Method for reducing pollutant discharge in phenol-acetone production

Abstract

The invention discloses a method for reducing pollutant discharge in phenol-acetone production. The method comprises at least one of the following steps: (A) collecting phenolic wastewater generated by a phenol-acetone production device, adjusting the pH value to be less than 7, and performing extraction and recovery on phenols in wastewater by taking cumene as an extracting agent; (B) through process optimization of an acetone refining tower, reducing the acetone content of wastewater in a tower kettle; (C) treating the wastewater in the tower kettle of the acetone refining tower with a permselective membrane, and recovering alkali; (D) neutralizing the wastewater in the tower kettle of the acetone refining tower after recovering alkali in the step (C), mixing the neutralized wastewater with a condensed liquid at the top of a cumene oxidation tower, and performing detoxification treatment; (E) performing oil separation treatment on total discharged water of the phenol-acetone device, and recovering organic matters comprising hydrocarbons; and (F) performing biological treatment, coagulation sedimentation treatment and enhanced degradation treatment on the wastewater subjected to the oil separation treatment. The method has at least one of characteristics of being capable of recovering resources, increasing product yield and reducing pollutant discharge, and being low in wastewater treatment cost and stable in outlet water quality.

Description

technical field

[0001] The present application relates to a reduction and control method for waste water pollutant recycling process of a phenol acetone production plant, which is also a method for reducing pollutant discharge in the production of phenol acetone. Background technique

[0002] Phenol and acetone are important basic chemical raw materials. The cumene method is currently the mainstream process for the production of phenol acetone. The process uses propylene and benzene as the main raw materials to produce cumene, which is then oxidized to produce cumene hydroperoxide, which decomposes under acidic heating conditions to produce phenol and acetone, and then undergoes rectification Refined to generate phenol and acetone products.

[0003] The phenol-acetone production plant has a long process flow and many wastewater discharge nodes. The existing wastewater treatment technologies for the phenol-acetone production plant mostly focus on the terminal treatment of t...

Examples

Embodiment 1

[0048] Adopt traditional cumene method to prepare phenol acetone (see figure 1 ), and its total drainage COD reaches 4000-8000mg / L.

[0049] The method of the present application carries out at least one of following transformations to traditional cumene method and device:

[0050] (1) An independent vacuum system is established in the acetone refining tower, and the pressure at the top of the tower is reduced by 15kPa, and a thin-layer structured packing is installed in the thickness of the liquid layer of the tray below the lye feed inlet (see image 3 , Figure 5 ), the reflux rate at the top of the tower and the reflux rate for removing aldehydes are reduced by 25%. Under the condition of ensuring the product quality of the side line, the steam consumption of the acetone refining tower tower is reduced by 20%, and the acetone content in the tower reactor is reduced from 2200mg / L to 520mg / L L.

[0051] (2) After the phenolic waste water is collected by the phenolic waste...

Embodiment 2

[0056] The method of the application carries out following transformation to traditional cumene method and device:

[0057] (1)~(4) item transformation is the same as embodiment 1.

[0058] (5) The total drainage of the device is treated with oil separation. After the treatment, the COD of the wastewater is 1800mg / L, and then it is treated with an aerobic biological fluidized bed, and the COD is removed by 87%. Use PAC and PAM as coagulants and coagulants for coagulation and sedimentation treatment, and then use H 2 o 2 Enhanced degradation treatment for oxidant, the dosage is 250mg / L, ferrous ion is used as the catalyst, the dosage is 50mg / L, the COD of the treated effluent is below 50mg / L, and phenol and acetone are not detected.

technical field

[0001] The present application relates to a reduction and control method for waste water pollutant recycling process of a phenol acetone production plant, which is also a method for reducing pollutant discharge in the production of phenol acetone. Background technique

[0002] Phenol and acetone are important basic chemical raw materials. The cumene method is currently the mainstream process for the production of phenol acetone. The process uses propylene and benzene as the main raw materials to produce cumene, which is then oxidized to produce cumene hydroperoxide, which decomposes under acidic heating conditions to produce phenol and acetone, and then undergoes rectification Refined to generate phenol and acetone products.

[0003] The phenol-acetone production plant has a long process flow and many wastewater discharge nodes. The existing wastewater treatment technologies for the phenol-acetone production plant mostly focus on the terminal treatment of t...

Examples

Embodiment 1

[0048] Adopt traditional cumene method to prepare phenol acetone (see figure 1 ), and its total drainage COD reaches 4000-8000mg / L.

[0049] The method of the present application carries out at least one of following transformations to traditional cumene method and device:

[0050] (1) An independent vacuum system is established in the acetone refining tower, and the pressure at the top of the tower is reduced by 15kPa, and a thin-layer structured packing is installed in the thickness of the liquid layer of the tray below the lye feed inlet (see image 3 , Figure 5 ), the reflux rate at the top of the tower and the reflux rate for removing aldehydes are reduced by 25%. Under the condition of ensuring the product quality of the side line, the steam consumption of the acetone refining tower tower is reduced by 20%, and the acetone content in the tower reactor is reduced from 2200mg / L to 520mg / L L.

[0051] (2) After the phenolic waste water is collected by the phenolic waste...

Embodiment 2

[0056] The method of the application carries out following transformation to traditional cumene method and device:

[0057] (1)~(4) item transformation is the same as embodiment 1.

[0058] (5) The total drainage of the device is treated with oil separation. After the treatment, the COD of the wastewater is 1800mg / L, and then it is treated with an aerobic biological fluidized bed, and the COD is removed by 87%. Use PAC and PAM as coagulants and coagulants for coagulation and sedimentation treatment, and then use H 2 o 2 Enhanced degradation treatment for oxidant, the dosage is 250mg / L, ferrous ion is used as the catalyst, the dosage is 50mg / L, the COD of the treated effluent is below 50mg / L, and phenol and acetone are not detected.

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