Recombinant splitting and water adding recovery process for acrylic acid

Abstract

The invention relates to the technical field of crylic acid recombination splitting and recycling, in particular to a crylic acid recombination splitting and water adding recycling process which comprises the following steps: injecting crylic acid heavy components and part of deionized water into a reaction kettle to obtain a mixed material; reducing the pressure in the reaction kettle, increasing the temperature, and carrying out reduced pressure distillation on the mixed material; and after the reduced pressure distillation is finished, controlling the reaction kettle to recover the normal pressure, and injecting the rest deionized water into the reaction kettle to continuously perform reevaporation to obtain an acrylic acid semi-finished product. The deionized water and the acrylic acid heavy component are mixed for reduced pressure distillation, and then the remaining deionized water is injected for atmospheric distillation, so that the recovery rate of the acrylic acid semi-finished product can be better improved; the deionized water is injected under different pressures for distillation, abnormal phenomena such as a large amount of polymerization heat release and overtemperature and overpressure do not occur, the polymerization phenomenon does not occur after products and waste residue samples are reserved for 15 days, pipeline blockage and equipment damage are not easily caused, and the production cost is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of acrylic acid recombination, splitting, decomposition and recovery, in particular to an acrylic acid recombination, splitting, decomposition and water-adding recovery process. Background Art

[0002] Acrylic acid is a vinyl monomer compound with active chemical properties. It can be synthesized into a variety of fine chemical products through homopolymerization or copolymerization with other organic chemical products, including coatings, daily chemicals, functional polymer materials and other special chemicals, and has great market prospects.

[0003] Since acrylic acid has the chemical property of being extremely easy to polymerize, polymerization is common in the production process, and acrylic acid heavy components are easily generated. The product can be recovered through a cracking recovery process. In the existing cracking process, a specified amount of acrylic acid heavy components is added to the cracking kettle, and then an inhibitor is added according to a ratio, the temperature in the kettle is controlled within a specified range by adjusting the medium-pressure steam flow, the discharge flow / temperature is controlled, and sampling and analysis are performed at regular intervals until the reaction is completed, and then the acrylic acid semi-finished product can be recovered. However, the recovery rate of acrylic acid semi-finished products in this process is relatively low, the waste residue has high viscosity / a lot of residual liquid, which can easily cause pipeline blockage and equipment damage, increasing production costs. Based on this, a process for the recovery of acrylic acid recombinant cracking and water addition is proposed. Summary of the invention

[0004] In order to address the deficiencies of the prior art, the present invention provides an acrylic acid recombinant cracking and water-adding recovery process, which comprises first mixing deionized water with the acrylic acid recombinant component and performing reduced pressure distillation, and then injecting deionized water for atmospheric pressure distillation, thereby better improving the recovery rate of acrylic acid semi-finished products.

[0005] To achieve the above object, the present invention provides the following technical solution: an acrylic acid recombination, cracking, decomposition and water recovery process, comprising the following steps:

[0006] (1) injecting acrylic acid heavy components and a portion of deionized water into a reaction kettle to obtain a mixed material;

[0007] (2) reducing the pressure in the reactor and increasing the temperature to perform vacuum distillation on the mixture;

[0008] (3) After the vacuum distillation is completed, the reactor is controlled to return to normal pressure, and the remaining deionized water is injected into the reactor to continue back distillation to obtain a semi-finished acrylic acid product.

[0009] Preferably, in steps (1) to (3), the mass ratio of the acrylic acid heavy component to the total amount of deionized water is 1:(0.4-0.6).

[0010] Preferably, in step (1), the mass ratio of the acrylic acid heavy component to the initially added portion of deionized water is 1:(0.02-0.06).

[0011] Preferably, in step (2), the pressure in the reactor is controlled between -0.05 and 0.1 MPa, and the reaction temperature is controlled between 160 and 170°C.

[0012] Preferably, in step (2), 40-50% of the acrylic acid semi-finished product is initially recovered by reduced pressure distillation.

[0013] The present invention provides a process for the recombination, cracking, decomposition and water recovery of acrylic acid, which has the following beneficial effects compared with the prior art:

[0014] The present invention first mixes a small amount of deionized water with acrylic acid heavy components for vacuum distillation to separate the light components, and then injects the remaining deionized water for atmospheric distillation, which can better improve the recovery rate of acrylic acid semi-finished products and has the characteristics of safety and environmental protection.

[0015] The present invention injects deionized water at different pressures for distillation, and no abnormal phenomena such as large-scale polymerization exotherm and over-temperature and over-pressure occur. No polymerization occurs even after the product and waste residue samples are retained for 15 days, and it is not easy to cause pipeline blockage and equipment damage, thereby greatly reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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:

[0017] Figure 1 This is a process diagram for the recombination, splitting, decomposition and water recovery of acrylic acid according to the present invention. DETAILED DESCRIPTION

[0018] 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.

[0019] An acrylic acid recombination, splitting, decomposition and water recovery process comprises the following steps:

[0020] (1) injecting acrylic acid heavy components and a portion of deionized water into a reaction kettle to obtain a mixed material;

[0021] (2) reducing the pressure in the reactor and increasing the temperature to perform vacuum distillation on the mixture;

[0022] (3) After the vacuum distillation is completed, the reactor is controlled to return to normal pressure, and the remaining deionized water is injected into the reactor to continue back distillation to obtain a semi-finished acrylic acid product.

[0023] Example 1

[0024] A process for recycling acrylic acid by recombinant cracking and decomposition with water, comprising: firstly injecting 500 kg of deionized water into a reactor, then adding 9000 kg of acrylic acid recombinant components, controlling the temperature of the reactor to 170°C, and performing reduced pressure distillation for 18 hours at a pressure of -0.052 MPa; further injecting 4000 kg of deionized water into the reactor, performing normal pressure back distillation for 10 hours at 170°C, and recycling acrylic acid semi-finished products, wherein the content of acrylic acid in the semi-finished products is 66.2%, and no polymerization phenomenon occurs after retaining the samples for 15 days.

[0025] Table 1 Recovery

[0026] category Acrylic acid heavy component Acrylic semi-finished products Recovery rate unit 9000kg 4543.2kg 50.48％

[0027] Example 2

[0028] A process for recycling acrylic acid by recombinant cracking and decomposition with water, comprising: firstly injecting 300 kg of deionized water into a reactor, then adding 9000 kg of acrylic acid recombinant components, controlling the temperature of the reactor to 170°C, and performing reduced pressure distillation for 19 hours at a pressure of -0.071 MPa; further injecting 4200 kg of deionized water into the reactor, performing normal pressure back distillation for 10 hours at 170°C, and recycling acrylic acid semi-finished products, wherein the content of acrylic acid in the semi-finished products is 65.7%, and no polymerization phenomenon occurs after retaining the samples for 15 days.

[0029] Table 2 Recovery

[0030] category Acrylic acid heavy component Acrylic semi-finished products Recovery rate unit 9000kg 4332.6 48.14％

[0031] Example 3

[0032] An acrylic acid recombinant cracking and water-adding recovery process comprises: firstly injecting 540 kg of deionized water into a reactor, then adding 9000 kg of acrylic acid recombinant components, controlling the temperature of the reactor to 170°C, and performing reduced pressure distillation for 17 hours at a pressure of -0.05 MPa; continuously injecting 4860 kg of deionized water into the reactor, performing normal pressure back distillation for 12 hours at 170°C, and recovering an acrylic acid semi-finished product, wherein the acrylic acid content in the semi-finished product is 65.2%, and no polymerization phenomenon occurs after retaining the sample for 15 days.

[0033] Table 3 Recovery

[0034] category Acrylic acid heavy component Acrylic semi-finished products Recovery rate unit 9000kg 4366.8 48.52％

[0035] Example 4

[0036] An acrylic acid recombinant cracking and water-adding recovery process comprises: firstly injecting 180 kg of deionized water into a reactor, then adding 9000 kg of acrylic acid recombinant components, controlling the temperature of the reactor to 170°C, and performing reduced pressure distillation for 15 hours at a pressure of -0.085 MPa; continuously injecting 3420 kg of deionized water into the reactor, performing normal pressure back distillation for 10 hours at 170°C, and recovering an acrylic acid semi-finished product, wherein the acrylic acid content in the semi-finished product is 64.5%, and no polymerization phenomenon occurs after retaining the sample for 15 days.

[0037] Table 4 Recovery

[0038] category Acrylic acid heavy component Acrylic semi-finished products Recovery rate unit 9000kg 4326.3 48.07％

[0039] Comparative Example 1

[0040] An acrylic acid recombinant cracking and water-adding recovery process comprises: adding 9000 kg of acrylic acid recombinant components into a reactor, controlling the temperature of the reactor to 170° C., reacting for 19 hours under normal pressure, and distilling and recovering to obtain acrylic acid semi-finished products.

[0041] Table 5 Recovery

[0042] category Acrylic acid heavy component Acrylic semi-finished products Recovery rate unit 9000kg 4311.9 47.91％

[0043] Comparative Example 2

[0044] An acrylic acid recombinant cracking and water-adding recovery process comprises: firstly injecting 2460 kg of deionized water into a reactor, then adding 4000 kg of acrylic acid recombinant components, controlling the temperature of the reactor to 170° C., reacting at normal pressure for 24 hours, and recovering acrylic acid semi-finished products.

[0045] Table 6 Recovery

[0046] category Acrylic acid heavy component Acrylic semi-finished products Recovery rate unit 4000kg 1800kg 45.00％

[0047] Comparative Example 3

[0048] An acrylic acid recombination, splitting, decomposition and water recovery process comprises: adding 8000 kg of acrylic acid recombination components into a reactor, controlling the temperature of the reactor to be 150-170° C., performing reduced pressure distillation for 16 hours at a pressure of -0.083 MPa (reacting at 150° C. for 3 hours; reacting at 160° C. for 2 hours; and reacting at 170° C. for 11 hours), and distilling and recovering an acrylic acid semi-finished product.

[0049] Table 7 Recovery

[0050] category Acrylic acid heavy component Acrylic semi-finished products Recovery rate unit 8000kg 3455.2 43.19％

[0051] Comparative Example 4

[0052] An acrylic acid recombination, cracking, decomposition and water recovery process comprises: firstly injecting 3000 kg of deionized water into a reactor, then adding 5000 kg of acrylic acid recombinant components, controlling the temperature of the reactor to 170°C, distilling at normal pressure for 10 hours, then distilling at a pressure of -0.080 MPa for 10 hours under reduced pressure, and recovering acrylic acid semi-finished products.

[0053] Table 8 Recovery

[0054] category Acrylic acid heavy component Acrylic semi-finished products Recovery rate unit 5000kg 2242.0kg 44.84％

[0055] Comparative Example 5

[0056] An acrylic acid recombinant cracking and water-adding recovery process comprises: firstly injecting 1660 kg of deionized water into a reactor, then adding 8000 kg of acrylic acid recombinant components, controlling the temperature of the reactor to 170° C., performing reduced pressure distillation at a pressure of -0.075 MPa for 17 hours, and recovering acrylic acid semi-finished products.

[0057] Table 9 Recovery

[0058] category Acrylic acid heavy component Acrylic semi-finished products Recovery rate unit 8000kg 3368.0kg 42.10％

[0059] Comparative Example 6

[0060] An acrylic acid recombinant cracking and water-adding recovery process comprises: adding 10,000 kg of acrylic acid recombinant components into a reactor, controlling the temperature of the reactor to 165° C., performing reduced pressure distillation at a pressure of -0.051 MPa for 20 hours, and recovering acrylic acid semi-finished products.

[0061] Table 10 Recovery

[0062] category Acrylic acid heavy component Acrylic semi-finished products Recovery rate unit 10000kg 4033.0kg 40.33％

[0063] 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. An acrylic acid recombination cracking decomposition and water recovery process, characterized in that: The following steps are involved: (1) injecting acrylic acid heavy components and a portion of deionized water into a reaction kettle to obtain a mixed material; (2) reducing the pressure in the reactor and increasing the temperature to perform vacuum distillation on the mixture; (3) After the vacuum distillation is completed, the reactor is controlled to return to normal pressure, and the remaining deionized water is injected into the reactor to continue back distillation to obtain a semi-finished acrylic acid product.

2. The acrylic acid recombination cracking and water recovery process according to claim 1, characterized in that: In steps (1)-(3), the mass ratio of the acrylic acid heavy component to the total amount of deionized water is 1:(0.4-0.6).

3. The acrylic acid recombination cracking and water recovery process according to claim 1, characterized in that: In step (1), the mass ratio of the acrylic acid heavy component to the initially added portion of deionized water is 1:(0.02-0.06).

4. The acrylic acid recombination cracking and water recovery process according to claim 1, characterized in that: In step (2), the pressure in the reactor is controlled between -0.05 and 0.1 MPa, and the reaction temperature is controlled between 160 and 170°C.

5. The acrylic acid recombination cracking and water recovery process according to claim 1, characterized in that: In step (2), 40-50% of the acrylic acid semi-finished product is initially recovered by reduced pressure distillation.

Images