Acrylic acid heavy component residue recovery process

Abstract

The present invention relates to the technical field of acrylic acid heavy component residue recovery, particularly to an acrylic acid heavy component residue recovery process, which comprises: mixing an acrylic acid heavy component and a catalyst, feeding into a first reaction kettle, and carrying out heating cracking to obtain light component steam and residual heavy component residue; light component steam is condensed and then recycled into a light component tank, and heavy component residues are taken out and temporarily stored into a residue tank; after enough residual heavy component residues are collected in the residue tank, the residues are fed into a second reaction kettle, deionized water is injected in the gradual heating process, and continuous evaporation is performed to recover an acrylic acid semi-finished product. According to the method, acrylic acid heavy component waste residues remaining in a kettle after a first-stage cracking reaction are recycled, the acrylic acid heavy component waste residues are put into the cracking reaction kettle, the temperature is controlled, deionized water is supplemented to the cracking kettle regularly and quantitatively, and the acrylic acid semi-finished product is continuously evaporated and recycled. Finally, the total recovery rate of acrylic semi-finished products is improved.

Description

Technical Field

[0001] The invention relates to the technical field of acrylic acid heavy component residue recovery, in particular to an acrylic acid heavy component residue recovery process. Background Art

[0002] Acrylic acid has active chemical properties and can react with other products to synthesize many other chemical products, so it has broad market prospects. However, during the production process, acrylic acid is prone to polymerization to form heavy components. The acrylic acid component of the acrylic acid heavy component can be recovered through the cracking and recovery process, effectively reducing the loss of raw materials and the production cost of acrylic acid. The existing acrylic acid cracking and recovery process mainly involves quantitatively adding the acrylic acid heavy component into the reaction cracking kettle, and then heating and cracking and evaporating and recovering it under the action of a catalyst. This process is not efficient enough in utilizing the acrylic acid heavy component, and the recovery rate of acrylic acid semi-finished products is low. There are still a lot of acrylic acid components in the cracking kettle waste residue that are not utilized, which invisibly increases the consumption of raw materials. Based on this, a process for recovering the heavy component residue of acrylic acid is provided. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides a process for recovering acrylic acid heavy component residues, which improves the total recovery rate of acrylic acid semi-finished products by recovering and then cracking the acrylic acid heavy component waste residues.

[0004] To achieve the above object, the present invention provides the following technical solution: a process for recovering acrylic acid heavy component residue, comprising the following steps:

[0005] (1) mixing the acrylic acid heavy component and the catalyst and feeding them into a first reactor, heating and cracking them to obtain light component steam and residual heavy component residue;

[0006] (2) The light component vapor is condensed and recovered into the light component tank, and the remaining heavy component residue is taken out and temporarily stored in the residue tank;

[0007] (3) After a sufficient amount of residual heavy component residue is collected in the residue tank, it is sent to the No. 2 reactor, and deionized water is injected into the reactor during the gradual heating process to continuously evaporate and recover the acrylic acid semi-finished product.

[0008] Preferably, in step (1), the catalyst accounts for 1-2% by weight of the heavy component of acrylic acid.

[0009] Preferably, in step (1), the catalyst comprises toluenesulfonic acid and sulfuric acid, and the mass ratio of toluenesulfonic acid to sulfuric acid is 1:(1-5).

[0010] Preferably, in step (1), in reactor No. 1, the cracking temperature is controlled to be 175-185° C. and the cracking time is 2-3 h.

[0011] Preferably, in step (3), in the No. 2 reactor, the pressure inside the reactor is controlled to be 0-0.036 MPa, and the temperature inside the reactor is controlled to be 85-175°C.

[0012] Preferably, in step (3), the injection rate of deionized water is 0-220 kg / h.

[0013] Preferably, in step (3), the mass ratio of the residual heavy component residue to the total amount of injected deionized water is 1:(0.3-0.6).

[0014] Preferably, in step (3), during the continuous evaporation process, sampling and analysis are performed regularly, and the reaction is stopped when the acid content in the sample is less than 25%.

[0015] The present invention provides a process for recovering acrylic acid heavy component residue, which has the following beneficial effects compared with the prior art:

[0016] The present invention is based on the existing cracking reaction process, by recovering the acrylic acid heavy component waste residue remaining in the kettle after the first stage cracking reaction, putting a specified amount of acrylic acid heavy component waste residue into the cracking reaction kettle, controlling the temperature and adding deionized water to the cracking kettle at a fixed time and in a fixed quantity, and continuously evaporating and recovering the acrylic acid semi-finished product. Through the above basic process flow, the acrylic acid heavy component waste residue is decomposed and utilized, and finally the total recovery rate of the acrylic acid semi-finished product is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0018] Figure 1 This is a process diagram for recovering the heavy component residue of acrylic acid according to the present invention. DETAILED DESCRIPTION

[0019] The following examples are used to explain the implementation methods of the present application in detail, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0020] Example 1

[0021] A production process of residual heavy component residue is as follows: acrylic acid heavy component and catalyst (composed of toluenesulfonic acid and sulfuric acid in a mass ratio of 1:5) are mixed and sent into a No. 1 reactor, and cracked at 175°C for 2 hours to obtain light component steam and residual heavy component residue. The catalyst accounts for 1% of the mass of acrylic acid heavy component. The light component steam is condensed and recovered into a light component tank, and the residual heavy component residue is taken out and temporarily stored in a residue tank.

[0022] Example 2

[0023] A production process for residual heavy component residue is as follows: acrylic acid heavy component and catalyst (composed of toluenesulfonic acid and sulfuric acid in a mass ratio of 1:1) are mixed and sent into a No. 1 reactor, and cracked at 185°C for 2 hours to obtain light component steam and residual heavy component residue. The catalyst accounts for 2% of the mass of acrylic acid heavy component. The light component steam is condensed and recovered into a light component tank, and the residual heavy component residue is taken out and temporarily stored in a residue tank.

[0024] Example 3

[0025] A production process for residual heavy component residue is as follows: acrylic acid heavy component and catalyst (composed of toluenesulfonic acid and sulfuric acid in a mass ratio of 1:3) are mixed and sent into a No. 1 reactor, and cracked at 180°C for 2.5 hours to obtain light component steam and residual heavy component residue. Among them, the catalyst accounts for 1.5% of the mass of acrylic acid heavy component. The light component steam is condensed and recovered into a light component tank, and the residual heavy component residue is taken out and temporarily stored in a residue tank.

[0026] Example 4

[0027] A process for recovering heavy component residue of acrylic acid comprises the following steps: collecting a sufficient amount of heavy component residue in Example 3 in a residue tank, feeding it into a No. 2 reactor, injecting deionized water during the gradual temperature increase, and continuously evaporating and recovering the acrylic acid semi-finished product, wherein the product sample does not polymerize after 15 days. During the continuous evaporation process, sampling and analysis are performed at regular intervals, and the reaction is stopped when the acid content in the sample is less than 25%.

[0028] Table 1 Recycling process

[0029]

[0030]

[0031] Example 5

[0032] A process for recovering heavy component residue of acrylic acid comprises the following steps: collecting a sufficient amount of heavy component residue in Example 3 in a residue tank, feeding it into a No. 2 reactor, injecting deionized water during the gradual temperature increase, and continuously evaporating and recovering the acrylic acid semi-finished product, wherein the product sample does not polymerize after 15 days. During the continuous evaporation process, sampling and analysis are performed at regular intervals, and the reaction is stopped when the acid content in the sample is less than 25%.

[0033] Table 2 Recycling process

[0034]

[0035]

[0036] Example 6

[0037] A process for recovering heavy component residue of acrylic acid comprises the following steps: collecting a sufficient amount of heavy component residue in Example 3 in a residue tank, feeding it into a No. 2 reactor, injecting deionized water during the gradual temperature increase, and continuously evaporating and recovering the acrylic acid semi-finished product, wherein the product sample does not polymerize after 15 days. During the continuous evaporation process, sampling and analysis are performed at regular intervals, and the reaction is stopped when the acid content in the sample is less than 25%.

[0038] Table 3 Recycling process

[0039]

[0040]

[0041] Results Analysis

[0042] According to the results of Examples 4-6, the samples taken during the reaction stage all contain a certain amount of acid, indicating that the residual heavy component residue in the kettle after the initial cracking reaction of the acrylic acid heavy component still contains a portion of acrylic acid. Recycling the residue can fully utilize the acrylic acid heavy component and improve the recovery rate of acrylic acid semi-finished products. The following is Example 3, and the total recovery rate of acrylic acid semi-finished products in Examples 4-6 based on Example 3. The details are shown in the following table.

[0043] Table 4 Recovery

[0044] category Recovery rate (%) Example 3 44.21 Example 3+Example 4 51.23 Example 3+Example 5 51.85 Example 3+Example 6 51.73

[0045] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for recovering acrylic acid heavy component residue, characterized in that: The following steps are involved: (1) mixing the acrylic acid heavy component and the catalyst and feeding them into a first reactor, heating and cracking them to obtain light component steam and residual heavy component residue; (2) The light component vapor is condensed and recovered into the light component tank, and the remaining heavy component residue is taken out and temporarily stored in the residue tank; (3) After a sufficient amount of residual heavy component residue is collected in the residue tank, it is sent to the No. 2 reactor, and deionized water is injected into the reactor during the gradual heating process to continuously evaporate and recover the acrylic acid semi-finished product.

2. The acrylic acid heavy component residue recovery process according to claim 1, characterized in that: In step (1), the catalyst accounts for 1-2% of the mass of the heavy component of acrylic acid.

3. The acrylic acid heavy component residue recovery process according to claim 1, characterized in that: In step (1), the catalyst comprises toluenesulfonic acid and sulfuric acid, and the mass ratio of toluenesulfonic acid to sulfuric acid is 1:(1-5).

4. The acrylic acid heavy component residue recovery process according to claim 1, characterized in that: In step (1), in reactor No. 1, the cracking temperature is controlled to be 175-185° C. and the cracking time is 2-3 h.

5. The process for recovering acrylic acid heavy component residue according to claim 1, characterized in that: In step (3), in the No. 2 reactor, the pressure inside the reactor is controlled to be 0-0.036 MPa and the temperature inside the reactor is controlled to be 85-175°C.

6. The acrylic acid heavy component residue recovery process according to claim 1, characterized in that: In step (3), the injection rate of deionized water is 0-220 kg / h.

7. The process for recovering acrylic acid heavy component residue according to claim 1, characterized in that: In step (3), the mass ratio of the residual heavy component residue to the total amount of injected deionized water is 1:(0.3-0.6).

8. The process for recovering acrylic acid heavy component residue according to claim 1, characterized in that: In step (3), during the continuous evaporation process, sampling and analysis are performed at regular intervals, and the reaction is stopped when the acid content in the sample is less than 25%.

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