Polymerization inhibitor composition and application thereof

Abstract

The invention provides a polymerization inhibitor composition and application thereof, and relates to the technical field of compounds. The polymerization inhibitor composition provided by the invention comprises a component A, a component B and a component C, the mass ratio of the component A to the component B to the component C is (10-30): (10-30): (5-15); the component A comprises a piperidinol compound; the component B comprises an N-oxygen free radical compound; the component C comprises a hydrazine compound. When the polymerization inhibitor composition provided by the invention is added into a refining unit of an acrylic acid production process, the effect of long-term polymerization inhibition can be achieved, and the polymerization inhibitor composition has the characteristics of small dosage, high polymerization inhibition efficiency and the like, and can ensure the stable operation of a device.

Description

Technical Field

[0001] The present invention relates to the technical field of compounds, and in particular to a polymerization inhibitor composition and application thereof. Background Art

[0002] Acrylic acid, due to its unsaturated double bonds and polar molecular structure, has high polymerization activity and is prone to polymerization under conditions such as light, heat, and the presence of peroxides. The polymerization tendency is particularly obvious under high temperature conditions in the refining unit of the production process (sometimes explosion polymerization occurs). On the one hand, polymerization will lead to the loss of acrylic acid monomers, that is, the reduction of yield; on the other hand, the generated polymer will precipitate from the process fluid and deposit on the surface of the equipment, thereby clogging the tower plates, reboilers, pipelines, pumps, etc., affecting the continuous operation of the device and increasing the cost of shutdown and maintenance.

[0003] In order to inhibit the polymerization of acrylic acid during the production process, the usual method is to add appropriate inhibitors to the system to inhibit the undesired polymerization reaction. At present, the commonly used inhibitors in acrylic acid plants include: 4-hydroxy-2,2,6,6-tetramethylpiperidinyl nitroxide free radical (HTMPO), diphenylamine, hydroquinone (HQ), phenothiazine (PTZ), p-benzoquinone (PBQ), p-hydroxyanisole (MEHQ), metal salts (copper salts, manganese salts, etc.). Such inhibitors have a certain effect in the production process of acrylic acid, but they have the disadvantages of short inhibition time, low inhibition efficiency, and large amount of inhibitor. Summary of the invention

[0004] In view of this, the object of the present invention is to provide an inhibitor composition and its application. The inhibitor composition provided by the present invention is added to the refining unit of the acrylic acid production process to achieve the effect of long-term inhibition of polymerization. It has the characteristics of small dosage and high inhibition efficiency, and can ensure the smooth operation of the device.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: The present invention provides an inhibitor composition, which comprises component A, component B and component C; the mass ratio of component A, component B and component C is 10-30:10-30:5-15; The component A comprises a piperidinol compound; the component B comprises an N-oxyl radical compound; and the component C comprises a hydrazine compound.

[0006] Preferably, the piperidinol compound includes one or more of 4-hydroxy-2,2,6,6-tetramethylpiperidinol, 4-acetamido-2,2,6,6-tetramethylpiperidinol, 4-acetoxy-2,2,6,6-tetramethylpiperidinol and 4-methanesulfonamido-2,2,6,6-tetramethylpiperidinol.

[0007] Preferably, the N-oxyl free radical compound includes one or more of 4-hydroxy-2,2,6,6-tetramethylpiperidine nitroxide free radical, 4-acetamido-2,2,6,6-tetramethylpiperidine nitroxide free radical, 4-acetoxy-2,2,6,6-tetramethylpiperidine nitroxide free radical and 4-methanesulfonamido-2,2,6,6-tetramethylpiperidine nitroxide free radical.

[0008] Preferably, the hydrazine compound comprises carbohydrazide.

[0009] Preferably, the mass ratio of component A, component B and component C is 15-20:15-20:5-10.

[0010] The present invention provides the use of the inhibitor composition described in the above technical solution in inhibiting the polymerization of acrylic acid.

[0011] Preferably, the application comprises the following steps: adding the polymerization inhibitor composition or a solution of the polymerization inhibitor composition to a refining unit of an acrylic acid production process to perform polymerization inhibition; The polymerization inhibitor composition and the polymerization inhibitor composition in the polymerization inhibitor composition solution are the polymerization inhibitor compositions described in the above technical solution.

[0012] Preferably, the amount of the polymerization inhibitor composition or the solution of the polymerization inhibitor composition added is independently 5 to 5000 ppm; the amount of the solution of the polymerization inhibitor composition added is calculated based on the polymerization inhibitor composition in the solution of the polymerization inhibitor composition.

[0013] The inhibitor composition provided by the present invention comprises component A, component B and component C; the mass ratio of component A, component B and component C is 10-30:10-30:5-15; component A comprises a piperidinol compound; component B comprises an N-oxyl radical compound; and component C comprises a hydrazine compound. The inhibitor composition provided by the present invention is added to the refining unit of the acrylic acid production process, and has the characteristics of small dosage and high inhibition efficiency. Through the synergistic inhibition effect between carbohydrazide and piperidinol compound and N-oxyl radical compound, the inhibition efficiency of the inhibitor composition can be significantly improved to achieve the effect of long-term inhibition of polymerization, and the smooth operation of the device can be ensured. At the same time, the inhibitor composition provided by the present invention is non-toxic, more green and environmentally friendly, and is easily soluble in the acrylic acid system, which solves the problem that metal salts (copper salts, manganese salts, etc.) have low solubility in the system, are easy to clog filters and pipelines, and bring about three wastes. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a comparison chart of the polymerization inhibition performance of Examples 1 to 7 of the present invention and Comparative Examples 1 to 3. DETAILED DESCRIPTION

[0015] The present invention provides an inhibitor composition, which comprises component A, component B and component C; the mass ratio of component A, component B and component C is 10-30:10-30:5-15; The component A comprises a piperidinol compound; the component B comprises an N-oxyl radical compound; and the component C comprises a hydrazine compound.

[0016] Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products in the art.

[0017] The polymerization inhibitor composition provided by the present invention comprises component A, component B and component C; the mass ratio of the component A, component B and component C is 10-30:10-30:5-15, preferably 15-20:15-20:5-10.

[0018] In the present invention, the component A includes a piperidinol compound; the piperidinol compound preferably includes one or more of 4-hydroxy-2,2,6,6-tetramethylpiperidinol, 4-acetamido-2,2,6,6-tetramethylpiperidinol, 4-acetoxy-2,2,6,6-tetramethylpiperidinol and 4-methanesulfonamido-2,2,6,6-tetramethylpiperidinol.

[0019] In the present invention, the component B includes an N-oxyl free radical compound; the N-oxyl free radical compound preferably includes one or more of 4-hydroxy-2,2,6,6-tetramethylpiperidine nitroxide free radical, 4-acetamido-2,2,6,6-tetramethylpiperidine nitroxide free radical, 4-acetoxy-2,2,6,6-tetramethylpiperidine nitroxide free radical and 4-methanesulfonamido-2,2,6,6-tetramethylpiperidine nitroxide free radical.

[0020] In the present invention, the component C comprises a hydrazine compound; the hydrazine compound preferably comprises carbohydrazide.

[0021] The present invention has no special requirements for the preparation method of the polymerization inhibitor composition, and a mixing method well known to those skilled in the art can be used. In a specific embodiment of the present invention, stirring at room temperature can be sufficient.

[0022] The present invention provides the use of the inhibitor composition described in the above technical solution in inhibiting the polymerization of acrylic acid.

[0023] In the present invention, the application preferably includes: adding the inhibitor composition or the solution of the inhibitor composition to the refining unit of the acrylic acid production process to inhibit polymerization; the inhibitor composition and the inhibitor composition in the inhibitor composition solution are the inhibitor compositions described in the above technical solution.

[0024] The present invention does not have any special restrictions on the type of solvent in the inhibitor composition solution and the concentration of the inhibitor composition in the inhibitor composition solution, and the type of solvent and the concentration of the inhibitor composition well known to those skilled in the art can be used. In the present invention, the amount of the inhibitor composition or the solution of the inhibitor composition added is independently preferably 5~5000ppm, more preferably 10~1000ppm, and further preferably 100~500ppm; the amount of the solution of the inhibitor composition added is calculated based on the inhibitor composition in the solution of the inhibitor composition. In a specific embodiment of the present invention, the amount of the inhibitor composition or the solution of the inhibitor composition added refers to the weight ratio of the inhibitor composition to the liquid phase in the refining unit of the acrylic acid production process.

[0025] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1 The inhibitor composition is composed of 4-hydroxy-2,2,6,6-tetramethylpiperidinol, 4-hydroxy-2,2,6,6-tetramethylpiperidinyl nitroxide free radical and carbohydrazide in a mass ratio of 20:20:5.

[0027] Embodiments 2 to 7 The polymerization inhibitor composition was prepared according to the method of Example 1, except for the differences shown in Table 1.

[0028] Table 1 Conditions and parameters for preparing the inhibitor composition in Examples 1 to 7

[0029] Comparative Example 1 4-Hydroxy-2,2,6,6-tetramethylpiperidinol and 4-hydroxy-2,2,6,6-tetramethylpiperidinyl nitroxide free radical in a mass ratio of 20:20 were used as inhibitors.

[0030] Comparative Example 2 Phenothiazine (PTZ) was used as the inhibitor.

[0031] Comparative Example 3 Hydroquinone (HQ) was used as an inhibitor.

[0032] Comparative Example 4 4-Hydroxy-2,2,6,6-tetramethylpiperidinyl nitroxide and copper acetate in a mass ratio of 90:10 were used as inhibitors.

[0033] The polymerization inhibitors in Examples 1 to 7 and Comparative Examples 1 to 4 were added to an acrylic acid experimental device to evaluate the polymerization inhibition performance of the polymerization inhibitors and examine the ability of the polymerization inhibitors to inhibit polymerization in an acrylic acid distillation device. The specific steps are as follows: The inhibitor of commercial acrylic acid was removed in advance. 60 g of acrylic acid was added to a 100 mL three-necked flask, and then 5 ppm of inhibitor was added. The three-necked flask was placed in a 130°C constant temperature oil bath and subjected to total reflux operation under stirring. Under this condition, samples were taken from the three-necked flask at regular intervals, and the relative concentration of the polymer was detected by the refractive index method. The results are as follows: Figure 1 As shown in Table 2: Table 2 Inhibition effect of the inhibitors described in Examples 1 to 7 and Comparative Examples 1 to 4

[0034] According to the experimental results Figure 1 It can be seen that at the same concentration of the polymerization inhibitor, the polymerization inhibition effect of the polymerization inhibitor composition of Examples 1 to 7 of the present invention is significantly better than that of Comparative Examples 1 to 4. From the experimental results of Examples 1 to 2 and Comparative Example 1, it can be seen that the polymerization inhibition effect of Examples 1 and 2 is significantly better than that of Comparative Example 1, indicating that carbohydrazide has a significant synergistic polymerization inhibition effect with piperidinol compounds and N-oxyl radical compounds, and can significantly improve the polymerization inhibition efficiency of the polymerization inhibitor composition.

[0035] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A polymerization inhibitor composition, characterized in that: The inhibitor composition comprises component A, component B and component C; the mass ratio of component A, component B and component C is 10-30:10-30:5-15; The component A comprises a piperidinol compound; the component B comprises an N-oxyl radical compound; and the component C comprises a hydrazine compound.

2. The polymerization inhibitor composition according to claim 1, characterized in that The piperidinol compound includes one or more of 4-hydroxy-2,2,6,6-tetramethylpiperidinol, 4-acetamido-2,2,6,6-tetramethylpiperidinol, 4-acetoxy-2,2,6,6-tetramethylpiperidinol and 4-methanesulfonamido-2,2,6,6-tetramethylpiperidinol.

3. The polymerization inhibitor composition according to claim 1, characterized in that The N-oxyl free radical compound includes one or more of 4-hydroxy-2,2,6,6-tetramethylpiperidine nitroxide free radical, 4-acetamido-2,2,6,6-tetramethylpiperidine nitroxide free radical, 4-acetoxy-2,2,6,6-tetramethylpiperidine nitroxide free radical and 4-methanesulfonamido-2,2,6,6-tetramethylpiperidine nitroxide free radical.

4. The polymerization inhibitor composition according to claim 1, characterized in that The hydrazine compound includes carbohydrazide.

5. The polymerization inhibitor composition according to claim 1, characterized in that: The mass ratio of component A, component B and component C is 15-20:15-20:5-10.

6. Use of the inhibitor composition according to any one of claims 1 to 5 in inhibiting the polymerization of acrylic acid.

7. The use according to claim 6, characterized in that: The application comprises the following steps: adding the inhibitor composition or the solution of the inhibitor composition to the refining unit of the acrylic acid production process to inhibit polymerization; The polymerization inhibitor composition and the polymerization inhibitor composition in the polymerization inhibitor composition solution are the polymerization inhibitor composition according to any one of claims 1 to 5.

8. The use according to claim 7, characterized in that: The amount of the polymerization inhibitor composition or the solution of the polymerization inhibitor composition added is independently 5 to 5000 ppm; the amount of the solution of the polymerization inhibitor composition added is calculated based on the polymerization inhibitor composition in the solution of the polymerization inhibitor composition.

Images