-isopropyl phenol, 3-isopropyl phenol and 4-isopropyl phenol.

Description

Method for preparing alkylphenol by alkylating phenol and isopropanol Technical Field The invention relates to the technical field of biomass energy chemical industry, in particular to a method for preparing alkylphenol by alkylating phenol and isopropanol. Background The chemical composition of lignin-derived oil is mainly influenced by raw material sources and preparation processes to show remarkable differences, and the core component of lignin-derived oil is mainly phenolic compounds and comprises polycyclic phenols, alkylphenols and alkoxyl phenols with different substitution types. These phenolic compounds are key precursors for the preparation of liquid fuels such as aromatic hydrocarbons, cycloalkanes, and alkylcyclohexanols. However, cycloalkanes produced by direct hydrodeoxygenation of low carbon number phenols (e.g., phenol, methylphenol, guaiacol, etc.) have carbon chain lengths insufficient to meet the molecular structure requirements of high carbon number fuels (e.g., aviation kerosene or high alcohols). Therefore, the introduction of alkyl branches on the benzene ring to increase the carbon number and regulate the product structure is particularly critical to promote the conversion of lignin-derived oil into high-value-added fuel. C-C coupling is one of the important ways to achieve alkylation of benzene rings, enabling the directed introduction of specific alkyl chains. As a typical acid catalysis process, the method has an irreplaceable effect in the conversion path of lignin-derived phenol to aviation fuel, and lays a foundation for preparing high-performance fuel by the subsequent complete hydrodeoxygenation by effectively improving the carbon number and the heat value of phenolic compounds. However, the conventional alkylphenol synthesis process, such as Friedel-Crafts alkylation of phenol and propylene, is mature in technology, but generally depends on homogeneous acid catalysts (such as concentrated sulfuric acid, aluminum trichloride, hydrofluoric acid and the like) with strong corrosiveness and pollution, and has the problems of difficult recovery of the catalyst, serious equipment corrosion, large environmental pollution and the like. Therefore, the development of a novel catalytic system which is green, efficient, high in selectivity and mild in reaction condition is not only an urgent need for improving the sustainability of the alkylation process of lignin-derived phenols, but also an important direction for realizing the high-valued conversion of lignin resources and promoting the industrialization of biomass fuels. Disclosure of Invention In view of this, the present invention provides a process for preparing alkylphenols based on H-Beta molecular sieve catalyzed alkylation of phenol with isopropanol. The method adopts a fixed bed continuous process, and has the advantages of adjustable product selectivity, good catalyst stability and the like. In order to achieve the above object, the present invention provides the following solutions: The invention provides a method for preparing alkylphenol by alkylating phenol and isopropanol, which comprises the following steps: step 1, calcining and preprocessing an H-Beta molecular sieve to obtain a preprocessed molecular sieve; step 2, filling the pretreated molecular sieve into a fixed bed reactor, discharging air, and preheating to 200-350 ℃; step 3, dissolving phenol in isopropanol to obtain a mixed raw material; And 4, pumping the mixed raw materials into a fixed bed reactor to contact with the pretreated molecular sieve, and carrying out alkylation reaction under the conditions of 200-350 ℃ of temperature, 0.1-1.5 MPa of hydrogen pressure and 2-5h -1 of mass airspeed to obtain alkylphenol. In a preferred embodiment of the invention, the H-Beta molecular sieve has a silicon to aluminum ratio of 10-20. In a preferred embodiment of the present invention, in step 1, the conditions for the calcination pretreatment are set such that the temperature is raised to 400℃at a rate of 10℃per minute, and the calcination is performed for 100 minutes. In a preferred embodiment of the invention, in step 2, the air in the fixed bed reactor is removed by passing nitrogen. In a preferred embodiment of the present invention, the flow rate of nitrogen is 100mL/min. In a preferred embodiment of the invention, in the step 3, the molar ratio of phenol to isopropanol is 1:1-5. The invention also provides a preparation method of the alkylphenol, which can directionally control the distribution of the product, and the method for preparing the alkylphenol by alkylating the phenol and the isopropanol is adopted, and the conversion of the alkylphenol into the polyisopropylphenol or the mono-isopropylphenol is realized by adjusting the mole ratio of the phenol and the isopropanol, the reaction temperature, the hydrogen pressure and the mass airspeed. In the preferred embodiment of the invention, when the target product is the polyisopropylphenol, the molar ratio