JP7401998B2 - Aromatic halide manufacturing method and manufacturing equipment - Google Patents

Description

The present invention relates to a method and equipment for producing aromatic halides. More specifically, an aromatic halide is produced from an aromatic compound and at least one of an inorganic halide and a halogen, and an extraction agent is brought into contact with the residual liquid after distillation purification to produce a metal compound, which is the main component of the catalyst, from the residual liquid. The present invention relates to a method and equipment for producing aromatic halides, characterized in that after removing the residual liquid, the residual liquid is burned in a combustion furnace, and the halide is recovered after the heat of combustion is recovered.

Aromatic halides are useful compounds as raw materials for medicines and agricultural chemicals, and p-dichlorobenzene is a compound of high industrial value that is used not only as raw materials for medicines and agricultural chemicals, but also as insecticides and insect repellents. be. p-dichlorobenzene is also used as a raw material for polyphenylene sulfide, which is an engineering plastic, and demand for it has increased rapidly in recent years.

A common method for producing aromatic halides is to halogenate an aromatic compound in the presence of a metal catalyst. The product obtained by such a method contains impurities, halides, and metal compounds derived from the catalyst in addition to aromatic halides.

A known method for producing aromatic halides, particularly p-dichlorobenzene, is to chlorinate benzene or chlorobenzene with chlorine molecules in the presence of a Lewis acid catalyst in a liquid phase. For example, Patent Document 1 discloses that by using ferric chloride as a Lewis acid and disulfur dichloride as a co-catalyst, chlorobenzene is chlorinated with chlorine gas while maintaining a reaction temperature of 35 to 37°C. A method is described for producing p-dichlorobenzene with a selectivity of .

Patent Document 2 describes a method for recovering halides from the process of producing aromatic halides, in which hydrogen chloride gas generated in the chlorination reaction is used to chlorinate benzene in a chlorination reaction tower to produce p-dichlorobenzene. is brought into contact with benzene in a cleaning tower to allow benzene to absorb and remove organic compounds with a higher boiling point than benzene contained in the reaction gas, and then the reaction gas after absorption and removal is passed through an adiabatic absorption hydrochloric acid recovery tower. A method for recovering hydrochloric acid is described in which crude hydrochloric acid is obtained from the bottom of a recovery column and exhaust gas is obtained from the top of the recovery column.

Patent Document 3 describes a method for removing iron from the manufacturing process of aromatic halides, in which chlorine is dissolved in a liquid chlorinated hydrocarbon containing mono- and divalent iron compounds, and then the liquid chlorinated hydrocarbon is dissolved in the liquid chlorinated hydrocarbon. A method for removing iron in liquid chlorinated hydrocarbons is described in which iron is contacted with activated carbon.

Patent Document 4 describes a method for extracting iron from an aromatic halide manufacturing process using a line mixer, in which a Fischer-Tropsch derived hydrocarbon stream is sent to a treatment zone, an acidic aqueous solution stream is sent to the treatment zone, and contacting a Fischer-Tropsch derived hydrocarbon stream with an acidic aqueous solution stream in the treatment zone to form a mixture stream; and combining the mixture stream with at least one extracted Fischer-Tropsch derived hydrocarbon stream and at least one modified Fischer-Tropsch derived hydrocarbon stream. A method of separation into an acidic aqueous solution is described.

US Patent No. 3,226,447 Japanese Patent Application Publication No. 2001-261308 Japanese Patent Application Publication No. 2-255631 Special Publication No. 2007-530710

However, in the general production method of p-dichlorobenzene as disclosed in Patent Document 1, it is necessary to wash the reaction solution with water to remove iron from the product, and the water used for this is chlorinated. Since hydrogen is also absorbed and becomes hydrochloric acid, a process is required to separate iron from the hydrochloric acid and recover the hydrochloric acid. As a result, the process may become more complicated, the energy consumption rate may worsen, and the amount of wastewater to be treated may increase.
In the method disclosed in Patent Document 2, there is a risk that high boiling point impurities may accumulate in the organic layer. In addition, these high-boiling compounds include chlorinated organic compounds, but heat recovery and chlorine content recovery are not carried out, and raw material and energy consumption rates may deteriorate.
In the method disclosed in Patent Document 3, it is necessary to dissolve iron in hydrochloric acid, and corrosion countermeasures are required for the equipment. Furthermore, activated carbon used as an adsorbent requires regeneration treatment in order to be used continuously. Furthermore, heat recovery and chlorine recovery are not carried out, which worsens the raw material and energy consumption rates.

In the method disclosed in Patent Document 4, even under the long-term conditions of 170°C for 4 days, only about 29 to 95% by weight of metals migrate to the extract side, and the extraction rate of iron in particular is lower than that of the extract. In the case of water, it is as low as 53% by weight. There is also concern that the filter that collects the extracted metals may become clogged.
In this way, in order to produce aromatic halides from aromatic compounds, a large amount of energy may be required to separate and recover the halides and metals, and equipment measures may be required. More efficient methods are needed. In addition, no process has been established to recover halides or heat from impurities (such as distillation residue) when aromatic halides are purified.

In view of the above circumstances, the present invention provides a method for producing an aromatic halide, which can remove metal components derived from a catalyst from a distillation residue liquid of an aromatic halide, and can improve the recovery rate of the halide. and manufacturing equipment.

The present inventors made extensive studies to achieve the above-mentioned problems, and after extracting the metal content in the distillation residue liquid by bringing the distillation residue liquid of aromatic halides into contact with an extractant, the extracted metal content was extracted in a combustion furnace. By burning the residual liquid to generate exhaust gas containing halides and recovering heat and halides, impurities, halides, and catalyst-derived metals can be efficiently separated and removed from the aromatic halide residue. - It was discovered that it can be reused and heat can be recovered.

In order to achieve the above object, each aspect of the present invention employs the following configuration.
The method for producing an aromatic halide according to the present invention comprises a step (a) of producing an aromatic halide from an aromatic compound and at least one of an inorganic halide and a halogen using a metal-containing catalyst; A distillation residue liquid obtained after distilling a group halide and an extractant that undergoes phase separation with the distillation residue liquid are mixed to obtain a mixed liquid, and in the mixed liquid, the metal-containing catalyst contained in the distillation residue liquid is mixed. a step (b) of extracting metal compounds originating from the extraction agent to the extraction agent side to obtain an extraction residue liquid; and a step (c) of burning the extraction residue liquid in a combustion furnace to generate exhaust gas containing halides. The method is characterized by including a step (d) of recovering the halide from the exhaust gas.

According to the above method for producing an aromatic halide, metal compounds originating from the metal-containing catalyst can be extracted, and the halide recovery rate can be improved. Thereby, aromatic halides can be stably produced and the extraction residue liquid can be stably combusted.

The method for producing an aromatic halide may include a step of passing the exhaust gas through a heat exchanger to recover heat. In this case, the energy consumption rate of the aromatic halide can be reduced.

The aromatic compound may be benzene, and the halogen may be chlorine. In this case, aromatic chloride, which is an industrially useful aromatic halide, can be obtained in high yield.

The aromatic halide may be dichlorobenzene. In this case, dichlorobenzene, which is an industrially useful aromatic halide and is in demand as a raw material for engineering plastics, can be obtained in high yield.

The metal-containing catalyst may contain an iron compound, and the metal compound may contain an iron compound. In this case, aromatic halides can be efficiently synthesized. Further, since the metal compound contains an iron compound, the extractant can extract the iron compound.

In the step (b), the proportion of the iron compound extracted from the distillation residue into the extractant may be 80% by weight or more. In this case, by extracting the iron compounds to the extraction agent side and recovering 80% by weight or more of the iron compounds contained in the distillation residue liquid, the combustion furnace and the heat recovery device can be operated more stably.

The extraction agent may contain 90% by weight or more of water. In this case, the extractant can extract the metal compound derived from the metal-containing catalyst contained in the distillation residue liquid.

The solubility of the metal compound in the extraction agent may be 1 g/100 g of extraction agent or more. In this case, the extractant can more efficiently extract the metal compounds contained in the distillation residue liquid.

The pH of the extraction agent may be in the range of 5-9. When the pH of the extraction agent is equal to or higher than the above lower limit value, the solubility of the metal compound in the extraction agent can be made sufficient. Further, since the pH of the extraction agent is below the above upper limit value, the extraction agent and the distillation residue liquid undergo phase separation.

The step (b) may include a step of separating the mixed liquid into the extraction residue liquid and the post-extraction extractant using a difference in specific gravity. In this case, the extraction residue liquid and the post-extraction extractant can be easily separated.

The temperature of the liquid mixture may be 20 to 50°C. When the temperature of the liquid mixture is equal to or higher than the lower limit, it is possible to suppress solidification of the aromatic halide contained in the liquid mixture and to suppress the metal compound from being incorporated into the solid. When the temperature of the mixed liquid is below the above upper limit value, the solubility of the metal compound in the distillation residue liquid can be made low, and the amount of the metal compound extracted by the extraction agent can be increased.

The distillation residue liquid and the extraction agent may be mixed using a line mixer. In this case, the space occupied by the device for mixing the distillation residue liquid and the extractant can be reduced, and the energy consumed by the mixing device can be reduced.

The weight of the extraction agent contained in the liquid mixture passed through the line mixer may be three times or more the weight of the distillation residue liquid. In this case, the proportion of the metal compound extracted from the distillation residue into the extractant can be increased.

The linear velocity of the liquid mixture in the line mixer may be 30 to 200 cm/s. By setting the linear velocity to the above lower limit value or more, the droplet diameter of the extraction residue liquid is made fine, liquid-liquid dispersion becomes sufficient, and the proportion of the metal compound extracted to the extraction agent side is increased. I can do it. By keeping the line speed below the above upper limit, pressure loss in the elements within the line mixer can be reduced to improve economic efficiency, and the risk of damage to the line mixer due to excessive load is reduced. I can do it.

The distillation residue liquid and the extraction agent may be mixed inside a stirring tank. In this case, the distillation residue liquid and the extraction agent can be sufficiently mixed.

The weight of the extraction agent supplied to the stirring tank may be three times or more the weight of the distillation residue liquid. In this case, the proportion of the metal compound extracted from the distillation residue into the extractant can be increased.

The aromatic halide manufacturing equipment according to the present invention includes a reaction device for producing an aromatic halide from an aromatic compound and at least one of an inorganic halide and a halogen using a metal-containing catalyst; A distillation apparatus for distilling the produced liquid containing the aromatic halide, a distillation residue liquid of the distillation apparatus, and an extraction agent that phase-separates from the distillation residue liquid are mixed, and the distillation residue liquid contained in the distillation residue liquid is mixed. a mixing device that extracts a metal compound derived from a metal-containing catalyst to the extraction agent side; a separation device that separates the mixed liquid mixed by the mixing device into an extraction residue liquid and an extraction agent after extraction; and the separation device The present invention is characterized by comprising a combustion furnace that burns the extraction residue liquid separated by the combustion furnace, and a halide recovery device that recovers halides from the halide-containing exhaust gas generated in the combustion furnace.

According to the aromatic halide manufacturing equipment, the metal compound derived from the metal-containing catalyst can be extracted from the distillation residue liquid, and the halide generated in the combustion furnace can be recovered. Thereby, the reactor and the combustion furnace can be stably operated.

The aromatic halide production facility may include a heat recovery device that recovers heat from the exhaust gas. In this case, the energy consumption rate of the aromatic halide can be reduced.

The separation device may be a device that separates the mixed liquid into the extraction residue liquid and the post-extraction extractant using a difference in specific gravity. In this case, the separation device can easily separate the mixed liquid into the extraction residue liquid and the post-extraction extractant.

The temperature of at least one of the distillation residue liquid and the extraction agent supplied to the mixing device may be adjusted. In this case, it is possible to prevent the extraction agent from vaporizing and the aromatic halide from solidifying.

The mixing device may be a line mixer. In this case, the space occupied by the mixing device can be reduced, and the energy consumed by the mixing device can be reduced.

The mixing device may be a stirring tank. In this case, the distillation residue liquid and the extraction agent can be sufficiently mixed.

According to the present invention, a method and equipment for producing an aromatic halide are capable of removing metal components derived from a catalyst from a distillation residue liquid of an aromatic halide and improving the recovery rate of the halide. can be provided.

FIG. 1 is a block diagram of aromatic halide manufacturing equipment according to an embodiment of the present invention. 1 is a diagram schematically showing an aromatic halide production facility according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method and equipment for producing aromatic halides according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an aromatic halide production facility according to an embodiment of the present invention. In this figure, the aromatic halide production equipment includes a reaction device 4 that produces aromatic halides, a distillation device 6 that distills the aromatic halide produced in the reaction device 4, and a distillation device that distills the aromatic halide produced in the reaction device 4. A mixing device 12 that obtains a mixed liquid from the residual liquid 8 and the extraction agent 10, a separation device 14 that separates the mixed liquid into an extraction residual liquid and an extraction agent after extraction, a combustion furnace 22 that burns the extraction residual liquid, and a combustion It includes a heat recovery device 24 that recovers heat from the exhaust gas of the furnace 22 and a halide recovery device 26 that recovers halides. According to such aromatic halide production equipment, it is possible to extract the metal compound derived from the metal-containing catalyst from the distillation residue liquid of aromatic halide, and at the same time, it is possible to reduce the energy consumption rate of aromatic halide. can do.

The reactor 4 is supplied with the aromatic hydrocarbon 1 and the halogen/halide 2 as raw materials, and a metal-containing catalyst 3, and the aromatic halide 18 is synthesized from the raw materials by the action of the metal-containing catalyst. The halogen/halide 2 is at least one of an inorganic halide and a halogen.

The aromatic compound is not particularly limited as long as it can produce an aromatic halide, but for example, benzene, toluene, xylene, or alkylated, nitrated, or aminated compounds of these aromatic compounds are used. be able to. Furthermore, polycyclic aromatic compounds such as naphthalene rings and anthracene rings, and alkylated, nitrated, and aminated products of these aromatic rings can also be used. In view of the usefulness of the produced aromatic halide, it is preferable to use an aromatic hydrocarbon as the aromatic compound, and it is more preferable to use benzene. Furthermore, in order to make the halogenation reaction proceed smoothly, a step of removing impurities, such as a dehydration step, may be performed before the halogenation reaction.

The aromatic halide is not particularly limited as long as it can be produced from an aromatic compound and at least one of an inorganic halide and a halogen. , and halides of aminated compounds. Further, polycyclic aromatic compounds such as naphthalene rings and anthracene rings, and halogenated products of alkylation, nitration, and amination of these aromatic rings may also be used. In view of the usefulness of the product, the aromatic halide is preferably a chlorinated aromatic hydrocarbon, more preferably dichlorobenzene such as p-dichlorobenzene. In this case, dichlorobenzene, which is an industrially useful aromatic halide, can be obtained in high yield.

As the halogen serving as a raw material for the aromatic halide, it is more preferable to use chlorine gas, and if necessary, other halogens such as fluorine, bromine, iodine, etc. may be used. It is preferable to use a chlorine compound as the inorganic halide that serves as a raw material for the aromatic halide. Furthermore, when using chlorine gas in the halogenation reaction, an inert gas such as nitrogen that does not participate in the reaction may be included.

The metal-containing catalyst is preferably a Lewis acid catalyst, and the Lewis acid catalyst is preferably a metal chloride. As the metal chloride, antimony chloride and ferric chloride are preferable, and among them, ferric chloride is more preferable. It is also possible to add a co-catalyst in addition to the metal-containing catalyst, and for example, disulfur dichloride is preferably used. By using a metal-containing catalyst containing an iron compound, aromatic halides can be efficiently synthesized. Further, as the halide contained in the exhaust gas of the combustion furnace, hydrogen halide is preferable, and hydrogen chloride is more preferable.

There are no particular restrictions on the method for synthesizing aromatic halides in the reaction device 4, but for example, an aromatic compound as a raw material, at least one of an inorganic halide and a halogen, and a metal-containing catalyst are fed into the reaction device 4. An example is a method in which the product is charged, heated at a predetermined temperature and pressure, and reacted for a predetermined time, and then the product is extracted. As a method for synthesizing the above-mentioned aromatic halides, for example, a batch method, a semi-batch method, or a continuous method may be used. The compound or intermediate product may be returned to the manufacturing process as a raw material. Further, when the aromatic halide contains a plurality of halogens, a method may be used in which the manufacturing process is divided into a plurality of steps and the number of halogens bonded to the aromatic compound is sequentially increased.

The aromatic halide produced in the reaction device 4 is introduced into the distillation device 6, and the produced aromatic halide is subjected to a distillation process for separating high-boiling compounds including metal-containing catalysts. The operating conditions for the distillation process are not particularly limited as long as they can separate aromatic halides and high-boiling compounds containing metal-containing catalysts. Distillation is carried out at a predetermined temperature, pressure, reflux ratio, and residence time, and the mixture containing aromatic halides as the main component is extracted from the upper part of the distillation column. One example is a method in which a mixture containing boiling point impurities (hereinafter referred to as "high boiling point residue") is extracted. Furthermore, if there are a plurality of produced aromatic halides, a method may be used in which a plurality of distillation steps are prepared and separation is performed under distillation conditions suitable for separating each aromatic halide. Alternatively, a plurality of generated high boiling point residues may be mixed and supplied to a step of contacting with an extraction agent.

The aromatic halide from which high-boiling point compounds have been separated may be subjected to purification treatments such as distillation, crystallization, washing, adsorption, extraction, centrifugation, drying, and ion exchange in order to further remove impurities. Further, impurities generated by these purification treatments and high boiling point residues may be mixed. The distillation residue liquid 8 contains a high-boiling point residue, and may contain an aromatic compound, an aromatic halide, a high-boiling point compound produced as a by-product in the manufacturing process, a metal-containing catalyst, and the like. The catalyst, high melting point compound, etc. contained in the distillation residue liquid 8 may be solid, but it is preferable that it has fluidity in order to be used for extraction processing, and a liquid may be added to improve fluidity. . As the liquid added to improve fluidity, it is preferable to use a substance that does not phase separate from the distillation residue liquid, and it is more preferable to use impurities such as high-boiling point residues generated in the purification process.

The distillation residue liquid 8 sent from the distillation apparatus 6 and the extraction agent 10 that undergoes phase separation from the distillation residue liquid 8 are introduced into a mixing apparatus 12 and mixed. The extraction agent 10 needs to be a liquid that undergoes phase separation from the distillation residue liquid 8 in order to extract the metal compound derived from the metal-containing catalyst contained in the distillation residue liquid 8. Since the distillation residue liquid 8 contains an aromatic compound or/and an aromatic halide, the extraction agent 10 is preferably a hydrophilic liquid, and more preferably contains 90% by weight or more of water. It is particularly preferred to use When the extraction agent 10 contains water in an amount equal to or more than the lower limit value, the extraction agent can sufficiently extract the metal compound derived from the metal-containing catalyst contained in the distillation residue liquid.

The solubility of the metal compound in the extraction agent is preferably 1 g/100g of extraction agent or more, more preferably 10g/100g of extraction agent or more. When the solubility of the metal compound in the extraction agent 10 is equal to or higher than the above lower limit, the extraction agent can more efficiently extract the metal compound contained in the distillation residue liquid. For example, when the metal compound derived from the metal-containing catalyst is ferric chloride and water is used as the extractant, the solubility of ferric chloride in the extractant is 92 g/100 g of extractant. The proportion of iron compounds extracted from the distillation residue liquid 8 into the extraction agent 10 may be 80% by weight or more. In this case, iron compounds can be extracted to the extraction agent side, and 80% by weight or more of the iron compounds contained in the distillation residue liquid 8 can be recovered.

The pH of the extraction agent 10 is preferably in the range of 5 to 9. When the pH of the extraction agent 10 is equal to or higher than the above lower limit, the solubility of the metal compound in the extraction agent 10 can be made sufficient. Further, since the pH of the extraction agent 10 is below the above upper limit value, the extraction agent and the distillation residue liquid 8 are sufficiently phase-separated.

The temperature of the liquid mixture is preferably in the range of 20 to 50°C, more preferably in the range of 20 to 35°C. When the temperature of the liquid mixture is equal to or higher than the above lower limit, solidification of the aromatic halide contained in the liquid mixture can be suppressed, and it is possible to suppress the metal compound from being incorporated into the solid. When the temperature of the liquid mixture is below the above-mentioned upper limit, the solubility of the metal compound in the distillation residue liquid 8 can be made low, and the amount of the metal compound extracted by the extraction agent 10 can be increased. Furthermore, before mixing the distillation residue liquid 8 and the extraction agent 10, it is preferable to adjust the temperature of at least one of the liquids using a temperature adjusting means before mixing. The temperature adjusting means is not particularly limited as long as it is capable of cooling or heating, and for example, a double pipe heat exchanger can be used.

For example, if the distillation residue liquid 8 at a high temperature (for example, 100°C or higher) and the extraction agent 10 are mixed, the extraction agent 10 may vaporize, and the extraction agent 10 and the distillation residue liquid 8 at a temperature lower than 20°C may be mixed. If they are mixed, there is a risk that the aromatic halide contained in the distillation residue liquid 8 will solidify. Therefore, the temperature of the distillation residue liquid 8 during mixing may be, for example, less than 100°C, and is preferably adjusted to 40 to 60°C. Further, the temperature of the extraction agent 10 during mixing may be, for example, 20°C or higher, preferably adjusted to 25 to 40°C. In addition, it is more preferable to mix after adjusting both the temperature of the distillation residue liquid 8 and the temperature of the extraction agent 10 within the said range. Thereby, vaporization of the extraction agent 10 and solidification of the aromatic halide can be more reliably prevented.

The method of mixing the distillation residue liquid 8 and the extraction agent 10 is not particularly limited, and may be, for example, a batch method, a semi-batch method, or a continuous method. A specific method for batchwise mixing includes, for example, a method in which the distillation residue liquid 8 and the extractant 10 are placed in a predetermined container and stirred for a predetermined period of time. Further, as a specific method of mixing in a continuous manner, the distillation residue liquid 8 and the extractant 10 are continuously introduced into the mixing device 12, and after staying and contacting for a predetermined period of time, the obtained mixed liquid is One example is a method of continuously extracting.

The mixing device 12 is not particularly limited, but if the mixing method is a batch method or a semi-batch method, it is preferable to use a container or tank capable of stirring the distillation residue liquid 8 and the extraction agent 10. When such a container or tank is used, the distillation residue liquid 8 and the extraction agent 10 can be sufficiently mixed. When the mixing method is continuous, it is preferable to use a container or tank capable of stirring the distillation residue liquid 8 and the extractant 10, and it is more preferable to use a line mixer (static mixer). When a line mixer is used as the mixing device 12, the space occupied by the mixing device 12 can be reduced, and the energy consumed by the mixing device 12 can be reduced. As the line mixer, for example, a static mixer T series (manufactured by Noritake Company) can be suitably used.

When a line mixer is used as a device for mixing the distillation residue liquid 8 and the extraction agent 10, the linear velocity of the mixed liquid (calculated from the flow rate of the supply liquid/the reference cross-sectional area of the inner diameter of the line mixer) must be 30 to 200 cm/s. is preferable, and more preferably 50 to 150 cm/s. When the linear velocity is equal to or higher than the above lower limit, the droplet size of the extraction residue liquid is made finer, liquid-liquid dispersion becomes sufficient, and the ratio of metal compounds extracted to the extraction agent side can be increased. . By keeping the line speed below the above upper limit, it is possible to reduce pressure loss in the elements within the line mixer, increasing economic efficiency, and also reducing the risk of equipment damage due to excessive load. can.

When using a container or a tank capable of stirring the distillation residue liquid 8 and the extraction agent 10 as the mixing device 12, or when using a line mixer, the weight of the extraction agent 10 is at least 3 times the weight of the distillation residue liquid 8. It is preferable that there be. In this case, the metal compound can be sufficiently extracted by the extractant 10.

Subsequently, the mixed liquid obtained in the mixing device 12 is introduced into the separation device 14, where it is separated into an extraction residue liquid (oil layer 20) and a post-extraction extractant (aqueous layer 16). Although there are no particular limitations on the separation method, it is preferable to use a separation method that utilizes the difference in specific gravity between the extraction residue liquid and the post-extraction extractant, for example. In this case, the extraction residue liquid and the post-extraction extractant can be easily separated. Examples of the separation method using the difference in specific gravity between the extraction residue liquid and the post-extraction extractant include centrifugation, static separation, and the like. A specific method for separating the extraction residue liquid and post-extraction extractant using the difference in specific gravity is to introduce the mixed liquid into a device for separating the extraction residue liquid and post-extraction extractant, and to If it is a batch type or a continuous type, it is more preferable to perform gravity separation into a hydrophilic post-extraction extractant and a lipophilic extraction residue liquid by static separation (predetermined residence time) and phase separation.

In the combustion furnace 22, exhaust gas is generated by combustion treatment of the residual liquid after contact with the extraction agent, combustion heat is recovered from the obtained exhaust gas in the heat recovery device 24, and halides 28 are recovered in the halide recovery device 26. becomes possible. The temperature of the combustion furnace is preferably set to a temperature that can prevent incomplete combustion of the waste liquid, and is preferably in the range of 1000 to 1450°C, for example, and more preferably in the range of 1000 to 1200°C. In order to supply oxygen necessary for combustion, the residual liquid after contact with the extraction agent and air may be mixed in advance and then supplied to the combustion furnace 22.

Next, an embodiment of the aromatic halide manufacturing equipment shown in FIG. 1 will be described in detail with reference to FIG. 2. The aromatic halide manufacturing equipment 30 of this embodiment includes a reaction device 36 for synthesizing aromatic halides, a distillation device 42 for distilling aromatic halides, and a heat exchanger 48 for keeping the distillation residue liquid at an appropriate temperature. , a mixing device 56 that mixes the distillation residue liquid and an extraction agent to obtain a mixed liquid, and a separation device 58 that separates the mixed liquid into an extraction residue and an extraction agent after extraction. The reaction device 36, distillation device 42, mixing device 56, and separation device 58 in FIG. 2 correspond to the reaction device 4, distillation device 6, mixing device 12, and separation device 14 in FIG. 1, respectively.

Benzene is introduced into the reactor 36 from a benzene supply source 31 , chlorine gas is introduced from a chlorine supply source 32 , and a metal-containing catalyst as a catalyst is introduced from a catalyst supply source 34 . The reactor 36 is equipped with a stirrer 38, which stirs the contents introduced into the reactor 36. In the reaction device 36, the catalytic activity of the metal-containing catalyst causes benzene to react with chlorine gas to produce an aromatic halide.

The reactor 36 has a tank-like shape, and the size of the reactor 36 is not particularly limited, and may be set to an appropriate size in order to obtain a desired amount of aromatic halide. The wall surface of the reactor 36 is made of a material that is not corroded by halogens such as chlorine. The shape and operation mode of the stirrer 38 are not particularly limited as long as they enhance the reaction efficiency of the aromatic halide, and may be any shape that can sufficiently and continuously mix the entire contents of the reaction device 36. good.

The number of reaction devices 36 included in the aromatic halide production facility 30 may be one, or two or more. When the desired aromatic halide contains multiple types of halogen atoms, different types of halogens and halides are sequentially reacted with the aromatic compound in multiple reaction apparatuses 36 provided in the aromatic halide production facility 30. You may let them.

A mixture containing an aromatic halide and a metal-containing catalyst is discharged from the reactor 36 and introduced by means of a pump 40 into a distillation device 42 . The distillation device 42 is equipped with an aromatic halide recovery tube 44 at the upper end, the introduced mixture is heated, and the vaporized aromatic halide is recovered from the aromatic halide recovery tube 44 . The number of distillation devices 42 included in the aromatic halide production facility 30 may be one, or two or more. When there are multiple types of desired aromatic halides, each aromatic halide may be purified in multiple distillation apparatuses 42.

The gas recovered from the aromatic halide recovery pipe 44 contains, in addition to the aromatic halide, benzene as a raw material, hydrogen chloride produced by the reaction, intermediate products, and the like. The aromatic halide production facility 30 may include a purification device (not shown) that purifies the aromatic halide from the gas recovered from the aromatic halide recovery pipe 44, and the aromatic halide is separated in the purification device. In addition, the raw materials and intermediate products may be returned to the reaction device 36.

In the distillation device 42, the heating temperature of the introduced mixture is preferably set to a temperature at which the aromatic halide does not decompose, and may be set in consideration of the physicochemical properties of the desired aromatic halide. The high-boiling compound containing the metal-containing catalyst remains at the bottom of the distillation device 42 without being vaporized and becomes a distillation residue liquid, and the distillation residue liquid is passed by a pump 46 to a heat exchanger 48 and cooled.

The extraction agent is supplied from an extraction agent supply pipe 54, passes through a heat exchanger 49, and is heated to a temperature at which the aromatic halide does not solidify. The distillation residue liquid kept at an appropriate temperature joins with the extractant supplied from the extraction agent supply pipe 54 and is introduced into the mixing device 56. In the mixing device 56, the distillation residue liquid and the extractant are well mixed. , resulting in a mixed solution. The extraction agent undergoes phase separation from the distillation residue liquid, and when the distillation residue liquid and extraction agent are well mixed, metal compounds derived from metal-containing catalysts contained in the distillation residue liquid are extracted to the extraction agent side. be done. The mixing device 56 may be of a batch type, semi-batch type, or continuous type. When the mixing device 56 is of a batch type or a semi-batch type, the mixing device 56 may be a tank capable of stirring the mixed liquid. When the mixing device 56 is continuous, the mixing device 56 may be a line mixer. The mixing device 56 may include a heater for keeping the aromatic halide at a temperature at which it does not solidify.

The liquid mixture mixed in the mixing device 56 is introduced into the separation device 58 through a liquid mixture supply pipe 60, and in the separation device 58, the liquid mixture is separated into an extraction residue liquid and an extractant after extraction. At this time, the metal compound derived from the metal-containing catalyst is extracted into the extractant after extraction. In the separation device 58, the mixed liquid is separated by utilizing the difference in specific gravity between the extraction residue liquid and the post-extraction extractant. The separation method may be, for example, centrifugation or static separation. When the separation method is centrifugation, the separation device 58 may be a device capable of centrifugation. When the separation method is static separation, the separation device 58 may be a tank that stores the mixed liquid. The separation device 58 may include a heater for keeping the aromatic halide at a temperature at which it does not solidify.

The post-extraction extractant separated from the mixed liquid is introduced into a storage tank 67 through a transport pipe 66 and then discharged through a discharge pipe 72 by a pump 70.

The extraction residue liquid separated from the mixed liquid is discharged through the extraction residue collection pipe 62 and introduced into the extraction residue storage tank 74. The extraction residue liquid stored in the extraction residue storage tank 74 is introduced into the combustion furnace through an extraction residue transport pipe 78 by a pump 76.

The extraction residue liquid introduced into the combustion furnace is subjected to combustion treatment, and, for example, combustible raw material such as benzene is burned. The extraction residue liquid may be mixed with air beforehand to provide the oxygen necessary for combustion. The exhaust gas after combustion is introduced into a heat recovery device, and the heat generated by combustion is recovered. Water may be recovered as pressurized steam using a heat recovery device that includes a shell-and-tube heat exchanger. The exhaust gas after heat recovery is introduced into a halide recovery device, and the halides are recovered.

Examples of the present invention will be given below to demonstrate the effects of the present invention. The present invention is not limited to the following examples.

In the aromatic halide production facility shown in Figure 2, paradichlorobenzene is produced by reacting benzene and chlorine using ferric chloride as a catalyst, and paradichlorobenzene is purified in a distillation device, and the catalyst-derived A high-boiling distillation residue liquid (hereinafter referred to as "residue") containing iron was obtained. The residue contained 5.73% by weight ferric chloride (1.98% iron).
The iron content in the residue and extractant was analyzed using the following method.
To remove organic matter in the residue and extractant, 1 g of the sample was accurately weighed in a platinum dish (inner diameter 50 mm, depth 25 mm), 15 mL of concentrated nitric acid (98% by weight, manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the sample was placed on an electric heater. The sample was carbonized by heating to dryness, and then heated to ash in an electric furnace (FP310 manufactured by Yamato Scientific Co., Ltd.) heated to 800° C. for 1 hour. After cooling the ashed platinum dish in a desiccator, 15 mL of hydrochloric acid (35-37% by weight, manufactured by Wako Pure Chemical Industries, Ltd.) diluted to 6N with ion-exchanged water was added, and the ash was heated and dissolved on an electric heater. After that, the ash solution was transferred to a volumetric flask and diluted with 1N hydrochloric acid to prepare a stock solution for measurement.
The iron content of this stock solution was measured using a flame-type atomic absorption spectrophotometer (manufactured by Agilent Technologies: 240FS AA) using a light source with a wavelength of 248.3 nm. The stock solution for measurement was appropriately diluted with 1N hydrochloric acid before measurement so that the iron concentration was within the calibration range (0.1 to 5 ppm).

(Example 1)
Put 20 g of residue, 10 g of extractant (ion-exchanged water), and a stirrer (made of PTFE resin: length 10 mm) into a vial (50 ml), and stir with a stirrer (manufactured by Nisshin Rika: SW-RS077D) at an outside temperature of 25°C. ) for 30 minutes at a rotation speed of 900 rpm. After stirring, leave to stand still for 5 minutes to allow phase separation, and collect the upper extractant layer (hereinafter referred to as "aqueous layer") and the lower layer extraction residue (hereinafter referred to as "oil layer"). The iron content (hereinafter referred to as "iron content") was measured. As a result, the iron content in the aqueous layer was 0.14 g, and the iron content in the residue was 0.40 g. The iron content (hereinafter referred to as "iron removal rate") was 35.6%. The pH of the aqueous layer was measured and found to be 1.06.

(Example 2)
Stirring, phase separation, and iron content measurement were performed under the same conditions as in Example 1, except that 0.5 g of an aqueous sodium hydroxide solution (25% by weight, manufactured by Kanto Kagaku) was further added to the vial. As a result, the iron content in the water layer was 0.11 g, the iron content in the residue was 0.40 g, and the iron content removal rate was 27.3%. Moreover, the pH of the aqueous layer was 1.46.

(Example 3)
Stirring, phase separation, and iron content measurement were carried out under the same conditions as in Example 1, except that 1.0 g of an aqueous sodium hydroxide solution (25% by weight) was further added to the vial. As a result, the iron content in the water layer was 0.10 g, the iron content in the residue was 0.40 g, and the iron content removal rate was 26.1%. Moreover, the pH of the aqueous layer was 1.83.

(Comparative example 1)
Stirring was carried out under the same conditions as in Example 1, except that 3.0 g of an aqueous sodium hydroxide solution (25% by weight) was further added to the vial. After stirring, the mixture was allowed to stand for 5 minutes, but the residue and extractant were not separated.

(Example 4)
Stirring, phase separation, and iron content measurement were carried out under the same conditions as in Example 1, except that the capacity of the vial was 300 ml and the extractant (ion-exchanged water) added was 200 g. As a result, the iron content in the water layer was 0.40 g, the iron content in the residue was 0.40 g, and the iron content removal rate was 100%. Moreover, the pH of the aqueous layer was 1.92.

(Example 5)
Stirring, phase separation, and iron content measurement were carried out under the same conditions as in Example 1, except that 30 g of the residue and 15 g of the extraction agent (ion-exchanged water) were placed in the vial. As a result, the iron content in the water layer was 0.19 g, the iron content in the residue was 0.60 g, and the iron content removal rate was 32.8%. Moreover, the pH of the aqueous layer was 1.02.
Stirring, phase separation, and iron content measurement were performed under the same conditions as Example 1, except that the oil layer after phase separation was collected, and 25 g of the collected oil layer and 12.5 g of extractant (ion-exchanged water) were placed in a vial. did. As a result, the iron content in the aqueous layer was 0.10 g, the iron content in the recovered oil layer put into the vial was 0.28 g, and the iron content removal rate was 35.2%. Moreover, the pH of the aqueous layer was 1.24.
The oil layer after phase separation was collected again, and stirring, phase separation, and iron content measurement were carried out under the same conditions as in Example 1, except that 20 g of the collected oil layer and 10 g of extractant (ion-exchanged water) were placed in a vial. . As a result, the iron content in the aqueous layer was 0.06 g, the iron content in the recovered oil layer put into the vial was 0.09 g, and the iron content removal rate was 38.6%. Moreover, the pH of the aqueous layer was 1.46.

(Example 6)
Stirring, phase separation, and iron content measurement were carried out under the same conditions as in Example 1, except that the capacity of the vial was 300 ml and the extractant (ion-exchanged water) added was 100 g. As a result, the iron content in the water layer was 0.40 g, the iron content in the residue was 0.39 g, and the iron content removal rate was 98.3%. Moreover, the pH of the aqueous layer was 1.76.

(Example 7)
Stirring, phase separation, and iron content measurement were carried out under the same conditions as in Example 1, except that the capacity of the vial was 100 ml and the extractant (ion-exchanged water) added was 40 g. As a result, the iron content in the water layer was 0.40 g, the iron content in the residue was 0.29 g, and the iron content removal rate was 72.6%. Moreover, the pH of the aqueous layer was 1.39.

(Example 8)
Stirring, phase separation, and iron content measurement were carried out under the same conditions as in Example 1, except that the extracting agent added was 10 g of hydrochloric acid (35-37% by weight). As a result, the iron content in the water layer was 0.06 g, the iron content in the residue was 0.40 g, and the iron content removal rate was 14.0%. Moreover, the pH of the aqueous layer was less than 0.

(Example 9)
Stirring, phase separation, and iron content measurement were carried out under the same conditions as in Example 1, except that the stirring time was 1 minute. As a result, the iron content in the water layer was 0.11 g, the iron content in the residue was 0.40 g, and the iron content removal rate was 27.8%. Moreover, the pH of the aqueous layer was 1.07.

(Example 10)
Stirring, phase separation, and iron content measurement were carried out under the same conditions as in Example 1, except that the capacity of the vial was 100 ml, and the extractant to be added was a mixture of 30 g of ion-exchanged water and 0.5 g of hydrochloric acid (6N). did. As a result, the iron content in the water layer was 0.22 g, the iron content in the residue was 0.40 g, and the iron content removal rate was 56.0%. Moreover, the pH of the aqueous layer was 1.11.

(Example 11)
The conditions were the same as in Example 1, except that using a constant temperature bath with a stirrer (manufactured by Yamato Scientific: MD-81), the temperature of the circulating water was set at 40°C, and the extraction was carried out by pouring it into the constant temperature bath during stirring. Stirring, phase separation, and iron content measurements were performed. As a result, the iron content in the water layer was 0.10 g, the iron content in the residue was 0.40 g, and the iron content removal rate was 25.8%. Moreover, the pH of the aqueous layer was 1.07.

(Example 12)
Stirring, phase separation, and iron content measurement were performed under the same conditions as in Example 11, except that the temperature of the circulating water was 80°C. As a result, the iron content in the water layer was 0.62 g, the iron content in the residue was 0.40 g, and the iron content removal rate was 15.7%. Moreover, the pH of the aqueous layer was 1.11.

(Example 13)
Stirring, phase separation, and iron content measurement were performed under the same conditions as in Example 1, except that the capacity of the vial was 300 ml, the extractant (ion-exchanged water) to be added was 100 g, and the stirring time was 1 minute. As a result, the iron content in the water layer was 0.34 g, the iron content in the residue was 0.40 g, and the iron content removal rate was 86.6%. Moreover, the pH of the aqueous layer was 1.82.

(Example 14)
Stirring, phase separation, and iron content measurement were carried out under the same conditions as in Example 1 except that the outside temperature was 20°C. As a result, the iron content in the water layer was 0.10 g, the iron content in the residue was 0.40 g, and the iron content removal rate was 24.1%. Moreover, the pH of the aqueous layer was 1.30. Note that solid matter precipitation was observed on the oil layer side during stirring and stationary separation.

(Example 15)
Residue supply line/extractant supply line created using a pump (Yamato Scientific: EASY-LOAD 7518-10) and fluoroelastomer tubes by attaching PTFE tubes to two locations of a 3-way joint (manufactured by Swagelok). and a PTFE tube, and a static mixer (manufactured by Noritake Company: T4-12-D, inner diameter 2.5 mm, length 100 mm) was connected to the rest of the three-way joint. From the residue supply line, the residue heated to 70°C in a water bath was passed at a rate of 2.4L/h, and from the extractant supply line, ion-exchanged water at room temperature (25°C) was passed at a rate of 13.6L/h. , and mixed with a static mixer. The linear velocity of the liquid passing through the static mixer was 23 cm/sec. After 5 seconds have elapsed since the liquid was passed, collect about 500 to 1000 ml of the mixed liquid from the static mixer into a 1 L graduated cylinder, leave it to stand for 5 minutes to allow phase separation, collect the water layer and oil layer, and remove the residue. The iron content was also measured. As a result, the iron content of the aqueous layer was 1.06 g, the iron content of the residue calculated from the amount of liquid passed was 1.41 g, and the iron content removal rate was 86.6%.

(Example 16)
Mixing, phase separation, and iron content measurement were carried out under the same conditions as in Example 15, except that the flow rate of the residue was 4.6 L/h and the flow rate of ion-exchanged water was 21.4 L/h. The linear velocity of the liquid passing through the static mixer was 37 cm/sec. The iron content of the aqueous layer was 1.79 g, the iron content of the residue calculated from the amount of liquid passed was 1.81 g, and the iron content removal rate was 99.0%.

(Example 17)
Mixing, phase separation, and iron content measurement were carried out under the same conditions as in Example 15, except that the flow rate of the residue was 12.2 L/h and the flow rate of ion-exchanged water was 27.8 L/h. The linear velocity of the liquid passing through the static mixer was 57 cm/sec. The iron content of the aqueous layer was 2.61 g, the iron content of the residue calculated from the amount of liquid passed was 3.21 g, and the iron content removal rate was 81.1%.

(Example 18)
Mixing, phase separation, and iron content measurement were carried out under the same conditions as in Example 15, except that the flow rate of the residue was 6.3 L/h and the flow rate of ion-exchanged water was 33.7 L/h. The linear velocity of the liquid passing through the static mixer was 57 cm/sec. The iron content of the aqueous layer was 1.49 g, the iron content of the residue calculated from the amount of liquid passed was 1.61 g, and the iron content removal rate was 92.7%.

(Example 19)
Mixing, phase separation, and iron content measurement were carried out under the same conditions as in Example 15, except that the amount of the residue was 14.6 L/h, and the amount of ion-exchanged water was 50.4 L/h. The linear velocity of the liquid passing through the static mixer was 92 cm/sec. The iron content of the aqueous layer was 3.00 g, the iron content of the residue calculated from the amount of liquid passed was 3.00 g, and the iron content removal rate was 100%.
In addition, when approximately 10 g of the oil layer after separation was placed in a platinum dish (inner diameter 50 mm, depth 25 mm) and heated to dryness on an electric heater, the gas generated contained ammonia water (28-30% by weight, manufactured by Kanto Kagaku). ), it was confirmed that white smoke of ammonium chloride was generated when the tank was brought close to the tank, so it is thought that it is possible to recover hydrogen chloride by heating the oil layer. In addition, during pretreatment for iron content measurement, iron from the catalyst remained in the platinum plate as a solid in the residue, but no residue could be visually confirmed in the oil layer, and the iron content was 0%. Therefore, it is thought that when heat is recovered from the oil layer after iron extraction by combustion and heat exchange, almost no blockages that would clog the heat exchanger will be deposited.

According to the present invention, a method for producing an aromatic halide can remove metal components derived from a catalyst from a distillation residue liquid of an aromatic halide, and can reduce the energy consumption of the aromatic halide. and manufacturing equipment.

1... Aromatic hydrocarbon, 2... Halogen/halide, 3... Metal-containing catalyst, 4... Reaction device, 6... Distillation device, 8... Distillation residue liquid, 10... Extracting agent, 12... Mixing device, 14... Separation device , 16... Post extraction extractant (aqueous layer), 18... Aromatic halide, 20... Extraction residue liquid (oil layer), 22... Combustion furnace, 24... Heat recovery device, 26... Halide recovery device, 28... Halide , 30... Aromatic halide production equipment, 31... Benzene supply source, 32... Chlorine supply source, 34... Catalyst supply source, 36... Reactor, 38... Stirrer, 40... Pump, 42... Distillation device, 44... Aromatic halide recovery pipe, 46... Pump, 48, 49... Heat exchanger, 54... Extraction agent supply pipe, 56... Mixing device, 58... Separation device, 60... Mixed liquid supply pipe, 62... Extraction residue recovery pipe, 66... Transport pipe, 67... Storage tank, 70... Pump, 72... Discharge pipe, 74... Extraction residue storage tank, 76... Pump, 78... Extraction residue transport pipe

Claims (21)

a step (a) of producing an aromatic halide from an aromatic compound and at least one of an inorganic halide and a halogen using a metal-containing catalyst;
A mixture is obtained by mixing the distillation residue after distilling the aromatic halide and an extraction agent that undergoes phase separation with the distillation residue, and in the mixture, the metal contained in the distillation residue is removed. a step (b) of extracting the metal compound derived from the catalyst contained into the extractant side to obtain an extraction residue liquid;
(c) burning the extraction residue liquid in a combustion furnace to generate exhaust gas containing halides;
(d) recovering the halide from the exhaust gas ,
A method for producing an aromatic halide, characterized in that the pH of the extraction agent is in the range of 5 to 9 . The method for producing an aromatic halide according to claim 1, further comprising the step of recovering heat by passing the exhaust gas through a heat exchanger. 3. The method for producing an aromatic halide according to claim 1, wherein the aromatic compound is benzene and chlorine is used as the halogen. 4. The method for producing an aromatic halide according to claim 3, wherein the aromatic halide is dichlorobenzene. The method for producing an aromatic halide according to any one of claims 1 to 4, wherein the metal-containing catalyst contains an iron compound, and the metal compound contains an iron compound. 6. The method for producing an aromatic halide according to claim 5, wherein in the step (b), a proportion of the iron compound extracted from the distillation residue into the extractant is 80% by weight or more. The method for producing an aromatic halide according to any one of claims 1 to 6, wherein the extraction agent contains 90% by weight or more of water. The method for producing an aromatic halide according to any one of claims 1 to 7, wherein the solubility of the metal compound in the extraction agent is 1 g/100 g of extraction agent or more. According to any one of claims 1 to 8 , the step (b) includes a step of separating the mixed liquid into the extraction residue liquid and the post-extraction extractant using a difference in specific gravity. A method for producing an aromatic halide. The method for producing an aromatic halide according to any one of claims 1 to 9 , characterized in that the temperature of the liquid mixture is in the range of 20 to 50°C. The method for producing an aromatic halide according to any one of claims 1 to 10 , wherein the distillation residue liquid and the extraction agent are mixed using a line mixer. The method for producing an aromatic halide according to claim 11 , wherein the weight of the extracting agent contained in the mixed liquid passed through the line mixer is three times or more that of the distillation residue liquid. . The method for producing an aromatic halide according to claim 11 or 12 , wherein the linear velocity of the mixed liquid in the line mixer is 30 to 200 cm/s. The method for producing an aromatic halide according to any one of claims 1 to 10 , characterized in that the distillation residue liquid and the extractant are mixed inside a stirring tank. 15. The method for producing an aromatic halide according to claim 14 , wherein the weight of the extraction agent supplied to the stirring tank is three times or more the weight of the distillation residue liquid. A reaction device for producing an aromatic halide from an aromatic compound and at least one of an inorganic halide and a halogen using a metal-containing catalyst;
a distillation device that distills the liquid containing the aromatic halide produced in the reaction device;
A mixing device that mixes the distillation residue liquid of the distillation apparatus and an extractant that undergoes phase separation with the distillation residue liquid, and extracts metal compounds derived from the metal-containing catalyst contained in the distillation residue liquid to the extraction agent side. and,
a separation device that separates the mixed liquid mixed by the mixing device into an extraction residue liquid and a post-extraction extractant;
a combustion furnace that burns the extraction residue liquid separated by the separation device;
A halide recovery device that recovers halides from the halide-containing exhaust gas generated in the combustion furnace ,
A manufacturing facility for aromatic halides, characterized in that the pH of the extractant is in the range of 5 to 9 . 17. The aromatic halide production facility according to claim 16 , further comprising a heat recovery device that recovers heat from the exhaust gas. The aromatic halide according to claim 16 or 17 , wherein the separation device is a device that uses a difference in specific gravity to separate the mixed liquid into the extraction residue liquid and the post-extraction extractant. manufacturing equipment. The aromatic halide manufacturing equipment according to any one of claims 16 to 18 , characterized in that the temperature of at least one of the distillation residue liquid and the extractant supplied to the mixing device is adjusted. The aromatic halide manufacturing equipment according to any one of claims 16 to 19 , wherein the mixing device is a line mixer. The aromatic halide manufacturing equipment according to any one of claims 16 to 19 , wherein the mixing device is a stirring tank.

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