A method for purifying a low-acid and low-fogging value plasticizer

Abstract

The present invention relates to a method for purifying a low-acid and low-atomization value plasticizer. The method comprises a workshop reactor, a separator, a first blade mixer, a water-washing separator, a dehydration tower, a first stripping tower and a filter connected in sequence; in the present invention, a first blade mixer and a water-washing separator are added between the separator and the dehydration tower, and after mixing, the solid impurities in the second mixture are cut and refined and mixed evenly through the first blade mixer, and then more water and tiny solid impurities are separated through the water-washing separator, thereby reducing the acid value and atomization value of the finished product, and improving the market competitiveness of the product; by adding an operation of mixing evenly and separating solid impurities on the basis of the above, the acid value and atomization value of the finished product are further reduced; by adding a second stripping tower on the basis of adding a secondary separator and a second blade mixer, secondary stripping purification is achieved, and the quality of the product is improved.

Description

Technical Field

[0001] The invention relates to the technical field of plasticizer production, in particular to a method for purifying a low-acid and low-atomization value plasticizer. Background Art

[0002] Epoxy plasticizers are compounds containing three-membered epoxy groups, mainly used in PVC. They not only have a plasticizing effect, but also can act as a stabilizer. If used together with metal salt stabilizers, their stabilizing effect is more significant. Commonly used epoxy plasticizers are divided into three categories: epoxidized oil, epoxy fatty acid monoesters, and epoxy tetrahydrophthalic acid esters. Among them, epoxidized oil, i.e. epoxy glycerol tricarboxylate, is the most commonly used type of epoxy plasticizer, and the main variety is epoxidized soybean oil. Epoxidized fatty acid monoesters have very different components due to the different sources of fatty acids, and are generally named after the names of fatty acids, such as epoxy furoate, epoxy soybean oleate, epoxy tall oleate, etc.

[0003] The existing production and purification method of epoxy plasticizer adopts a purification device including a workshop reactor A, a separator B, a dehydration tower C, a first stripping tower D and a filter E connected in sequence; and the dehydration tower C and the first stripping tower D are both provided with interfaces for introducing steam; The specific steps include: firstly, using a separator B to separate the first mixture obtained by the reaction of the workshop reactor A to separate the solid impurities in the product to obtain a second mixture; Then the second mixture is sent to a dehydration tower C for dehydration to obtain a third mixture; Then, the third mixture is sent to the first stripping tower D to obtain a fourth mixture; Finally, the fourth mixture is filtered through filter E to obtain a finished epoxy plasticizer.

[0004] After testing, the acid value of the finished epoxy plasticizer was 0.6mg KOH / g, the atomization value was 19mg, the impurity content and water content were relatively high, the quality of the finished product was not high enough, and the market competitiveness was insufficient. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for purifying a low-acid and low-fogging value plasticizer.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: a method for purifying a low-acid and low-fogging value plasticizer, the innovation of which is: comprising a workshop reactor, a separator, a first knife mixer, a water washing separator, a dehydration tower, a first stripping tower and a filter connected in sequence; Firstly, a separator is used to separate the first mixture obtained by the reaction in the workshop reactor to separate solid impurities in the product to obtain a second mixture; Then, the second mixture is fed into the first blade mixer to obtain a third mixture; The third mixture is then sent to a water washing separator for secondary separation to obtain a fourth mixture; Then the fourth mixture is sent to a dehydration tower for dehydration to obtain a fifth mixture; sending the fifth mixture into the first stripping tower to obtain a sixth mixture; Finally, the sixth mixture is filtered through a filter to obtain the product.

[0007] Furthermore, the separator is a disc-type separator capable of separating solid impurities and water.

[0008] Furthermore, the first blade mixer, the dehydration tower and the first stripping tower are all provided with interfaces for introducing steam, and steam is introduced into the first blade mixer while the second mixture is introduced into the first blade mixer, steam is introduced into the dehydration tower while the fourth mixture is introduced into the dehydration tower for dehydration, and steam is introduced into the first stripping tower while the fifth mixture is introduced into the first stripping tower.

[0009] Furthermore, it also includes a secondary separator and a second blade mixer disposed between the first blade mixer and the water-washing separator, and the first blade mixer, the secondary separator, the second blade mixer and the water-washing separator are connected in sequence; Then the third mixture will be sent to the secondary separator for tertiary separation to obtain the seventh mixture; Mixing the seventh mixture with a second blade mixer to obtain an eighth mixture; The eighth mixture is subjected to secondary separation in the water washing separator to obtain the fourth mixture.

[0010] By adding a secondary separator and a second knife mixer on the basis of claim 1 to add the operations of mixing evenly and separating solid impurities, the acid value and atomization value of the finished product can be further reduced.

[0011] Furthermore, the second blade mixer also has an interface for introducing steam, and steam is introduced into the second blade mixer while the seventh mixture is introduced into the second blade mixer.

[0012] Furthermore, it also includes a second stripping tower disposed between the first stripping tower and the filter, and the second stripping tower is provided with an interface for introducing nitrogen; Then nitrogen is introduced into the second stripping tower, and the sixth mixture is introduced into the second stripping tower to obtain a ninth mixture, and the ninth mixture is filtered through a filter to obtain a product.

[0013] By adding a second stripping tower on the basis of adding a second separator and a second knife mixer, secondary stripping purification is achieved to improve the quality of the product.

[0014] The advantages of the present invention are: In the present invention, a first blade mixer and a water-washing separator are added between the separator and the dehydration tower. After mixing, the solid impurities in the second mixture are cut and refined and mixed evenly through the first blade mixer, and then more water and tiny solid impurities are separated through the water-washing separator, thereby reducing the acid value and atomization value of the finished product, thereby improving the market competitiveness of the product; by adding an operation of mixing evenly and separating solid impurities on the basis of the above, the acid value and atomization value of the finished product are further reduced; by adding a second stripping tower on the basis of the addition of a secondary separator and a second blade mixer, secondary stripping purification is achieved, thereby improving the quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The figure is a flow chart of the purification method of the prior art.

[0016] Figure 2 A process for purifying a low-acid and low-fogging value plasticizer of the present invention Figure 1 .

[0017] Figure 3 A process for purifying a low-acid and low-fogging value plasticizer of the present invention Figure 2 .

[0018] Figure 4 A process for purifying a low-acid and low-fogging value plasticizer of the present invention Figure 3 . DETAILED DESCRIPTION

[0019] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0020] Embodiment 1: like Figure 2 The method for purifying a low-acid and low-atomization value plasticizer shown in the figure comprises a workshop reactor 1, a separator 2, a first knife mixer 3, a water washing separator 4, a dehydration tower 5, a first stripping tower 6 and a filter 7 which are connected in sequence, wherein the separator 2 is a disc separator 2 which can separate solid impurities and water.

[0021] The first blade mixer 3, the dehydration tower 5 and the first stripping tower 6 are all provided with interfaces for introducing steam.

[0022] The purification steps are as follows: First, the first mixture obtained by the reaction in the workshop reactor 1 is separated by a separator 2 to separate solid impurities in the product to obtain a second mixture; Then the second mixture is fed into the first blade mixer 3, and steam is fed into the first blade mixer 3 at the same time, to obtain a third mixture; The third mixture is then sent to a water washing separator 4 for secondary separation to obtain a fourth mixture; Then the fourth mixture is sent to the dehydration tower 5 for dehydration, and steam is simultaneously sent to the dehydration tower 5 to obtain a fifth mixture; sending the fifth mixture into the first stripping tower 6, and simultaneously sending steam into the first stripping tower 6, to obtain a sixth mixture; Finally, the sixth mixture is filtered through a filter 7 to obtain product S.

[0023] Embodiment 2: like Figure 3 The method for purifying a low-acid and low-atomization value plasticizer shown in the figure comprises a workshop reactor 1, a separator 2, a first knife-type mixer 3, a secondary separator 8, a second knife-type mixer 9, a water washing separator 4, a dehydration tower 5, a first stripping tower 6 and a filter 7 which are connected in sequence, wherein the separator 2 is a disc separator 2 which can separate solid impurities and water.

[0024] The first blade mixer 3, the dehydration tower 5, the first stripping tower 6 and the second blade mixer 9 are all provided with interfaces for introducing steam.

[0025] The purification steps are as follows: First, the first mixture obtained by the reaction in the workshop reactor 1 is separated by a separator 2 to separate solid impurities in the product to obtain a second mixture; Then the second mixture is fed into the first blade mixer 3, and steam is fed into the first blade mixer 3 at the same time, to obtain a third mixture; The third mixture is sent to the secondary separator 8 for tertiary separation to obtain a seventh mixture; The seventh mixture is mixed by a second blade mixer 9, and steam is simultaneously introduced into the second blade mixer 9 to obtain an eighth mixture; The eighth mixture is subjected to secondary separation in the water washing separator 4 to obtain a fourth mixture.

[0026] Then the fourth mixture is sent to the dehydration tower 5 for dehydration, and steam is simultaneously sent to the dehydration tower 5 to obtain a fifth mixture; sending the fifth mixture into the first stripping tower 6, and simultaneously sending steam into the first stripping tower 6, to obtain a sixth mixture; Finally, the sixth mixture is filtered through filter 7 to obtain product M.

[0027] By adding a secondary separator 8 and a second blade mixer 9 on the basis of the first embodiment to perform uniform mixing and solid impurity separation operations, the acid value and atomization value of the finished product can be further reduced.

[0028] Embodiment three: like Figure 4 The method for purifying a low-acid and low-atomization value plasticizer shown in the figure comprises a workshop reactor 1, a separator 2, a first knife mixer 3, a secondary separator 8, a second knife mixer 9, a water washing separator 4, a dehydration tower 5, a first stripping tower 6, a second stripping tower 10 and a filter 7 which are connected in sequence, wherein the separator 2 is a disc separator 2 which can separate solid impurities and water.

[0029] The first blade mixer 3 , the dehydration tower 5 , the first stripping tower 6 , and the second blade mixer 9 are all provided with interfaces for introducing steam, and the second stripping tower 10 is provided with an interface for introducing nitrogen.

[0030] The purification steps are as follows: First, the first mixture obtained by the reaction in the workshop reactor 1 is separated by a separator 2 to separate solid impurities in the product to obtain a second mixture; Then the second mixture is fed into the first blade mixer 3, and steam is fed into the first blade mixer 3 at the same time, to obtain a third mixture; The third mixture is sent to the secondary separator 8 for tertiary separation to obtain a seventh mixture; The seventh mixture is mixed by a second blade mixer 9, and steam is simultaneously introduced into the second blade mixer 9 to obtain an eighth mixture; The eighth mixture is subjected to secondary separation in the water washing separator 4 to obtain a fourth mixture.

[0031] Then the fourth mixture is sent to the dehydration tower 5 for dehydration, and steam is simultaneously sent to the dehydration tower 5 to obtain a fifth mixture; sending the fifth mixture into the first stripping tower 6, and simultaneously sending steam into the first stripping tower 6, to obtain a sixth mixture; While nitrogen is fed into the second stripping tower 10 , the sixth mixture is fed into the second stripping tower 10 to obtain a ninth mixture, and the ninth mixture is filtered through a filter 7 to obtain a product L.

[0032] By adding a second stripping tower 10 on the basis of the second embodiment, secondary stripping and purification is achieved, thereby improving the quality of the product.

[0033] The data obtained by testing the products produced by the above three embodiments and the prior art are shown in the following table: Prior art Embodiment 1 Embodiment 2 Embodiment 3 Acid value index 0.6mg KOH / g 0.5mg KOH / g 0.4mg KOH / g 0.3mg KOH / g Atomization value index 19mg 10mg 5mg 0.5mg In summary, it can be seen that the purification method is equipped with a first knife mixer 3, a water washing separator 4, a secondary separator 8, a second knife mixer 9 and a second stripping tower 10. The two knife mixers cut and refine the solid impurities in the mixture for multiple times and mix them evenly to separate more tiny solid impurities, and then use the water washing separator 4 to separate more water. A secondary stripping purification is also provided to minimize the acid value and atomization value of the finished product, thereby improving the market competitiveness of this product.

[0034] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for purifying a low-acid, low-fogging value plasticizer, characterized in that: It includes a workshop reactor, a separator, a first knife mixer, a water washing separator, a dehydration tower, a first stripping tower and a filter connected in sequence; Firstly, a separator is used to separate the first mixture obtained by the reaction in the workshop reactor to separate solid impurities in the product to obtain a second mixture; Then, the second mixture is fed into the first blade mixer to obtain a third mixture; The third mixture is then sent to a water washing separator for secondary separation to obtain a fourth mixture; Then the fourth mixture is sent to a dehydration tower for dehydration to obtain a fifth mixture; sending the fifth mixture into the first stripping tower to obtain a sixth mixture; Finally, the sixth mixture is filtered through a filter to obtain the product.

2. The method for purifying a low-acid and low-fogging value plasticizer according to claim 1, characterized in that: The separator is a disc-type separator capable of separating solid impurities and water.

3. The method for purifying a low-acid and low-fogging value plasticizer according to claim 1, characterized in that: The first blade mixer, the dehydration tower and the first stripping tower are all provided with interfaces for introducing steam, and steam is introduced into the first blade mixer while the second mixture is introduced into the first blade mixer, steam is introduced into the dehydration tower while the fourth mixture is introduced into the dehydration tower for dehydration, and steam is introduced into the first stripping tower while the fifth mixture is introduced into the first stripping tower.

4. The method for purifying a low-acid and low-fogging value plasticizer according to claim 1, characterized in that: It also includes a secondary separator and a second blade mixer disposed between the first blade mixer and the water-washing separator, and the first blade mixer, the secondary separator, the second blade mixer and the water-washing separator are connected in sequence; Then the third mixture will be sent to the secondary separator for tertiary separation to obtain the seventh mixture; Mixing the seventh mixture with a second blade mixer to obtain an eighth mixture; The eighth mixture is subjected to secondary separation in the water washing separator to obtain the fourth mixture.

5. The method for purifying a low-acid and low-fogging value plasticizer according to claim 4, characterized in that: The second blade mixer also has an interface for introducing steam, and steam is introduced into the second blade mixer while the seventh mixture is introduced into the second blade mixer.

6. The method for purifying a low-acid and low-fogging value plasticizer according to claim 4, characterized in that: It also includes a second stripping tower disposed between the first stripping tower and the filter, and the second stripping tower is provided with an interface for introducing nitrogen; Then nitrogen is introduced into the second stripping tower, and the sixth mixture is introduced into the second stripping tower to obtain a ninth mixture, and the ninth mixture is filtered through a filter to obtain a product.

Images