Continuous production device for isooctyl chloroformate
The continuous production unit of isooctyl chloroformate, consisting of a photochemical tower and a falling film evaporator, solves the problems of uneven heat exchange in the photochemical tower and high consumption of deacidification gas, and realizes the production of high-purity and high-yield isooctyl chloroformate, which is suitable for industrial application.
Patent Information
- Application Number
- CN202520158581.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2035-01-23
AI Technical Summary
Existing isooctyl chloroformate production units suffer from problems such as uneven heat exchange inside the photochemical tower leading to low product quality and the need to consume a large amount of auxiliary inert gas for deacidification.
The synthesis unit uses a photochemical tower and the deacidification unit uses a falling film evaporator. The photochemical tower consists of a perforated heat exchange section and a random packed tower section. Combined with a tail gas condenser and a liquid photochemical reflux pipeline, it realizes the continuous production of isooctyl chloroformate. The heat exchange is enhanced by the perforated heat exchange section, and the falling film evaporator achieves deacidification without the need for auxiliary gas.
It improves product quality, reduces phosgene consumption, lowers the risk of potential leakage, and enables safe and efficient industrial continuous production with product purity ≥99.1% and yield ≥99%.
Smart Images
Figure CN223945626U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the fine chemical technology field, especially relates to a chloroformic acid isooctyl ester continuous production device. BACKGROUND
[0002] Chloroformic acid isooctyl ester, also called chloroformic acid 2-ethylhexyl ester, is the main raw material for synthesizing di(2-ethyl)hexyl peroxide dicarbonate (EHP for short); EHP is a colorless transparent liquid, and EHP belongs to a high-activity initiator; compared with other peroxide dicarbonate initiators, the stability of EHP during transportation and storage is better; since EHP is insoluble in water, water-phase polymer is not easy to be generated during initiation of polymerization, the tendency of sticking to a kettle is small, and the heat release of polymerization is uniform, so that uniform-speed reaction is easy to obtain. Therefore, EHP has become one of the initiators with the most promising development, and is widely used as a polymerization initiator for products such as polyethylene, polyvinyl chloride, polyvinyl acetate, polyacrylate, polyacrylonitrile, thermoplastic polyurethane, polyurethane-vinyl chloride composite material, high-strength rubber composite material and the like; and can also be used for producing bleaching agents, oxidation accelerators, flame retardants, explosives and the like.
[0003] The reaction principle of chloroformic acid isooctyl ester is that phosgene and isooctanol are subjected to a photochemical reaction under certain conditions to generate chloroformic acid isooctyl ester and hydrogen chloride, and the reaction process is as follows:
[0004] Main reaction:
[0005]
[0006] Side reaction:
[0007]
[0008] In order to ensure the safety of the photochemical reaction process and reduce the generation of side reactions, the phosgene must be kept at a certain excess coefficient, and the reaction temperature is controlled at about 0-35 DEG C, so that the reaction mixture system includes hydrogen chloride and phosgene. In order to obtain a product with high content, it is necessary to remove hydrogen chloride and phosgene, and the step of removing hydrogen chloride and phosgene is called deacidification.
[0009] There are mainly two types of chloroformic acid isooctyl ester production devices: one is a reaction kettle, in which isooctanol and phosgene are added, the temperature and pressure of the reaction kettle are controlled, the reaction is maintained for a period of time to obtain a reaction mixture system, and then deacidification treatment is performed; the other is a conventional reaction tower, in which the cavity or the packed random packing is arranged, and the jacket heat exchange is arranged outside the tower, the phosgene and isooctanol are added from the bottom of the tower, and the reaction mixture system is obtained at the top of the tower.
[0010] Since the stirring and mixing intensity of the reaction kettle is weak, the gas-liquid two phases cannot be fully mixed and contacted for reaction, therefore, in order to ensure sufficient isooctanol conversion rate, the device of the reaction kettle type needs a longer reaction time and more excess phosgene.
[0011] Compared with the reaction kettle, the mixing intensity of the conventional reaction tower is enhanced, and the amount of phosgene is reduced compared with the reaction kettle type, but the conventional reaction tower generally uses jacket heat exchange, the heat exchange effect is poor, the temperature control in the tower is not good, the side reaction increases, and the product quality is reduced. Therefore, a new type of reaction tower with high heat exchange efficiency needs to be researched.
[0012] There are two types of conventional deacidification processes: one is to use nitrogen gas to bubble deacidification in the deacidification kettle, the reaction mixture system enters the deacidification kettle, then nitrogen gas is introduced from the bottom of the kettle to bubble deacidification, heated by jacket hot water, to improve the temperature of the reaction mixture system and improve the deacidification effect; the other is to introduce nitrogen gas into the deacidification tower to achieve the deacidification effect. The reaction mixture system is introduced into the deacidification tower after heating, and the nitrogen gas and the reaction mixture system are mixed countercurrently, then gas-liquid separation is carried out, deacidification is realized, and qualified products are obtained after multiple cycle operations.
[0013] The deacidification kettle deacidification, because the unreacted isooctanol and isooctyl chloroformate will have side reactions at high temperature, affecting the product quality, so the deacidification temperature is controlled at a lower temperature, resulting in low deacidification efficiency; a large amount of nitrogen gas will entrain the product, resulting in high product waste; the kettle type deacidification cannot realize continuous operation.
[0014] The tower type deacidification can realize continuous operation, and the deacidification efficiency is obviously improved compared with the kettle type deacidification, but the deacidification method still needs to consume a large amount of nitrogen gas. Practical new type content
[0015] In view of the problems of uneven heat exchange in the existing technology, low product quality, and the need to consume a large amount of auxiliary inert gas for deacidification, the utility model provides a continuous production device for solving the above problems. In order to achieve the above purpose, the utility model adopts the following technical scheme:
[0016] A continuous production device for isooctyl chloroformate, characterized in that the device comprises a synthesis unit and a deacidification unit connected by a pipeline.
[0017] The synthesis unit comprises a photochemical tower, a tail gas condenser and a crude product buffer tank, the photochemical tower is provided with a tail gas outlet at the top, a phosgene inlet at the bottom, an isooctanol inlet, a liquid phosgene inlet and a crude product outlet at the side, and the crude product outlet is connected with the crude product buffer tank through a pipeline; the tail gas condenser is provided with a tail gas discharge outlet at the top, a refrigerant inlet and a refrigerant outlet at the side, and a common port of a tail gas inlet and a liquid phosgene outlet at the bottom, and the liquid phosgene outlet is connected with the liquid phosgene inlet of the photochemical tower through a liquid phosgene reflux pipeline;
[0018] The deacidification unit comprises a falling film evaporator, a gas-liquid separation tank and a product temporary storage tank, the top of the falling film evaporator is communicated with the crude product buffer tank through a pipeline, the lower side of the falling film evaporator is communicated with the gas-liquid separation tank through a pipeline, the bottom of the falling film evaporator is communicated with the top of the product temporary storage tank through a pipeline, the top of the product temporary storage tank is also communicated with the gas-liquid separation tank through a pipeline, the bottom of the falling film evaporator and the top of the product temporary storage tank are both provided with a gas phase outlet for vacuumizing, and the side of the falling film evaporator is also provided with a heat medium inlet and a heat medium outlet for temperature control.
[0019] The technical problems solved by the utility model also can be realized through the following technical schemes, the photochemical tower is composed of several hole type heat exchange sections and scattered packing tower sections for removing reaction heat, the several hole type heat exchange sections are vertically arranged side by side, and the hole type heat exchange sections and the scattered packing tower sections are arranged at intervals, the crude product outlet is arranged on the tower body above the uppermost hole type heat exchange section, the tail gas outlet is arranged on the top of the tower body, the crude product outlet is arranged on the tower body above the uppermost hole type heat exchange section, the tail gas outlet is arranged on the top of the tower body, and the liquid light inlet is arranged above the isooctanol inlet of the tower body.
[0020] The technical problems solved by the utility model also can be realized through the following technical schemes, the hole type heat exchange section is a graphite hole type heat exchange section or a silicon carbide hole type heat exchange section, a refrigerant inlet and a refrigerant outlet are arranged on the hole type heat exchange section, the hole type heat exchange section includes but is not limited to three groups, the scattered packing tower section includes but is not limited to three sections, and the scattered packing tower section is arranged above the hole type heat exchange section.
[0021] The technical problems solved by the utility model also can be realized through the following technical schemes, the height-diameter ratio of the photochemical tower is 4-34, preferably 10-15.
[0022] The technical problems solved by the utility model also can be realized through the following technical schemes, the height of the photochemical tower is 5m-10m, and the diameter is 0.3m-1.5m.
[0023] Compared with the prior art, the utility model realizes the continuous synthesis and deacidification of chloroformic acid isooctyl ester by arranging the photochemical tower for synthesis and the falling film evaporator for deacidification, the tail gas condenser and the liquid light reflux pipeline are arranged, so that the reaction stage consumes little phosgene, the scattered packing section on the tower body can strengthen the mixing and contact of phosgene and isooctanol, the hole type heat exchange section can strengthen heat exchange and avoid local temperature being too high, the product quality is high, the falling film evaporator, the product temporary storage tank and the gas-liquid separation tank do not consume auxiliary inert gas in the deacidification process, the devices do not have dynamic seals, the potential leakage possibility is very low, the liquid holdup in the reaction process is very low, and the utility model is safe and environmentally friendly.
[0024] The chloroformic acid iso-octyl ester continuous production device is used for deacidification in a falling film evaporator, and chloroformic acid iso-octyl ester products with content ≥99.1% and yield ≥99% are obtained. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1 It is a structure diagram of the chloroformic acid iso-octyl ester continuous production device.
[0026] Figure 2 It is a structure diagram of the photochemical tower.
[0027] In the figure, 1 is a photochemical tower, 2 is a crude product buffer tank, 3 is a tail gas condenser, 4 is a falling film evaporator, 5 is a product temporary storage tank, 6 is a gas-liquid separation tank, 7 is a refrigerant inlet, 8 is a refrigerant outlet, 9 is a scattered heap filler tower section, 10 is a block hole type heat exchange section, 11 is a light gas inlet, 12 is a tail gas outlet, 13 is an iso-octyl alcohol inlet, 14 is a liquid light inlet, and 15 is a crude product outlet. DETAILED DESCRIPTION
[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application.
[0029] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.
[0030] REFERENCE Figure 1 and Figure 2 A chloroformic acid iso-octyl ester continuous production device, which comprises a photochemical tower 1, a tail gas condenser 3, a crude product buffer tank 2, a falling film evaporator 4, a gas-liquid separation tank 6 and a product temporary storage tank 5, wherein the above-mentioned devices are connected to each other through pipelines.
[0031] The height-diameter ratio of the photochemical tower 1 is 4-34, preferably 10-15, the height of the photochemical tower 1 is 5-10 meters, and the diameter is 0.3-1.5 meters,
[0032] The photochemical tower 1 is provided with a phosgene inlet 11 at the bottom, an isooctanol inlet 13 at the side of the bottom, a liquid phosgene inlet 14 at the lower side, a block-hole type heat exchange section 10 for removing reaction heat in each section of the tower, a refrigerant inlet 7 and a refrigerant outlet 8, a tail gas outlet 12 at the top of the tower, and a crude isooctyl chloroformate outlet 15 at the side of the top of the tower; the tail gas condenser 3 is provided with a common port of a tail gas inlet and a liquid phosgene outlet at the bottom, a tail gas discharge port at the top, and a refrigerant inlet and a refrigerant outlet for temperature control at the side; the crude product buffer tank 2 is provided with a crude isooctyl chloroformate inlet at the top and a crude isooctyl chloroformate outlet at the bottom; the falling film evaporator 4 is provided with a crude isooctyl chloroformate inlet at the top, a crude isooctyl chloroformate outlet at the bottom, a gas phase outlet for vacuumizing at the side of the bottom, and a heat medium inlet and a heat medium outlet for temperature control at the side; the gas-liquid separation tank is provided with a gas phase outlet for vacuumizing at the top, a liquid phase outlet at the bottom, and an inlet of the falling film evaporator and an inlet of the finished product temporary storage tank at the side; and the finished product temporary storage tank is provided with a finished isooctyl chloroformate inlet at the top and a gas phase outlet for vacuumizing.
[0033] The number of material holes and the number of refrigerant holes in each block-hole type heat exchange section of the photochemical tower are calculated according to the diameter of the tower, the size of the holes and the hole center distance, and the size of the falling film evaporator for deacidification is calculated according to the crude isooctyl chloroformate production rate of the photochemical tower.
[0034] The working process of the continuous production device for isooctyl chloroformate is as follows: isooctanol and phosgene are introduced into the photochemical tower for reaction, and the contact reaction of phosgene and isooctanol is enhanced by using the scattered packing on the tower to strengthen mixing; the reaction heat is removed by the multi-section block-hole type heat exchange section into which refrigerant is introduced, the generated crude isooctyl chloroformate overflows to the crude product buffer tank, the generated tail gas is separated by the tail gas condenser outside the photochemical tower, and the obtained liquid phosgene is introduced into the photochemical tower for recycling.
[0035] The reaction temperature in the photochemical tower is controlled at 0-35 DEG C, preferably 0-25 DEG C; the molar ratio of isooctanol to phosgene is 1:1.01-2, preferably 1:1.01-1.2; the residence time of the reaction mixture system in the photochemical tower is 1 min-15 min, preferably 1-5 min; the temperature of the crude product buffer tank is controlled at 25-50 DEG C, preferably 30-35 DEG C; the pressure of the falling film evaporator is controlled at -998 mBarg--500 mBarg; and the temperature is controlled at 25-50 DEG C, preferably 30-35 DEG C.
[0036] After the crude product buffer tank accumulates a certain liquid level, the material is passed into the falling film evaporator under negative pressure, and deacidification is carried out at a constant temperature. The obtained isooctyl chloroformate product has a purity of ≥99.1% and a yield of ≥99%, and is sent to the product temporary storage tank through a pipeline.
[0037] Example 1, a method using the above-mentioned isooctyl chloroformate continuous production device, the method is,
[0038] The coolant inlets 7 of the upper, middle and lower three-section block-hole heat exchange sections 10 in the light tower 1 (diameter 300 mm, height 6000 mm) are all opened, and the reaction mixture system temperature is controlled at 30-35°C. The phosgene is passed into the light tower 1 through the phosgene inlet 11 of the light tower at a speed of 40 Kg / h, and the isooctanol is passed into the light tower 1 through the isooctanol inlet 13 of the light tower at a speed of 37.5 Kg / h, i.e. the molar ratio of isooctanol to phosgene is 1:1.4, and after reaction in the light tower 1, the reacted isooctyl chloroformate crude product is obtained at the top of the tower, is passed through the isooctyl chloroformate crude product overflow outlet 15 of the light tower, and is overflowed to the crude product buffer tank 2 (volume 2m 3 ) through a pipeline. The heat medium for temperature control of the falling film evaporator 4 is opened in advance, and the falling film evaporator 4, the product temporary storage tank 5 and the gas-liquid separation tank 6 are vacuumed, and the pressure is maintained at -800 mBarg. When the liquid level of the crude product buffer tank 2 reaches 50%, the isooctyl chloroformate crude product is slowly transported from the crude product buffer tank 2 to the falling film evaporator 4 through a pipeline, and the temperature of the falling film evaporator is controlled at 45°C. After deacidification treatment in the falling film evaporator 4, the qualified product is obtained in the product temporary storage tank 5, the product content is 99.1%, the yield is 99%, the free chlorine is ≤0.1%, and the phosgene is ≤0.1%.
[0039] Example 2, a method using the above-mentioned isooctyl chloroformate continuous production device, the method is,
[0040] The coolant inlets 7 of the upper, middle and lower three-section block-hole heat exchange sections 10 in the light tower 1 (diameter 600 mm, height 7500 mm) are all opened, and the reaction mixture system temperature is controlled at 0-25°C. The phosgene is passed into the light tower 1 through the phosgene inlet 11 of the light tower at a speed of 140 Kg / h, and the isooctanol is passed into the light tower 1 through the isooctanol inlet 13 of the light tower at a speed of 108.8 Kg / h, i.e. the molar ratio of isooctanol to phosgene is 1:1.02, and after reaction in the light tower 1, the reacted isooctyl chloroformate crude product is obtained at the top of the tower, is passed through the isooctyl chloroformate crude product overflow outlet 15 of the light tower, and is overflowed to the crude product buffer tank 2 (volume 2m 3). The heat medium for temperature control of falling film evaporator 4 is opened in advance, and the falling film evaporator 4, product temporary storage tank 5 and gas-liquid separation tank 6 are vacuumized, and the pressure is maintained at -990 mbarg. When the liquid level of crude product buffer tank 2 reaches 50%, the crude product of isooctyl chloroformate is slowly transported from crude product buffer tank 2 to falling film evaporator 4 through pipeline, and the temperature of falling film evaporator is controlled at 30℃. After deacidification treatment in falling film evaporator 4, qualified product is obtained in product temporary storage tank 5, the product content is 99.3%, the yield is 99.1%, the free chlorine is ≤0.1%, and the phosgene is ≤0.1%.
[0041] The above merely describes a preferred specific implementation of the present application, but the scope of protection of the present application is not limited to this. Any person skilled in the art, according to the technical scheme and the inventive concept of the present application, can make equivalent replacement or change within the technical range disclosed by the present application, and all of them should be covered within the scope of protection of the present application.
Claims
1. A continuous production apparatus for isooctyl chloroformate, characterized in that, The device includes a synthesis unit and a deacidification unit connected by pipelines. The synthesis unit includes a photochemical tower, a tail gas condenser, and a crude product buffer tank. The top of the photochemical tower is provided with a tail gas outlet, the bottom of the photochemical tower is provided with a phosgene inlet, and the side of the photochemical tower is provided with an isooctanol inlet, a liquid phosgene inlet, and a crude product outlet. The crude product outlet is connected to the crude product buffer tank through a pipeline. The tail gas condenser is equipped with a tail gas outlet at the top, a refrigerant inlet and a refrigerant outlet on the side, and a common outlet for the tail gas inlet and liquid photocatalytic outlet at the bottom. The liquid photocatalytic outlet is connected to the liquid photocatalytic inlet of the photochemical tower through a liquid photocatalytic reflux pipe. The deacidification unit includes a falling film evaporator, a gas-liquid separator, and a finished product storage tank. The top of the falling film evaporator is connected to the crude product buffer tank via a pipe, the bottom of the falling film evaporator is connected to the gas-liquid separator via a pipe, the bottom of the falling film evaporator is connected to the top of the finished product storage tank via a pipe, and the top of the finished product storage tank is also connected to the gas-liquid separator via a pipe. Both the bottom of the falling film evaporator and the top of the finished product storage tank are equipped with a vacuum gas phase outlet. The side of the falling film evaporator is also equipped with a heat medium inlet and a heat medium outlet for temperature control.
2. The continuous production apparatus for isooctyl chloroformate according to claim 1, characterized in that, The photochemical tower consists of several perforated heat exchange sections and randomly packed tower sections. The perforated heat exchange sections are arranged vertically side by side, and the perforated heat exchange sections and randomly packed tower sections are arranged at intervals. The crude product outlet is located above the uppermost perforated heat exchange section of the tower body, and the exhaust gas outlet is located at the top of the tower body.
3. The continuous production apparatus for isooctyl chloroformate according to claim 2, characterized in that, The block-hole heat exchange section is either a graphite block-hole heat exchange section or a silicon carbide block-hole heat exchange section.
4. The continuous production apparatus for isooctyl chloroformate according to claim 1, characterized in that, The height-to-diameter ratio of the photochemical tower is 4-34.
5. The continuous production apparatus for isooctyl chloroformate according to claim 4, characterized in that, The height-to-diameter ratio of the photochemical tower is 10-15.
6. A continuous production apparatus for isooctyl chloroformate according to any one of claims 1-5, characterized in that, The photochemical tower is 5-10 meters high and 0.3-1.5 meters in diameter.