Recovery system for phenol in phenol-containing extract liquor
By introducing a combined system of an extractant distillation column and a phenol recovery column into the production of phenolic resin, and utilizing negative pressure and atmospheric pressure operation as well as the design of the top condensation section, the problems of purity and color of phenol recovery products in the existing technology have been solved, achieving high-purity and low-energy phenol recovery.
Patent Information
- Application Number
- CN202520410165.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-11
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-03-11
AI Technical Summary
Existing phenol recovery devices produce phenol products with low phenol content and dark color, which is insufficient to meet usage requirements.
A phenol recovery system for phenol-containing extracts is employed, comprising an extractant distillation column and a phenol recovery column. Through countercurrent extraction and distillation processes, utilizing the negative pressure operation of the extractant distillation column and the atmospheric pressure operation of the phenol recovery column, combined with the reflux design of the top condenser section, high-purity phenol products are obtained.
This improved the purity and color quality of phenol products, making them meet usage requirements, while reducing energy consumption and equipment complexity.
Smart Images
Figure CN223831819U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of chemical production equipment technology, and in particular to a phenol recovery system from phenol-containing extract. Background Technology
[0002] The production process of phenolic resin generates washing wastewater and evaporation wastewater. Both washing wastewater and evaporation wastewater contain high concentrations of phenol and cannot be directly treated by biochemical methods. The phenol in the wastewater must be separated first.
[0003] In the phenolic resin production industry, phenol recovery from phenol-containing wastewater typically employs a combination of extraction, distillation, and stripping. During recovery, the phenolic resin production wastewater and extractant are fed into an extraction tower. After countercurrent extraction, the phenol-containing extract is collected from the top of the tower. This extract is then sent to an extractant distillation tower. After distillation, the low-molecular-weight resin and phenol oxides are collected as the product from the bottom of the distillation tower along with the phenol. The collected product has a low phenol content and is colored, appearing golden yellow, brown, red, or even black. The recovered phenol product does not adequately meet usage requirements. Utility Model Content
[0004] The main objective of this invention is to propose a phenol recovery system for phenol-containing extracts, aiming to solve the problem of low phenol content in the phenol products recovered by existing phenol recovery devices.
[0005] To achieve the above objectives, this utility model proposes a phenol recovery system from a phenol-containing extract, comprising:
[0006] The extractant distillation column has an extractant inlet in the middle and a gaseous material side stream outlet in the lower part.
[0007] A phenol recovery tower, serving as a side-stream tower of the extractant distillation tower, has a phenol inlet at its lower part, which is connected to the gaseous material side-stream outlet via a pipeline. A phenol product outlet is located at the top of the phenol recovery tower.
[0008] In one embodiment, the height of the phenol recovery tower is 1 / 2 to 1 / 20 of the height of the extractant distillation tower.
[0009] In one embodiment, the horizontal height of the phenol inlet is not lower than that of the gaseous material side-stream outlet.
[0010] In one embodiment, the lower part of the extractant distillation column is provided with a liquid phase material reflux port, and the liquid phase material reflux port is located below the gas phase material side stream outlet;
[0011] The bottom of the phenol recovery tower is provided with a second recombinant separation outlet, which is connected to the liquid phase material return port through a pipeline, and the horizontal height of the second recombinant separation outlet is above the liquid phase material return port.
[0012] In one embodiment, the extractant distillation column is a packed column, and a reboiler is provided in the reboiler of the extractant distillation column. The reboiler is used to heat the liquid material at the bottom of the reboiler of the extractant distillation column to a gaseous state and return it to the extractant distillation column. The gaseous material side stream outlet is located between the bottom of the packing layer in the extractant distillation column and the gaseous material reflux port at the bottom of the extractant distillation column; wherein, the gaseous material reflux port is connected to the material outlet of the reboiler through a pipeline. The liquid material reflux port should not be located above the gaseous material reflux port.
[0013] In one embodiment, the phenol recovery tower is provided with a top condensation section, which includes a condenser, a reflux tank, a reflux pump, and a reflux pipe connected in sequence. The feed inlet of the condenser is connected to the vapor outlet at the top of the phenol recovery tower via a pipe, and the liquid outlet of the reflux pipe is connected to the liquid return port at the top of the phenol recovery tower. The reflux pipe is also branched with a phenol product collection outlet.
[0014] In one embodiment, the phenol recovery tower is a packed tower or a plate tower.
[0015] In one embodiment, the bottom of the extractant distillation column is provided with a first heavy component collection pipe, and the top of the column is provided with an extractant collection pipe.
[0016] In one embodiment, the phenol recovery system in the phenol-containing extract further includes an extraction tower, the top of which is provided with an extract outlet, and the extract outlet is connected to the extract inlet via a pipeline.
[0017] In this invention, the phenol-containing extract is fed into an extractant distillation column through the extractant inlet. The distillation column operates under negative pressure. After distillation, the extractant is collected from the top of the column and can be recovered and reused. The gaseous material at the bottom of the distillation column is collected through a side outlet and fed into a small phenol recovery column. The gaseous material flowing from the top of the phenol recovery column is condensed, with some being refluxed and the rest collected through the phenol product outlet. The collected phenol product has high purity and is slightly yellow or colorless, which can well meet the requirements for phenol product use. The heavy components containing low-molecular-weight resin and phenol oxide at the bottom of the phenol recovery column flow back to the extractant distillation column by gravity.
[0018] The phenol recovery tower is a small distillation tower. As a side-stream tower, since the extractant distillation tower operates under negative pressure and the collected material is gaseous, the phenol recovery tower can directly utilize the temperature and pressure of the extractant distillation tower bottom without separate heating. The phenol recovery tower operates under atmospheric pressure distillation.
[0019] The bottom of the extractant distillation column contains colored heavy components such as low-molecular-weight resins and phenol oxides, which can be treated as waste or used to produce low-end phenolic resin products. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of an embodiment of a phenol recovery system from a phenol-containing extract provided by this utility model.
[0022] Explanation of icon numbers:
[0023] 1. Extraction tower; 11. Extractant outlet; 2. Extractant distillation tower; 21. Extractant outlet pipe; 22. Reboiler; 23. Packing layer; 24. Gas phase material side stream outlet; 25. First heavy component outlet pipe; 26. Liquid phase material reflux port; 27. Gas phase material reflux port; 28. Extractant inlet; 3. Phenol recovery tower; 31. Condenser; 32. Reflux tank; 33. Reflux pump; 34. Reflux pipe; 35. Phenol product outlet; 36. Second heavy component outlet; 37. Phenol inlet.
[0024] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.
[0026] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.
[0027] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0028] Please see Figure 1 This utility model proposes a phenol recovery system for phenol-containing extracts, comprising an extractant distillation column 2 and a phenol recovery column 3. The extractant distillation column 2 is provided with an extractant inlet 28 in the middle and a gaseous material side stream outlet 24 at the bottom. The phenol recovery column 3 serves as a side stream column of the extractant distillation column 2. The phenol recovery column 3 is provided with a phenol inlet 37 at the bottom, and the phenol inlet 37 is connected to the gaseous material side stream outlet 24 via a pipeline. The phenol recovery column 3 is provided with a phenol product outlet 35 at the top.
[0029] By adopting the above technical solution, the phenolic resin production wastewater to be treated is fed into extraction tower 1 from the upper feed inlet, and the methyl isobutyl ketone extractant is fed into extraction tower 1 from the lower feed inlet. The mass flow ratio of wastewater to extractant is 0.5 to 5:1. Extraction tower 1 is a packed tower or a plate tower. Extraction tower 1 operates at atmospheric pressure and a temperature of 10 to 40°C. Through countercurrent extraction, extraction tower 1 is equipped with an extract outlet 11 at the top. The extractant containing phenol is collected through extract outlet 11, and the wastewater containing a small amount of extractant is collected from the bottom of extraction tower 1.
[0030] The extract outlet 11 and the extract inlet 28 are connected by a pipeline to send the phenol-containing extract from the top of the extracting tower 1 to the extractant distillation tower 2. The extractant distillation tower 2 is a packed tower. The operating conditions of the extractant distillation tower 2 are: -90kPa to -20kPa, bottom temperature 100 to 150℃, and top temperature 30 to 70℃. After distillation, the extractant is collected from the top of the extractant distillation tower 2. The extractant can be recovered and reused. The gaseous material is collected from the lower side stream of the extractant distillation tower 2 and sent to a small phenol recovery tower 3. Phenol recovery tower 3 is a packed tower or a plate tower. It operates at atmospheric pressure. The gaseous material flowing from the top of tower 3 is condensed, with a portion being refluxed at a reflux ratio of 0.5–3, and the remainder collected through phenol product outlet 35 as the phenol product. This product has a high phenol content and is slightly yellow or colorless, which adequately meets the requirements for phenol product use. The bottom of tower 3 contains heavy components of low-molecular-weight resin and phenol oxide, which flow back by gravity into the extractant distillation tower 2.
[0031] The bottom of the extractant distillation column 2 contains colored heavy components such as low molecular weight resin and phenol oxide, which can be treated as waste or used to produce low-end phenolic resin products.
[0032] Specifically, the phenol recovery tower 3 is located adjacent to the extractant distillation tower 2, and the height of the phenol recovery tower 3 is 1 / 2 to 1 / 20 of the height of the extractant distillation tower 2. By controlling the height of the phenol recovery tower 3, the temperature and pressure of the bottom of the extractant distillation tower 2 can be fully utilized, so that the phenol recovery tower 3 can be distilled under normal pressure without heating to obtain a high-content phenol product.
[0033] Furthermore, the horizontal height of the phenol inlet 37 is not lower than that of the gaseous material side-stream outlet 24. The phenol inlet 37 is located above the gaseous material side-stream outlet 24, or the phenol inlet 37 and the gaseous material side-stream outlet 24 are at the same horizontal height, which facilitates the smooth entry of the gaseous material in the lower part of the extractant distillation column 2 into the phenol recovery column 3.
[0034] Furthermore, the lower part of the extractant distillation column 2 is provided with a liquid phase material reflux port 26, and the liquid phase material reflux port 26 is located below the gas phase material side stream outlet 24; the bottom of the phenol recovery column 3 is provided with a second heavy component outlet 36, the second heavy component outlet 36 is connected to the liquid phase material reflux port 26 through a pipeline, and the second heavy component outlet 36 is located above the liquid phase material reflux port 26.
[0035] By adopting the above technical solution, the heavy component containing low molecular weight resin and phenol oxide at the bottom of the phenol recovery tower 3 is collected through the second heavy component collection outlet 36 and returned to the extractant distillation tower 2 through the liquid phase material return port 26. The second heavy component collection outlet 36 is located above the liquid phase material return port 26, which can realize the gravity flow of the heavy component containing low molecular weight resin and phenol oxide at the bottom of the phenol recovery tower 3 back to the extractant distillation tower 2.
[0036] Furthermore, the extractant distillation column 2 is a packed column, and a reboiler 22 is provided in the bottom of the extractant distillation column 2. The reboiler 22 is used to heat the liquid material at the bottom of the bottom of the extractant distillation column 2 to a gaseous state and return it to the extractant distillation column 2. The gas phase material side stream outlet 24 is located between the bottom of the packing layer 23 in the extractant distillation column 2 and the gas phase material reflux port 27 at the bottom of the extractant distillation column 2. The gas phase material reflux port 27 is connected to the material outlet of the reboiler 2 by a pipeline.
[0037] By adopting the above technical solution, the extractant distillation column 2 is equipped with a packing layer 23, the bottom of the extractant distillation column 2 is equipped with a reboiler 22, and the gas phase material side stream outlet 24 is located between the bottom of the packing layer 23 and the gas phase material reflux outlet 27, so as to better ensure that the gas phase material at the bottom of the extractant distillation column 2 enters the phenol recovery column 3 smoothly.
[0038] Specifically, the phenol recovery tower 3 is provided with a top condensation section, which includes a condenser 31, a reflux tank 32, a reflux pump 33 and a reflux pipe 34 connected in sequence. The feed inlet of the condenser 31 is connected to the steam outlet at the top of the phenol recovery tower 3 through a pipe. The liquid outlet of the reflux pipe 34 is connected to the liquid return port at the top of the phenol recovery tower 3, and the phenol product outlet 35 is branched on the reflux pipe 34.
[0039] By adopting the above technical solution, the steam at the top of the phenol recovery tower 3 is condensed in the top condensing section, and part of it is returned to the phenol recovery tower 3, while part of it is extracted through the phenol product outlet 35 to obtain phenol product.
[0040] Specifically, the extractant distillation column 2 is provided with an extractant collection pipe 21 at the top and a first heavy component collection pipe 25 at the bottom.
[0041] By adopting the above technical solution, the extractant at the top of the extractant distillation column 2 can be collected through the extractant collection pipe 21, and the collected extractant can be recovered for reuse; the bottom of the extractant distillation column 2 contains colored heavy components such as low molecular weight resin and phenol oxide, which can be collected through the first heavy component collection pipe 25, and the collected heavy component can be treated as waste or used to produce low-end phenolic resin products.
[0042] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.
Claims
1. A system for recovering phenol from a phenol-containing extract, characterized in that, include: The extractant distillation column has an extractant inlet in the middle and a gaseous material side stream outlet in the lower part. A phenol recovery tower, serving as a side-stream tower of the extractant distillation tower, has a phenol inlet at its lower part, which is connected to the gaseous material side-stream outlet via a pipeline. A phenol product outlet is located at the top of the phenol recovery tower.
2. The phenol recovery system from the phenol-containing extract as described in claim 1, characterized in that, The height of the phenol recovery tower is 1 / 2 to 1 / 20 of the height of the extractant distillation tower.
3. The phenol recovery system from the phenol-containing extract as described in claim 1, characterized in that, The horizontal height of the phenol inlet shall not be lower than that of the gas phase material side-stream outlet.
4. The phenol recovery system from the phenol-containing extract as described in claim 1, characterized in that, The lower part of the extractant distillation column is provided with a liquid phase material reflux port, and the liquid phase material reflux port is located below the gas phase material side stream outlet. The bottom of the phenol recovery tower is provided with a second recombinant separation outlet, which is connected to the liquid phase material return port through a pipeline, and the second recombinant separation outlet is located above the liquid phase material return port.
5. The phenol recovery system from the phenol-containing extract as described in claim 1, characterized in that, The extractant distillation column is a packed column. The bottom of the extractant distillation column is equipped with a reboiler. The reboiler is used to heat the liquid material at the bottom of the bottom of the extractant distillation column to a gaseous state and return it to the extractant distillation column. The gaseous material side stream outlet is located between the bottom of the packing layer in the extractant distillation column and the gaseous material reflux port at the bottom of the extractant distillation column. The gas phase material reflux port is connected to the material outlet of the reboiler via a pipeline.
6. The phenol recovery system from the phenol-containing extract as described in claim 1, characterized in that, The phenol recovery tower is provided with a top condensation section, which includes a condenser, a reflux tank, a reflux pump and a reflux pipe connected in sequence. The feed inlet of the condenser is connected to the steam outlet at the top of the phenol recovery tower through a pipe. The liquid outlet of the reflux pipe is connected to the liquid return port at the top of the phenol recovery tower, and the phenol product collection outlet is provided on a branch of the reflux pipe.
7. The phenol recovery system from the phenol-containing extract as described in claim 1, characterized in that, The phenol recovery tower is a packed tower or a plate tower.
8. The phenol recovery system from the phenol-containing extract as described in claim 1, characterized in that, The bottom of the extractant distillation column is equipped with a first heavy component collection pipe, and the top of the column is equipped with an extractant collection pipe.
9. The phenol recovery system from the phenol-containing extract as described in claim 1, characterized in that, The phenol recovery system in the phenol-containing extract also includes an extraction tower, the top of which is provided with an extract outlet, which is connected to the extract inlet via a pipeline.