A process for the controlled preparation of p-ethylphenol

Abstract

This application discloses a method for the controllable preparation of p-ethylphenol. In a reactor, phenol and ethanol are contacted with a catalyst and reacted to obtain p-ethylphenol. The catalyst is obtained through the following steps: mixing molecular sieves, a binder, guar gum powder, and acid; kneading; aging; molding; drying; calcining; acid washing; drying again; and calcining to obtain the catalyst. By combining a pore modification strategy and adjusting the ratio of ten-membered to twelve-membered rings in the composite molecular sieve, the problem of uncontrollable products from a single molecular sieve is solved. Using ethanol and phenol as raw materials enables continuous liquid-phase feeding, solving the problem of easy condensation and pipeline blockage during phenol vaporization feeding. The curing and acid washing processes in this process are crucial for product selectivity control. Through curing and acid washing, the pore structure of the molecular sieve can be effectively controlled, thereby utilizing the shape-selective effect of the pores to control the selectivity of p-ethylphenol. This production process is free of equipment corrosion, the catalyst is environmentally friendly, and it has good prospects for industrial application.

Description

Technical Field

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

[0002] o-Ethylphenol, m-Ethylphenol, and p-Ethylphenol, extracted from petroleum refining, coal coking, and gasification processes, are important raw materials for manufacturing resins, flame retardants, antioxidants, and insulating asphalt, and are also key intermediates in pharmaceuticals and pesticides. With the rapid development of human society, the uses and consumption of ethylphenol are increasing rapidly, and traditional separation and purification processes can no longer meet current production requirements. Therefore, the development of chemical synthesis processes for ethylphenol is urgently needed.

[0003] Currently, a large amount of literature and patents focus on the synthesis process of cresol, while there are relatively few reports on the chemical synthesis process of ethylphenol. JUS4927979A discloses a catalyst technology for the selective preparation of p-ethylphenol; the catalysts in this technology include ZSM-5, ZSM-11, ZSM-12, ZSM-35, and ZSM-38, using phenol and ethanol as raw materials to synthesize p-ethylphenol; however, m-ethylphenol is also an important chemical, and this invention lacks a strategy for controllably modulating the selectivity of p-ethylphenol and m-ethylphenol in the product. JPS59181231A discloses a method for the hydrogenation of 4,4'-ethylenebisphenol to prepare p-ethylphenol. Although the reported metal catalyst has excellent stability, the raw materials are expensive and difficult to obtain, lacking the potential for large-scale production. JPS59155331A discloses a method for the alkylation of phenol and ethanol to ethylphenol catalyzed by heteropolyacids, but the heteropolyacid catalyst used in this process faces problems such as easy deactivation and acid loss.

[0004] Furthermore, a large number of documents and patents focus on the separation and purification processes of m-ethylphenol and p-ethylphenol, with few reports on the selective synthesis of ethylphenol. Fine Petrochemicals, 2009, 26:35-38, reported the reaction performance of phenol and ethylene on Beta molecular sieves and studied in detail the influence of reaction conditions on catalytic performance; the product was mainly p-ethylphenol, but the selectivity was low, and the adjustable range of product selectivity was small. Summary of the Invention

[0005] This invention leverages the strong confinement effect of ten-membered ring channels and the high selectivity of m-ethylphenol on twelve-membered ring molecular sieves. By combining channel modification strategies and adjusting the ratio of ten-membered to twelve-membered rings in the composite catalyst, it solves the problem of uncontrollable ethylphenol selectivity in single molecular sieve catalysts, achieving flexible control of ethylphenol selectivity between 20% and 80%. The composite molecular sieve catalyst has a simple preparation process, is chemically synthesized in an environmentally friendly manner, and shows promising prospects for industrial applications.

[0006] According to one aspect of this application, a method for the controllable preparation of p-ethylphenol is provided, wherein phenol and ethanol are contacted with a catalyst in a reactor and reacted to obtain p-ethylphenol;

[0007] The catalyst is obtained through the following steps:

[0008] Molecular sieves, binders, guar gum powder, and acid are mixed, kneaded, aged, shaped, dried, roasted, acid-washed, dried again, and calcined to obtain the catalyst.

[0009] The molecular sieves include ten-membered ring molecular sieves and twelve-membered ring molecular sieves;

[0010] The ten-membered ring molecule is selected from at least one of ZSM-5 or ZSM-11;

[0011] The twelve-membered ring molecules were screened from at least one of Beta, MOR, ZSM-12, MCM-22, MCM-56, and MCM-59;

[0012] The molecular sieve contains 0.5 to 99.5 wt% ten-membered ring molecular sieves, with the remainder being twelve-membered ring molecular sieves.

[0013] The adhesive is selected from at least one of silica sol or alumina sol;

[0014] The acid is selected from at least one of a dilute nitric acid solution with a mass concentration of 8-12% or an acetic acid solution with a mass concentration of 8-10%.

[0015] The mass ratio of the molecular sieve to the binder is 60-90:10-40;

[0016] The mass of the guar gum powder is 2-5 wt% of the total mass of the molecular sieve and binder;

[0017] The mass of the acid is 50-100 wt% of the total mass of the molecular sieve and binder;

[0018] The aging temperature is 30–60°C;

[0019] The aging time is 2 to 20 hours;

[0020] The drying temperature is 70–120°C;

[0021] The drying time is 4–30 hours;

[0022] The roasting temperature is 400–550°C;

[0023] The roasting time is 2 to 20 hours.

[0024] The pickling solution used in the pickling process is an aqueous solution selected from at least one of nitric acid, hydrochloric acid, oxalic acid, and citric acid.

[0025] The concentration of the pickling solution is 0.1–1 mol / L;

[0026] The pickling temperature is 30–80°C;

[0027] The pickling time is 1 to 5 hours.

[0028] The drying temperature is 80–120°C;

[0029] The drying time is 8–24 hours;

[0030] The calcination temperature is 400–500°C;

[0031] The calcination time is 2 to 10 hours.

[0032] The reaction temperature is 150–400°C;

[0033] The reaction pressure is 0.1–4 MPa.

[0034] The molar ratio of phenol to ethanol is 0.7 to 5;

[0035] The mass hourly space velocity (MSV) of the phenol is 0.5–5 h⁻¹. -1 .

[0036] The selectivity of p-ethylphenol can be flexibly adjusted between 20% and 80%.

[0037] The beneficial effects that this application can produce include:

[0038] This invention leverages the strong confinement effect of ten-membered ring channels and the high selectivity of m-ethylphenol on twelve-membered ring molecular sieves. By combining channel modification strategies and adjusting the ratio of ten-membered to twelve-membered rings in the composite catalyst, it solves the problem of uncontrollable ethylphenol selectivity in single molecular sieve catalysts, achieving flexible control of ethylphenol selectivity between 20% and 80%. The composite molecular sieve catalyst has a simple preparation process, is chemically synthesized in an environmentally friendly manner, and shows promising prospects for industrial applications. Detailed Implementation

[0039] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0040] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased commercially, and the molecular sieve used was H-type raw powder.

[0041] This application uses a flame ionization detector (FID) to analyze hydrocarbon products;

[0042] The conversion rate and selectivity calculation formulas in the embodiments of this application are as follows:

[0043] Phenol conversion rate = (inlet phenol - outlet phenol) / inlet phenol × 100% Eq.(1)

[0044] Product selectivity = Hydrocarbon A / Total hydrocarbon products detected × 100% Eq.(2)

[0045] Example 1

[0046] 15g of ZSM-11, 65g of Beta, 50g of silica sol solution (SiO2 content 30wt.%), 3g of guar gum powder, and 60g of 10% dilute nitric acid solution were mixed and kneaded; after curing at 40℃ for 4h, the mixture was extruded and shaped into strips; then dried at 100℃ for 12h; and then heated to 450℃ at 1℃ / min and held for 3.5h. The calcined sample was added to a hydrochloric acid aqueous solution (0.25mol / L) with a solid / liquid mass ratio of 10, acid-washed at 40℃ for 4h, filtered, dried at 100℃ for 12h, and then heated to 450℃ at 2℃ / min and held for 4h. A finished catalyst (A1) with ZSM-11 comprising 18.75% of the molecular sieve mass was obtained.

[0047] Example 2

[0048] 30g of ZSM-5, 50g of MCM-59, 50g of silica sol solution (SiO2 content 30wt.%), 3g of guar gum powder, and 60g of 10% dilute nitric acid solution were mixed and kneaded; after curing at 40℃ for 4h, the mixture was extruded and shaped into strips; then dried at 100℃ for 12h; and then heated to 450℃ at 1℃ / min and held for 3.5h. The calcined sample was added to a nitric acid aqueous solution (0.20mol / L) with a solid / liquid mass ratio of 10, acid-washed at 40℃ for 4h, filtered, dried at 100℃ for 12h, and then heated to 450℃ at 2℃ / min and held for 4h. A finished catalyst (A2) with ZSM-5 comprising 37.5% of the molecular sieve mass was obtained.

[0049] Example 3

[0050] 50g of ZSM-5, 30g of ZSM-12, 50g of silica sol solution (SiO2 content 30wt.%), 3g of guar gum powder, and 60g of 10% dilute nitric acid solution were mixed and kneaded; after curing at 40℃ for 4h, the mixture was extruded into strips; dried at 100℃ for 12h; then, the temperature was increased to 450℃ at 1℃ / min and held for 3.5h. The calcined sample was added to an acetic acid aqueous solution (0.15mol / L) with a solid / liquid mass ratio of 9, acid-washed at 40℃ for 4h, filtered, dried at 100℃ for 12h, and then heated to 450℃ at 2℃ / min and held for 4h. A finished catalyst (A3) with ZSM-5 comprising 62.5% of the molecular sieve mass was obtained.

[0051] Example 4

[0052] 70g of ZSM-5, 10g of MCM-22, 50g of silica sol solution (SiO2 content 30wt.%), 3g of guar gum powder, and 60g of 10% dilute nitric acid solution were mixed and kneaded; after curing at 40℃ for 4h, the mixture was extruded into strips; dried at 100℃ for 12h; then, the temperature was increased to 450℃ at 1℃ / min and held for 3.5h. The calcined sample was added to a citric acid aqueous solution (0.10mol / L) with a solid / liquid mass ratio of 8, acid-washed at 40℃ for 4h, filtered, dried at 100℃ for 12h, and then heated to 450℃ at 2℃ / min and held for 4h. A finished catalyst (A4) with ZSM-5 comprising 87.5% of the molecular sieve mass was obtained.

[0053] Test case

[0054] 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 320 °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 5 hours of reaction are listed in Table 1.

[0055] Table 1 shows the reactivity and selectivity of the catalysts in each example.

[0056] Table 1

[0057]

[0058] 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 controllable preparation of p-ethylphenol, characterized in that, In a reactor, phenol and ethanol are contacted with a catalyst and reacted to obtain p-ethylphenol; The catalyst is obtained through the following steps: Molecular sieves, binders, guar gum powder and acid are mixed, kneaded, aged, shaped, dried, roasted, acid-washed, dried and calcined to obtain the catalyst; The molecular sieves include ten-membered ring molecular sieves and twelve-membered ring molecular sieves.

2. The method according to claim 1, characterized in that, The ten-membered ring molecule is selected from at least one of ZSM-5 or ZSM-11; The twelve-membered ring molecules were screened from at least one of Beta, MOR, ZSM-12, MCM-22, MCM-56, and MCM-59; The molecular sieve contains 0.5 to 99.5 wt% ten-membered ring molecular sieves, with the remainder being twelve-membered ring molecular sieves. The adhesive is selected from at least one of silica sol or alumina sol; The acid is selected from at least one of a dilute nitric acid solution with a mass concentration of 8-12% or an acetic acid solution with a mass concentration of 8-10%.

3. The method according to claim 1, characterized in that, The mass ratio of the molecular sieve to the binder is 60-90:10-40; The mass of the guar gum powder is 2-5 wt% of the total mass of the molecular sieve and binder; The mass of the acid is 50-100 wt% of the total mass of the molecular sieve and binder; The aging temperature is 30–60°C; The aging time is 2 to 20 hours; The drying temperature is 70–120°C; The drying time is 4–30 hours; The roasting temperature is 400–550°C; The roasting time is 2 to 20 hours.

4. The method according to claim 1, characterized in that, The pickling solution used in the pickling process is an aqueous solution selected from at least one of nitric acid, hydrochloric acid, oxalic acid, and citric acid. The concentration of the pickling solution is 0.1–1 mol / L; The pickling temperature is 30–80°C; The pickling time is 1 to 5 hours.

5. The method according to claim 1, characterized in that, The drying temperature is 80–120°C; The drying time is 8–24 hours; The calcination temperature is 400–500°C; The calcination time is 2 to 10 hours.

6. The method according to claim 1, characterized in that, The reaction temperature is 150–400°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 ethanol is 0.7 to 5; The mass hourly space velocity (MSV) of the phenol is 0.5–5 h⁻¹. -1 .

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