Phenol tar comprehensive recycling system

Abstract

The utility model relates to a comprehensive phenol tar recycling system which comprises a first rectifying tower, a second rectifying tower, a third rectifying tower, a fourth rectifying tower and a stripping tower, the stripping tower is provided with a phenol tar feed port and a steam feed port, a tower top discharge port of the stripping tower is connected with a feed port of the first rectifying tower, a tower top discharge port of the first rectifying tower is connected with a feed port of the second rectifying tower, and a tower top discharge port of the second rectifying tower is connected with a feed port of the third rectifying tower; a tower bottom discharge port of the first rectifying tower is connected with a feed port of the fourth rectifying tower, a tower top discharge port of the fourth rectifying tower is connected with a product acetophenone discharge pipe, a tower bottom discharge port of the second rectifying tower is connected with an acetophenone-containing heavy component discharge pipe, and a tower bottom discharge port of the third rectifying tower is connected with a product phenol discharge pipe. Compared with the prior art, the device has the advantages of improving the utilization value of the phenol tar, avoiding resource waste and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to waste liquid recovery processing technical field especially is related to a phenol tar comprehensive recycling system. BACKGROUND

[0002] At present, the phenol is mainly produced by the isopropylbenzene method in the domestic, the isopropylbenzene is oxidized to produce hydrogen peroxide isopropylbenzene, and then is decomposed into phenol and acetone under acidic conditions. However, the reaction of isopropylbenzene and oxygen inevitably produces phenol tar, which contains phenol, acetophenone, p-cumyl phenol, methyl styrene dimer and other high-boiling substances. Among them, phenol and acetophenone are the main monomers for manufacturing synthetic resins and plastics. Therefore, if the by-products in the phenol tar can be recycled and utilized, not only the production value can be improved, but also the production cost of the product can be further reduced.

[0003] The domestic phenol production enterprises basically treat the phenol tar by incineration, which causes resource waste and increases the production cost of the enterprises. The combustion waste gas also affects the environment. The existing phenol tar comprehensive recycling process is not mature. When the phenol tar is treated by the rectifying column, the tar viscosity at the bottom of the column is high, and coking is easy to occur, which is difficult to handle. And under the high-temperature operating conditions, the valuable products in the tar are easily damaged.

[0004] The patent CN 212560047U discloses a system for separating phenol and acetophenone from tar, which comprises a heavy component removal tower for removing heavy components in the tar, a rough separation tower for rough separation of the material, a phenol recovery tower for recovering phenol at the top, and an acetophenone recovery tower for recovering acetophenone at the top. The system reduces the harmful substances in the tar to a relatively safe residual amount, achieves the goal of harmless treatment, reduces the amount of three wastes, and improves the utilization value of the tar. However, the heavy component removal tower in the system has a high risk of coking at the bottom. UTILITY MODEL CONTENT

[0005] The utility model aims at providing a phenol tar comprehensive recycling system to improve the utilization value of the phenol tar.

[0006] The utility model can be realized by the following technical scheme: a phenol tar comprehensive recycling system, comprising a first rectifying column, a second rectifying column, a third rectifying column, a fourth rectifying column and a stripping tower.

[0007] The stripping tower is provided with a phenol tar feed inlet and a steam feed inlet, the top outlet of the stripping tower is connected with the feed inlet of the first rectifying tower, the top outlet of the first rectifying tower is connected with the feed inlet of the second rectifying tower, the top outlet of the second rectifying tower is connected with the feed inlet of the third rectifying tower, the bottom outlet of the first rectifying tower is connected with the feed inlet of the fourth rectifying tower, the top outlet of the fourth rectifying tower is connected with a product acetophenone discharge pipe for discharging product acetophenone, and the bottom outlet of the second rectifying tower is connected with an acetophenone-containing heavy component discharge pipe for discharging acetophenone-containing heavy components.

[0008] In the utility model, product acetophenone, acetophenone-containing heavy components and product phenol can be respectively discharged and reused after treatment.

[0009] Preferably, the phenol tar feed inlet is arranged at the top of the tower, and the steam feed inlet is arranged at the bottom of the tower.

[0010] Preferably, the feed inlet of the first rectifying tower is arranged at the middle of the tower.

[0011] Preferably, the feed inlet of the second rectifying tower is arranged at the middle of the tower.

[0012] Preferably, the feed inlet of the third rectifying tower is arranged at the middle of the tower.

[0013] Preferably, the feed inlet of the fourth rectifying tower is arranged at the middle of the tower.

[0014] Preferably, the stripping tower is a negative pressure tower.

[0015] Further preferably, the stripping tower is connected with a vacuum pumping device for controlling the absolute pressure in the tower to be 15-50 kPa.

[0016] Preferably, the steam feed inlet is connected with a steam conveying pipe for conveying 140-170 DEG C steam into the stripping tower.

[0017] Preferably, the first rectifying tower is an atmospheric tower.

[0018] Preferably, the first rectifying tower is provided with a condenser at the top for controlling the top temperature to be 70-110 DEG C and a reboiler at the bottom for controlling the bottom temperature to be 180-240 DEG C.

[0019] Preferably, the second rectifying tower is an atmospheric tower.

[0020] Preferably, the second rectifying tower is provided with a condenser at the top for controlling the top temperature to be 80-130 DEG C and a reboiler at the bottom for controlling the bottom temperature to be 170-240 DEG C.

[0021] Preferably, the third rectification tower is an atmospheric tower.

[0022] Preferably, the third rectification tower is provided with a condenser at the top for controlling the temperature at the top to be 80-130 DEG C, and a reboiler at the bottom for controlling the temperature at the bottom to be 150-220 DEG C.

[0023] Preferably, the fourth rectification tower is a negative pressure tower.

[0024] Further preferably, the fourth rectification tower is connected with a vacuum extraction device for controlling the absolute pressure in the tower to be 15-50 kPa.

[0025] Preferably, the fourth rectification tower is provided with a condenser at the top for controlling the temperature at the top to be 120-210 DEG C, and a reboiler at the bottom for controlling the temperature at the bottom to be 170-250 DEG C.

[0026] Preferably, the stripping tower is connected with a high-boiling substance discharge pipe at the bottom for discharging high-boiling substances.

[0027] Preferably, the third rectification tower is connected with a light component discharge pipe at the top for discharging light components.

[0028] Preferably, the fourth rectification tower is connected with a heavy component discharge pipe at the bottom for discharging heavy components.

[0029] Compared with the prior art, the utility model has the following beneficial effects:

[0030] 1. Using the utility model system to separate and purify phenol tar can recover phenol and phenylacetone, improve the utilization value of phenol tar, and avoid resource waste;

[0031] 2. The utility model system can maximize the recovery and utilization of high-value components of phenol tar to improve economic and environmental benefits;

[0032] 3. When a rectification tower is used to separate phenol tar, the bottom temperature is relatively high, and the phenol tar is easy to coke, but the utility model uses a negative pressure stripping tower to reduce the operating temperature, and the bottom tar is not easy to coke;

[0033] 4. Compared with a heavy component removal tower, the utility model stripping tower can reduce the risk of bottom coking;

[0034] 5. In the utility model system, the stripping tower and the fourth rectification tower are operated under negative pressure to reduce the heat source requirement;

[0035] 6. Using the utility model system can realize the recovery of phenol with a purity of ≥98%, and phenylacetone with a purity of ≥92%, which has high utilization value;

[0036] 7. The utility model provides a kind of comprehensive recycling process of rectification residue generated in phenol production process, which can solve the problems faced by the recovery of rectification residue generated in phenol production process. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 It is the structure diagram of the phenol tar comprehensive recycling system of the utility model;

[0038] In the figure: 1-first rectification tower, 2-second rectification tower, 21-acetophenone heavy component discharge pipe containing, 3-third rectification tower, 31-product phenol discharge pipe, 32-light component discharge pipe, 4-fourth rectification tower, 41-product acetophenone discharge pipe, 42-heavy component discharge pipe, 5-stripping tower, 51-phenol tar feed inlet, 52-steam feed inlet, 53-high-boiling substance discharge pipe. DETAILED DESCRIPTION

[0039] The utility model will be described in detail below in combination with drawings and specific embodiments. The embodiment is implemented on the premise of the technical scheme of the utility model, and gives detailed implementation mode and specific operation process, but the protection scope of the utility model is not limited to the following examples.

[0040] It should be noted that: similar signs and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0041] Some embodiments of the utility model will be described in detail below in combination with drawings. In the case of no conflict, the following examples and features in examples can be combined with each other.

[0042] Example 1

[0043] A phenol tar comprehensive recycling system, as shown in Figure 1 It includes first rectification tower 1, second rectification tower 2, third rectification tower 3, fourth rectification tower 4 and stripping tower 5.

[0044] Among them, stripping tower 5 is equipped with phenol tar feed inlet 51 and steam feed inlet 52, the top discharge port of stripping tower 5 is connected with the feed inlet of first rectification tower 1, the top discharge port of first rectification tower 1 is connected with the feed inlet of second rectification tower 2, the top discharge port of second rectification tower 2 is connected with the feed inlet of third rectification tower 3, and the bottom discharge port of first rectification tower 1 is connected with the feed inlet of fourth rectification tower 4.

[0045] And in the embodiment, the top discharge port of fourth rectification tower 4 is connected with product acetophenone discharge pipe 41, the bottom discharge port of second rectification tower 2 is connected with acetophenone heavy component discharge pipe 21 containing, and the bottom discharge port of third rectification tower 3 is connected with product phenol discharge pipe 31.

[0046] When using the system of this embodiment for comprehensive recovery and utilization of phenol tar, phenol tar enters stripping tower 5 from phenol tar inlet 51, and steam enters stripping tower 5 from steam inlet 52. The light component at the top of stripping tower 5 enters first distillation tower 1, and the light component at the top of first distillation tower 1 enters second distillation tower 2 for separation. The heavy component at the bottom of first distillation tower 1 enters fourth distillation tower 4 for separation. The light component obtained at the top of fourth distillation tower 4, the main product of which is acetophenone, is collected from product acetophenone outlet pipe 41. The light component at the top of second distillation tower 2 enters third distillation tower 3 for separation. The heavy component at the bottom of second distillation tower 2, mainly acetophenone, is collected from acetophenone-containing heavy component outlet pipe 21. The heavy component at the bottom of third distillation tower 3, mainly phenol, is collected from product phenol outlet pipe 31.

[0047] Example 2

[0048] A comprehensive phenol tar recovery and utilization system is provided, wherein stripping tower 5 and fourth distillation tower 4 are negative pressure towers, and first distillation tower 1, second distillation tower 2 and third distillation tower 3 are atmospheric pressure towers.

[0049] Furthermore, in this embodiment, the bottom outlet of the stripping column 5 is connected to a high-boiling-point outlet pipe 53 for collecting high-boiling-point substances such as cumylphenol and methylstyrene dimer; the top outlet of the third distillation column 3 is connected to a light component outlet pipe 32 for collecting light components such as water; and the bottom outlet of the fourth distillation column 4 is connected to a heavy component outlet pipe 42 for collecting heavy components such as p-cumylphenol. The rest is the same as in Embodiment 1.

[0050] Example 3

[0051] A comprehensive phenol tar recovery and utilization system uses phenol tar produced by a phenol production unit as raw material. The composition (wt%) of the phenol tar is: phenol 3-10%, acetophenone 6-25%, p-cumylphenol 20-30%, styrene dimer 30-50%, and other heavy components 5-20%. The phenol tar enters stripping tower 5 from the top, while steam enters stripping tower 5 from the bottom. The steam temperature is approximately 140-170℃. Stripping tower 5 is a negative pressure tower, operating at a pressure of 15-50 kPa (absolute pressure). The light components stripped from the steam at the top of stripping tower 5 enter the condenser for condensation and cooling. The heavy components are obtained at the bottom of stripping tower 5, mainly p-cumylphenol, methylstyrene dimer, and other reboilers. The cooled light component enters the first distillation column 1. The first distillation column 1 separates the light key component phenol from the heavy key component acetophenone. The top of the column yields the light component, mainly water, phenol, and a small amount of acetophenone, while the bottom yields the heavy component, mainly acetophenone, a small amount of p-cumylphenol, and methylstyrene dimer. The first distillation column 1 is an atmospheric pressure column with a top temperature of 70–110°C and a bottom temperature of 180–240°C, and a controlled reflux ratio of 3–8. The light component from the top of the first distillation column 1 enters the second distillation column 2 for further separation. The top of the second distillation column 2 yields the light component, mainly phenol and water, while the bottom yields the heavy component, mainly acetophenone. The second distillation column 2 is also an atmospheric pressure column with a top temperature of 80–130°C and a bottom temperature of 170–240°C, and a controlled reflux ratio of 2–7. The light components at the top of the second distillation column 2 enter the third distillation column 3. The light components, mainly water, are obtained at the top of the third distillation column 3, while the heavy components, mainly phenol, are obtained at the bottom of the third distillation column 3. The purity of phenol is ≥98%. The third distillation column 3 is an atmospheric pressure column with a top temperature of 80-130℃ and a bottom temperature of 150-220℃. The reflux ratio is controlled at 2-7.

[0052] The heavy components at the bottom of the first distillation column 1 enter the fourth distillation column 4. The light components are obtained at the top of the fourth distillation column 4, and the main product is acetophenone with a purity of ≥92%. The heavy components are obtained at the bottom of the fourth distillation column 4, mainly p-cumylphenol and methylstyrene dimer. The fourth distillation column 4 is a negative pressure column with an operating pressure of 15-50 kPa (absolute pressure), a top temperature of 120-210℃, a bottom temperature of 170-250℃, and a controlled reflux ratio of 2-7.

[0053] The above description of the embodiments is provided to enable those skilled in the art to understand and use the utility model. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present utility model is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present utility model without departing from its scope should be within the protection scope of the present utility model.

Claims

1. A comprehensive phenol tar recovery and utilization system, characterized in that, It includes a first distillation column (1), a second distillation column (2), a third distillation column (3), a fourth distillation column (4), and a stripping column (5); The stripping tower (5) is provided with a phenol tar inlet (51) and a steam inlet (52). The top outlet of the stripping tower (5) is connected to the inlet of the first distillation tower (1). The top outlet of the first distillation tower (1) is connected to the inlet of the second distillation tower (2). The top outlet of the second distillation tower (2) is connected to the inlet of the third distillation tower (3). The bottom outlet of the first distillation tower (1) is connected to the inlet of the fourth distillation tower (4). The top outlet of the fourth distillation tower (4) is connected to a product acetophenone outlet pipe (41) for collecting the product acetophenone. The bottom outlet of the second distillation tower (2) is connected to a product acetophenone heavy component outlet pipe (21) for collecting the heavy component containing acetophenone. The bottom outlet of the third distillation tower (3) is connected to a product phenol outlet pipe (31) for collecting the product phenol.

2. The phenol tar comprehensive recycling system according to claim 1, characterized in that, The stripping tower (5) is a negative pressure tower and is connected to a vacuum pumping device for controlling the absolute pressure inside the tower at 15 to 50 kPa.

3. The phenol tar comprehensive recycling system according to claim 1, characterized in that, The steam inlet (52) is connected to a steam delivery pipe for delivering steam at 140-170°C into the stripping tower (5).

4. The phenol tar comprehensive recycling system according to claim 1, characterized in that, The first distillation column (1) is an atmospheric column. A condenser is provided at the top of the column to control the temperature at the top of the column between 70 and 110°C, and a reboiler is provided at the bottom of the column to control the temperature at the bottom of the column between 180 and 240°C.

5. The phenol tar comprehensive recycling system according to claim 1, characterized in that, The second distillation column (2) is an atmospheric column. A condenser is provided at the top of the column to control the temperature at the top of the column between 80 and 130°C, and a reboiler is provided at the bottom of the column to control the temperature at the bottom of the column between 170 and 240°C.

6. The phenol tar comprehensive recycling system according to claim 1, characterized in that, The third distillation column (3) is an atmospheric pressure column. A condenser is provided at the top of the column to control the temperature at the top of the column between 80 and 130°C, and a reboiler is provided at the bottom of the column to control the temperature at the bottom of the column between 150 and 220°C.

7. The phenol tar comprehensive recycling system according to claim 1, characterized in that, The fourth distillation column (4) is a negative pressure column and is connected to a vacuum pumping device for controlling the absolute pressure inside the column at 15 to 50 kPa.

8. The phenol tar comprehensive recycling system according to claim 1, characterized in that, The fourth distillation column (4) is equipped with a condenser at the top to control the temperature at the top of the column at 120-210°C, and a reboiler at the bottom of the column to control the temperature at the bottom of the column at 170-250°C.

9. The phenol tar comprehensive recycling system according to claim 1, characterized in that, The bottom outlet of the stripping tower (5) is connected to a high-boiling-point discharge pipe (53) for extracting high-boiling-point substances.

10. The phenol tar comprehensive recycling system according to claim 1, characterized in that, The top outlet of the third distillation column (3) is connected to a light component discharge pipe (32) for collecting light components; The bottom outlet of the fourth distillation column (4) is connected to a heavy component discharge pipe (42) for collecting heavy components.

Images