Production equipment and method of isophthaloyl dichloride
By realizing the instant synthesis and recycling of carbonyl chloride in the filler tower reactor, the problems of high production costs and high environmental pressure are solved, and a safe and efficient production process is achieved.
Patent Information
- Application Number
- CN202410100789.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-25
- Publication Date
- 2025-07-25
AI Technical Summary
In the prior art, isophthalyl chloride has high production costs and high environmental pressure. Both the sulfyl chloride method and the carbonyl chloride method have restrictions, resulting in weak market competitiveness and it is difficult to promote the carbonyl chloride method in China.
The green carbonyl chloride production method is adopted, and the filler layer and heat exchange pipe system in the filler tower reactor are used to realize the instant synthesis and recycling of carbonyl chloride, avoid leakage of highly toxic materials, and the exhaust gas is treated by water washing and drying, and converted into carbon monoxide for recycling.
It reduces production costs, reduces production sites and storage and transportation requirements, improves production efficiency, and achieves safe and efficient isophthalyl chloride production.
Smart Images
Figure FT_1
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of chemical synthesis, and particularly relates to a production method of isophthaloyl chloride. Background Art
[0002] Isophthaloyl chloride is a raw material for the production of high-strength aramid, which is widely used in the textile industry. It has broad application prospects, especially in the field of military manufacturing, and is a cutting-edge technology in the international military industry.
[0003] Currently, the production of isophthaloyl chloride mainly uses the sulfuryl chloride method. Due to the industrial policy restrictions of sulfuryl chloride and the limitations in the yield, environmental protection, and production equipment of isophthaloyl chloride, the production cost remains high and the market competitiveness is weak. The production of isophthaloyl chloride by the phosgene method mainly involves the production, storage, and transportation restrictions of highly toxic phosgene. It cannot be conventionally produced in China, and the requirements for the production site are extremely high, which also leads to the fact that the production of isophthaloyl chloride by the phosgene method has not been widely applied in China. Summary of the Invention
[0004] The purpose of the present invention is to break through the conventional production technology and provide a new green production method of isophthaloyl chloride by the phosgene method in view of the deficiencies of the existing technology and industry technical barriers.
[0005] To achieve the above purpose, the present invention provides the following technical methods:
[0006] A production method of isophthaloyl chloride, comprising:
[0007] A packed tower reactor, which is internally provided with an upper packing layer, a lower packing layer, heat exchange tubes, bubble cap valves, and distributors;
[0008] The upper packing layer is arranged at the upper part of the packed tower reactor and is used for the contact reaction between phosgene and isophthalic acid;
[0009] The lower packing layer is arranged at the lower part of the packed tower reactor and is used for the mixing and contact reaction between chlorine gas and carbon monoxide gas;
[0010] The bubble cap valves are arranged in the middle of the packed tower reactor and are used for unidirectionally connecting the gas reacted in the lower packing layer to rise into the upper packing layer;
[0011] The heat exchange tubes are arranged at the lower part of the packed tower reactor and are located above the lower packing layer, and are used for exchanging heat between the heat generated by the reaction between chlorine gas and carbon monoxide and the carbon dioxide gas in the shell side of the heat exchange tubes;
[0012] A batching kettle is connected to the packed tower reactor and is used for preparing an isophthalic acid solution, and is provided with a solid feed port, a liquid feed port, and a solution discharge port;
[0013] The water washing kettle is connected to the packed tower reactor and is used to process the carbon dioxide gas of the packed tower reactor;
[0014] The drying tower is connected to the water washing kettle and is used to process the carbon dioxide discharged from the water washing kettle and introduce it into the shell side of the heat exchange tube of the packed tower reactor;
[0015] The fixed bed packed tower reactor is connected to the gas outlet of the shell side of the heat exchange tube of the packed tower reactor and is used to convert the carbon dioxide gas discharged from the shell side of the heat exchange tube into carbon monoxide and introduce it into the lower packing layer inside the treatment chamber;
[0016] Preferably, the bubble cap valve is located in the middle of the packed tower reactor. Its function is to allow the gas in the lower part of the packed tower reactor to rise through the bubble cap valve and enter the upper part of the packed tower reactor. On the contrary, it does not allow the liquid in the upper part of the packed tower reactor to enter the lower part of the packed tower reactor through the bubble cap valve;
[0017] Preferably, the solution inside the batching kettle is introduced into the liquid inlet at the top of the packed tower reactor through the solution discharge port;
[0018] Preferably, the gas outlet at the top of the packed tower reactor is connected to the gas inlet of the water washing kettle;
[0019] Preferably, the gas outlet of the water washing kettle is connected to the gas inlet of the drying tower;
[0020] Preferably, the gas outlet of the drying tower is connected to the gas inlet of the shell side of the heat exchange tube;
[0021] Preferably, the gas outlet of the shell side of the heat exchange tube is connected to the gas inlet of the fixed bed packed tower reactor, and the gas outlet of the fixed bed packed tower reactor is connected to the carbon monoxide gas inlet of the packed tower reactor;
[0022] Specifically, the packed tower reactor (1) for producing isophthaloyl chloride is composed of two parts. The lower, thicker part is the lower packing layer (4) for synthesizing phosgene gas and the tube heat exchange (5) part, and the upper, thinner part is the upper packing layer (7) for the reaction of isophthalic acid and phosgene;
[0023] The specific technical method is as follows: carbon monoxide gas enters through the carbon monoxide gas inlet (3), and at the same time, chlorine gas enters through the chlorine gas inlet (2). After the carbon monoxide and chlorine are mixed, they enter the lower packing layer (4) of the packed tower reactor simultaneously for full reaction. The high-temperature phosgene gas after the reaction exchanges heat fully with carbon dioxide from the dry tower gas outlet (17) through the heat exchange tube (5), and finally is discharged through the heat exchange tube shell-side gas outlet (19). The phosgene gas after heat exchange rises and enters the upper packing layer (7) of the packed tower reactor through the bubble cap valve (6). After the isophthalic acid solvent liquid enters the packed tower reactor through the top liquid inlet (8) of the packed tower reactor, it enters the upper packing layer (7) evenly through the distributor (9) and reacts fully with the phosgene gas rising in reverse. The generated isophthaloyl chloride is led out from the top liquid outlet (10) of the packed tower reactor. The gas generated from the reaction in the upper packing layer and the excessive unreacted carbon monoxide are discharged from the top gas outlet (11).
[0024] The specific technical method is as follows: isophthalic acid and the solvent dichloroethane enter the mixing kettle through the solid feed inlet (25) and the liquid feed inlet (26) of the batching kettle respectively, are stirred and melted in the mixing kettle, and then are led out from the solution discharge outlet (27), enter the top liquid inlet (8) of the packed tower reactor, and enter the upper packing layer (7) evenly through the distributor (9), react with the rising phosgene gas in the upper packing layer (7) to generate an isophthaloyl chloride solution, and are discharged from the top liquid outlet (10). The carbon dioxide gas and hydrogen chloride gas generated by the reaction are discharged from the top gas outlet (11) and enter the water washing kettle (12). After washing away the generated hydrogen chloride, unreacted chlorine gas and phosgene gas, the remaining carbon dioxide gas and unreacted carbon monoxide gas are led out from the water washing kettle gas outlet (14), enter the dry tower gas inlet (16), are led out from the dry tower gas outlet (17) after drying, enter the heat exchange tube shell-side gas inlet (18) of the packed tower reactor, and after heat exchange with the 450 °C high-temperature phosgene gas in the heat exchange tube, the approximately 400 °C high-temperature gas is led out from the heat exchange tube shell-side gas outlet (19) and enters the fixed bed packed tower reactor gas inlet (21). After the carbon dioxide reacts with the carbon layer in the fixed bed at 900 °C in the electrically heated fixed bed (22) and all the carbon dioxide is converted into carbon monoxide, it is led out from the fixed bed packed tower reactor gas outlet (23) and enters the carbon monoxide gas inlet (3) to continue participating in the reaction to generate phosgene gas.
[0025] This method takes a special packed tower reactor as the core. After phosgene is synthesized instantaneously in the tower, the reaction gas reacts with the terephthalic acid solution at the upper part of the packed tower reactor immediately without leaving the tower to produce isophthaloyl chloride. It achieves the on-site production and immediate use of phosgene. The final tail gas leaving the tower is mainly carbon dioxide. After the carbon dioxide tail gas is washed and purified in a water scrubbing kettle and dried to remove water in a drying tower, it enters the fixed bed packed tower reactor after being heated up in the heat exchange tube part of the packed tower reactor. After being converted into carbon monoxide at high temperature, it circulates and re-enters the lower packing layer of the packed tower reactor, and reacts with the simultaneously introduced chlorine gas to produce phosgene. The whole production system recycles materials throughout the process, eliminating the possibility of leakage of highly toxic materials during the reaction process. The closed-loop material circulation throughout the process has the advantages of being green and efficient. The on-site production and immediate use of phosgene avoid the requirements for the production site, and also avoid the high requirements and high-cost investments for the storage and transportation of highly toxic phosgene. Description of the Drawings
[0026] In order to more clearly illustrate the technical methods in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.
[0027] Figure 1 Production method of isophthaloyl chloride
[0028] The reference numerals are as follows:
[0029] 1 is a packed tower reactor, 2 is a chlorine gas inlet, 3 is a carbon monoxide gas inlet, 4 is the lower packing layer, 5 is a heat exchange tube, 6 is a bubble cap valve, 7 is the upper packing layer, 8 is a tower top liquid inlet, 9 is a distributor, 10 is a tower top liquid outlet, 11 is a tower top gas outlet, 12 is a water scrubbing kettle, 13 is a water scrubbing kettle gas inlet, 14 is a water scrubbing kettle gas outlet, 15 is a drying tower, 16 is a drying tower gas inlet, 17 is a drying tower gas outlet, 18 is a heat exchange tube shell side gas inlet, 19 is a heat exchange tube shell side gas outlet, 20 is a fixed bed packed tower reactor, 21 is a fixed bed packed tower reactor gas inlet, 22 is an electric heating fixed bed, 23 is a fixed bed packed tower reactor gas outlet, 24 is a batching kettle, 25 is a solid feed inlet, 26 is a liquid feed inlet, 27 is a solution discharge outlet, 28 is a water addition port of the water scrubbing kettle, 29 is a water scrubbing kettle liquid outlet, 30 is a desiccant inlet, 31 is a desiccant outlet. Detailed Description of the Embodiments
[0030] The following will give a detailed description of the specific embodiments of the present invention, where dichloroethane in the embodiments is the solvent in the claims.
[0031] Example 1
[0032] 4271 kg / h of chlorine gas and 1687 kg / h of carbon monoxide enter the reactor from the chlorine gas and carbon monoxide gas inlets at the bottom of the packed tower reactor, and react to produce 5958 kg / h of phosgene. Meanwhile, 5000 kg / h of isophthalic acid and 7500 kg / h of dichloroethane solvent are added to the batching kettle, dissolved, and then introduced into the upper feed inlet of the packed tower reactor at a rate of 5000 kg / h (calculated based on the mass of isophthalic acid). The 5958 kg / h of phosgene produced enters the upper layer of the tower for contact reaction, and reacts to produce 6114 kg / h of isophthaloyl chloride, generating a mixed gas of 2650.6 kg / h of carbon dioxide and 2196.4 kg / h of hydrogen chloride, which is discharged from the top outlet of the packed tower reactor and enters the water washing kettle. After removing hydrogen chloride gas by water washing, the remaining 2650.6 kg / h of carbon dioxide gas is exported from the outlet, enters the drying tower. After drying, 2650.6 kg / h of carbon dioxide is exported from the gas outlet and enters the inlet of the heat exchange tube of the packed tower reactor. After heat exchange with the 450 °C high-temperature phosgene gas in the heat exchange tube, the approximately 400 °C high-temperature carbon dioxide gas is exported from the outlet of the heat exchange tube and enters the gas inlet of the fixed bed packed tower reactor. At 900 °C in the fixed bed, 2650.6 kg / h of carbon dioxide reacts with the carbon layer in the fixed bed to be converted into 3374 kg / h of carbon monoxide, which is exported from the outlet of the fixed bed packed tower reactor and enters the phosgene reaction gas inlet of the packed tower reactor to continue participating in the reaction to produce phosgene gas.
[0033] Example 2
[0034] 3417 kg / h of chlorine gas and 1349 kg / h of carbon monoxide enter the reactor through the chlorine gas and carbon monoxide gas inlets at the bottom of the packed tower reactor. They react to produce 4766 kg / h of phosgene. Meanwhile, 4000 kg / h of isophthalic acid and 6000 kg / h of dichloroethane solvent are added to the batching kettle, dissolved, and then introduced into the upper feed port of the packed tower reactor at a rate of 4000 kg / h (calculated based on the mass of isophthalic acid). The 4766 kg / h of phosgene produced enters the upper part of the tower for contact reaction, reacting to produce 4892 kg / h of isophthaloyl chloride, and generating a mixed gas of 2120 kg / h of carbon dioxide and 1757 kg / h of hydrogen chloride, which is discharged from the top outlet of the packed tower reactor and enters the water washing kettle. After washing to remove hydrogen chloride gas, the remaining 2120 kg / h of carbon dioxide gas is exported from the outlet, enters the drying tower. After drying, 2120 kg / h of carbon dioxide is exported from the gas outlet and enters the inlet of the heat exchange tube of the packed tower reactor. After heat exchange with the 450 °C high-temperature phosgene gas in the heat exchange tube, the approximately 400 °C high-temperature carbon dioxide gas is exported from the outlet of the heat exchange tube and enters the gas inlet of the fixed bed packed tower reactor. At 900 °C in the fixed bed, 2120 kg / h of carbon dioxide reacts with the carbon layer in the fixed bed to be converted into 2698 kg / h of carbon monoxide, which is exported from the outlet of the fixed bed packed tower reactor and enters the phosgene reaction gas inlet of the packed tower reactor to continue participating in the reaction to generate phosgene gas.
[0035] Example 3
[0036] As described in Example 1 and Example 2, the process technology method uses a chlorine gas to carbon monoxide feed ratio of 1:1. In this example, the chlorine gas to carbon monoxide feed ratio is 1:0.8 as described in Claim 14.
[0037] 2392 kg / h of chlorine gas and 1180 kg / h of carbon monoxide enter the reactor from the chlorine gas and carbon monoxide gas inlets at the bottom of the packed tower reactor. They react to produce 3364 kg / h of phosgene. Meanwhile, 2800 kg / h of isophthalic acid and 5200 kg / h of dichloroethane solvent are added to the batching kettle, dissolved, and then introduced into the upper feed inlet of the packed tower reactor at a rate of 2800 kg / h (calculated based on the mass of isophthalic acid). The 3364 kg / h of phosgene produced enters the upper layer of the tower for contact reaction, reacting to produce 3424 kg / h of isophthaloyl chloride, and generating a mixed gas of 1484 kg / h of carbon dioxide, 1230 kg / h of hydrogen chloride, and 234 kg / h of excess carbon monoxide. This mixed gas is discharged from the top outlet of the packed tower reactor and enters the water washing kettle. After removing hydrogen chloride gas by water washing, the remaining 1484 kg / h of carbon dioxide gas and 234 kg / h of excess carbon monoxide gas are exported from the outlet and enter the drying tower. After drying, 1484 kg / h of carbon dioxide and 234 kg / h of excess carbon monoxide gas are exported from the gas outlet and enter the inlet of the heat exchange tube of the packed tower reactor. After heat exchange with the 450 °C high-temperature phosgene gas in the heat exchange tube, the approximately 400 °C high-temperature carbon dioxide gas is exported from the outlet of the heat exchange tube and enters the gas inlet of the fixed bed packed tower reactor. At 900 °C in the fixed bed, 1484 kg / h of carbon dioxide reacts with the carbon layer in the fixed bed to be converted into 1179 kg / h of carbon monoxide (including 234 kg / h of excess unreacted carbon monoxide in the system). This is exported from the outlet of the fixed bed packed tower reactor and enters the phosgene reaction gas inlet of the packed tower reactor to continue participating in the reaction to produce phosgene gas.
[0038] As described above, only the preferred embodiments of the present invention are provided, and there is no limitation, either in form or in essence, to the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the method of the present invention, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as within the protection scope of the present invention. For those skilled in the art, without departing from the spirit and scope of the present invention, any minor changes, modifications, and equivalent variations made by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications, and variations made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical method of the present invention.
Claims
1. A production device and method for isophthaloyl chloride, characterized in that: The production equipment and method include two parts: production equipment and technical method.
2. The isophthaloyl chloride production equipment according to claim 1, characterized in that: The production equipment is a packed tower reactor.
3. The isophthaloyl chloride production equipment according to claim 2, characterized in that: The packed tower reactor consists of two parts, the upper part of the packed tower reactor is the upper packing layer where phosgene reacts with isophthalic acid to produce isophthaloyl chloride; the lower part of the packed tower reactor is the lower packing layer where carbon monoxide reacts with chlorine to produce phosgene gas and heat exchange tubes.
4. The isophthaloyl chloride production equipment according to claim 2, characterized in that: The middle of the packed tower reactor is isolated by a bubble cap valve; the bubble cap valve allows the phosgene gas in the lower part of the packed tower reactor to rise, but does not allow the liquid in the upper part of the packed tower reactor to enter the lower part of the packed tower reactor through the bubble cap valve.
5. The isophthaloyl chloride production equipment according to claim 2, characterized in that: The upper part of the packed tower reactor is provided with an isophthalic acid solution distributor, a top gas outlet, a top liquid inlet and a top liquid outlet.
6. According to the technical method described in claim 1, the characteristics are as follows: (1) Carbon monoxide and chlorine are preliminarily mixed at the bottom of the tower and then enter the lower packing layer described in claim 3, and are fully mixed and reacted in the lower packing layer to produce high-temperature phosgene. The high-temperature phosgene rises and enters the tube side of the heat exchange tube described in claim 3, and exchanges heat with the carbon dioxide flowing reversely in the shell side of the heat exchange tube. After the heat exchange is completed, the phosgene enters the upper packing layer described in claim 3 through the bubble cap valve described in claim 4; (2) Isophthalic acid and dichloroethane solvent are added to the batching kettle and fully dissolved and mixed. The solution enters from the outlet of the batching kettle and successively passes through the top liquid inlet and the distributor described in claim 5, and then flows to the upper packing layer described in claim 3; (3) The phosgene gas rises through the bubble cap valve described in claim 4 and enters the upper packing layer described in claim 3 to react reversely with the isophthalic acid solution to produce isophthaloyl chloride solution, carbon dioxide gas and hydrogen chloride gas. The produced isophthaloyl chloride is discharged from the top liquid outlet, and the gas is discharged from the top gas outlet; (4) The mixed gas of carbon dioxide and hydrogen chloride taken out from the top outlet of the packed tower reactor enters the water washing kettle. After absorbing hydrogen chloride and unreacted chlorine and phosgene gas, the remaining carbon dioxide gas is taken out from the gas outlet of the water washing kettle; (5) The carbon dioxide after water washing enters the drying tower, and after removing water vapor, it enters the heat exchange tube of the packed tower reactor described in claims 2-3 to be heated; (6) The heated carbon dioxide enters the fixed bed packed tower reactor and reacts with high-temperature carbon, and all the carbon dioxide is converted into carbon monoxide; (7) The produced carbon monoxide is all recycled and enters the carbon monoxide inlet at the bottom of the packed tower reactor described in claims 2-3 to continue to react with chlorine to produce phosgene.
7. The method according to claim 6, characterized in that: Carbon monoxide and chlorine are fed simultaneously from the bottom of the tower in a molar ratio of 1:0.5 to 1, and preferably the feeding ratio is 1:1 in molar ratio.