阅读说明：本技术 一种环氧环己烷的连续生产装置及方法 (Continuous production device and method of epoxy cyclohexane ) 是由 冷炳文 邵晶晶 魏小林 张小明 于 2021-10-08 设计创作，主要内容包括：本发明提供一种环氧环己烷的连续生产装置及方法,装置包括：环己烯分离塔、环己烯精制塔、产品塔和至少两级反应粗分离装置,反应粗分离装置包括环氧化反应器和油水分离器；环氧化反应器的出料口与油水分离器的进料口连接,油水分离器的油相出口与环己烯分离塔的进料口连接；油水分离器的水相出口与后一级环氧化反应器的进料口连接,环己烯分离塔的塔顶出料口与环己烯精制塔的进料口连接,环己烯精制塔的塔釜出料口与环氧化反应器的进料口连接,环己烯分离塔的塔釜出料口与产品塔的进料口连接,产品塔的塔釜出料口与环氧化反应器的进料口连接。本发明实现了催化剂的回收并稳定连续生产环氧环己烷,环氧环己烷收率高,物耗及能耗较低。(The invention provides a continuous production device and a method of epoxy cyclohexane, wherein the device comprises: the device comprises a cyclohexene separating tower, a cyclohexene refining tower, a product tower and at least two stages of reaction crude separation devices, wherein each reaction crude separation device comprises an epoxidation reactor and an oil-water separator; a discharge hole of the epoxidation reactor is connected with a feed inlet of an oil-water separator, and an oil phase outlet of the oil-water separator is connected with a feed inlet of the cyclohexene separation tower; the water phase outlet of the oil-water separator is connected with the feed inlet of the next-stage epoxidation reactor, the discharge outlet of the top of the cyclohexene separating tower is connected with the feed inlet of the cyclohexene refining tower, the discharge outlet of the tower kettle of the cyclohexene refining tower is connected with the feed inlet of the epoxidation reactor, the discharge outlet of the tower kettle of the cyclohexene separating tower is connected with the feed inlet of the product tower, and the discharge outlet of the tower kettle of the product tower is connected with the feed inlet of the epoxidation reactor. The invention realizes the recovery of the catalyst and the stable and continuous production of the cyclohexene oxide, and has high yield of the cyclohexene oxide and lower material consumption and energy consumption.)

1. A continuous production device of cyclohexene oxide, which is characterized by comprising:

the device comprises a cyclohexene separation tower, a cyclohexene refining tower, a product tower and at least two stages of reaction crude separation devices, wherein each stage of reaction crude separation device comprises an epoxidation reactor and an oil-water separator;

in each stage of the reaction crude separation device, a discharge hole of the epoxidation reactor is connected with a feed inlet of the oil-water separator, and an oil phase outlet of the oil-water separator is connected with a feed inlet of the cyclohexene separation tower; former one-level the crude separator of reaction the water phase export of oil water separator and back one-level the crude separator of reaction the feed inlet of epoxidation reactor is connected, the top of the tower discharge gate of cyclohexene knockout tower with the feed inlet of cyclohexene refining tower is connected, the cauldron discharge gate and the at least one-level of cyclohexene refining tower the crude separator of reaction the feed inlet of epoxidation reactor is connected, the cauldron discharge gate of cyclohexene knockout tower with the feed inlet of product tower is connected, the cauldron discharge gate and the at least one-level of product tower the crude separator of reaction the feed inlet of epoxidation reactor is connected.

2. The apparatus for continuously producing cyclohexene oxide according to claim 1, further comprising:

a catalyst extraction column;

the water phase outlet of the oil-water separator of the last-stage reaction coarse separation device is connected with the feed inlet of the catalyst extraction tower, the oil phase outlet of the catalyst extraction tower is connected with the feed inlet of the cyclohexene separation tower, the discharge hole at the middle upper part of the cyclohexene separation tower is connected with the extractant feed inlet of the catalyst extraction tower, and the discharge hole at the top of the cyclohexene separation tower is connected with the extractant feed inlet at the bottom of the catalyst extraction tower.

3. The apparatus for continuously producing cyclohexene oxide according to claim 1, further comprising:

a catalyst regeneration device;

the discharge port of the tower bottom of the product tower is also connected with the feed port of the catalyst regeneration device, and the discharge port of the catalyst regeneration device is connected with the feed port of the epoxidation reactor of the at least one-stage reaction crude separation device.

4. The apparatus for continuously producing cyclohexene oxide according to claim 3, wherein:

a discharge hole of a tower kettle of the cyclohexene refining tower is connected with a feed hole of the epoxidation reactor of each stage of the reaction crude separation device; and a discharge port of a tower kettle of the product tower is connected with a feed port of the epoxidation reactor of each stage of the reaction crude separation device.

5. A continuous production method of cyclohexene oxide is characterized by comprising the following steps:

s1, mixing a catalyst, a hydrogen peroxide solution and a cyclohexene raw material, and carrying out at least two-stage epoxidation reaction; performing oil-water separation on the product of each stage of epoxidation reaction, sending the water phase obtained by separation to the next stage of epoxidation reaction as a raw material, and sending the oil phase obtained by separation to a cyclohexene separation tower for separation of cyclohexene and cyclohexene oxide; extracting cyclohexene material from the top of the cyclohexene separation tower, and extracting material containing epoxy cyclohexane and a catalyst from a tower kettle;

s2, sending the cyclohexene material obtained in the step S1 to a cyclohexene refining tower for separation, and sending the purified cyclohexene obtained by separation to at least one stage of epoxidation reaction to serve as a raw material; sending the material containing the cyclohexene oxide and the catalyst in the step S1 to a product tower for separation to obtain a cyclohexene oxide product and a material containing the catalyst and the cyclohexene oxide;

s3, sending the material containing the catalyst and the cyclohexene oxide obtained in the step S2 to at least one stage of epoxidation reaction to be used as a raw material.

6. The continuous process for producing epoxycyclohexane according to claim 5, further comprising:

s4, sending the water phase obtained in the oil-water separation of the product of the last-stage epoxidation reaction in the step S1 to a catalyst extraction tower, taking a material containing 5-30% of cyclohexene oxide and extracted from the cyclohexene separation tower as an extracting agent, and injecting the cyclohexene material extracted from the top of the cyclohexene separation tower at the lower part of the catalyst extraction tower to recover the cyclohexene oxide.

7. The continuous process for producing epoxycyclohexane according to claim 5, further comprising:

s5, feeding a part of the material containing the catalyst and the epoxy cyclohexane, which is extracted from the product tower bottom in the step S2, into a catalyst regeneration device for catalyst regeneration, and feeding the regenerated catalyst to at least one stage of epoxidation reaction for use.

8. The continuous production method of epoxycyclohexane according to claim 7, characterized in that:

in step S5, the catalyst regeneration includes sequentially performing the following steps on the material containing the catalyst and the cyclohexene oxide: extracting, filtering, washing, activating by hydrogen peroxide and drying;

wherein the extracting agent for extraction is one or a mixture of ethanol, ethyl acetate, petroleum ether, dichloromethane and chloroform;

the washing is carried out by adopting an organic solvent and deionized water; the organic solvent is one or a mixture of ethanol, diethyl ether, ethyl acetate, petroleum ether, dichloromethane and chloroform;

the hydrogen peroxide activation is carried out in a water phase, the hydrogen peroxide concentration is 1-50%, and the mass ratio of hydrogen peroxide to the catalyst is (0.5-10): 1;

the drying temperature is 25-100 ℃.

9. The continuous production method of epoxycyclohexane according to claim 5, characterized in that:

in step S1:

the catalyst is a heteropoly acid quaternary ammonium salt catalyst;

the mol ratio of the cyclohexene to the hydrogen peroxide is (1-10): 1;

the adding amount of the catalyst is 0.02-5% of the total mass of the cyclohexene, the hydrogen peroxide solution and the catalyst;

the temperature of the latter stage epoxidation reaction is higher than that of the former stage epoxidation reaction;

the reaction temperature of the first-stage epoxidation reaction is 30-100 ℃;

the residence time of the first-stage epoxidation reaction is 0.5-6 h;

the reaction temperature of the second-stage epoxidation reaction is 35-100 ℃;

the residence time of the second stage epoxidation reaction is 0.5-8 h.

10. The continuous production method of cyclohexene oxide according to claim 6, characterized by:

the number of theoretical plates of the cyclohexene separating tower, the cyclohexene refining tower, the product tower and the catalyst extraction tower is 3-30;

the reflux ratio of the cyclohexene separating tower, the cyclohexene refining tower and the product tower is 1-10, and the pressure is 10-101.325 kPa;

in the catalyst extraction tower, the mass ratio of the cyclohexene material to the material containing 5-30% of cyclohexene oxide is 1: (0.1-10); the mass ratio of the cyclohexene material, the material containing 5% -30% of cyclohexene oxide and the water phase of the catalyst extraction tower is (0.5-20): 1; the extraction temperature is 30-60 ℃.

Technical Field

The invention belongs to the technical field of fine chemical engineering, and particularly relates to a continuous production device and method of epoxy cyclohexane.

Background

The cyclohexene oxide is a fine chemical raw material with active chemical properties, can be used as an intermediate to synthesize various chemical products, is an organic solvent with strong dissolving capacity, has very wide application, and can be used in the fields of medicines, pesticides, solvents, plasticizers, curing agents, flame retardants, diluents, adhesives, surfactants, biodegradable material monomers and the like. Among the most promising applications is the copolymerization of cyclohexene oxide and carbon dioxide to produce polycyclohexene carbonate (PCHC), which is considered a promising alternative to conventional Polystyrene (PS) plastics.

Scholars at home and abroad carry out a great deal of research on the production of cyclohexene oxide, and the industrial advance is to use the epoxidation technology of hydrogen peroxide and cyclohexene, so that the route has no pollution to the environment and is a green and environment-friendly process route for preparing cyclohexene oxide.

The catalysts used for olefin epoxidation at present mainly comprise two major types, namely a titanium silicalite molecular sieve catalyst and a heteropoly acid quaternary ammonium salt system catalyst, the titanium molecular sieve catalysts such as TS-1 and the like are mainly applied to epoxidation reaction of micromolecule olefins such as propylene and the like due to the characteristic of a pore structure, solvents such as methanol and the like are required in the reaction process, the inactivation of the molecular sieve catalysts is generally caused by loss of active species titanium, agglomeration of active sites and the like, the regeneration of the catalysts is difficult and high in cost, and the catalysts need to be directly replaced after industrial inactivation. The heteropoly acid catalyst is widely applied to olefin epoxidation reaction, but the activity of the heteropoly acid salt catalyst is obviously reduced when the number of times of application is increased in the reaction process, and the recycling performance of the heteropoly acid catalyst and the recovery rate of the catalyst are main problems restricting the industrial application of the heteropoly acid catalyst.

Patent CN1401640A xi Zuwei et al developed a reaction control phase transfer catalyst, in the reaction process, the catalyst was dissolved in the reaction system to generate epoxidation reaction, and after the reaction, the catalyst was precipitated from the reaction system and converted into a heterogeneous catalyst, the process adopts batch reaction, and a large amount of solvents such as dichloromethane are used in the process, so that the catalyst has the problems of long catalyst precipitation and separation time, large loss and high catalyst use cost in the process of recycling. Patent CN101343261B proposes that in the oxidation reaction process, the catalyst can be completely precipitated by increasing the conversion rate of hydrogen peroxide, so as to increase the recovery rate of the oil phase catalyst, but the catalyst loss is inevitable in the water phase, and the expensive olefin needs to be excessive compared with the cheap hydrogen peroxide, so that the cyclohexene polymerization brings about a large loss of cyclohexene. Patent CN101992125B proposes a method for regenerating heteropoly acid quaternary ammonium salt catalyst, firstly washing the deactivated catalyst with solvent, then dissolving the catalyst with halohydrocarbon mixed solvent containing hydrogen peroxide, and supplementing phosphorus source and quaternary ammonium salt to regenerate the catalyst. However, the method has long process route, low treatment efficiency and high cost, and can not meet the industrial requirements. Patent CN108073143A believes that the particle size of the precipitated catalyst can be increased and the recovery rate of the catalyst can be improved by regulating and controlling the particle size of the catalyst, but the loss of the catalyst is still more than 2kg/t, and the loss of the product remained in the rectifying still is still remained. Patent CN110156726A proposes a method for recovering and regenerating deactivated heteropolyacid catalyst from still bottoms, but no patent reports recovery of aqueous phase catalyst due to more than 15% catalyst loss in the aqueous phase. The subject group proposed in patent CN112142689A that a reactive distillation mode was adopted, the catalyst remained in the reactor all the time, no loss of catalyst was observed, only the inactivated catalyst was discharged and fresh catalyst was supplemented, but the problems of catalyst inactivation and catalyst recycling still existed.

Therefore, in order to apply the heteropolyacid quaternary ammonium salt catalyst to the epoxidation reaction of olefin and hydrogen peroxide to the industrial preparation of olefin oxide or olefin epoxide, a technology which has high reactant conversion rate and high reaction yield and can improve the catalyst utilization rate and realize the production of olefin epoxide with complete recovery of the catalyst, low material consumption and low energy consumption is urgently needed to be developed.

Disclosure of Invention

The invention solves the technical problem of providing a continuous production device and a method of epoxy cyclohexane, wherein through multi-stage epoxidation reaction, water phase separated after each stage of reaction and refined cyclohexene are used as the next stage of reaction raw material, the temperature of each stage of reaction is gradually raised to ensure complete conversion of hydrogen peroxide, the concentration of the epoxy cyclohexane in a system is low, and the reaction yield is high; extracting and recovering the lost catalyst in the water phase by using cyclohexene and cyclohexene oxide, and simultaneously injecting cyclohexene into the bottom of the extraction tower to further recover the cyclohexene oxide in the water phase, thereby improving the utilization rate of the catalyst and raw materials; the catalyst is dissolved in organic phases such as cyclohexene oxide, cyclohexene and the like, circulates along with high boiling point substances such as cyclohexene oxide and the like, and is regenerated after being inactivated, so that the activity stability of the catalyst is ensured.

In order to solve the above problems, an aspect of the present invention provides an apparatus for continuously producing cyclohexene oxide, comprising:

the device comprises a cyclohexene separation tower, a cyclohexene refining tower, a product tower and at least two stages of reaction crude separation devices, wherein each stage of reaction crude separation device comprises an epoxidation reactor and an oil-water separator;

in each stage of the reaction crude separation device, a discharge hole of the epoxidation reactor is connected with a feed inlet of the oil-water separator, and an oil phase outlet of the oil-water separator is connected with a feed inlet of the cyclohexene separation tower; former one-level the crude separator of reaction the water phase export of oil water separator and back one-level the crude separator of reaction the feed inlet of epoxidation reactor is connected, the top of the tower discharge gate of cyclohexene knockout tower with the feed inlet of cyclohexene refining tower is connected, the cauldron discharge gate and the at least one-level of cyclohexene refining tower the crude separator of reaction the feed inlet of epoxidation reactor is connected, the cauldron discharge gate of cyclohexene knockout tower with the feed inlet of product tower is connected, the cauldron discharge gate and the at least one-level of product tower the crude separator of reaction the feed inlet of epoxidation reactor is connected.

The device for continuously producing cyclohexene oxide adopts multi-stage epoxidation reaction, and fresh catalyst, hydrogen peroxide solution and cyclohexene enter a first-stage reaction crude separation device for epoxidation reaction; separating oil and water of products after each stage of epoxidation reaction; the water phase is used as a raw material of the next-stage epoxidation reaction, the oil phase enters a cyclohexene separation tower to separate a cyclohexene material and a material rich in cyclohexene oxide and a catalyst, the cyclohexene material is sent to a cyclohexene refining tower to separate refined cyclohexene to serve as a raw material of at least one-stage epoxidation reaction, the material rich in cyclohexene oxide and the catalyst is sent to a product tower to separate an epoxy cyclohexane product and a material rich in the catalyst and a small amount of cyclohexene oxide, and the material rich in the catalyst and the small amount of cyclohexene oxide is used as a raw material of at least one-stage epoxidation reaction. According to the continuous production device for the cyclohexene oxide, at least two stages of reactors are connected in series step by step, oil-water separation is carried out after each stage of reaction, products are separated in time, side reaction losses such as hydrolysis of the cyclohexene oxide at high temperature and high concentration due to high reaction temperature and long residence time in the latter stage are prevented, the concentration of the cyclohexene oxide in a system is low, and the reaction yield is high; the temperature can be gradually increased in each stage of epoxidation reaction, complete conversion of hydrogen peroxide is ensured, the content of peroxide in final wastewater is reduced, and wastewater treatment is facilitated.

Preferably, the method further comprises the following steps:

a catalyst extraction column;

the water phase outlet of the oil-water separator of the last-stage reaction coarse separation device is connected with the feed inlet of the catalyst extraction tower, the oil phase outlet of the catalyst extraction tower is connected with the feed inlet of the cyclohexene separation tower, the discharge hole at the middle upper part of the cyclohexene separation tower is connected with the extractant feed inlet of the catalyst extraction tower, and the discharge hole at the top of the cyclohexene separation tower is connected with the extractant feed inlet at the bottom of the catalyst extraction tower.

The invention relates to a continuous production device of cyclohexene oxide, wherein a solvent-free system is adopted for reaction, the loss rate of a conventional heteropoly acid catalyst in a water phase is about 15%, the device adopts a cyclohexene material containing 5-30% of cyclohexene oxide at a discharge port at the middle upper part of a cyclohexene separation tower to extract and recover a catalyst in the water phase, the material containing cyclohexene from the top of the cyclohexene separation tower is injected into the lower part of a catalyst extraction tower to carry out countercurrent contact, the catalyst is further recovered, the catalyst in the catalyst is almost completely transferred into an oil phase, meanwhile, an epoxy cyclohexane product dissolved in the water phase is extracted and recovered and returned to the cyclohexene separation tower, and wastewater containing almost no catalyst is discharged from the catalyst extraction tower, so that the loss of the catalyst is greatly reduced, and the yield of the epoxy cyclohexane is improved.

Preferably, the method further comprises the following steps:

a catalyst regeneration device;

the discharge port of the tower bottom of the product tower is also connected with the feed port of the catalyst regeneration device, and the discharge port of the catalyst regeneration device is connected with the feed port of the epoxidation reactor of the at least one-stage reaction crude separation device.

The continuous production device of the epoxy cyclohexane is a solvent-free system epoxidation reaction, the catalyst is dissolved in an oil phase, a circulating reaction is carried out in the system along with a small amount of epoxy cyclohexane products and the like, and the catalyst is regenerated by a catalyst regeneration device after the activity is reduced, so that the stability of the activity of the epoxy catalyst is ensured.

Preferably, a discharge port of a tower kettle of the cyclohexene refining tower is connected with a feed port of the epoxidation reactor of each stage of the reaction crude separation device; and a discharge port of a tower kettle of the product tower is connected with a feed port of the epoxidation reactor of each stage of the reaction crude separation device.

Further, the device comprises a two-stage reaction crude separation device, wherein an oil phase outlet of an oil-water separator of the first-stage reaction crude separation device is connected with a feed inlet at the middle lower part of the cyclohexene separation tower; an oil phase outlet of an oil-water separator of the second-stage reaction crude separation device is connected with a feed inlet at the middle upper part of the cyclohexene separation tower.

Another aspect of the present invention provides a continuous production method of cyclohexene oxide, comprising the steps of:

s1, mixing a catalyst, a hydrogen peroxide solution and a cyclohexene raw material, and carrying out at least two-stage epoxidation reaction; performing oil-water separation on the product of each stage of epoxidation reaction, sending the water phase obtained by separation to the next stage of epoxidation reaction as a raw material, and sending the oil phase obtained by separation to a cyclohexene separation tower for separation of cyclohexene and cyclohexene oxide; extracting cyclohexene material from the top of the cyclohexene separation tower, and extracting material containing epoxy cyclohexane and a catalyst from a tower kettle;

s2, sending the cyclohexene material obtained in the step S1 to a cyclohexene refining tower for separation, and sending the purified cyclohexene obtained by separation to at least one stage of epoxidation reaction to serve as a raw material; sending the material containing the cyclohexene oxide and the catalyst in the step S1 to a product tower for separation to obtain a cyclohexene oxide product and a material containing the catalyst and the cyclohexene oxide;

s3, sending the material containing the catalyst and the cyclohexene oxide obtained in the step S2 to at least one stage of epoxidation reaction to be used as a raw material.

The continuous production method of cyclohexene oxide adopts multi-stage epoxidation reaction, and fresh catalyst, hydrogen peroxide solution and cyclohexene are subjected to first-stage epoxidation reaction; separating oil and water of products after each stage of epoxidation reaction; the water phase is used as a raw material of the next-stage epoxidation reaction, the oil phase enters a cyclohexene separation tower to separate a cyclohexene material and a material rich in cyclohexene oxide and a catalyst, the cyclohexene material is sent to a cyclohexene refining tower to separate refined cyclohexene to serve as a raw material of at least one-stage epoxidation reaction, the material rich in cyclohexene oxide and the catalyst is sent to a product tower to separate an epoxy cyclohexane product and a material rich in the catalyst and a small amount of cyclohexene oxide, and the material rich in the catalyst and the small amount of cyclohexene oxide is used as a raw material of at least one-stage epoxidation reaction. According to the method for continuously producing the cyclohexene oxide, at least two stages of epoxidation reactions are connected in series step by step, oil-water separation is carried out after each stage of reaction, products are separated out in time, side reaction losses such as hydrolysis of the cyclohexene oxide at high temperature and high concentration due to high reaction temperature and long retention time in the later stage are prevented, the concentration of the cyclohexene oxide in a system is low, and the reaction yield is high.

Preferably, the method further comprises the following steps:

s4, sending the water phase obtained in the oil-water separation of the product of the last-stage epoxidation reaction in the step S1 to a catalyst extraction tower, taking a material containing 5-30% of cyclohexene oxide and extracted from the cyclohexene separation tower as an extracting agent, and injecting the cyclohexene material extracted from the top of the cyclohexene separation tower at the lower part of the catalyst extraction tower to recover the cyclohexene oxide.

In the continuous production method of the cyclohexene oxide, the water phase of the oil-water separation product of the final stage epoxidation reaction contains part of the catalyst, and is sent to a catalyst extraction tower, in the catalyst extraction tower, the cyclohexene material containing 5-30% of the cyclohexene oxide from the cyclohexene separation tower contacts with the wastewater containing the catalyst, so that the catalyst in the cyclohexene material is extracted to an oil phase, the material containing the cyclohexene is injected into the lower part of the catalyst extraction tower to be in countercurrent contact, the catalyst is further recovered, the cyclohexene oxide dissolved in the water phase is recovered, the catalyst in the water phase is almost completely transferred to the oil phase and returned to the cyclohexene separation tower, and the wastewater containing almost no catalyst is discharged from the bottom of the catalyst extraction tower. Thereby greatly reducing the loss of the catalyst and improving the yield of the cyclohexene oxide.

Preferably, the method further comprises the following steps:

s5, feeding a part of the material containing the catalyst and the epoxy cyclohexane, which is extracted from the product tower bottom in the step S2, into a catalyst regeneration device for catalyst regeneration, and feeding the regenerated catalyst to at least one stage of epoxidation reaction for use.

The continuous production method of the epoxy cyclohexane is a solvent-free system epoxidation reaction, the catalyst is dissolved in an oil phase, a circulating reaction is carried out in the system along with a small amount of epoxy cyclohexane products and the like, and the catalyst is regenerated by a catalyst regeneration device after the activity is reduced, so that the stability of the activity of the epoxy catalyst is ensured.

Preferably, in step S5, the catalyst regeneration includes sequentially performing: extracting, filtering, washing, activating by hydrogen peroxide and drying; in the continuous production method of cyclohexene oxide, the regeneration process of the catalyst is simple, only a small amount of hydrogen peroxide is consumed, and the consumption cost of the catalyst is greatly reduced.

Wherein the extracting agent for extraction is one or a mixture of ethanol, ethyl acetate, petroleum ether, dichloromethane and chloroform; preferably, the extracting agent for extraction is one or a mixture of ethanol and ethyl acetate;

the washing is carried out by adopting an organic solvent and deionized water; the organic solvent is one or a mixture of ethanol, diethyl ether, ethyl acetate, petroleum ether, dichloromethane and chloroform;

the hydrogen peroxide activation is carried out in a water phase, the hydrogen peroxide concentration is 1-50%, and the mass ratio of hydrogen peroxide to the catalyst is (0.5-10): 1; preferably, the concentration of the hydrogen peroxide is 5 to 30 percent;

the drying temperature is 25-100 ℃, preferably, the drying temperature is 30-80 ℃.

Preferably, in step S1:

the catalyst is a heteropoly acid quaternary ammonium salt catalyst; further preferably, the catalyst is a phosphotungstic heteropoly acid quaternary ammonium salt catalyst or a phosphomolybdic heteropoly acid quaternary ammonium salt catalyst; further preferably, the catalyst is a phosphotungstic heteropoly acid quaternary ammonium salt catalyst.

The mol ratio of the cyclohexene to the hydrogen peroxide is (1-10): 1; further preferably, the molar ratio of cyclohexene to aqueous hydrogen peroxide is (1-6): 1; further preferably, the molar ratio of cyclohexene to hydrogen peroxide is (1.5-5): 1.

the adding amount of the catalyst is 0.02-5% of the total mass of the cyclohexene, the hydrogen peroxide solution and the catalyst; preferably, the adding amount of the catalyst is 0.05-3% of the total mass of the cyclohexene, the hydrogen peroxide and the catalyst; further preferably, the adding amount of the catalyst is 0.5-2% of the total mass of the cyclohexene, the hydrogen peroxide and the catalyst.

The temperature of the latter stage epoxidation reaction is higher than that of the former stage epoxidation reaction;

the reaction temperature of the first-stage epoxidation reaction is 30-100 ℃; preferably, the reaction temperature of the first-stage epoxidation reaction is 30-80 ℃; further preferably, the reaction temperature of the first-stage epoxidation reaction is 35-60 ℃;

the residence time of the first-stage epoxidation reaction is 0.5-6 h; preferably, the residence time of the first stage epoxidation reaction is from 1 to 5 hours; further preferably, the residence time of the first stage epoxidation reaction is 2 to 4 hours;

the reaction temperature of the second-stage epoxidation reaction is 35-100 ℃; preferably, the reaction temperature of the second-stage epoxidation reaction is 35-80 ℃; further preferably, the reaction temperature of the second-stage epoxidation reaction is 40-70 ℃;

the residence time of the second-stage epoxidation reaction is 0.5-8 h; preferably, the residence time of the second stage epoxidation reaction is from 1 to 6 hours; further preferably, the residence time of the second stage epoxidation reaction is 2 to 5 h.

The continuous production method of cyclohexene oxide of the invention gradually increases the temperature in each stage of epoxidation reaction, ensures complete conversion of hydrogen peroxide, reduces the content of peroxide in final wastewater, and is convenient for wastewater treatment.

Preferably, the number of theoretical plates of the cyclohexene separating tower, the cyclohexene refining tower, the product tower and the catalyst extraction tower is 3-30; preferably, the number of theoretical plates of the cyclohexene separation column is 5-20; the number of theoretical plates of the cyclohexene refining tower is 5-20; the number of theoretical plates of the product tower is 10-30; the number of theoretical plates of the catalyst extraction tower is 3-10;

the reflux ratio of the cyclohexene separating tower, the cyclohexene refining tower and the product tower is 1-10, and the pressure is 10-101.325kPa (absolute pressure); preferably, the reflux ratio of the product column is from 2 to 8; the pressure of the cyclohexene separating tower and the cyclohexene refining tower is 30-101.325kPa (absolute pressure); the pressure of the product tower is 10-50kPa (absolute pressure);

in the catalyst extraction tower, the mass ratio of the cyclohexene material to the material containing 5-30% of cyclohexene oxide is (0.1-10): 1, preferably (1-6): 1; the mass ratio of the cyclohexene material, the material containing 5% -30% of cyclohexene oxide and the water phase of the catalyst extraction tower is (0.5-20): 1, preferably (1-10): 1; the extraction temperature is 30-60 deg.C, preferably 40-60 deg.C.

Compared with the prior art, the invention has the following beneficial effects:

1. the invention relates to a device and a method for continuously producing cyclohexene oxide, which adopt multi-stage epoxidation reaction, wherein fresh catalyst, hydrogen peroxide solution and cyclohexene are subjected to first-stage epoxidation reaction; separating oil and water of products after each stage of epoxidation reaction; the water phase is used as a raw material of the next-stage epoxidation reaction, the oil phase enters a cyclohexene separation tower to separate a cyclohexene material and a material rich in cyclohexene oxide and a catalyst, the cyclohexene material is sent to a cyclohexene refining tower to separate refined cyclohexene to serve as a raw material of at least one-stage epoxidation reaction, the material rich in cyclohexene oxide and the catalyst is sent to a product tower to separate an epoxy cyclohexane product and a material rich in the catalyst and a small amount of cyclohexene oxide, and the material rich in the catalyst and the small amount of cyclohexene oxide is used as a raw material of at least one-stage epoxidation reaction. According to the method for continuously producing the cyclohexene oxide, at least two stages of epoxidation reactions are connected in series step by step, oil-water separation is carried out after each stage of reaction, products are separated out in time, side reaction losses such as hydrolysis of the cyclohexene oxide at high temperature and high concentration due to high reaction temperature and long retention time in the next stage are prevented, the concentration of the cyclohexene oxide in a system is low, and the reaction yield is high; the temperature is gradually increased in each stage of epoxidation reaction, complete conversion of hydrogen peroxide is ensured, the content of peroxide in final wastewater is reduced, and wastewater treatment is facilitated;

2. according to the continuous production device and method of the epoxy cyclohexane, the water phase of the oil-water separation product of the last-stage epoxidation reaction contains part of the catalyst, and is sent to the catalyst extraction tower, in the catalyst extraction tower, the cyclohexene material containing 5% -30% of epoxy cyclohexane from the cyclohexene separation tower contacts with the wastewater containing the catalyst, the catalyst in the cyclohexene material is extracted to an oil phase, the material containing cyclohexene is injected into the lower part of the catalyst extraction tower to be in countercurrent contact, the catalyst is further recovered, the epoxy cyclohexane dissolved in the water phase is recovered, the catalyst in the water phase is almost completely transferred to the oil phase and returned to the cyclohexene separation tower, and the wastewater containing almost no catalyst is discharged from the bottom of the catalyst extraction tower. The reaction adopts a solvent-free system, the loss rate of the conventional heteropoly acid catalyst in the water phase is about 15 percent, the invention adopts a mode of recovering the catalyst in the water phase by oil phase extraction, recovers the catalyst lost in the water phase, and simultaneously extracts and recovers the epoxy cyclohexane product dissolved in the water phase, thereby greatly reducing the loss of the catalyst and simultaneously improving the yield of the epoxy cyclohexane;

3. the device and the method for continuously producing the epoxy cyclohexane are a solvent-free system epoxidation reaction, a catalyst is dissolved in an oil phase and circularly reacts in a system along with a small amount of epoxy cyclohexane products and the like, and the catalyst is regenerated by a catalyst regeneration device after the activity is reduced, so that the stability of the activity of the epoxy catalyst is ensured;

4. in the device and the method for continuously producing the cyclohexene oxide, the regeneration process of the catalyst is simple, only a small amount of hydrogen peroxide is consumed, and the consumption cost of the catalyst is greatly reduced.

Drawings

FIG. 1 is a schematic view showing the structure of an apparatus for continuously producing epoxycyclohexane according to example 1 of the present invention.

Wherein: 1-cyclohexene separation column; 2-cyclohexene refining tower; 3-a product tower; 4-a first epoxidation reactor; 5-a first oil-water separator; 6-a second epoxidation reactor; 7-a second oil-water separator; 8-a catalyst extraction column; 9-catalyst regeneration device.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

As shown in fig. 1, the apparatus for continuously producing cyclohexene oxide of the present embodiment includes:

the system comprises a cyclohexene separation tower 1, a cyclohexene refining tower 2, a product tower 3, a primary reaction coarse separation device and a secondary reaction coarse separation device, wherein the primary reaction coarse separation device comprises a first epoxidation reactor 4 and a first oil-water separator 5, and the secondary reaction coarse separation device comprises a second epoxidation reactor 6 and a second oil-water separator 7;

the first epoxidation reactor 4 is provided with feed inlets for fresh catalyst, hydrogen peroxide solution and cyclohexene; the discharge hole of the first epoxidation reactor 4 is connected with the feed inlet of the first oil-water separator 5; the discharge hole of the second epoxidation reactor 6 is connected with the feed inlet of the second oil-water separator 7; an oil phase outlet of the first oil-water separator 5 is connected with a feed inlet at the middle lower part of the cyclohexene separation tower 1, an oil phase outlet of the second oil-water separator 7 is connected with a feed inlet at the middle upper part of the cyclohexene separation tower 1, and a water phase outlet of the first oil-water separator 5 is connected with a feed inlet of the second oxidation reactor 6; a discharge port at the top of the cyclohexene separation tower 1 is connected with a feed port of a cyclohexene refining tower 2; a discharge port of a tower kettle of the cyclohexene separating tower 1 is connected with a feed port of a product tower 3; a tower kettle discharge port of the cyclohexene refining tower 2 is respectively connected with feed ports of the first epoxidation reactor 4 and the second epoxidation reactor 6, and a tower kettle discharge port of the product tower 3 is connected with feed ports of the first epoxidation reactor 4 and the second epoxidation reactor 6.

Injecting a fresh catalyst material, a hydrogen peroxide solution and a cyclohexene material into a first epoxidation reactor, carrying out epoxidation reaction under certain temperature, pressure and stirring and mixing conditions, and sending a product after the reaction into a first oil-water separator for oil-water separation; sending the oil phase material separated in the first oil-water separator to a feed inlet at the middle lower part of a cyclohexene separation tower, sending the separated water phase material containing part of unreacted hydrogen peroxide, the circulating catalyst material from a product tower kettle and the refined cyclohexene material from a cyclohexene refining tower to a second epoxidation reactor together, carrying out epoxidation reaction under the conditions of certain temperature, pressure and stirring mixing, completely converting the hydrogen peroxide, and sending the reaction liquid into a second oil-water separator for oil-water separation; the oil phase separated by the second oil-water separator is sent to the middle upper part of the cyclohexene separating tower; the cyclohexene separation tower completes the separation of cyclohexene, cyclohexene oxide and the like, the cyclohexene material extracted from the tower top is sent to a cyclohexene refining tower, and the material rich in cyclohexene oxide and catalyst in the tower bottom is sent to a product tower; separating out epoxy cyclohexane product from the top of the product tower, and circulating the materials rich in catalyst, a small amount of epoxy cyclohexane and the like in the tower bottom to the first epoxidation reactor and the second epoxidation reactor for continuous reaction.

Further, still include: a catalyst extraction column 8;

the water phase outlet of the second oil-water separator 7 is connected with the feed inlet of the catalyst extraction tower 8, the oil phase outlet of the catalyst extraction tower 8 is connected with the feed inlet of the cyclohexene separation tower 1, the discharge outlet at the middle upper part of the cyclohexene separation tower 1 is connected with the extractant feed inlet of the catalyst extraction tower 8, and the discharge outlet at the top of the cyclohexene separation tower 1 is connected with the extractant feed inlet at the bottom of the catalyst extraction tower 8.

And (3) the water phase material separated by the second oil-water separator contains a part of catalyst, and is sent to a catalyst extraction tower, in the catalyst extraction tower, the cyclohexene material containing 5-30% of cyclohexene oxide from the middle upper part of the cyclohexene separation tower contacts with wastewater containing the catalyst, the catalyst in the cyclohexene material is extracted to an oil phase, the cyclohexene material from the top of the cyclohexene separation tower is injected from the lower part of the catalyst extraction tower to carry out countercurrent contact, the catalyst is further recovered, the cyclohexene oxide in the solvent in the water phase is recovered, the catalyst in the cyclohexene separation tower is almost completely transferred to the oil phase, the cyclohexene separation tower is returned, and the wastewater containing almost no catalyst is discharged from the bottom of the catalyst extraction tower.

Further, still include: a catalyst regeneration device 9;

the discharge port of the tower bottom of the product tower 3 is also connected with the feed port of the catalyst regeneration device 9, and the discharge port of the catalyst regeneration device 9 is respectively connected with the feed ports of the first epoxidation reactor 4 and the second epoxidation reactor 6.

During the reaction process, part of the material rich in the catalyst is extracted from the tower bottom of the product tower and enters a catalyst regeneration device to complete the regeneration of the catalyst, and meanwhile, regenerated or fresh catalyst materials are supplemented in the first epoxidation reactor and the second epoxidation reactor.

Example 2

The continuous production method of cyclohexene oxide of the embodiment comprises the following steps:

s1, mixing 0.2kg/h of phosphotungstic heteropoly acid quaternary ammonium salt catalyst, 3kg/h of hydrogen peroxide solution with the concentration of 30% and 12kg/h of fresh cyclohexene, carrying out two-stage epoxidation reaction in series, putting fresh materials into first-stage epoxidation reaction, and putting water phase separated by the first-stage epoxidation reaction into second-stage epoxidation reaction; specifically, the reaction temperature of the first-stage epoxidation reaction is 40 ℃, the residence time is 4 hours, the reaction temperature of the second-stage epoxidation reaction is 60 ℃, the residence time is 4 hours, and the volume ratio of the first-stage epoxidation reaction to the second-stage epoxidation reaction is 2: 1; performing oil-water separation on products of the primary epoxidation reaction and the secondary epoxidation reaction, and sending a water phase obtained by separation of the primary epoxidation reaction to the secondary epoxidation reaction to be used as a raw material; feeding the oil phase obtained by the first-stage epoxidation reaction separation into the middle-lower part of a cyclohexene separating tower, and feeding the oil phase obtained by the second-stage epoxidation reaction separation into the middle-upper part of the cyclohexene separating tower for separating cyclohexene from cyclohexene oxide; extracting cyclohexene material from the top of the cyclohexene separation tower, and extracting material containing cyclohexene oxide and a catalyst from a tower kettle; wherein the number of theoretical plates of the cyclohexene separating tower is 15, the reflux ratio is 2, and the pressure is 50kPa absolute pressure;

s2, sending the cyclohexene material obtained in the step S1 to a cyclohexene refining tower for separation, extracting refined cyclohexene from a tower kettle of the cyclohexene refining tower, and sending the refined cyclohexene to a primary epoxidation reaction and a secondary epoxidation reaction to serve as raw materials; sending the material containing the cyclohexene oxide and the catalyst in the step S1 to a product tower for separation, wherein the product tower top is used for extracting a cyclohexene oxide product, and the tower kettle is used for extracting a material containing the catalyst and the cyclohexene oxide; wherein the theoretical plate number of the cyclohexene refining tower is 15, the reflux ratio is 2, and the pressure is 50kPa absolute pressure; the theoretical plate number of the product tower is 20, the reflux ratio is 5, and the pressure is 20kPa absolute pressure;

s3, conveying the material containing the catalyst and the cyclohexene oxide, which is extracted from the tower bottom of the product in the step S2, to a first-stage epoxidation reaction and a second-stage epoxidation reaction as raw materials;

s4, sending the water phase obtained by oil-water separation of the product of the secondary epoxidation reaction in the step S1 to a catalyst extraction tower, taking a material containing 5-30% of cyclohexene oxide extracted from the middle upper part of the cyclohexene separation tower as an extractant, and injecting the cyclohexene material extracted from the top of the cyclohexene separation tower into the lower part of the catalyst extraction tower to recover the cyclohexene oxide; wherein the number of theoretical plates of the catalyst extraction tower is 8; in the catalyst extraction tower, the mass ratio of the cyclohexene material to the material containing 5-30% of cyclohexene oxide is 5; the mass ratio of the cyclohexene material, the material containing 5-30% of cyclohexene oxide and the water phase of the catalyst extraction tower is 10; the extraction temperature is 40 ℃;

s5, feeding a part of materials containing the catalyst and the epoxy cyclohexane, which are extracted from the tower bottom of the product tower in the step S2, into a catalyst regeneration device for catalyst regeneration, and feeding the regenerated catalyst into a first-stage epoxidation reaction and a second-stage epoxidation reaction to serve as raw materials. Wherein, the catalyst regeneration comprises the following steps of sequentially carrying out the following steps on materials containing the catalyst and cyclohexene oxide: extracting, filtering, washing, activating by hydrogen peroxide and drying. The extractant used for extraction is ethyl acetate; washing is carried out by adopting organic solvents of ethyl acetate and ethanol for 1-2 times respectively and then adopting deionized water for washing; the hydrogen peroxide activation is carried out in a water phase, the concentration of the hydrogen peroxide is 5-15%, and the mass ratio of the hydrogen peroxide to the catalyst is 4; the drying temperature was 40 ℃.

Example 3

The continuous production method of cyclohexene oxide of this example was the same as that of example 2 except that the amount of fresh catalyst added in the primary epoxidation reaction was 0.075 kg/hr, the primary epoxidation reaction temperature was 35 ℃ and the secondary epoxidation reaction temperature was 45 ℃.

Example 4

The continuous production method of cyclohexene oxide of this example was the same as that of example 2 except that the amount of fresh catalyst added in the primary epoxidation reaction was 0.075 kg/hr, the primary epoxidation reaction temperature was 35 ℃ and the secondary epoxidation reaction temperature was 50 ℃.

Example 5

The continuous production method of cyclohexene oxide of this example was the same as that of example 2 except that the amount of fresh catalyst added in the first-stage epoxidation reaction was 0.1kg/h, the temperature of the first-stage epoxidation reaction was 45 ℃ and the temperature of the second-stage epoxidation reaction was 50 ℃.

Example 6

The continuous production method of cyclohexene oxide of this example was the same as example 2 except that the amount of fresh catalyst added in the first-stage epoxidation reaction was 0.2kg/h, the first-stage epoxidation reaction temperature was 45 ℃ and the second-stage epoxidation reaction temperature was 60 ℃.

Example 7

The continuous production method of cyclohexene oxide of this example was the same as that of example 2 except that the amount of fresh catalyst added in the first-stage epoxidation reaction was 0.5kg/h, the temperature of the first-stage epoxidation reaction was 45 ℃ and the temperature of the second-stage epoxidation reaction was 60 ℃.

Example 8

The continuous production method of cyclohexene oxide of this example was the same as that of example 2 except that the amount of fresh catalyst added in the first-stage epoxidation reaction was 0.5kg/h, the temperature of the first-stage epoxidation reaction was 45 ℃ and the temperature of the second-stage epoxidation reaction was 70 ℃.

Table 1 shows the hydrogen peroxide conversion, cyclohexene conversion and cyclohexene selectivity after different reaction times for the continuous production of cyclohexene oxide in example 2.

TABLE 1

Table 2 shows the hydrogen peroxide conversion, cyclohexene conversion and cyclohexene selectivity after 4 hours of reaction in the above continuous production method of cyclohexene oxide. As can be seen from the data in Table 2, the catalyst of the invention is added in an amount of 0.5-3% of the total feed, and the two-stage reaction can obtain better reaction effect and the reaction is continuous and stable.

TABLE 2

Table 3 shows the catalyst content and the cyclohexene oxide content in the wastewater in the above examples, and it can be seen from the data in the following table that, in the continuous production method of cyclohexene oxide, the catalyst content in the aqueous phase is less than 500mg/L, and the catalyst loss rate is less than 1% in terms of the data in the following table; and the content of the cyclohexene oxide in the wastewater is lower than 100ppm, so the loss of the catalyst is less, and the loss of the cyclohexene oxide in the water phase is low.

TABLE 3

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.