CN114213262A - Method for co-producing hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine - Google Patents

Abstract

The invention provides a method for co-producing hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine, which comprises the following steps: A) conveying ethylenediamine and ethylene oxide to a reaction unit through a continuous conveying system for reaction to obtain a reaction solution; the molar ratio of the ethylenediamine to the ethylene oxide is (1-5): 1; the reaction unit is provided with at least two temperature zones, and the temperature of each temperature zone is 60-160 ℃; B) conveying the reaction liquid to a lightness removing unit, and removing ethylenediamine in the reaction liquid to obtain lightness removing mother liquid; C) and conveying the light removal mother liquor to a separation unit, and collecting a hydroxyethyl ethylenediamine product and a dihydroxyethyl ethylenediamine product. In the continuous production device, the ethylenediamine and the ethylene oxide in a certain ratio react at a certain temperature and under a certain pressure, so that the content of byproducts is effectively reduced, the hydroxyethyl ethylenediamine and the dihydroxyethyl ethylenediamine are obtained, the loss and the waste amount of products in the separation process are reduced, and the product yield is improved.

Description

Method for co-producing hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine

Technical Field

The invention belongs to the technical field of organic chemical industry, and particularly relates to a method for co-producing hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine.

Background

Hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine have important application in the chemical field, and hydroxyethyl ethylenediamine can be used for producing dyes, resins, rubber, flotation agents, insecticides, surfactants, corrosion inhibitors and the like, can also be used as a curing agent of epoxy resin, has excellent performance, low toxicity and environmental protection. The dihydroxyethyl ethylenediamine is mainly used as a plastic product curing agent, an epoxy resin curing agent, a lubricating oil additive, a desulfurizing agent, an acid gas adsorbent, a wetting agent, a surfactant, a medical intermediate, a polymer monomer raw material, a liquid crystal intermediate and the like.

At present, the production of hydroxyethyl ethylenediamine adopts an ethylene oxide method, namely ethylene oxide reacts with ethylenediamine to obtain hydroxyethyl ethylenediamine, four active hydrogens on the molecule of ethylenediamine can react with ethylene oxide, so that the hydroxyethyl ethylenediamine can react with ethylene oxide to obtain a product of hydroxyethyl ethylenediamine, when the hydroxyethyl ethylenediamine is generated in a reaction system, the hydroxyethyl ethylenediamine still having two active hydrogens can continuously react with ethylene oxide to generate trihydroxyethyl ethylenediamine and tetrahydroxyethyl ethylenediamine even under mild conditions, when four products in the reaction system have high contents of the trihydroxyethyl ethylenediamine and the tetrahydroxyethyl ethylenediamine, polymers with higher molecular weight or ether substances with higher molecular weight can be generated in the separation process, the separation difficulty and the post-treatment burden of the products are increased, the waste amount is increased, and the yield and the purity of each product can hardly reach higher levels, the added value of the product is reduced.

In the traditional production process of hydroxyethyl ethylenediamine, the hydroxyethyl ethylenediamine is easily produced, but the coproduction of hydroxyethyl ethylenediamine and hydroxyethyl ethylenediamine is difficult to realize, because the problem of high content of the hydroxyethyl ethylenediamine and the tetrahydroxyethyl ethylenediamine exists during the coproduction, the separation of the product is influenced, and even if the hydroxyethyl ethylenediamine is obtained at the same time, the yield and the purity of the product are lower, therefore, in the selection of the product, the existing manufacturers focus on the research and development on the process for producing the hydroxyethyl ethylenediamine alone, increase the content of the hydroxyethyl ethylenediamine and reduce the content of the hydroxyethyl ethylenediamine in the production process of the hydroxyethyl ethylenediamine, and treat the material which is separated in the separation stage and contains the hydroxyethyl ethylenediamine and other byproducts as waste materials, thereby causing the waste of the hydroxyethyl ethylenediamine.

Disclosure of Invention

The invention aims to provide a method for co-producing hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine, which can realize co-production of hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine, and has the advantages of few byproducts, easy product separation and high yield.

The invention provides a method for co-producing hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine, which comprises the following steps:

A) conveying ethylenediamine and ethylene oxide to a reaction unit through a continuous conveying system for reaction to obtain a reaction solution;

the molar ratio of the ethylenediamine to the ethylene oxide is (1-5): 1; the reaction unit is provided with at least two temperature zones, and the temperature of each temperature zone is 60-160 ℃;

B) conveying the reaction liquid to a lightness removing unit, and removing ethylenediamine in the reaction liquid to obtain lightness removing mother liquid;

C) and conveying the light removal mother liquor to a separation unit, and collecting a hydroxyethyl ethylenediamine product and a dihydroxyethyl ethylenediamine product.

Preferably, the reaction unit is provided with two reaction temperature zones, wherein the temperature of the first temperature zone is 60-100 ℃, and the temperature of the second temperature zone is 100-160 ℃.

Preferably, the reaction unit is provided with two temperature zones, wherein the temperature of the first temperature zone is 100-160 ℃, and the temperature of the second temperature zone is 60-100 ℃.

Preferably, the reaction unit is provided with three reaction temperature zones, wherein the temperature of the first temperature zone is 60-100 ℃, the temperature of the second temperature zone is 100-160 ℃, and the temperature of the third temperature zone is 60-100 ℃.

Preferably, the pressure of the reaction in the step A) is 1-4.5 MPa.

Preferably, the residence time in the reaction unit is 0.2-10 min.

Preferably, the temperature for removing the ethylenediamine in the step B) is 100-200 ℃; the pressure is 1 to 80 kPa.

Preferably, the separation unit in step C) comprises a first rectification column;

the temperature of the first rectifying tower is 180-200 ℃, and the pressure is 0.5-3 kPa.

Preferably, the separation unit in step C) comprises a first rectification column and a second rectification column;

the temperature of the first rectifying tower is 180-200 ℃, and the pressure is 0.5-3 kPa;

the temperature of the second rectifying tower is 200-220 ℃, and the pressure is 0.5-3 kPa.

Preferably, the reaction unit comprises a reactor, or a combination of a micromixer and a reactor; the reactor is one or the combination of two of a micro-channel reactor and a tubular reactor;

the light component removal unit comprises a flash drum and/or a light component removal rectifying tower.

The invention provides a method for co-producing hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine, which comprises the following steps: A) conveying ethylenediamine and ethylene oxide to a reaction unit through a continuous conveying system for reaction to obtain a reaction solution; the molar ratio of the ethylenediamine to the ethylene oxide is (1-5): 1; the reaction unit is provided with at least two temperature zones, and the temperature of each temperature zone is 60-160 ℃; B) conveying the reaction liquid to a lightness removing unit, and removing ethylenediamine in the reaction liquid to obtain lightness removing mother liquid; C) and conveying the light removal mother liquor to a separation unit, and collecting a hydroxyethyl ethylenediamine product and a dihydroxyethyl ethylenediamine product. Compared with the method for producing only one product of hydroxyethyl ethylenediamine, the method for producing the hydroxyethyl ethylenediamine in large quantity reduces the circulation quantity of ethylenediamine and reduces energy consumption, in the continuous production device, the ethylenediamine and the ethylene oxide in a certain proportion react at a certain temperature and under a certain pressure, so that the content of the trihydroxyethyl ethylenediamine and the tetrahydroxyethyl ethylenediamine in a reaction liquid after the ethylenediamine and the ethylene oxide react is effectively reduced, the separation difficulty of the product is reduced, the hydroxyethyl ethylenediamine can be obtained, the dihydroxyethyl ethylenediamine can also be obtained, the loss of the product in the separation process is reduced, the waste amount is reduced, the product yield is improved, and the comprehensive yield of the product can reach 98% by taking the ethylene oxide as a reference.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic diagram of an apparatus for co-producing hydroxyethylethylenediamine and dihydroxyethylethylenediamine used in examples 1 and 3 of the present invention;

FIG. 2 is a schematic view of an apparatus for co-producing hydroxyethylethylenediamine and dihydroxyethylethylenediamine used in example 2 of the present invention;

FIG. 3 is a schematic view of an apparatus for co-producing hydroxyethylethylenediamine and dihydroxyethylethylenediamine used in example 4 of the present invention;

FIG. 4 is a schematic view of an apparatus for co-producing hydroxyethylethylenediamine and dihydroxyethylethylenediamine used in examples 5 and 6 of the present invention;

FIG. 5 is a schematic view of an apparatus for co-producing hydroxyethylethylenediamine and dihydroxyethylethylenediamine used in example 7 of the present invention;

FIG. 6 is a schematic view of an apparatus for co-producing hydroxyethylethylenediamine and dihydroxyethylethylenediamine used in examples 8 and 9 of the present invention;

in fig. 1 to 6, 1-1 is an ethylenediamine storage tank, 1-2 is an ethylene oxide storage tank, 2-1 is an ethylenediamine feed pump, 2-2 is an ethylene oxide feed pump, 3 is a reaction unit having two reaction temperature regions, 3-1 is a reaction unit having three reaction temperature regions, 4-1-a is a light component removal rectification column, 4-1-b is a flash tank, 4-2-1 is a first rectification column, 4-2-2 is a second rectification column, 5-1 is a hydroxyethylethylenediamine receiving tank, 5-2 is a mixed dihydroxyethyl ethylenediamine receiving tank, 5-3 is N, N-Bis (2-hydroxyethyl) ethylenediamine receiving tank, 5-4 is N, N-Bis (2-hydroxyethyl) ethylenediamine receiving tank.

Detailed Description

The invention provides a method for co-producing hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine, which comprises the following steps:

A) conveying ethylenediamine and ethylene oxide to a reaction unit through a continuous conveying system for reaction to obtain a reaction solution;

the molar ratio of the ethylenediamine to the ethylene oxide is (1-5): 1; the reaction unit is provided with at least two temperature zones, and the temperature of each temperature zone is 60-160 ℃;

B) conveying the reaction liquid to a lightness removing unit, and removing ethylenediamine in the reaction liquid to obtain lightness removing mother liquid;

C) and conveying the light removal mother liquor to a separation unit, and collecting a hydroxyethyl ethylenediamine product and a dihydroxyethyl ethylenediamine product.

In the invention, the ethylenediamine and the ethylene oxide are respectively conveyed to the reaction unit from an ethylenediamine storage tank and an ethylene oxide storage tank through a continuous conveying system to react to obtain a reaction solution.

In the present invention, the continuous conveying unit comprises at least two feed pumps, and the reaction unit preferably comprises one or a combination of two of a microchannel reactor and a tubular reactor.

In the invention, the molar ratio of the ethylene diamine to the ethylene oxide is preferably (1-5): 1, more preferably (1 to 4.5): 1, most preferably (1.5-3.5): 1, such as 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, preferably ranges having any of the above values as upper or lower limits.

According to the invention, through research, when the molar ratio of the ethylene diamine to the ethylene oxide is controlled to be 1-5: 1 in the continuous production device under certain temperature and pressure, the proportion of the dihydroxyethyl ethylene diamine in the product can be controlled to be not higher than 20%, and the generation of by-products of the trihydroxyethyl ethylene diamine and the tetrahydroxy ethyl ethylene diamine can be effectively controlled. The larger the molar ratio of the ethylenediamine to the ethylene oxide is, the higher the specific gravity of the hydroxyethyl ethylenediamine in the product composition can be, but the circulating amount of the ethylenediamine in the production process is increased, the energy consumption for promoting the circulation of the ethylenediamine is increased, and the production efficiency is reduced; the molar ratio of ethylene diamine to ethylene oxide is too small, the ratio of dihydroxyethyl ethylene diamine in the product composition is higher than 20%, and the generation of by-products of trihydroxyethyl ethylene diamine and tetrahydroxyethyl ethylene diamine cannot be effectively controlled, so that the product is difficult to separate and the yield is reduced.

In the present invention, the reaction unit is provided with at least two temperature zones, specifically, in one embodiment of the present invention, the temperature of the reaction unit is controlled to be two temperature zones, the temperature of the first temperature zone is preferably 60 to 100 ℃, more preferably 70 to 90 ℃, such as 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃ and 100 ℃, and preferably any of the above values is used as an upper limit or a lower limit; the temperature of the second temperature zone is preferably 100 to 160 ℃, more preferably 110 to 150 ℃, such as 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃, 135 ℃, 140 ℃, 145 ℃, 150 ℃, 155 ℃ and 160 ℃, preferably the range value taking any value as the upper limit or the lower limit. By adopting the temperature zone setting scheme, the generation of the trihydroxyethyl ethylenediamine and the tetrahydroxyethyl ethylenediamine caused by the fact that the ethylenediamine and the ethylene oxide enter a high-temperature reaction unit and react quickly to generate more dihydroxyethyl ethylenediamine under the condition of not mixing uniformly can be avoided.

In another embodiment of the present invention, the reaction unit is controlled by two temperature zones, the temperature of the first temperature zone is preferably 100 to 160 ℃, more preferably 110 to 150 ℃, such as 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃, 135 ℃, 140 ℃, 145 ℃, 150 ℃, 155 ℃, 160 ℃, preferably a range value with any of the above values as an upper limit or a lower limit; the temperature of the second temperature zone is preferably 60 to 100 ℃, more preferably 70 to 90 ℃, such as 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃ and 100 ℃, preferably the temperature is in a range with any value as the upper limit or the lower limit. By adopting the temperature zone setting scheme, the generation of the trihydroxyethyl ethylenediamine and the tetrahydroxyethyl ethylenediamine caused by over violent reaction under the condition of higher content of the dihydroxyethyl ethylenediamine can be avoided.

In another embodiment of the present invention, the reaction unit is controlled by three temperature zones, the temperature of the first temperature zone is preferably 60 to 100 ℃, more preferably 70 to 90 ℃, such as 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃ and 100 ℃, and preferably any of the above values is used as an upper limit or a lower limit; the temperature of the second temperature zone is preferably 100 to 160 ℃, more preferably 110 to 150 ℃, such as 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃, 135 ℃, 140 ℃, 145 ℃, 150 ℃, 155 ℃ and 160 ℃, preferably the range value taking any value as the upper limit or the lower limit; the temperature of the third temperature zone is preferably 60 to 100 ℃, more preferably 70 to 90 ℃, such as 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃ and 100 ℃, preferably the temperature is in a range with any value as the upper limit or the lower limit. By adopting the temperature zone setting, the side reaction caused by violent reaction under the condition of high content of the dihydroxyethyl ethylenediamine at the later stage of the reaction can be avoided.

In the reaction unit of the present invention, the pressure of the reaction is preferably 1 to 4.5MPa, more preferably 1.5 to 4.5MPa, such as 1MPa, 1.5MPa, 2MPa, 2.5MPa, 3MPa, 3.5MPa, 4MPa, 4.5MPa, and preferably any of the above values is a range of upper limit or lower limit. Because of the boiling point of ethylene oxide is lower, at 60 ~ 160 ℃ and ordinary pressure, the state of ethylene oxide is gaseous, and when the ordinary pressure and temperature are higher than 117 ℃, the state of ethylenediamine is also gaseous, in order to guarantee that ethylene oxide and ethylenediamine can mix evenly fast and take place the reaction after getting into the reaction unit, need to guarantee that the reaction unit controls certain pressure, if the pressure is too low, ethylene oxide and ethylenediamine volume phase difference is great, there is the material ratio unbalance, mix inadequately, the inhomogeneous condition of reaction, still can cause residence time inadequately and reduce the conversion of ethylene oxide because of the reactant volume grow, thereby reduce product yield.

In the present invention, the total residence time of the ethylene glycol and ethylene oxide material in the reactor is preferably 0.2-10 min, more preferably 0.5-5 min, such as 0.2min, 0.5min, 1.0min, 1.5min, 2.0min, 2.5min, 3.0min, 3.5min, 4.0min, 4.5min, 5.0min, 5.5min, 6.0min, 6.5min, 7.0min, 7.5min, 8.0min, 8.5min, 9.0min, 9.5min, 10min, preferably a range value with any value as an upper limit or a lower limit. According to the invention, researches show that the retention time of materials in the continuous production device is too short, the conversion rate of ethylene oxide is low, the yield of one-way products is low, the conversion rate of ethylene oxide can be improved by prolonging the retention time under a certain temperature and pressure, but the retention time is too long, so that the production efficiency is reduced, and the equipment investment cost is increased.

The reaction liquid obtained by the reaction of the ethylenediamine and the ethylene oxide contains ethylenediamine, hydroxyethyl ethylenediamine, dihydroxyethyl ethylenediamine, and a small amount of trihydroxyethyl ethylenediamine and tetrahydroxyethyl ethylenediamine. According to the different volatility of each component in the reaction liquid, firstly, separating light components, namely unreacted raw material ethylenediamine, in a light component removal unit, and then separating in a separation unit to obtain hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine.

And the reaction liquid flowing out of the reaction unit enters a lightness removing unit through a pipeline or enters a heater to be heated to the required temperature and then is conveyed to the lightness removing unit, the ethylenediamine which does not participate in the reaction liquid is removed, and the lightness removing mother liquid enters a separation unit.

In the invention, the light component removal unit is preferably a flash tank or a rectifying tower; further, the light component removing unit comprises a flash tank and a light component removing rectifying tower which are sequentially communicated, and the light component removing rectifying tower is used for further distilling the flash mother liquor flowing out of the flash tank to obtain residual ethylenediamine.

When the lightness removing unit is a flash tank, the reaction liquid flowing out of the reaction unit enters a heater through a pipeline and is heated to 120-200 ℃, then flows into the flash tank, the ethylenediamine which does not participate in the reaction liquid is quickly separated under the condition of 1-80 kPa, and the flash mother liquid, namely lightness removing mother liquid directly enters a product separation unit;

in the invention, the temperature in the flash tank is preferably 100-200 ℃, more preferably 120-200 ℃, such as 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 180 ℃, 190 ℃ and 200 ℃, preferably the range value taking any value as the upper limit or the lower limit; the pressure is preferably 1 to 80kPa, more preferably 10 to 70kPa, such as 1kPa, 10kPa, 20kPa, 30kPa, 40kPa, 50kPa, 60kPa, 70kPa, 80kPa, 90kPa, preferably in the range of any of the above values as the upper limit or the lower limit.

When the light component removal unit is a light component removal rectifying tower, the reaction liquid flowing out of the reaction unit flows into the light component removal rectifying tower through a pipeline, the ethylenediamine which does not participate in the reaction liquid is separated under the conditions that the heating temperature of a tower kettle is 100-200 ℃ and 1-80 kPa, and the light component removal mother liquid directly enters the product separation unit.

The temperature of a tower kettle in the light component removal rectifying tower is preferably 100-200 ℃, more preferably 120-200 ℃, such as 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 180 ℃, 190 ℃ and 200 ℃, and is preferably a range value taking any value as an upper limit or a lower limit; the pressure is preferably 1 to 50kPa, more preferably 10 to 40kPa, such as 1kPa, 10kPa, 20kPa, 30kPa, 40kPa, 50kPa, preferably in the range of any of the above values as the upper limit or the lower limit.

When the light component removal unit is a flash tank and a light component removal rectifying tower which are sequentially communicated, reaction liquid flowing out of the reaction unit is heated to 120-200 ℃ by a heater and then flows into the flash tank, and the unreacted ethylenediamine in the reaction liquid is quickly evaporated under the condition of 1-80 kPa; and (3) feeding the flash evaporation mother liquor into a rectifying tower, further distilling off residual ethylenediamine in the reaction liquid under the conditions that the heating temperature of a tower kettle is 120-200 ℃ and the pressure is 1-50 kPa, and feeding the light mother liquor obtained by separating the ethylenediamine into a product separation unit.

The process parameter conditions of the flash tank and the light component removal rectifying tower are consistent with those described above, and the invention is not described in detail herein.

And the lightness removing mother liquid flowing out of the lightness removing unit enters a separation unit, and the separation unit is used for obtaining hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine in the reaction liquid of ethylenediamine and ethylene oxide. The dihydroxyethyl ethylenediamine produced by the reaction of ethylenediamine and ethylene oxide has two isomers, N, N-Bis (2-hydroxyethyl) ethylenediamine and N, N-Bis (2-hydroxyethyl) ethylenediamine, and the dihydroxyethyl ethylenediamine with the two isomers can be obtained in the separation process or can be obtained respectively.

In the invention, the separation unit comprises a first rectifying tower, and further comprises a first rectifying tower and a second rectifying tower which are communicated in sequence.

When the separation unit is a first rectifying tower, the light component removal mother liquor from the light component removal unit enters a rectifying tower of a product separation unit, the hydroxyethyl ethylenediamine product is obtained from the top of the tower under the conditions that the heating temperature of a tower kettle is 160-200 ℃ and 0.5-20 kPa, and the hydroxyethyl ethylenediamine product enters a hydroxyethyl ethylenediamine collection tank after condensation; the product obtained from the lateral line of the upper part of the tower is mixed with dihydroxyethyl ethylenediamine with two isomers, the product enters a dihydroxyethyl ethylenediamine collecting tank after being condensed, and the rectification residual liquid at the bottom of the tower is a heavy component containing trihydroxyethyl ethylenediamine and tetrahydroxyethyl ethylenediamine, and the heavy component is treated as waste after being collected.

When the separation unit is a first rectifying tower, the heating temperature of the tower kettle of the first rectifying tower is preferably 160-200 ℃, more preferably 170-190 ℃, such as 160 ℃, 170 ℃, 180 ℃, 190 ℃ and 200 ℃, and is preferably a range value taking any value as an upper limit or a lower limit; the pressure is preferably 0.5 to 20kPa, more preferably 1 to 15kPa, such as 0.5kPa, 1kPa, 2kPa, 3kPa, 4kPa, 5kPa, 6kPa, 7kPa, 8kPa, 9kPa, 10kPa, 11kPa, 12kPa, 13kPa, 14kPa, 15kPa, 16kPa, 17kPa, 18kPa, 19kPa, 20kPa, and preferably in the range of any of the above values as the upper limit or the lower limit.

When the separation unit is a first rectifying tower and a second rectifying tower which are communicated in sequence, light-weight-removed mother liquor from the light-weight-removing unit enters a first rectifying tower of a product separation unit, a small amount of residual ethylenediamine in reaction liquid is separated from the tower top under the conditions that the heating temperature of a tower kettle is 180-200 ℃ and 0.5-3 kPa, hydroxyethyl ethylenediamine obtained by separation from the side line of the upper part of the tower is condensed and enters a hydroxyethyl ethylenediamine collection tank, tower kettle liquid or the distillate of the side line of the lower part of the tower enters a second rectifying tower, dihydroxyethyl ethylenediamine with two isomers is obtained from the tower top under the conditions of 200-220 ℃ and 0.5-3 kPa and is condensed and then enters a dihydroxyethyl ethylenediamine collection tank, or N, N-Bis (2-hydroxyethyl) ethylenediamine is obtained from the tower top, N-Bis (2-hydroxyethyl) ethylenediamine is obtained from the side line of the upper part of the tower, the two isomers are respectively condensed and then enter corresponding product collection tanks, and the rectification residual liquid at the bottom of the tower is a heavy component containing trihydroxyethyl ethylenediamine and tetrahydroxyethyl ethylenediamine, and is collected and treated as waste. When only a flash tank or a rectifying tower is used in the light component removal unit, the scheme is preferably used for ensuring the removal effect of the ethylenediamine.

In the scheme, the heating temperature of the tower kettle of the first rectifying tower is preferably 180-200 ℃, such as 180 ℃, 190 ℃ and 200 ℃, and is preferably a range value taking any value as an upper limit or a lower limit; the pressure is preferably 0.5 to 3kPa, more preferably 1 to 2.5kPa, such as 0.5kPa, 1kPa, 1.5kPa, 2kPa, 2.5kPa, 3kPa, preferably in the range of any of the above values as the upper limit or the lower limit.

The heating temperature of the tower kettle of the second rectifying tower is preferably 200-220 ℃, such as 200 ℃, 210 ℃ and 220 ℃, and is preferably a range value taking any value as an upper limit or a lower limit; the pressure is preferably 0.5 to 3kPa, more preferably 1 to 2.5kPa, such as 0.5kPa, 1kPa, 1.5kPa, 2kPa, 2.5kPa, 3kPa, preferably in the range of any of the above values as the upper limit or the lower limit.

When the separation unit is a first rectifying tower and a second rectifying tower which are communicated in sequence, the light component removal mother liquor from the light component removal unit enters the first rectifying tower of the product separation unit, hydroxyethyl ethylenediamine is obtained by separating from the top of the tower under the condition that the heating temperature of a tower kettle is 180-200 ℃ and 0.5-3 kPa, tower kettle liquor or side-stream distillate at the lower part of the tower enters the second rectifying tower, dihydroxyethyl ethylenediamine with two isomers is obtained by separating from the top of the tower under the condition that the heating temperature of the tower kettle is 200-220 ℃ and 0.5-3 kPa and enters a dihydroxyethyl ethylenediamine collecting tank after being condensed, or N, N-Bis (2-hydroxyethyl) ethylenediamine is obtained by separating from the top of the tower, N-Bis (2-hydroxyethyl) ethylenediamine is obtained by separating from the side-stream at the upper part of the tower, the two isomers enter corresponding product collecting tanks after being condensed respectively, and the bottom of the tower is a heavy component containing trihydroxyethyl ethylenediamine and tetrahydroxyethyl ethylenediamine, collected and treated as waste.

In the scheme, the heating temperature of the tower kettle of the first rectifying tower is preferably 180-200 ℃, such as 180 ℃, 190 ℃ and 200 ℃, and is preferably a range value taking any value as an upper limit or a lower limit; the pressure is preferably 0.5 to 3kPa, more preferably 1 to 2.5kPa, such as 0.5kPa, 1kPa, 1.5kPa, 2kPa, 2.5kPa, 3kPa, preferably in the range of any of the above values as the upper limit or the lower limit.

The heating temperature of the tower kettle of the second rectifying tower is preferably 200-220 ℃, such as 200 ℃, 210 ℃ and 220 ℃, and is preferably a range value taking any value as an upper limit or a lower limit; the pressure is preferably 0.5 to 3kPa, more preferably 1 to 2.5kPa, such as 0.5kPa, 1kPa, 1.5kPa, 2kPa, 2.5kPa, 3kPa, preferably in the range of any of the above values as the upper limit or the lower limit.

The invention also provides a device for co-producing hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine, which is used for realizing the co-production of the hydroxyethyl ethylenediamine and the dihydroxyethyl ethylenediamine by matching with the method.

In the invention, the device for co-producing hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine is a continuous production device and comprises a storage unit, a continuous conveying unit, a reaction unit, a light component removal unit, a separation unit and a product collection unit.

In the invention, the storage unit comprises an ethylene diamine storage tank and an ethylene oxide storage tank which are respectively provided with an ethylene diamine outlet and an ethylene oxide outlet; for storing ethylene diamine and ethylene oxide feedstocks. And an ethylene diamine outlet and an ethylene oxide outlet of the storage unit are respectively communicated with an ethylene diamine inlet and an ethylene oxide inlet of the continuous conveying system.

In the invention, the continuous conveying unit comprises at least two feeding pumps, wherein each feeding pump is provided with an ethylenediamine inlet, an ethylene oxide inlet, an ethylenediamine outlet and an ethylene oxide outlet; and an ethylene diamine outlet and an ethylene oxide outlet of the continuous conveying system are respectively communicated with an ethylene diamine inlet and an ethylene oxide inlet of the reaction unit.

The continuous conveying system is used for realizing the continuous conveying of materials ethylene diamine and ethylene oxide and providing power for the flowing of the materials in a continuous production device, in order to realize the continuous and safe conveying of the materials to a reaction unit by overcoming pressure resistance, the continuous conveying system comprises at least two feeding pumps which are used for respectively conveying the ethylene diamine and the ethylene oxide, the upper pressure limit of the feeding pumps is not lower than 1MPa, if the upper pressure limit of the feeding pumps is lower than 1MPa, the power provided in the process of conveying the materials is limited, so that the products cannot smoothly enter the reaction unit, or the feeding is stopped because the pressure of the reaction system is higher than the upper pressure limit of the feeding pumps.

In the invention, the reaction unit is used for providing a place for mixing and reacting ethylene diamine and ethylene oxide, and the ethylene oxide and the ethylene diamine can react quickly and stably in the flowing process in the reaction unit, so that the contact probability of a product and a raw material is reduced, and the occurrence of side reactions is reduced.

The reaction unit can be a microchannel reactor, a tubular reactor, a combination of a microchannel reactor and a tubular reactor, a combination of a micromixer and a microchannel reactor, a combination of a micromixer and a tubular reactor, or a combination of a micromixer, a microchannel reactor and a tubular reactor; wherein the microchannel reactor is provided with a reaction channel and a heat exchange channel, and the characteristic dimension of the reaction channel is 1-15 mm; the reactor is characterized in that a mixing element playing a role of turbulence is arranged in a reaction cavity of the tubular reactor which is used independently, and a heat exchange jacket is arranged outside the reaction cavity; the tubular reactor used in combination with the microchannel reactor or the micromixer can be a reactor which is provided with a mixing element playing a role in turbulent flow in a reaction cavity and a heat exchange jacket outside the reaction cavity, and can also be one or more of a wound tubular reactor, a coil tubular reactor and a tubular reactor; the size (width or depth) of the mixing channel in the micromixer is preferably 1 to 10 mm.

In the present invention, when only the tubular reactor is used, it is preferable to set three temperature zones in order to secure the reaction effect; when a micromixer is arranged in the reaction unit before the reactor, two temperature zones or three temperature zones may be provided.

The microchannel reactor and the tubular reactor which is provided with a mixing element playing a role of turbulent flow in the reaction cavity and a heat exchange jacket outside the reaction cavity have excellent mass transfer effect and heat transfer effect, and can be independently used as a main reactor of a reaction unit, two feed inlets of the main reactor are respectively connected with an outlet of an ethylene diamine feed pump and an outlet of an ethylene oxide feed pump in a continuous conveying unit, and an outlet of the main reactor, namely a reaction liquid outlet, is connected with a reaction liquid inlet of a lightness removing unit.

In order to realize segmented temperature control, a single set of micro-channel reactor or tubular reactor capable of segmented temperature control can be adopted, or a combination of a plurality of sets of micro-channel reactors in series, a plurality of tubular reactors in series or a combination of micro-channel reactors and tubular reactors in series in sequence can be adopted, and each set of equipment controls different temperatures so as to meet the requirement of controlling different temperature zones.

The micro-channel reactor or the tubular reactor can be used in series with a micro-mixer, the micro-mixer is connected in series in front of the micro-channel reactor or the tubular reactor to realize premixing of materials, an outlet of an ethylenediamine feeding pump and an outlet of an ethylene oxide feeding pump in a continuous conveying unit are respectively connected with two inlets of the micro-mixer, an outlet of the micro-mixer is connected with an inlet of a reaction unit, the micro-mixer is preferably provided with a heat exchange channel, and the micro-channel reactor or the tubular reactor which is directly connected in series with the micro-mixer can control the same temperature and can also independently control the temperature.

In the invention, the light component removal unit is a flash tank or a rectifying tower; further, the light component removing unit comprises a flash tank and a light component removing rectifying tower which are sequentially communicated, and the light component removing rectifying tower is used for further distilling the flash mother liquor flowing out of the flash tank to obtain residual ethylenediamine. Further, the light component removing unit comprises a heater, a condenser and other conventional equipment matched with the light component removing unit.

In one embodiment of the invention, the lightness-removing unit is a flash tank, the reaction liquid flowing out of the reaction unit enters a heater through a pipeline to be heated and then flows into the flash tank to quickly separate the ethylenediamine which does not participate in the reaction from the reaction liquid, and the flash mother liquid, namely the lightness-removing mother liquid directly enters the product separation unit; the inlet of the flash tank is communicated with the reaction liquid outlet of the reaction unit, and the outlet of the flash tank is communicated with the inlet of the separation unit.

In another embodiment of the invention, the light component removal unit is a light component removal rectifying tower, the reaction liquid flowing out of the reaction unit flows into the light component removal rectifying tower through a pipeline, the ethylenediamine which does not participate in the reaction liquid is separated out under the conditions that the heating temperature of a tower kettle is 100-200 ℃ and 1-80 kPa, and the light component removal mother liquor directly enters the product separation unit. The inlet of the light component removal rectifying tower is communicated with the reaction liquid outlet of the reaction unit, and the outlet of the light component removal rectifying tower is communicated with the inlet of the separation unit.

In another embodiment of the invention, when the light component removal unit is a flash tank and a light component removal rectifying tower which are sequentially communicated, reaction liquid flowing out of the reaction unit flows into the flash tank after being heated by a heater, and ethylenediamine which does not participate in the reaction liquid is quickly evaporated; and (3) feeding the flash evaporation mother liquor into a light component removal rectifying tower, further distilling out residual ethylenediamine in the reaction liquid under the conditions that the heating temperature of a tower kettle is 120-200 ℃ and the pressure is 1-50 kPa, and feeding the light component removal mother liquor for separating the ethylenediamine into a product separation unit. The inlet of the flash tank is communicated with the reaction liquid outlet of the reaction unit, the outlet of the flash tank is communicated with the inlet of the light component removal rectifying tower, and the outlet of the light component removal rectifying tower is communicated with the inlet of the separation unit.

In the invention, the separation unit comprises a first rectifying tower, and further comprises a first rectifying tower and a second rectifying tower which are communicated in sequence.

In one embodiment of the invention, the separation unit is a first rectification column, and in this case, an inlet of the first rectification column is communicated with an outlet of the lightness-removing unit and is used for receiving lightness-removing mother liquor flowing out of the lightness-removing unit; the top of the first rectifying tower is provided with a hydroxyethyl diethylamine product outlet, and is communicated with a hydroxyethyl ethylenediamine collecting tank for collecting hydroxyethyl diethylamine products; and a dihydroxyethyl ethylenediamine product outlet is arranged on the lateral line of the upper part of the first rectifying tower, is communicated with a dihydroxyethyl ethylenediamine collecting tank and is used for collecting a dihydroxyethyl ethylenediamine product mixed with two isomers.

In another embodiment of the invention, the separation unit is a first rectifying tower and a second rectifying tower which are sequentially communicated, at this time, an inlet of the first rectifying tower is communicated with an outlet of the light component removal unit, an outlet of a tower kettle is communicated with an inlet of the second rectifying tower, and an ethylenediamine outlet is arranged at the top of the first rectifying tower and used for outputting a small amount of residual ethylenediamine in the reaction liquid; a hydroxyethyl ethylenediamine product outlet is arranged on the lateral line of the upper part of the first rectifying tower, and is communicated with a hydroxyethyl ethylenediamine collecting tank for collecting hydroxyethyl diethylamine products. And the top of the second rectifying tower is provided with a dihydroxyethyl ethylenediamine product outlet which is communicated with a dihydroxyethyl ethylenediamine collecting tank and used for collecting a dihydroxyethyl ethylenediamine product mixed with two isomers.

Preferably, for the separation of two isomers of the mixed dihydroxyethyl ethylenediamine, the top of the second rectifying tower is provided with an N, N-Bis (2-hydroxyethyl) ethylenediamine product outlet and communicated with an N, N-Bis (2-hydroxyethyl) ethylenediamine collecting tank, and the lateral line of the upper part of the second rectifying tower is provided with an N, N-Bis (2-hydroxyethyl) ethylenediamine product outlet and communicated with an N, N-Bis (2-hydroxyethyl) ethylenediamine collecting tank.

In another embodiment of the invention, the separation unit is a first rectifying tower and a second rectifying tower which are sequentially communicated, at this time, an inlet of the first rectifying tower is communicated with an outlet of the light component removal unit, an outlet of the tower kettle is communicated with an inlet of the second rectifying tower, and an outlet of the hydroxyethyl ethylenediamine product is arranged at the top of the first rectifying tower and is communicated with a hydroxyethyl ethylenediamine collecting tank for collecting the hydroxyethyl diethylamine product. And the top of the second rectifying tower is provided with a dihydroxyethyl ethylenediamine product outlet which is communicated with a dihydroxyethyl ethylenediamine collecting tank and used for collecting a dihydroxyethyl ethylenediamine product mixed with two isomers.

Preferably, for the separation of two isomers of the mixed dihydroxyethyl ethylenediamine, the top of the second rectifying tower is provided with an N, N-Bis (2-hydroxyethyl) ethylenediamine product outlet and communicated with an N, N-Bis (2-hydroxyethyl) ethylenediamine collecting tank, and the lateral line of the upper part of the second rectifying tower is provided with an N, N-Bis (2-hydroxyethyl) ethylenediamine product outlet and communicated with an N, N-Bis (2-hydroxyethyl) ethylenediamine collecting tank.

In order to improve the utilization rate of the ethylenediamine, the ethylenediamine outlet of the lightness-removing unit is connected with an ethylenediamine storage tank in the storage unit, and the ethylenediamine obtained by separation from the lightness-removing unit is condensed and then returns to the ethylenediamine storage tank of the storage unit through a pipeline for production of hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine.

Because the rapid reaction of the ethylenediamine and the ethylene oxide requires a certain temperature to be provided in advance, and the reaction of the ethylenediamine and the ethylene oxide is an exothermic reaction, in the specific embodiment of the invention, the temperature required for the reaction of the ethylenediamine and the ethylene oxide is provided by the heat exchange system, and the heat released by the reaction is removed in time. The heat exchange system can be an independent heat exchange device, such as a high-low temperature cold-hot integrated machine, is connected with a heat exchange channel of the device in the reaction unit, and adjusts the temperature through an ACS automatic control system; the heat exchange system can also adopt public works, a flow regulating valve group is arranged on an outlet pipeline of a steam system or a heat conduction oil system, and the temperature of materials is detected through a thermal resistor, so that the flow of the public works is regulated to realize the temperature control of the mixing unit, the reaction unit and the separation unit.

The invention adopts a backpressure system to carry out backpressure on a reaction system, a pressure regulating valve is arranged on a connecting pipeline between a reaction unit and a separation unit, the pressure of the system is fed back in real time through pressure sensing, and the pressure regulation and control of the reaction system are realized through automatic regulating systems such as feeding control, temperature control, discharge control and the like.

In the continuous production device for producing the hydroxyethyl ethylenediamine, each system and each unit are connected with the automatic control system for automatic operation, so that the continuous automatic production of the hydroxyethyl ethylenediamine can be realized. In the invention, the continuous production device of the hydroxyethyl ethylenediamine is provided with the detection and control of flow, pressure and temperature, and overpressure and overtemperature safety interlock. The overpressure safety interlock is arranged in the continuous conveying system, when any one parameter reaches a set value, the ESD emergency stop system is executed, a protection interlock signal is sent out, the feeding pump is closed, the equipment is safely protected, and serious loss caused by danger diffusion is avoided. The over-temperature safety interlock is characterized in that a temperature alarm interlock (high-temperature alarm value: 250 ℃) is arranged on the reactor, when the temperature exceeds the high-temperature alarm value, the system increases the public work consumption through an adjusting valve, and simultaneously executes an ESD emergency shutdown system to send out a protection interlock signal, close a feed pump, perform safety protection on equipment and avoid serious loss caused by dangerous diffusion. In addition, the continuous production device has four working modes: the production mode, the cleaning mode, the trial run mode and the shutdown mode are controlled by remote operation, so that the safety of automation and production processes is greatly improved.

In the present invention, unless otherwise explicitly specified or limited, the connection means between the systems/devices such as "communicate" and "connect" should be understood in a broad sense. For example, the connection may be direct pipe connection, or may be pipe connection connected with conventional conveying, metering, controlling, and temporary storage equipment such as pumping equipment, metering equipment, valve pipe fittings, and storage tanks, or may be fixed connection or detachable connection. The specific meaning of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In order to further illustrate the present invention, the method for co-producing hydroxyethylethylenediamine and dihydroxyethylethylenediamine provided by the present invention is described in detail with reference to the following examples, which should not be construed as limiting the scope of the present invention.

Example 1

Ethylene oxide from a storage tank is conveyed to a microchannel reactor with the liquid holdup of 1L in a reaction unit through a feed pump of a continuous conveying system at the flow rate of 2.15L/min and ethylenediamine in the molar ratio of 1:1 for reaction, stays for 12s and then flows out of the reaction unit to obtain reaction liquid, wherein the microchannel reactor is provided with three sections for controlling the temperature, the temperature is 80 ℃, 160 ℃ and 100 ℃, and the pressure of the reaction unit is controlled to be 4.5MPa in the reaction process.

And the reaction liquid flowing out of the reaction unit enters a rectifying tower of the lightness-removing unit through a pipeline, the ethylenediamine is separated from the top of the tower under the conditions that the heating temperature of a tower kettle is 180 ℃ and 35kPa, and the ethylenediamine is condensed and then returns to an ethylenediamine storage tank of the storage unit.

The mother liquor without the ethylenediamine enters a first rectifying tower of a product separation unit, hydroxyethyl ethylenediamine is obtained by separation from the top of the tower under the conditions that the heating temperature of a tower kettle is 190 ℃ and 1.5kPa, the condensed hydroxyethyl ethylenediamine is transferred to a hydroxyethyl ethylenediamine collecting tank, the tower bottom liquor enters a second rectifying tower, N-Bis (2-hydroxyethyl) ethylenediamine is obtained by separation from the top of the tower under the conditions that the heating temperature of the tower kettle is 205 ℃ and 1kPa, N-Bis (2-hydroxyethyl) ethylenediamine is obtained from the lateral line of the upper part of the tower, and the two products are transferred to corresponding product collecting tanks after being respectively condensed.

The reaction liquid and the product which flow out from the reaction unit are respectively subjected to gas phase detection, the content of hydroxyethyl ethylenediamine in the reaction liquid is 78.5 percent, the content of dihydroxyethyl ethylenediamine is 20 percent, the sum of the contents of trihydroxyethyl ethylenediamine and tetrahydroxyethyl ethylenediamine is 1.9 percent, the yield of the product hydroxyethyl ethylenediamine obtained after separation is 76.5 percent, the purity is 99.1 percent, the yield of N, N-Bis (2-hydroxyethyl) ethylenediamine is 11.3 percent, the yield of N, N-Bis (2-hydroxyethyl) ethylenediamine is 8.1 percent, the purity is 98.2 percent, and the comprehensive product yield based on ethylene oxide is 96.1 percent.

Example 2

Ethylene oxide from a storage tank is conveyed to two microchannel reactors with the liquid holdup of 1L connected in series in a reaction unit through a feed pump of a continuous conveying system at the flow rate of 1.34L/min and ethylenediamine in the molar ratio of 1:1.5 for reaction, and flows out of the reaction unit after staying for 30s to obtain reaction liquid, wherein the microchannel reactors are provided with two sections for controlling the temperature, the temperature is 100 ℃ and 140 ℃ sequentially, and the pressure of the reaction unit is controlled to be 3.2MPa in the reaction process.

And the reaction liquid flowing out of the reaction unit enters a rectifying tower of the lightness-removing unit through a pipeline, the ethylenediamine is separated from the top of the tower under the conditions that the heating temperature of a tower kettle is 150 ℃ and 10kPa, and the ethylenediamine is condensed and then returns to an ethylenediamine storage tank of the storage unit.

The mother liquor without the ethylenediamine enters a first rectifying tower of a product separation unit, hydroxyethyl ethylenediamine is obtained by separation from the top of the tower under the conditions that the heating temperature of a tower kettle is 200 ℃ and 3kPa, the condensed hydroxyethyl ethylenediamine is transferred to a hydroxyethyl ethylenediamine collecting tank, the tower bottom liquor enters a second rectifying tower, N-Bis (2-hydroxyethyl) ethylenediamine is obtained by separation from the top of the tower under the conditions that the heating temperature of the tower kettle is 200 ℃ and 0.5kPa, N-Bis (2-hydroxyethyl) ethylenediamine is obtained from the lateral line of the upper part of the tower, and the two products are transferred to corresponding product collecting tanks after being respectively condensed.

Gas phase detection is carried out on the obtained reaction liquid and the obtained product respectively, the content of hydroxyethyl ethylenediamine in the reaction liquid is 83.2%, the content of dihydroxyethyl ethylenediamine is 14.7%, the sum of the contents of trihydroxyethyl ethylenediamine and tetrahydroxyethyl ethylenediamine is 1.8%, the yield of the product hydroxyethyl ethylenediamine obtained by separation is 81.5%, the purity is 99.3%, the yield of N, N-Bis (2-hydroxyethyl) ethylenediamine is 8.3%, the yield of N, N-Bis (2-hydroxyethyl) ethylenediamine is 6.4%, the purity is 98.1%, and the comprehensive product yield based on ethylene oxide is 96.2%.

Example 3

Ethylene oxide from a storage tank is conveyed to three microchannel reactors which are sequentially connected in series and have the total liquid holdup of 5L for reaction by a feed pump of a continuous conveying system at the flow rate of 1.16L/min and ethylene diamine in a molar ratio of 1:2, the three microchannel reactors stay for 60s and flow out of the reaction unit to obtain reaction liquid, wherein three sections of temperature control are arranged on the microchannel reactors, the temperature is controlled at 60 ℃, the temperature is controlled at 130 ℃ and the temperature is controlled at 80 ℃, and the pressure of the reaction unit is controlled to be 2.6MPa in the reaction process.

And the reaction liquid flowing out of the reaction unit enters a rectifying tower of the lightness-removing unit through a pipeline, the ethylenediamine is separated from the top of the tower under the conditions that the heating temperature of a tower kettle is 120 ℃ and 2.5kPa, and the ethylenediamine is condensed and then returns to an ethylenediamine storage tank of the storage unit.

The mother liquor without the ethylenediamine enters a first rectifying tower of a product separation unit, hydroxyethyl ethylenediamine is obtained by separation from the top of the tower under the conditions that the heating temperature of a tower kettle is 180 ℃ and 0.5kPa, the condensed hydroxyethyl ethylenediamine is transferred to a hydroxyethyl ethylenediamine collecting tank, the tower bottom liquor enters a second rectifying tower, N-Bis (2-hydroxyethyl) ethylenediamine is obtained by separation from the top of the tower under the conditions that the heating temperature of the tower kettle is 220 ℃ and 3kPa, N-Bis (2-hydroxyethyl) ethylenediamine is obtained from the lateral line of the upper part of the tower, and the two products are transferred to corresponding product collecting tanks after being respectively condensed.

Gas phase detection is carried out on the obtained reaction liquid and the obtained product respectively, the content of hydroxyethyl ethylenediamine in the reaction liquid is 86.1%, the content of dihydroxyethyl ethylenediamine is 11.8%, the sum of the contents of trihydroxyethyl ethylenediamine and tetrahydroxyethyl ethylenediamine is 1.7%, the yield of the product hydroxyethyl ethylenediamine obtained by separation is 84.6%, the purity is 99.3%, the yield of N, N-Bis (2-hydroxyethyl) ethylenediamine is 6.5%, the yield of N, N-Bis (2-hydroxyethyl) ethylenediamine is 5.2%, the purity is 98.4%, and the comprehensive product yield based on ethylene oxide is 96.3%.

Example 4

Conveying ethylene oxide from a storage tank to a reaction unit through a feed pump of a continuous conveying system at a flow rate of 1.51L/min and ethylenediamine in a molar ratio of 1:2.5, reacting the reaction unit with a microchannel reactor with a total liquid holdup of 15L which are sequentially connected in series, and allowing the reaction unit to stay for 120s and then flow out of the reaction unit to obtain a reaction liquid, wherein the reaction unit is provided with two sections of temperature control, the temperature is sequentially 130 ℃ and 100 ℃, and the pressure of the reaction unit is controlled to be 2.5MPa in the reaction process.

And the reaction liquid flowing out of the reaction unit enters a heater through a pipeline and is heated to 160 ℃, then enters a flash tank to separate the ethylenediamine under the condition of 15kPa, and returns to an ethylenediamine storage tank of the storage unit after being condensed.

The mother liquor without the ethylenediamine enters a first rectifying tower of a product separation unit, residual ethylenediamine is separated from the top of the tower under the conditions that the heating temperature of a tower kettle is 185 ℃ and 1kPa, hydroxyethyl ethylenediamine is obtained by separating from the side line of the upper part of the tower, the condensed mother liquor is transferred to a hydroxyethyl ethylenediamine collecting tank, the tower bottom liquor enters a second rectifying tower, N-Bis (2-hydroxyethyl) ethylenediamine is obtained by separating from the top of the tower under the conditions that the heating temperature of the tower kettle is 210 ℃ and 1.8kPa, N-Bis (2-hydroxyethyl) ethylenediamine is obtained by separating from the side line of the upper part of the tower, and the two products are transferred to corresponding product collecting tanks after being respectively condensed.

The obtained reaction solution and the product were subjected to gas phase detection respectively, the content of hydroxyethylethylenediamine in the reaction solution was 87.4%, the content of dihydroxyethylethylenediamine was 11.4%, the sum of the contents of trishydroxyethylethylenediamine and tetrahydroxyethylethylenediamine was 1.5%, the yield of hydroxyethylethylenediamine, which was a product obtained by separation, was 85.8%, the purity was 99.2%, the yield of N, N-Bis (2-hydroxyethyl) ethylenediamine was 6.1%, the yield of N, N-Bis (2-hydroxyethyl) ethylenediamine was 4.6%, the purities were 97.2%, and the comprehensive product yield based on ethylene oxide was 96.5%.

Example 5

Ethylene oxide from a storage tank is conveyed to a reaction unit through a feed pump of a continuous conveying system at a flow rate of 1.78L/min and ethylenediamine in a molar ratio of 1:3, the microchannel reactor and the tubular reactor are sequentially connected in series, the total liquid holdup is 30L, the reaction is carried out, the reaction liquid is obtained after the reaction liquid stays for 180s and flows out of the reaction unit, two sections of temperature control are arranged in the reaction unit, the temperature is controlled at 100 ℃ and 120 ℃ sequentially, and the pressure of the reaction unit is controlled to be 2.1MPa in the reaction process.

And the reaction liquid flowing out of the reaction unit enters a heater through a pipeline and is heated to 200 ℃, then enters a flash tank to separate the ethylenediamine under the condition of 80kPa, and returns to an ethylenediamine storage tank of the storage unit after being condensed.

The mother liquor without the ethylenediamine enters a first rectifying tower of a product separation unit, hydroxyethyl ethylenediamine is obtained by separation from the top of the tower under the conditions that the heating temperature of a tower kettle is 200 ℃ and 20kPa, the hydroxyethyl ethylenediamine is transferred into a hydroxyethyl ethylenediamine collecting tank after condensation, dihydroxyethyl ethylenediamine mixed with two isomers is obtained by separation from the lateral line of the upper part of the tower, and the dihydroxyethyl ethylenediamine is transferred into a dihydroxyethyl ethylenediamine collecting tank after condensation.

The obtained reaction solution and the product are respectively subjected to gas phase detection, the content of hydroxyethyl ethylenediamine in the reaction solution is 89.3%, the content of dihydroxyethyl ethylenediamine is 9.6%, the sum of the contents of the trihydroxyethyl ethylenediamine and the tetrahydroxyethyl ethylenediamine is 1.3%, the yield of the product hydroxyethyl ethylenediamine obtained by separation is 88.1%, the purity is 99.4%, the yield of the dihydroxyethyl ethylenediamine is 8.6%, the purity is 97.5%, and the comprehensive product yield based on ethylene oxide is 96.7%.

Example 6

Ethylene oxide from a storage tank is conveyed into a reaction unit through a feed pump of a continuous conveying system at a flow rate of 2.22L/min and ethylenediamine in a molar ratio of 1:3.5 so that a series-connected microchannel reactor with a total liquid holdup of 50L reacts with a tubular reactor, and flows out of the reaction unit after staying for 240s to obtain a reaction liquid, wherein the reaction unit is provided with two sections of temperature control, the temperature is controlled at 100 ℃ and 70 ℃ in sequence, and the pressure of the reaction unit is controlled at 1.7MPa in the reaction process.

And the reaction liquid flowing out of the reaction unit enters a heater through a pipeline and is heated to 120 ℃, then enters a flash tank to separate the ethylenediamine under the condition of 1kPa, and returns to an ethylenediamine storage tank of the storage unit after being condensed.

The mother liquor without the ethylenediamine enters a first rectifying tower of a product separation unit, hydroxyethyl ethylenediamine is obtained by separation from the top of the tower under the conditions that the heating temperature of a tower kettle is 185 ℃ and 10kPa, the hydroxyethyl ethylenediamine is transferred into a hydroxyethyl ethylenediamine collecting tank after condensation, dihydroxyethyl ethylenediamine mixed with two isomers is obtained by separation from the lateral line of the upper part of the tower, and the dihydroxyethyl ethylenediamine is transferred into a dihydroxyethyl ethylenediamine collecting tank after condensation.

The obtained reaction solution and the product are respectively subjected to gas phase detection, the content of hydroxyethyl ethylenediamine in the reaction solution is 91.6%, the content of dihydroxyethyl ethylenediamine is 7.3%, the sum of the contents of the trihydroxyethyl ethylenediamine and the tetrahydroxyethyl ethylenediamine is 1.2%, the yield of the product hydroxyethyl ethylenediamine obtained by separation is 90.4%, the purity is 99.3%, the yield of the dihydroxyethyl ethylenediamine is 6.9%, the purity is 97.8%, and the comprehensive product yield based on ethylene oxide is 97.3%.

Example 7

Ethylene oxide from a storage tank is conveyed to a reaction unit through a feed pump of a continuous conveying system at a flow rate of 3.18L/min and ethylenediamine in a molar ratio of 1:4, the microchannel reactor and the tubular reactor are sequentially connected in series, the total liquid holdup is 100L, the microchannel reactor and the tubular reactor react, the reaction unit stays for 300s and then flows out to obtain reaction liquid, three sections of temperature control are arranged in the reaction unit, the temperature control is sequentially 80 ℃, 100 ℃ and 60 ℃, and the pressure of the reaction unit is controlled to be 1.5MPa in the reaction process.

And the reaction liquid flowing out of the reaction unit enters a heater through a pipeline and is heated to 150 ℃, then enters a flash tank to separate the ethylenediamine under the condition of 10kPa, the separated mother liquid enters a light component removal rectifying tower to separate the residual ethylenediamine under the conditions of 150 ℃ and 11kPa, and the two parts of separated ethylenediamine are condensed and then return to an ethylenediamine storage tank of the storage unit.

The mother liquor without the ethylenediamine enters a first rectifying tower of a product separation unit, hydroxyethyl ethylenediamine is obtained by separation from the top of the tower under the conditions that the heating temperature of a tower kettle is 160 ℃ and 0.5kPa, the hydroxyethyl ethylenediamine is transferred into a hydroxyethyl ethylenediamine collecting tank after condensation, dihydroxyethyl ethylenediamine mixed with two isomers is obtained by separation from the lateral line of the upper part of the tower, and the dihydroxyethyl ethylenediamine is transferred into a dihydroxyethyl ethylenediamine collecting tank after condensation.

Gas phase detection is carried out on the obtained reaction liquid and the obtained product respectively, the content of hydroxyethyl ethylenediamine in the reaction liquid is 93.4%, the content of dihydroxyethyl ethylenediamine is 5.3%, the sum of the contents of the trihydroxyethyl ethylenediamine and the tetrahydroxyethyl ethylenediamine is 1.1%, the yield of the product hydroxyethyl ethylenediamine obtained by separation is 93.1%, the purity is 99.4%, the yield of the dihydroxyethyl ethylenediamine is 4.9%, the purity is 98.3%, and the comprehensive product yield based on ethylene oxide is 98%.

Example 8

Conveying ethylene oxide from a storage tank to a reaction unit through a feed pump of a continuous conveying system at a flow rate of 2.7L/min and ethylenediamine in a molar ratio of 1:4.5, sequentially connecting a micro mixer with a total liquid holdup of 150L in series with the reaction unit, reacting the micro mixer with the tubular reactor, staying for 480s, and then flowing out of the reaction unit to obtain a reaction liquid, wherein the reaction unit is provided with two sections of temperature control, and the temperature control is sequentially 110 ℃ and 70 ℃.

And the reaction liquid flowing out of the reaction unit enters a heater through a pipeline and is heated to 180 ℃, then enters a flash tank to separate the ethylenediamine under the condition of 40kPa, the separated mother liquid enters a light-weight removal rectifying tower to separate the residual ethylenediamine under the conditions of 180 ℃ and 30kPa, and the two parts of separated ethylenediamine return to an ethylenediamine storage tank of the storage unit after being condensed.

The mother liquor without the ethylenediamine enters a first rectifying tower of a product separation unit, hydroxyethyl ethylenediamine is obtained by separation from the top of the tower under the conditions that the heating temperature of a tower kettle is 180 ℃ and 0.5kPa, the hydroxyethyl ethylenediamine is transferred to a hydroxyethyl ethylenediamine collecting tank after condensation, the tower bottom liquor enters a second rectifying tower, dihydroxyethyl ethylenediamine mixed with two isomers is obtained by separation from the top of the tower under the conditions that the heating temperature of the tower kettle is 200 ℃ and 1kPa, and the dihydroxyethyl ethylenediamine is transferred to a dihydroxyethyl ethylenediamine collecting tank after condensation.

Respectively carrying out gas phase detection on the obtained reaction liquid and the product, wherein the content of hydroxyethyl ethylenediamine in the reaction liquid is 94.7%, the content of dihydroxyethyl ethylenediamine is 4.2%, the sum of the contents of the trihydroxyethyl ethylenediamine and the tetrahydroxyethyl ethylenediamine is 0.9%, the yield of the product hydroxyethyl ethylenediamine obtained by separation is 93.6%, the purity is 99.2%, the yield of the dihydroxyethyl ethylenediamine is 3.9%, the purity is 97.7%, and the comprehensive product yield based on ethylene oxide is 97.5%.

Example 9

Conveying ethylene oxide from a storage tank to a tubular reactor with total liquid holdup of 200L connected in series in a reaction unit in sequence for reaction by a feed pump of a continuous conveying system at a flow rate of 2.63L/min and ethylene diamine in a molar ratio of 1:5, and flowing out of the reaction unit after staying for 600s to obtain reaction liquid, wherein the tubular reactor is provided with two sections for controlling temperature, the temperature is 60 ℃ and 100 ℃ in sequence, and the pressure of the reaction unit is controlled to be 1.5MPa in the reaction process.

And the reaction liquid flowing out of the reaction unit enters a heater through a pipeline and is heated to 120 ℃, then enters a flash tank to separate the ethylenediamine under the condition of 2kPa, the separated mother liquid enters a light component removal rectifying tower to separate the residual ethylenediamine under the conditions of 130 ℃ and 1kPa, and the two parts of separated ethylenediamine are condensed and then return to an ethylenediamine storage tank of the storage unit.

The mother liquor without the ethylenediamine enters a first rectifying tower of a product separation unit, hydroxyethyl ethylenediamine is obtained by separation from the top of the tower under the conditions that the heating temperature of a tower kettle is 195 ℃ and 2.5kPa, the condensed hydroxyethyl ethylenediamine is transferred to a hydroxyethyl ethylenediamine collecting tank, the tower bottom liquor enters a second rectifying tower, N-bis (2-hydroxyethyl) ethylenediamine is obtained by separation from the top of the tower under the conditions that the heating temperature of the tower kettle is 210 ℃ and 2kPa, dihydroxyethyl ethylenediamine mixed with two isomers is obtained by separation from the top of the tower, and the condensed hydroxyethyl ethylenediamine is transferred to a dihydroxyethyl ethylenediamine collecting tank.

The obtained reaction solution and the product are respectively subjected to gas phase detection, the content of hydroxyethyl ethylenediamine in the reaction solution is 95.8%, the content of dihydroxyethyl ethylenediamine is 3.1%, the sum of the contents of the trihydroxyethyl ethylenediamine and the tetrahydroxyethyl ethylenediamine is 0.8%, the yield of the product hydroxyethyl ethylenediamine obtained by separation is 94.4%, the purity is 99.1%, the yield of the dihydroxyethyl ethylenediamine is 2.5%, the purity is 97.3%, and the comprehensive product yield based on ethylene oxide is 96.9%.

Comparative example 1

Adding ethylenediamine into a tower reactor, heating to 100 ℃ and 130 ℃, carrying out two-stage condensation reflux at the top, allowing the ethylenediamine to fall into a gas-liquid contactor to be in gas-liquid contact with the entering ethylene oxide gas, wherein the ratio of the ethylenediamine to the ethylene oxide is 2:1, allowing the generated hydroxyethyl ethylenediamine to fall into the bottom of the tower after the reaction, continuously evaporating the ethylenediamine at the bottom of the tower, transferring feed liquid into a rectifying tower after the reaction is finished, separating the hydroxyethyl ethylenediamine at 180 ℃ and 2kPa, and transferring the tower bottom liquid into a subsequent rectifying tower to separate the dihydroxyethyl ethylenediamine at 200 ℃ and 2 kPa.

The obtained reaction liquid and the product are respectively subjected to gas phase detection, the content of hydroxyethyl ethylenediamine in the reaction liquid is 71.2%, the content of dihydroxyethyl ethylenediamine is 21.1%, the sum of the contents of the trihydroxyethyl ethylenediamine and the tetrahydroxyethyl ethylenediamine is 7.4%, the purity of the hydroxyethyl ethylenediamine obtained after separation is 98.5%, the purity of the dihydroxyethyl ethylenediamine is 87.2%, and the comprehensive product yield based on ethylene oxide is 88.7%.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (10)

1. A method for co-producing hydroxyethyl ethylenediamine and dihydroxyethyl ethylenediamine comprises the following steps:

A) conveying ethylenediamine and ethylene oxide to a reaction unit through a continuous conveying system for reaction to obtain a reaction solution;

the molar ratio of the ethylenediamine to the ethylene oxide is (1-5): 1; the reaction unit is provided with at least two temperature zones, and the temperature of each temperature zone is 60-160 ℃;

B) conveying the reaction liquid to a lightness removing unit, and removing ethylenediamine in the reaction liquid to obtain lightness removing mother liquid;

C) and conveying the light removal mother liquor to a separation unit, and collecting a hydroxyethyl ethylenediamine product and a dihydroxyethyl ethylenediamine product.

2. The method according to claim 1, wherein the reaction unit is provided with two reaction temperature zones, the temperature of the first temperature zone is 60-100 ℃, and the temperature of the second temperature zone is 100-160 ℃.

3. The method according to claim 1, wherein the reaction unit is provided with two temperature zones, the temperature of the first temperature zone is 100-160 ℃, and the temperature of the second temperature zone is 60-100 ℃.

4. The method according to claim 1, wherein the reaction unit is provided with three reaction temperature zones, the temperature of the first temperature zone is 60-100 ℃, the temperature of the second temperature zone is 100-160 ℃, and the temperature of the third temperature zone is 60-100 ℃.

5. The method according to claim 1, wherein the pressure of the reaction in the step A) is 1-4.5 MPa.

6. The method according to claim 1, wherein the residence time in the reaction unit is 0.2 to 10 min.

7. The method as claimed in claim 6, wherein the temperature for removing the ethylenediamine in the step B) is 100-200 ℃; the pressure is 1 to 80 kPa.

8. The method according to claim 7, characterized in that the separation unit in step C) comprises a first rectification column;

the temperature of the first rectifying tower is 180-200 ℃, and the pressure is 0.5-3 kPa.

9. The method according to claim 7, characterized in that the separation unit in step C) comprises a second rectification column;

the temperature of the second rectifying tower is 200-220 ℃, and the pressure is 0.5-3 kPa.

10. The method according to any one of claims 1 to 9, wherein the reaction unit comprises a reactor, or a combination of a micromixer and a reactor; the reactor is one or the combination of two of a micro-channel reactor and a tubular reactor;

the light component removal unit comprises a flash drum and/or a light component removal rectifying tower.

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