A flame retardant byproduct separation device

Abstract

This invention discloses a flame retardant byproduct separation device, comprising: a feeding mechanism for conveying reactants to a reaction vessel, which contains the reactants and serves as the reaction site; a membrane separator connected to the reaction vessel for separating flame retardants from byproducts; a cooler connected to the membrane separator and the reaction vessel to enable cyclic reaction of the reactants; and a tail gas treatment mechanism connected to the membrane separator. This invention achieves efficient real-time separation of products and hydrogen chloride in esterification reactions, reducing the hydrogen chloride content in the esterification liquid from 10%-15% in traditional processes to 0.5%-1%, significantly reducing the probability of acid hydrolysis and byproduct formation, and increasing product yield to 94.2%-95%. Simultaneously, it reduces the amount of organic alcohol fed, lowering the energy consumption and cost of subsequent dealcoholization and distillation, and eliminates the need for complex raw material systems or high-pressure conditions, making it more industrially feasible.

Description

Technical Field

[0001] This utility model relates to the technical field of flame retardant preparation, and specifically to a flame retardant byproduct separation device. Background Technology

[0002] Current industrial production of phosphate ester flame retardants mostly uses phosphorus oxychloride and organic alcohols as raw materials through esterification reactions. During the process, hydrogen chloride is generated, which leads to acid decomposition of the product, reducing yield and increasing cost.

[0003] In existing technologies, some techniques employ multi-stage condensation and azeotropic distillation under negative pressure for separation, but the high hydrogen chloride content results in numerous byproducts and low yields. Some technologies employ a three-stage series reactor combined with a degassing distillation column, which improves the yield but relies on high-energy-consuming distillation and does not solve the problem of real-time separation of hydrogen chloride.

[0004] While micro-reaction technology offers higher yields, it fails to remove hydrogen chloride promptly, requiring additional ammonia for neutralization, generating byproducts, and increasing the complexity and cost of post-processing. Furthermore, in related technologies, batch reactions result in uneven mixing, necessitating high-power stirring and causing large local temperature fluctuations; insufficient hydrogen chloride separation efficiency leads to residual hydrogen chloride causing reverse reactions, making it difficult to achieve yields exceeding 95%. Utility Model Content

[0005] The purpose of this invention is to provide a flame retardant byproduct separation device to solve the above problems.

[0006] To achieve the above objectives, this utility model specifically adopts the following technical solution: A flame retardant byproduct separation device, characterized in that it comprises: The feeding mechanism is used to transport the reactants to the reactor, which is used to contain the reactants and serve as the reaction site for the reactants. A membrane separator, connected to the reaction vessel, is used to separate flame retardants from byproducts; A cooler is connected to the membrane separator and the reactor to enable the recycling of the reactants. An exhaust gas treatment mechanism is connected to the membrane separator.

[0007] As a further description of the above technical solution, a temporary storage tank is also included, which is connected to the discharge pipeline of the reaction vessel, and the temporary storage tank is used to store flame retardant products.

[0008] As a further description of the above technical solution, the feeding mechanism includes: An alcohol storage tank is connected to the inlet of the reactor via a metering pump. The phosphorus oxychloride storage tank is connected to the feed inlet of the reactor via a metering pump.

[0009] As a further description of the above technical solution, the molar ratio of phosphorus oxychloride to alcohol entering the reaction vessel is 1:3 to 1:3.5.

[0010] As a further description of the above technical solution, the membrane module in the membrane separator is an acid-resistant hybrid membrane.

[0011] As a further description of the above technical solution, the cooler is a graphite cooler with circular holes, and the cooler is provided with a cooling medium flow channel.

[0012] As a further description of the above technical solution, the exhaust gas treatment mechanism includes an absorption tower one and an absorption tower two connected to the absorption tower one, and a vacuum pump is externally connected to the absorption tower two. The absorption tower is connected to the absorption water tank, and the absorption tower is connected to the alkali circulation tank.

[0013] As a further description of the above technical solution, the first absorption tower is a tail gas absorption tower, and the second absorption tower is an alkaline solution absorption tower.

[0014] As a further description of the above technical solution, an external circulation pump is connected between the reaction vessel and the membrane separator.

[0015] As a further description of the above technical solution, the reactor is made of enamel material and has a volume of 10m³; the external circulation pump is made of steel lined with PTFE.

[0016] The beneficial effects of this utility model are as follows: This invention utilizes a separation device consisting of an esterification external circulation pump, a membrane separator, an external external circulation cooler, and a matching hydrogen chloride tail gas absorption and vacuum system. This device achieves efficient real-time separation of products and hydrogen chloride during the esterification reaction, reducing the hydrogen chloride content in the esterification liquid from 10%-15% in traditional processes to 0.5%-1%. This significantly reduces the probability of acid hydrolysis and the generation of byproducts, increasing the product yield to 94.2%-95%. Simultaneously, it reduces the amount of organic alcohol required, lowering the energy consumption and cost of subsequent dealcoholization and distillation. Furthermore, it eliminates the need for complex raw material systems or high-pressure conditions, making it more industrially feasible.

[0017] To more clearly illustrate the structural features and functions of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the separation device of this utility model.

[0019] Attached reference numerals: 1. Alcohol storage tank; 2. Metering pump one; 3. Phosphorus oxychloride storage tank; 4. Metering pump two; 5. Reactor; 6. Membrane separator; 7. External circulation pump; 8. Cooler; 9. Temporary storage tank; 10. Tail gas absorption tower; 11. Alkali absorption tower; 12. Absorption water tank; 13. Alkali circulation tank. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0021] like Figure 1 As shown in one embodiment, a flame retardant byproduct separation device includes a feeding mechanism. The feeding mechanism is used to transport the reactants to a reaction vessel 5, which contains the reactants and serves as the reaction site. The feeding mechanism includes an alcohol storage tank 1, which is connected to the inlet of the reaction vessel 5 via a metering pump 2. It also includes a phosphorus oxychloride storage tank 3, which is connected to the inlet of the reaction vessel 5 via a metering pump 4. The alcohol storage tank 1 can store organic alcohols such as ethanol or isooctanol, and the phosphorus oxychloride storage tank 3 can store phosphorus oxychloride. Phosphorus oxychloride and organic alcohols are continuously fed through metering pumps 2 and 4, with the molar ratio controlled at 1:3-1:3.5. Due to the timely removal of hydrogen chloride, the reaction efficiency is improved, and the amount of organic alcohol is significantly reduced compared to traditional processes, achieving precise control and reducing subsequent de-alcoholization energy consumption.

[0022] The timely removal of hydrogen chloride is primarily achieved through membrane separator 6, which is connected to the reaction vessel 5. Membrane separator 6 separates flame retardants from byproducts. The membrane module in membrane separator 6 is made of acid-resistant hybrid membrane. Utilizing the principle of diffusion permeation, due to the significant molecular weight difference between hydrogen chloride and phosphate ester flame retardants, effective separation of hydrogen chloride and phosphate ester flame retardants is achieved during the esterification reaction stage. The hydrogen chloride content in the esterification liquid after dehydrochlorination is reduced to 0.5-1%, a significant decrease compared to the 10-15% of traditional processes. This reduces the probability of product acidification and the pressure of subsequent distillation separation, increasing the product yield to 94.2%-95% and effectively improving product quality.

[0023] It should be noted that the membrane module is made of acid-resistant hybrid materials, formed through composite modification of organic and inorganic materials. For example, it may use acid-resistant organic polymers such as polyvinylidene fluoride and polytetrafluoroethylene as the matrix, and dopant inorganic nanoparticles such as silica and alumina.

[0024] The outlet of membrane separator 6 is connected to cooler 8, and the outlet of cooler 8 is connected to the inlet of reactor 5. Cooler 8 can remove the heat generated during the reaction in a timely manner, and the cooled material is returned to reactor 5 for further reaction, so as to realize the circulation of the reactants. At the same time, temporary storage tank 9, i.e., esterification liquid tank, is connected to the outlet pipeline of reactor 5, which can temporarily store the esterification liquid, i.e., the flame retardant product, for later transfer and use. It should also be noted that an external circulation pump 7 is installed on the outlet pipeline of reactor 5. The external circulation pump 7 can draw the reaction liquid from the bottom of the reactor, and then cool it to the reaction temperature through membrane separator 6 and cooler 8 before returning it to reactor 5 to continue the reaction.

[0025] The exhaust gas treatment mechanism is connected to the membrane separator 6. The exhaust gas treatment mechanism can absorb hydrogen chloride in a timely manner. At the same time, the vacuum pump in the exhaust gas treatment mechanism provides negative pressure to the exhaust gas treatment mechanism, which can achieve timely removal of hydrogen chloride.

[0026] In one embodiment, the cooler 8 is a graphite cooler with circular holes. The cooler 8 is provided with a cooling medium flow channel. -15°C frozen brine is introduced into the cooling medium channel. The esterification liquid entering the cooler 8 can be cooled by the cooling medium, and the temperature is reduced to 18-20°C.

[0027] In one embodiment, the exhaust gas treatment system includes an absorption tower 1 and an absorption tower 2 connected to the absorption tower 1, with a vacuum pump externally connected to the absorption tower 2. The absorption tower 1 is connected to an absorption water tank 12, and the absorption tower is connected to an alkaline solution circulation tank 13. The absorption tower 1 is the exhaust gas absorption tower 10, and the absorption tower 2 is the alkaline solution absorption tower 11. Hydrogen chloride gas is transported to the exhaust gas absorption tower 10 via pipeline. Water is typically used as the absorption medium. Taking advantage of the easy solubility of hydrogen chloride in water, the gas is allowed to fully contact with the water, and most of the hydrogen chloride is absorbed by the water to form a hydrochloric acid solution. The small amount of hydrogen chloride that is not completely absorbed enters the alkaline solution absorption tower 11, where it undergoes a neutralization reaction with alkaline solutions such as sodium hydroxide, completely converting the remaining hydrogen chloride into harmless salts. Through this staged absorption method, the hydrogen chloride gas is ensured to be fully treated, and the final emitted gas meets environmental standards, avoiding damage to the equipment from corrosive gases and preventing environmental pollution.

[0028] In one embodiment, the reactor 5 is made of enamel and has a volume of 10 m³; the external circulation pump 7 is made of steel lined with PTFE.

[0029] In one embodiment, materials from the ethanol and phosphorus oxychloride storage tanks are continuously pumped into the esterification reactor at a certain ratio using ethanol and phosphorus oxychloride metering pumps, respectively. After mixing with ethanol, an esterification reaction occurs, producing triethyl phosphate and hydrogen chloride. The reacted material is then pumped into a membrane separator via an external circulation pump to remove the hydrogen chloride generated during the reaction. The dehydrochlorinated triethyl phosphate material is then cooled by an external circulation cooler to remove the heat generated during the reaction. The cooled material is returned to the esterification reactor for further reaction. Once the liquid level in the esterification reactor reaches a certain height, the product is transferred to the esterification tank via an external circulation pump. To efficiently remove the hydrogen chloride gas generated during the reaction, a vacuum pump provides negative pressure outside the membrane of the membrane separator. The hydrogen chloride generated during the reaction is absorbed in two stages: a tail gas absorption tower and an alkaline absorption tower. The absorbents enter the tail gas absorption water tank and the alkaline circulation tank, respectively, and are then circulated and absorbed by the tail gas absorption water pump and the alkaline circulation pump. During the reaction, the temperature of the esterification reactor is controlled at 18-20℃. The vacuum pump provides an absolute pressure of 5 kPa to the outside of the membrane separator, while the pressure inside the membrane is provided by the esterification external circulation pump, with an absolute pressure of 300 kPa. The large pressure difference between the inside and outside of the membrane increases the diffusion rate of hydrogen chloride gas, thereby achieving efficient separation of triethyl phosphate and hydrogen chloride. The hydrogen chloride content in the generated triethyl phosphate esterification liquid is 0.5%.

[0030] In one embodiment, the materials in the isooctanol storage tank and the phosphorus oxychloride storage tank are continuously pumped into the esterification reactor at a certain ratio through the isooctanol metering pump and the phosphorus oxychloride metering pump, respectively. After the phosphorus oxychloride and isooctanol are mixed, an esterification reaction occurs to generate triisooctyl phosphate and hydrogen chloride. After the reaction, the material is pumped into the membrane separator through the esterification external circulation pump to remove the hydrogen chloride generated during the reaction. The triisooctyl phosphate material after the hydrogen chloride is removed is then cooled through the esterification external circulation cooler to remove the heat generated by the reaction. The cooled material is returned to the esterification reactor for further reaction. When the liquid level of the material in the esterification reactor reaches a certain height, the product is transferred to the esterification liquid tank in a timely manner through the esterification external circulation pump. To efficiently remove hydrogen chloride gas generated during the reaction, a vacuum pump provides negative pressure to the outside of the membrane separator. The hydrogen chloride generated during the reaction is absorbed in two stages: a tail gas absorption tower and an alkaline solution absorption tower. The absorbent enters the tail gas absorption water tank 11 and the alkaline solution circulation tank, respectively, and is then circulated and absorbed by the tail gas absorption water pump and the alkaline solution circulation pump. During the reaction, the temperature of the esterification reactor is controlled at 50-60℃. The vacuum pump provides an absolute pressure of 5 kPa to the outside of the membrane separator, while the pressure inside the membrane is provided by the esterification external circulation pump at an absolute pressure of 300 kPa. The large pressure difference between the inside and outside of the membrane increases the diffusion rate of hydrogen chloride gas, achieving efficient separation of triisooctyl phosphate and hydrogen chloride. The hydrogen chloride content in the esterification liquid is 0.7%.

[0031] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flame retardant byproduct separation device, characterized in that, include: A feeding mechanism is used to convey the reactants to the reactor, which is used to contain the reactants and serve as the reaction site for the reactants. A membrane separator, connected to the reaction vessel, is used to separate flame retardants from byproducts; A cooler is connected to the membrane separator and the reactor to enable the recycling of the reactants. An exhaust gas treatment mechanism is connected to the membrane separator.

2. The flame retardant by-product separation device according to claim 1, characterized in that, It also includes a temporary storage tank, which is connected to the discharge pipeline of the reactor, and the temporary storage tank is used to store flame retardant products.

3. The flame retardant by-product separation device according to claim 1, characterized in that, The feeding mechanism includes: An alcohol storage tank is connected to the inlet of the reactor via a metering pump. The phosphorus oxychloride storage tank is connected to the feed inlet of the reactor via a metering pump.

4. The flame retardant by-product separation device according to claim 1, characterized in that, The molar ratio of phosphorus oxychloride to alcohol entering the reactor is 1:3 to 1:3.

5.

5. The flame retardant by-product separation device according to claim 1, characterized in that, The membrane module inside the membrane separator is an acid-resistant hybrid membrane.

6. The flame retardant by-product separation device according to claim 1, characterized in that, The cooler is a graphite cooler with circular holes, and the cooler is provided with a cooling medium flow channel.

7. The flame retardant by-product separation device according to claim 1, characterized in that, The exhaust gas treatment mechanism includes an absorption tower one and an absorption tower two connected to the absorption tower one, and a vacuum pump is externally connected to the absorption tower two. The absorption tower is connected to the absorption water tank and the absorption tower is connected to the alkali circulation tank.

8. The flame retardant by-product separation device according to claim 7, characterized in that, The first absorption tower is a tail gas absorption tower, and the second absorption tower is an alkaline solution absorption tower.

9. The flame retardant by-product separation device according to claim 1, characterized in that, An external circulation pump is connected between the reactor and the membrane separator.

10. The flame retardant by-product separation device according to claim 9, characterized in that, The reactor is made of enamel and has a volume of 10 m³; the external circulation pump is made of steel lined with PTFE.

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