Isophorone dicarbamate refining and purifying device and purifying method

Abstract

The invention provides an isophorone dicarbamate refining and purifying device and a purifying method. The device sequentially comprises a flash tank, a filter, a solvent separating tower, a carbonyl esterifying agent separating tower, a cooler, a phase separating tank, a centrifugal machine I, a washing kettle, a washing water separating tank, a centrifugal machine II and a drying machine which are communicated with one another, according to the purification method, an intermediate IPDC mixed solution is sequentially subjected to the procedures of flash evaporation, filtration, solvent separation, carbonyl esterification agent separation, cooling, liquid phase separation, washing, drying and the like through the purification device, high-purity refined IPDC is obtained, industrial continuous production can be achieved, the product purity is high, the purification efficiency is high, and the cost is low.

Description

Technical Field

[0001] The invention relates to the field of compound separation and purification, and specifically to an isophorone diurethane purification device and a purification method. Background Art

[0002] Polyurethane is a high molecular polymer generated by the reaction of isocyanate (MDI, TDI, ADI) with polyols and various additives. It is widely used in leather and shoe making, construction, furniture, home appliances and other fields. Isocyanate is the core raw material of polyurethane, among which aliphatic isocyanate is collectively called ADI, and its representative varieties include isophorone diisocyanate (IPDI), 1,6-hexamethylene diisocyanate (HDI) and dicyclohexylmethane diisocyanate (H12MDI).

[0003] IPDI is an aliphatic isocyanate with the advantages of low toxicity, good weather resistance and yellowing resistance. The polyurethane resin made from it has excellent light stability and chemical resistance. It is generally used to manufacture high-end polyurethane resins such as light-resistant and weather-resistant polyurethane coatings, wear-resistant and hydrolysis-resistant polyurethane elastomers, and can also be used to manufacture non-yellowing microporous polyurethane foam plastics.

[0004] At present, the synthesis of IPDI mainly adopts the phosgene method. Although the production technology is mature, the main raw materials phosgene and chlorine are highly toxic gases, and there are problems such as environmental pollution, equipment corrosion, and residual chlorine affecting product quality. Non-phosgene green synthesis technology has become the future development direction due to its high atom economy, low toxicity, safety and reliability. Non-phosgene synthesis of IPDI technology can be divided into two processes. First, isophorone diamine and carbonate are used to synthesize isophorone dicarbamate (IPDC), and then IPDC is pyrolyzed to obtain IPDI. Among them, the key technology is the purification method and purification device of the intermediate IPDC, and the purity and impurity types of the intermediate IPDC have an important influence on the yield of the next pyrolysis reaction.

[0005] CN103012210A discloses a method for preparing IPDC, which comprises: using dimethyl carbonate and isophorone diamine as raw materials, reacting under the catalysis of a supported solid catalyst to obtain a product with a purity of more than 96% and a yield of more than 85%. After the reaction is completed, the catalyst is filtered to remove, and then distilled water is added to the filtrate. After the product is completely precipitated, the filter cake is filtered, washed and dried to obtain IPDC. However, the patent only provides a method for refining and purifying IPDC in the laboratory, and it is impossible to achieve industrial continuous production and refining and purification. Moreover, the purity of the intermediate IPDC purified by the patent is only 96%, and the purity of the intermediate IPDC has an important influence on the synthesis of IPDI by pyrolysis reaction.

[0006] Therefore, providing an industrial continuous refining and purification device and method for isophorone dicarbamate (IPDC), and obtaining a high-purity intermediate IPDC with high efficiency and low cost, has become a key issue that urgently needs to be solved in the current IPDI green synthesis process. Summary of the invention

[0007] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide an isophorone dicarbamate refining and purification device and a purification method which can be industrially continuously produced, have high product purity, high purification efficiency and low cost, thereby improving the yield of the pyrolysis reaction, realizing the continuous refining and purification of the intermediate IPDC, and improving the refining yield and reducing the solvent consumption.

[0008] To solve the above problems, the present invention provides the following technical solutions: An isophorone dicarbamate refining and purification device comprises a flash tank, wherein an IPDC flash liquid outlet of the flash tank is connected to a feed end of a filter, a discharge end of the filter is connected to a feed end of a solvent separation tower, solvent outlets are arranged at the tops of the flash tank and the solvent separation tower, an IPDC concentrated liquid outlet of the solvent separation tower is connected to a feed end of a carbonyl esterification agent separation tower, a carbonyl esterification agent outlet is arranged at the top of the carbonyl esterification agent separation tower, a crude IPDC solution outlet of the carbonyl esterification agent separation tower is connected to a feed end of a cooler, a discharge end of the cooler is connected to a phase separation tank, a crude IPDC precipitation outlet of the phase separation tank is connected to a first centrifuge, a crude IPDC discharge end of the first centrifuge is connected to a water washing kettle, an IPDC water washing liquid outlet of the water washing kettle is connected to a washing water separation tank, a crude IPDC outlet of the washing water separation tank is sequentially connected to a second centrifuge and a dryer, and the dryer is provided with a refined IPDC discharge port.

[0009] Preferably, the technical solution of the present invention also includes that the filter is one or a combination of a microfiltration filter, a nanofiltration filter, an activated carbon filter, and a molecular sieve filter.

[0010] In order to reduce the solvent consumption and energy consumption of intermediate purification, the technical solution of the present invention also includes that the solvent outlets of the flash tank and the solvent separation tower are both connected to a solvent recovery tank.

[0011] The technical solution of the present invention also includes that the carbonyl esterification agent outlet is connected to a carbonyl esterification agent recovery tank.

[0012] In order to reduce the amount of waste water generated, the technical solution of the present invention also includes that the washing water outlet of the washing water separation tank is connected to a washing water recovery tank.

[0013] The second object of the present invention is to provide a purification method of the isophorone diurethane refining and purification device, comprising the following steps: (1) The intermediate IPDC mixed liquid is passed into a flash tank for primary flash evaporation, and the obtained IPDC flash liquid is sequentially passed into a filter and a solvent separation tower for separation operation, and an IPDC concentrated liquid is obtained at the bottom of the solvent separation tower. The solvent separated from the flash tank and the solvent separation tower is recovered; (2) passing the IPDC concentrate into a carbonyl esterification agent separation tower to separate the carbonyl esterification agent, obtaining a crude IPDC solution at the bottom of the carbonyl esterification agent separation tower, and recovering the carbonyl esterification agent obtained at the top of the tower; (3) The crude IPDC solution enters a cooler for cooling, and then enters a phase separation tank for precipitation separation to obtain a crude IPDC precipitate; (4) The crude IPDC precipitate is passed into a centrifuge for liquid phase separation, and the crude IPDC is transported to a water washing kettle for water washing to remove water-soluble impurities. The IPDC washing liquid obtained after water washing is passed into a washing water separation tank to separate washing water and impurities to obtain crude IPDC; (5) The crude IPDC is passed into centrifuge 2 for centrifugal dehydration, and then dried in a dryer to obtain refined IPDC.

[0014] The technical solution of the present invention also includes that the cooling temperature of the crude IPDC solution entering the cooler for cooling in step (3) is lower than 30°C.

[0015] The technical solution of the present invention also includes that in step (4), the washing water after washing is passed into a washing water recovery tank for recovery.

[0016] The beneficial effects of the present invention are: Compared with the prior art, the purpose of the present invention is to provide an isophorone dicarbamate refining and purification device and a purification method that can be industrially continuously produced, has high product purity, high purification efficiency and low cost. In order to achieve the above technical effects, the present invention provides a purification device that can be operated continuously, which sequentially includes a flash tank, a filter, a solvent separation tower, a carbonyl esterification agent separation tower, a cooler, a phase separation tank, a centrifuge one, a water washing kettle, a washing water separation tank, a centrifuge two and a dryer that are interconnected, and provides a purification method, wherein the intermediate IPDC mixed liquid is sequentially passed through the above purification device for flash evaporation, filtration, solvent separation, carbonyl esterification agent separation, cooling, liquid phase separation, water washing, drying and other processes, so as to realize continuous refining and purification of the intermediate IPDC, and improve the purity of the IPDC product. After testing, the refining and purification device and method of the present application can improve the purity of IPDC to more than 99%, thereby improving the efficiency of the pyrolysis reaction, and at the same time reduce the solvent consumption and reduce the purification cost through solvent recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 It is a schematic diagram of the structure of an isophorone diurethane refining and purification device in a specific implementation manner.

[0019] Among them, 1 is a flash tank, 2 is a filter, 3 is a solvent separation tower, 4 is a carbonyl esterification agent separation tower, 5 is a cooler, 6 is a phase separation tank, 7 is a centrifuge 1, 8 is a water washing kettle, 9 is a washing water separation tank, 10 is a centrifuge 2, 11 is a dryer, 12 is a solvent recovery tank, 13 is a carbonyl esterification agent recovery tank, and 14 is a washing water recovery tank. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be understood that the terms "center", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only intended to simplify the description of the present invention, rather than to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0022] As can be seen from the accompanying drawings, an isophorone dicarbamate refining and purification device comprises a flash tank 1, an IPDC flash liquid outlet of the flash tank 1 is connected to the feed end of a filter 2, the discharge end of the filter 2 is connected to the feed end of a solvent separation tower 3, the solvent outlets at the tops of the flash tank 1 and the solvent separation tower 3 are both connected to a solvent recovery tank 12, the IPDC concentrated liquid outlet of the solvent separation tower 3 is connected to the feed end of a carbonyl esterification agent separation tower 4, the top of the carbonyl esterification agent separation tower 4 is provided with a carbonyl esterification agent outlet and is connected to a carbonyl esterification agent recovery tank 13, and the carbonyl esterification agent separation tower The crude IPDC solution outlet of 4 is connected with the feed end of the cooler 5, the discharge end of the cooler 5 is connected with the phase separation tank 6, the crude IPDC precipitation outlet of the phase separation tank 6 is connected with the centrifuge 7, the crude IPDC discharge end of the centrifuge 7 is connected with the water washing kettle 8, the IPDC water washing liquid outlet of the water washing kettle 8 is connected with the washing water separation tank 9, the washing water outlet of the washing water separation tank 9 is connected with the washing water recovery tank 14, the crude IPDC outlet of the washing water separation tank 9 is connected with the centrifuge 2 10 and the dryer 11 in sequence, and the dryer 11 is provided with a refined IPDC discharge port.

[0023] The method for refining and purifying isophorone diurethane using the above-mentioned device comprises the following steps: (1) The intermediate IPDC mixed liquid is passed into the flash tank 1 for primary flash evaporation, and the obtained IPDC flash liquid is sequentially passed into the filter 2 and the solvent separation tower 3 for separation operation, and the IPDC concentrated liquid is obtained at the bottom of the solvent separation tower 3. The solvent separated from the flash tank 1 and the solvent separation tower 3 is recovered; (2) passing the IPDC concentrate into a carbonyl esterification agent separation tower 4 to separate the carbonyl esterification agent, obtaining a crude IPDC solution at the bottom of the carbonyl esterification agent separation tower 4, and recovering the carbonyl esterification agent obtained at the top of the tower; (3) The crude IPDC solution enters the cooler 5 for cooling, the cooling temperature is lower than 30°C, and then enters the phase separation tank 6 for precipitation separation to obtain a crude IPDC precipitate; (4) The crude IPDC precipitate is passed into a centrifuge 7 for liquid separation, and the separated liquid is transported to a water washing tank 8 for water washing to remove water-soluble impurities. The IPDC washing liquid obtained after water washing is passed into a washing water separation tank 9 to separate washing water and impurities to obtain crude IPDC. The washing water after washing is passed into a washing water recovery tank 14 for recovery; (5) The crude IPDC is passed into a centrifuge 10 for centrifugal dehydration, and then dried in a dryer 11 to obtain refined IPDC.

[0024] By adopting the intermediate IPDC refining and purification device and method of this embodiment, the purity of the refined IPDC obtained is greater than 99%, which realizes industrial continuous operation, high refining yield, and the solvent can be recycled, thereby reducing the solvent consumption and energy consumption of intermediate purification, overcoming the shortcomings of intermittent operation, low product purity, high solvent loss, and more wastewater generation in the prior art.

[0025] Although the present invention has been described in detail by referring to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art who is familiar with the present invention may easily think of changes or substitutions within the technical scope disclosed by the present invention, and all of these shall be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. An isophorone diurethane refining and purification device, characterized in that: The invention comprises a flash tank, wherein the IPDC flash liquid outlet of the flash tank is connected with the feed end of the filter, the discharge end of the filter is connected with the feed end of the solvent separation tower, the tops of the flash tank and the solvent separation tower are both provided with solvent outlets, the IPDC concentrated liquid outlet of the solvent separation tower is connected with the feed end of the carbonyl esterification agent separation tower, the top of the carbonyl esterification agent separation tower is provided with a carbonyl esterification agent outlet, the crude IPDC solution outlet of the carbonyl esterification agent separation tower is connected with the feed end of a cooler, the discharge end of the cooler is connected with a phase separation tank, the crude IPDC precipitation outlet of the phase separation tank is connected with a centrifuge 1, the crude IPDC discharge end of the centrifuge 1 is connected with a water washing kettle, the IPDC water washing liquid outlet of the water washing kettle is connected with a washing water separation tank, the crude IPDC outlet of the washing water separation tank is connected with a centrifuge 2 and a dryer in sequence, and the dryer is provided with a refined IPDC discharge port.

2. The isophorone diurethane refining and purification device according to claim 1, characterized in that: The filter is one or a combination of a microfiltration filter, a nanofiltration filter, an activated carbon filter, and a molecular sieve filter.

3. The isophorone diurethane refining and purification device according to claim 1, characterized in that: The solvent outlets of the flash tank and the solvent separation tower are both connected to a solvent recovery tank.

4. The isophorone diurethane refining and purification device according to claim 1, characterized in that: The carbonyl esterification agent outlet is connected to a carbonyl esterification agent recovery tank.

5. The isophorone diurethane refining and purification device according to claim 1, characterized in that: The washing water outlet of the washing water separation tank is connected to a washing water recovery tank.

6. A purification method of the isophorone diurethane refining and purification device according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) The intermediate IPDC mixed liquid is passed into a flash tank for primary flash evaporation, and the obtained IPDC flash liquid is sequentially passed into a filter and a solvent separation tower for separation operation, and an IPDC concentrated liquid is obtained at the bottom of the solvent separation tower. The solvent separated from the flash tank and the solvent separation tower is recovered; (2) passing the IPDC concentrate into a carbonyl esterification agent separation tower to separate the carbonyl esterification agent, obtaining a crude IPDC solution at the bottom of the carbonyl esterification agent separation tower, and recovering the carbonyl esterification agent obtained at the top of the tower; (3) The crude IPDC solution enters a cooler for cooling, and then enters a phase separation tank for precipitation separation to obtain a crude IPDC precipitate; (4) The crude IPDC precipitate is passed into a centrifuge for liquid phase separation, and the crude IPDC is transported to a water washing kettle for water washing to remove water-soluble impurities. The IPDC washing liquid obtained after water washing is passed into a washing water separation tank to separate washing water and impurities to obtain crude IPDC; (5) The crude IPDC is passed into centrifuge 2 for centrifugal dehydration, and then dried in a dryer to obtain refined IPDC.

7. The method for refining and purifying isophorone diurethane according to claim 6, characterized in that: In step (3), the cooling temperature of the crude IPDC solution entering the cooler for cooling is lower than 30°C.

8. The method for refining and purifying isophorone diurethane according to claim 6, characterized in that: In step (4), the washing water after washing is passed into a washing water recovery tank for recovery.

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