A process for the controlled preparation of o-ethylphenol

Abstract

This application discloses a method for the controllable preparation of o-ethylphenol, comprising the following steps: in a reactor, phenol and an ethylating agent are contacted with a catalyst and reacted to obtain o-ethylphenol; the ethylating agent is selected from at least one of ethylene, ethanol, or acetaldehyde; the catalyst is obtained by the following steps: mixing a metal oxide, a molecular sieve, a binder, an extrusion aid, and an acid, kneading, aging, molding, drying, and calcining to obtain the catalyst. Based on the high selectivity of o-ethylphenol on metal oxides and the predominance of p- and m-ethylphenols on molecular sieves, a bifunctional catalyst prepared by adjusting the ratio of metal oxides and molecular sieves solves the problem of uncontrollable ethylphenol product distribution. Furthermore, the bifunctional catalyst can simultaneously catalyze the hydrogenation reaction of acetaldehyde, broadening the range of ethylating agents. This process is environmentally friendly, the catalyst has good stability, and it has good prospects for industrial application.

Description

Technical Field

[0001] This application relates to a method for the controllable preparation of o-ethylphenol, which belongs to the field of chemical engineering. Background Technology

[0002] Ethylphenol comprises three isomers: ortho-, meta-, and para-ethylphenol, which can be recovered and separated from petroleum refining, coal coking, and gasification processes. Ethylphenol is used in the manufacture of pesticides, resins, flame retardants, antioxidants, and insulating asphalt, making it an important chemical raw material and pharmaceutical intermediate. However, traditional separation and purification processes face problems such as complex raw materials, high energy consumption, and small production scale, making it difficult to meet the needs of human societal development.

[0003] Therefore, the development of efficient chemical synthesis processes is urgently needed. Currently, a large amount of literature and patents focus on the synthesis of cresol, with relatively few reports on the chemical synthesis of ethylphenol. JPS59181231A discloses a method for the hydrogenation of 4,4'-ethylidene bisphenol to prepare p-ethylphenol; the metal catalyst has good stability, but the raw materials are expensive and difficult to obtain, making this process unsuitable for large-scale production. JUS4927979A discloses a method for the alkylation of phenol and ethanol to ethylphenol using molecular sieve catalysis, with catalysts containing ZSM-5, ZSM-11, ZSM-12, ZSM-35, and ZSM-38, enabling highly selective synthesis of p-ethylphenol; however, o-ethylphenol is also an important chemical, and this invention lacks a strategy for controllably adjusting the ratio of p-ethylphenol to o-ethylphenol in the product. JPS59155331A discloses a method for the alkylation of phenol and ethanol to ethylphenol using heteropolyacid catalysis, but the use of heteropolyacid catalysts leads to problems of poor catalyst stability and acid loss.

[0004] Furthermore, current reports on ethylphenol mainly focus on the separation and purification processes of m-ethylphenol and p-ethylphenol, with fewer reports on the selective synthesis of ethylphenol. Fine Petrochemicals, 2009, 26:35-38, reported the performance of Beta molecular sieves in the alkylation reaction of phenol and ethylene, and explored in detail the influence of experimental parameters on catalytic performance. The product was mainly p-ethylphenol, with lower selectivity for o-ethylphenol. Summary of the Invention

[0005] This invention leverages the high selectivity of o-ethylphenol on metal oxides and the predominantly para- and m-ethylphenol on molecular sieve catalysts. By adjusting the ratio of metal oxides to molecular sieves, the selectivity of o-ethylphenol can be flexibly adjusted between 5% and 95%. Furthermore, the bifunctional catalyst can simultaneously catalyze the hydrogenation of acetaldehyde, broadening the range of ethylation reagents. The bifunctional catalyst preparation process is simple, and the alkylation process is environmentally friendly, demonstrating promising prospects for industrial applications.

[0006] According to one aspect of this application, a method for the controllable preparation of o-ethylphenol is provided, comprising the following steps:

[0007] In a reactor, phenol and an ethylating agent are reacted with a catalyst to produce o-ethylphenol;

[0008] The ethylating agent is selected from at least one of ethylene, ethanol, or acetaldehyde;

[0009] The catalyst is obtained through the following steps:

[0010] The catalyst is obtained by mixing metal oxides, molecular sieves, binders, extrusion aids and acids, kneading, aging, molding, drying and calcining.

[0011] The metal oxide is selected from at least one of ferric oxide, manganese oxide, indium oxide, and cerium oxide;

[0012] The molecules are screened from at least one of MCM-22, MCM-56, Beta, and ZSM-5;

[0013] The SiO2 / Al2O3 ratio of the molecular sieve is in the range of 20 to 300.

[0014] The adhesive is selected from at least one of silica sol or alumina sol;

[0015] The extrusion aid is selected from at least one of guar gum powder, cellulose and starch;

[0016] The acid is selected from at least one of a 6-12% dilute nitric acid solution or a 6-12% acetic acid solution.

[0017] The mass ratio of the metal oxide to the molecular sieve is 6–94:94–6.

[0018] The ratio of the binder to the total mass of the metal oxide and molecular sieve is 60–90:10–40;

[0019] The mass of the extrusion aid is 1 to 10 wt% of the total mass of the metal oxide and molecular sieve;

[0020] The mass of the acid is 50-100 wt% of the total mass of the metal oxide and molecular sieve.

[0021] The aging temperature is 20–50°C;

[0022] The aging time is 1 to 12 hours;

[0023] The drying temperature is 80–150°C;

[0024] The drying time is 4–30 hours;

[0025] The roasting temperature is 400–550°C;

[0026] The roasting time is 2 to 20 hours.

[0027] The metal oxide is obtained by organic-assisted pyrolysis of metal oxide precursors;

[0028] The metal oxide precursor is selected from at least one of the nitrates or chlorides of iron, manganese, indium, and cerium;

[0029] The organic compound is selected from at least one of citric acid, glucose, melamine, or cyanuric acid;

[0030] The mass of the organic compound is 10 to 30 wt% of the mass of the metal oxide precursor;

[0031] The pyrolysis temperature is 250–550°C;

[0032] The pyrolysis time is 2 to 12 hours.

[0033] The reaction temperature is 200–450°C;

[0034] The reaction pressure is 0.1–4 MPa.

[0035] The molar ratio of phenol to ethylating agent is 1 to 10;

[0036] The mass hourly space velocity (MSV) of the phenol is 0.5–10 h⁻¹. -1 .

[0037] It can flexibly adjust the selectivity of o-ethylphenol between 5% and 95%.

[0038] The beneficial effects that this application can produce include:

[0039] This invention leverages the high selectivity of o-ethylphenol on metal oxides and the predominantly para- and m-ethylphenol on molecular sieve catalysts. By adjusting the ratio of metal oxides to molecular sieves, the selectivity of o-ethylphenol can be flexibly adjusted between 5% and 95%. Furthermore, the bifunctional catalyst can simultaneously catalyze the hydrogenation of acetaldehyde, broadening the range of ethylation reagents. The bifunctional catalyst preparation process is simple, and the alkylation process is environmentally friendly, demonstrating promising prospects for industrial applications. Detailed Implementation

[0040] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0041] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased commercially, and all molecular sieves used were H-type raw powder.

[0042] This application uses a flame ionization detector (FID) to analyze hydrocarbon products in the product;

[0043] The conversion rate and selectivity calculation formulas in the embodiments of this application are as follows:

[0044] Phenol conversion rate = (inlet phenol - outlet phenol) / inlet phenol × 100% Eq.(1)

[0045] Product selectivity = hydrocarbon i / total hydrocarbon products detected × 100% Eq.(2)

[0046] Example 1

[0047] Ferric nitrate nonahydrate, cerium nitrate hexahydrate, and indium nitrate were ground and mixed (the mass ratio of ferric nitrate nonahydrate: cerium nitrate hexahydrate: indium nitrate was 30:10:2). Citric acid, accounting for 15% of the nitrate mass fraction, was then added and mixed evenly. The mixture was heated to 300℃ at a rate of 0.5℃ / min and held for 2 hours under a flowing air atmosphere. Then, the temperature was increased to 450℃ at a rate of 0.5℃ / min and held for 4 hours to obtain Fe2O3&CeO2&In2O3 (M1).

[0048] 15g of MCM-22, 60g of M1, 50g of silica sol solution (SiO2 content 30wt.%), 3g of guar gum powder, and 50g of 9% dilute nitric acid solution were mixed and kneaded; after curing at 40℃ for 4h, the mixture was extruded into strips; dried at 100℃ for 10h; then, the temperature was increased to 450℃ at 2℃ / min and held for 4h. A molded catalyst (A1) with a metal oxide active component accounting for 80% of the bifunctional component was obtained.

[0049] Example 2

[0050] Ferric nitrate nonahydrate, cerium nitrate hexahydrate, and indium nitrate were ground and mixed (the mass ratio of ferric nitrate nonahydrate: cerium nitrate hexahydrate: indium nitrate was 29:9:4). Citric acid, accounting for 15% of the nitrate mass fraction, was then added and mixed evenly. The mixture was heated to 300℃ at a rate of 0.5℃ / min and held for 2 hours under a flowing air atmosphere. Then, the temperature was increased to 450℃ at a rate of 0.5℃ / min and held for 4 hours to obtain Fe2O3&CeO2&In2O3 (M2).

[0051] 37.5 g of M2, 37.5 g of MCM-56, 50 g of silica sol solution (SiO2 content 30 wt.%), 3 g of guar gum powder, and 50 g of 9% dilute nitric acid solution were mixed and kneaded; after curing at 40℃ for 4 h, the mixture was extruded into strips; dried at 100℃ for 10 h; then, the temperature was increased to 450℃ at 2℃ / min and held for 4 h. A molded catalyst (A2) with a metal oxide active component accounting for 50% of the bifunctional component was obtained.

[0052] Example 3

[0053] Ferric nitrate nonahydrate, cerium nitrate hexahydrate, and indium nitrate were ground and mixed (the mass ratio of ferric nitrate nonahydrate: cerium nitrate hexahydrate: indium nitrate was 27:9:6). Citric acid, accounting for 15% of the nitrate mass fraction, was then added and mixed evenly. The mixture was heated to 300℃ at a rate of 0.5℃ / min and held for 2 hours under a flowing air atmosphere. Then, the temperature was increased to 450℃ at a rate of 0.5℃ / min and held for 4 hours to obtain Fe2O3&CeO2&In2O3 (M3).

[0054] 15g of M3, 60g of ZSM-5, 50g of silica sol solution (SiO2 content 30wt.%), 3g of guar gum powder, and 50g of 9% dilute nitric acid solution were mixed and kneaded; after curing at 40℃ for 4h, the mixture was extruded into strips; dried at 100℃ for 10h; then, the temperature was increased to 450℃ at 2℃ / min and held for 4h. A molded catalyst (A3) with a metal oxide active component accounting for 20% of the bifunctional component was obtained.

[0055] Test case

[0056] 2.0 g of the catalyst prepared by the above method was loaded into a fixed-bed reactor, and then a mixture of phenol and ethanol was introduced. The reactor was maintained at 400 °C, 0.2 MPa, ethanol / phenol ratio = 1, and phenol mass hourly space velocity = 1.5 h⁻¹. -1 The reaction was carried out under the specified conditions, and the results after 10 hours of reaction are listed in Table 1.

[0057] Table 1 shows the reactivity and selectivity of the catalysts in each example.

[0058] Table 1

[0059]

[0060] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for the controlled preparation of o-ethylphenol, characterized in that, Includes the following steps: In a reactor, phenol and an ethylating agent are reacted with a catalyst to produce o-ethylphenol; The ethylating agent is selected from at least one of ethylene, ethanol, or acetaldehyde; The catalyst is obtained through the following steps: The catalyst is obtained by mixing metal oxides, molecular sieves, binders, extrusion aids and acids, kneading, aging, molding, drying and calcining.

2. The method according to claim 1, characterized in that, The metal oxide is selected from at least one of ferric oxide, manganese oxide, indium oxide, and cerium oxide; The molecules are screened from at least one of MCM-22, MCM-56, Beta, and ZSM-5; The SiO2 / Al2O3 ratio of the molecular sieve is in the range of 20 to 300. The adhesive is selected from at least one of silica sol or alumina sol; The extrusion aid is selected from at least one of guar gum powder, cellulose and starch; The acid is selected from at least one of a 6-12% dilute nitric acid solution or a 6-12% acetic acid solution.

3. The method according to claim 1, characterized in that, The mass ratio of the metal oxide to the molecular sieve is 6–94:94–6. The ratio of the binder to the total mass of the metal oxide and molecular sieve is 60–90:10–40; The mass of the extrusion aid is 1 to 10 wt% of the total mass of the metal oxide and molecular sieve; The mass of the acid is 50-100 wt% of the total mass of the metal oxide and molecular sieve.

4. The method according to claim 1, characterized in that, The aging temperature is 20–50°C; The aging time is 1 to 12 hours; The drying temperature is 80–150°C; The drying time is 4–30 hours; The roasting temperature is 400–550°C; The roasting time is 2 to 20 hours.

5. The method according to claim 1, characterized in that, The metal oxide is obtained by organic-assisted pyrolysis of metal oxide precursors; The metal oxide precursor is selected from at least one of the nitrates or chlorides of iron, manganese, indium, and cerium; The organic compound is selected from at least one of citric acid, glucose, melamine, or cyanuric acid; The mass of the organic compound is 10 to 30 wt% of the mass of the metal oxide precursor; The pyrolysis temperature is 250–550°C; The pyrolysis time is 2 to 12 hours.

6. The method according to claim 1, characterized in that, The reaction temperature is 200–450°C; The reaction pressure is 0.1–4 MPa.

7. The method according to claim 1, characterized in that, The molar ratio of phenol to ethylating agent is 1 to 10; The mass hourly space velocity (MSV) of the phenol is 0.5–10 h⁻¹. -1 .

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