Phenol vaporization device for preparing cyclohexanone through phenol hydrogenation

Abstract

The utility model discloses a phenol vaporizing device for preparing cyclohexanone through phenol hydrogenation, which consists of a phenol vaporizer and a feeding superheater, and is characterized in that the phenol vaporizer and the feeding superheater are integrated. According to the utility model, hydrogen or nitrogen or mixed gas thereof is introduced into the phenol vaporization process, so that the partial pressure of phenol vaporization is reduced, and the phenol vaporization temperature can be reduced; the phenol vaporizer and the feeding superheater are arranged into an integral device, so that the feeding mixed gas conveying resistance is reduced, and meanwhile, the equipment investment is also saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of cyclohexanone production and relates to a phenol vaporization device for preparing cyclohexanone by hydrogenating phenol. Background Art

[0002] Cyclohexanone is a key chemical raw material, widely used in industrial production and daily life. Cyclohexanone is generally categorized by its downstream applications: amide and non-amide. Currently, 70% of cyclohexanone is used in the production of polyamides. Commonly used fibers, such as nylon 6 and nylon 66, are produced from cyclohexanone. Furthermore, due to its high solubility and low volatility, cyclohexanone can be used as an organic solvent, thus providing non-amide cyclohexanone. Cyclohexanone also has extensive applications in the pharmaceutical field and as an anti-aging agent. For example, pharmaceutical intermediates such as Temaren and Kemeche are produced by reacting cyclohexanone with cyanoacetic acid and then treating it.

[0003] There are three main methods for producing cyclohexanone: cyclohexane oxidation, cyclohexene hydration and phenol hydrogenation.

[0004] The cyclohexane oxidation method is gradually being eliminated because of its very low primary conversion rate, high energy consumption, and serious environmental pollution.

[0005] Cyclohexene hydration has attracted much attention due to its environmental protection. However, it has a long process, high production energy consumption, and produces a large amount of cyclohexane as a by-product.

[0006] The production of cyclohexanone by phenol hydrogenation has attracted much attention due to its simple production process, short flow, and best product quality. However, due to the high vaporization temperature of phenol, phenol is prone to coking during vaporization. Summary of the Invention

[0007] The object of the present invention is to provide a phenol vaporization device for preparing cyclohexanone by hydrogenating phenol, which can reduce the phenol activation temperature and achieve phenol vaporization and feed superheating effects through an integrated superheater.

[0008] Technical solution of the present invention

[0009] The invention discloses a phenol vaporization device for preparing cyclohexanone by hydrogenating phenol, which consists of a phenol vaporizer and a feed superheater, and is characterized in that the phenol vaporizer and the feed superheater are integrated into one.

[0010] The phenol vaporizer consists of a cylinder, a heat exchanger, a phenol feed distributor, a phenol inlet, a hydrogen inlet, a hydrogen distributor, a steam inlet, a condensed water outlet, an upper liquid level gauge port, and a lower liquid level gauge port. The heat exchanger is installed in the cylinder, the phenol feed distributor is connected to the phenol inlet, and is installed above the heat exchanger; the hydrogen inlet is at the bottom of the cylinder, the hydrogen distributor is connected to the hydrogen inlet, and an upper liquid level gauge port and a lower liquid level gauge port are respectively provided at the upper and lower parts of the cylinder; the low-pressure steam inlet is connected to the hot side inlet of the heat exchanger, and the hot outlet of the heat exchanger is connected to the condensed water outlet.

[0011] The feed superheater is a shell and tube heat exchanger or a coil, which is installed on the upper part of the phenol vaporizer and directly connected to the gas phase space of the phenol vaporizer.

[0012] The phenol vaporizer is provided with a wire mesh demister installed in the upper space of the cylinder.

[0013] The feed superheater is provided with a steam inlet, a condensed water outlet, and a feed mixed gas outlet.

[0014] The feed superheater is connected to the phenol vaporizer through the head cover of the phenol vaporizer.

[0015] The hydrogen inlet can also be a nitrogen inlet or a hydrogen and nitrogen mixed gas inlet. Hydrogen, nitrogen, or a hydrogen and nitrogen mixed gas can be introduced.

[0016] Effects achieved by the utility model

[0017] 1) By introducing hydrogen or nitrogen or their mixed gases into the phenol vaporization process, the partial pressure of phenol vaporization is reduced, and the phenol vaporization temperature can be lowered.

[0018] 2) The phenol vaporizer and feed superheater are set as an integrated device to reduce the feed mixed gas transmission resistance and also save equipment investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of a phenol vaporizer for preparing cyclohexanone by hydrogenating phenol according to the present invention

[0020] In the figure: 1-hydrogen inlet, 2-condensate outlet, 3-lower liquid level gauge port, 4-cylinder, 5-heat exchanger, 6-upper liquid level gauge port, 7-phenol feed distributor, 8-condensate outlet, 9-steam inlet, 10-mixed gas outlet, 11-phenol inlet, 12-low-pressure steam inlet, 13-hydrogen distributor, 14-drain port DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited thereto.

[0022] Example 1:

[0023] The invention discloses a phenol vaporization device for preparing cyclohexanone by hydrogenating phenol, which consists of a phenol vaporizer and a feed superheater. The phenol vaporizer and the feed superheater are integrated into one body.

[0024] The phenol vaporizer consists of a cylinder, a coil, a phenol feed distributor, a phenol inlet, a hydrogen inlet, a hydrogen distributor, a low-pressure steam inlet, a condensate outlet, an upper liquid level gauge port, and a lower liquid level gauge port. The coil is installed in the cylinder, the phenol feed distributor is connected to the phenol inlet, and is installed on the coil; the hydrogen inlet is at the bottom of the cylinder, the hydrogen distributor is connected to the hydrogen inlet, and an upper liquid level gauge port and a lower liquid level gauge port are respectively provided at the upper and lower parts of the cylinder; the low-pressure steam inlet is connected to the coil, and the coil is connected to the condensate outlet.

[0025] The feed superheater is connected to the phenol vaporizer through the head cover of the phenol vaporizer and is provided with a steam inlet, a condensed water outlet and a feed mixed gas outlet.

[0026] The raw phenol is heated to 120-140°C in a phenol preheater through heat exchange with the phenol hydrogenation reaction product. It is then fed into a phenol vaporizer, where hydrogen is introduced through the bottom inlet. The pressure at the top of the phenol vaporizer is controlled at 0.2-0.25 MPaG. The phenol vaporization temperature is 130-150°C, driven by the dual effects of phenol-hydrogen partial pressure and steam heating. The vaporized phenol is mixed with hydrogen and fed into a feed superheater above the phenol vaporizer. In the feed superheater, the phenol-hydrogen mixture is activated by superheating to 175-195°C before being fed into a phenol hydrogenation reactor. The molar ratio of phenol to hydrogen in the gas mixture entering the hydrogenation reactor is controlled to be 1:2-1:6.

[0027] Example 2

[0028] Other aspects are the same as in Example 1, except that hydrogen is replaced by a mixture of hydrogen and nitrogen, the molar ratio of hydrogen to nitrogen is 1:0.5-1:2, and the molar ratio of phenol to the mixture of hydrogen and nitrogen in the gas mixture entering the hydrogenation reactor is 1:3-1:8.

Claims

1. A phenol vaporization device for preparing cyclohexanone by hydrogenation of phenol, comprising a phenol vaporizer and a feed superheater, characterized in that The phenol vaporizer is integrated with the feed superheater; the phenol vaporizer consists of a cylinder, a heat exchanger, a phenol feed distributor, a phenol inlet, a hydrogen inlet, a hydrogen distributor, a low-pressure steam inlet, a condensed water outlet, an upper liquid level gauge port, and a lower liquid level gauge port. The heat exchanger is installed in the cylinder, and the phenol feed distributor is connected to the phenol inlet and installed above the heat exchanger; the hydrogen inlet is at the bottom of the cylinder, the hydrogen distributor is connected to the hydrogen inlet, and an upper liquid level gauge port and a lower liquid level gauge port are respectively provided at the upper and lower parts of the cylinder; the low-pressure steam inlet is connected to the hot side inlet of the heat exchanger, and the hot side outlet of the heat exchanger is connected to the condensed water outlet.

2. The phenol vaporizing device for preparing cyclohexanone by hydrogenating phenol according to claim 1, wherein The feed superheater is a shell and tube heat exchanger or a coil, which is installed on the upper part of the phenol vaporizer and directly connected to the gas phase space of the phenol vaporizer.

3. The phenol vaporizing device for preparing cyclohexanone by hydrogenating phenol according to claim 1, wherein The phenol vaporizer is provided with a wire mesh demister installed in the upper space of the cylinder.

4. The phenol vaporizing device for preparing cyclohexanone by hydrogenating phenol according to claim 1, wherein The feed superheater is connected to the phenol vaporizer through the head cover of the phenol vaporizer.

5. The phenol vaporizing device for preparing cyclohexanone by hydrogenating phenol according to claim 1, wherein The heat exchanger is a coil.

6. The phenol vaporization device for preparing cyclohexanone by hydrogenation of phenol according to claim 1, wherein The hydrogen inlet is a nitrogen inlet or a hydrogen and nitrogen mixed gas inlet.

7. The phenol vaporizing device for preparing cyclohexanone by hydrogenating phenol according to claim 2, wherein The feed superheater is provided with a steam inlet, a condensed water outlet, and a feed mixed gas outlet.

8. The phenol vaporizing device for preparing cyclohexanone by hydrogenating phenol according to claim 2, wherein The feed superheater is a vertical shell and tube heat exchanger.

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