Production method of mixed alcohol amine without rectification and ammonia recovery

Abstract

The invention discloses a production method of mixed alcohol amine without rectification and ammonia recovery. The production method specifically comprises the following steps: S1, a reaction stage of ethylene oxide and ammonia water; s2, a further reaction stage with epoxypropane; the invention relates to the technical field of chemical synthesis. According to the production method of the mixed alcohol amine without rectification and ammonia recovery, a method for producing ethanolamine and isopropanolamine without distillation and free ammonia recovery is adopted, the links of distillation and free amine recovery are omitted, the cost is greatly saved, the method is simple and convenient, a water absorption molecular sieve is used as a catalyst, and the production cost is greatly reduced. According to the method, the catalytic water consumption is greatly reduced, so that the energy consumption is reduced, liquid ammonia is directly used as a raw material, the material cost and the operation cost are reduced, meanwhile, the reaction rate is increased, the generation of impurities is reduced, the decomposition of the product is avoided, the purity of isopropanolamine is increased (99% or above), and the method is suitable for large-scale production and has a wide application prospect. And the production process flow is simplified.

Description

Technical Field

[0001] The invention relates to the technical field of chemical synthesis, in particular to a method for producing mixed alcohol amines without rectification and ammonia recovery. Background Art

[0002] Alcoholamines are a class of organic compounds that contain both amino and hydroxyl functional groups in their molecules. They can be divided into primary, secondary and tertiary alkanolamines according to the position of the hydroxyl group. Alkanolamines contain amino functional groups. Alkanolamines are alkaline and can react with acids to form corresponding salts. Alkanolamines have good solvent properties and can dissolve water-insoluble substances. Generally speaking, alkanolamines can be prepared by reacting ammonia with aldehydes or carboxylates. Common preparation methods include diazotization reduction, amine and acid anhydride reaction, chloroalkane and ammonia reaction, etc. Alkanolamines are easy to absorb moisture in humid air and should be kept in a sealed container when in contact with water or humid air. Alkanolamines are irritating and corrosive. Personal protective equipment should be worn during use to avoid contact with skin and eyes. During storage and operation, contact with incompatible substances such as oxidants, acids and organochlorine compounds should be avoided to avoid dangerous reactions. Alkanolamines should be kept away from fire sources and high temperature environments to avoid the risk of fire and explosion. If leakage occurs, appropriate emergency measures should be taken promptly and handled and disposed of in accordance with relevant regulations.

[0003] So far, ethanolamines produced from ethylene oxide and liquid ammonia, as well as isopropanolamines produced on the basis of ethanolamine, need to be distilled and free ammonia recovered before they can be used by downstream industries. The process of distilling and recovering free amines greatly increases the production cost. In the prior art, the production of mixed alcoholamine products such as monoethanolamine, diethanolamine, triethanolamine, etc. usually requires multi-step reactions and subsequent distillation and separation processes to purify the products and recover unreacted ammonia. This process is not only energy-intensive and equipment-complex, but also increases production costs and environmental pollution risks. Therefore, it is of great significance to develop a method for producing mixed alcoholamines that simplifies the process and reduces energy consumption. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides a method for producing mixed alcohol amines without distillation and recovery of ammonia, which solves the problems mentioned in the above background technology.

[0005] To achieve the above object, the present invention is implemented by the following technical scheme: a method for producing mixed alcohol amines without distillation and recovery of ammonia, specifically comprising the following steps:

[0006] S1, reaction stage of ethylene oxide and ammonia:

[0007] (1) Raw material preparation: prepare ethylene oxide and ammonia water that meet the process requirements;

[0008] (2) mixing and reacting: mixing ethylene oxide and aqueous ammonia in a molar ratio of (1-99):(99-1), and feeding the mixture into a reactor, wherein the ethylene oxide and aqueous ammonia react under a pressure of 0.1 MPa to 10 MPa and a temperature of 20° C. to 150° C. in the reactor;

[0009] (3) Product collection: After the reaction is completed, the reaction product is collected. The product is a mixture, mainly containing monoethanolamine, diethanolamine, triethanolamine, free ammonia and water;

[0010] S2, further reaction stage with propylene oxide:

[0011] (1) Raw material mixing: the mixture obtained in the previous step is directly introduced into the reaction system containing propylene oxide without the need for ammonia removal or distillation treatment;

[0012] (2) Control of reaction conditions: Propylene oxide reacts with the alcohol amine in the mixture at a temperature of 50°C to 120°C and a pressure of normal pressure;

[0013] (3) Product formation: During the reaction, propylene oxide reacts with alcohol amines to form a variety of products, including EDIPA, DEIPA, TIPA, propylene glycol, some residual triethanolamine, some ethers, and a small amount of free ammonia and water;

[0014] (4) Product collection and treatment: After the reaction is completed, the reaction products are collected.

[0015] Preferably, in S1(1), the aqueous ammonia can be prepared in advance to a desired concentration, usually 95% to 99% concentrated aqueous ammonia. In S1(2), the reactor can be a tower reactor or a tubular reactor.

[0016] Preferably, in S1(3), the content of the mixture includes monoethanolamine (10%-50%), diethanolamine (10%-50%), triethanolamine (1%-30%), free ammonia (10%-30%) and water (10%-40%).

[0017] Preferably, in S2(3), the product content includes EDIPA (N-ethyldiisopropanolamine, 10%-50%), DEIPA (N,N-diethylisopropanolamine, 10%-50%), TIPA (triisopropanolamine, 10%-30%), propylene glycol (1%-10%), some residual triethanolamine, some ethers and a small amount of free ammonia (<5%) and water (10%-20%).

[0018] Preferably, in S2(2), these reaction conditions also need to be optimized according to the design of the reactor and the properties of the raw materials to ensure the generation of the target product.

[0019] Preferably, in S1(3), in the process of producing ethanolamine by ammonolysis of ethylene oxide, the product collection step generally includes the following key stages:

[0020] (1) Post-reaction treatment:

[0021] Flash deamination: After the reaction is completed, the reaction mixture is first flashed through a high-pressure flash tower to remove more than 90% of the ammonia in the mixture;

[0022] Dehydration: After flash deammoniation, the mixed ethanolamine enters the atmospheric pressure dehydration tower to further remove most of the water in the material. The remaining water is evaporated in the dehydration tower to ensure the smooth progress of subsequent refining;

[0023] (2) Refining process:

[0024] Continuous distillation: Mixed ethanolamines are separated and purified by continuous distillation technology;

[0025] Monoethanolamine (MEA) refining: mixed ethanolamine is fed from the middle of the MEA tower, and high-purity MEA is evaporated from the top of the tower under high vacuum conditions;

[0026] Refining of diethanolamine (DEA) and triethanolamine (TEA): The mixed liquid after removing MEA enters the DEA and TEA towers, DEA is refined from the top of the tower, and TEA is obtained through the side line and the bottom of the tower respectively;

[0027] Product classification and collection: various ethanolamine products obtained through distillation are classified and collected according to purity requirements to meet different market demands;

[0028] (3) Quality control and testing:

[0029] During the entire collection process, quality control and testing of products at each stage are required to ensure that the purity and quality of the products meet the standard requirements.

[0030] Preferably, in the product collection step, (1) flash deamination in the post-reaction treatment is the key to reducing the difficulty of subsequent treatment and improving the purity of the product; (2) continuous distillation in the refining process, which is usually carried out in multiple distillation towers to ensure the purity of different ethanolamine products.

[0031] Beneficial Effects

[0032] The present invention provides a method for producing mixed alcohol amines without rectification and ammonia recovery. Compared with the prior art, the method has the following beneficial effects: the method for producing mixed alcohol amines without rectification and ammonia recovery can produce ethanolamines and isopropanolamines without distillation and recovery of free ammonia, thereby eliminating the steps of distillation and recovery of free amines, greatly saving costs, the method is simple and convenient, uses water-absorbing molecular sieves as catalysts, greatly reduces the amount of catalytic water, thereby reducing energy consumption, and directly uses liquid ammonia as a raw material, reducing material costs and operating costs, and at the same time, the method also improves the reaction rate, reduces the generation of impurities and avoids the decomposition of products, improves the purity of isopropanolamine (more than 99%), is suitable for large-scale production, simplifies the production process, eliminates the steps of rectification and ammonia recovery, significantly reduces production costs and energy consumption, improves reaction efficiency and product yield, and reduces waste discharge and environmental pollution, and the obtained mixed product has a wide range of application prospects, especially in the field of building materials, showing good performance advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a flow chart of the steps of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figure 1 The present invention provides three technical solutions: a method for producing mixed alcohol amines without distillation and recovery of ammonia, specifically including the following embodiments:

[0036] Embodiment 1

[0037] S1, reaction stage of ethylene oxide and ammonia:

[0038] (1) Raw material preparation: prepare ethylene oxide and ammonia water that meet the process requirements;

[0039] (2) Mixing and reacting: mixing ethylene oxide and aqueous ammonia in a molar ratio of (1-99):(99-1), and feeding the mixture into a reactor, where the ethylene oxide and aqueous ammonia react under a pressure of 5 MPa and a temperature of 85° C.;

[0040] (3) Product collection: After the reaction is completed, the reaction product is collected. The product is a mixture, mainly containing monoethanolamine, diethanolamine, triethanolamine, free ammonia and water;

[0041] S2, further reaction stage with propylene oxide:

[0042] (1) Raw material mixing: the mixture obtained in the previous step is directly introduced into the reaction system containing propylene oxide without the need for ammonia removal or distillation treatment;

[0043] (2) Control of reaction conditions: Propylene oxide reacts with the alcohol amine in the mixture at a temperature of 85°C and a pressure of normal pressure;

[0044] (3) Product formation: During the reaction, propylene oxide reacts with alcohol amines to form a variety of products, including EDIPA, DEIPA, TIPA, propylene glycol, some residual triethanolamine, some ethers, and a small amount of free ammonia and water;

[0045] (4) Product collection and treatment: After the reaction is completed, the reaction products are collected.

[0046] Embodiment 2

[0047] S1, reaction stage of ethylene oxide and ammonia:

[0048] (1) Raw material preparation: prepare ethylene oxide and ammonia water that meet the process requirements;

[0049] (2) Mixing and reacting: mixing ethylene oxide and aqueous ammonia in a molar ratio of (1-99):(99-1), and feeding the mixture into a reactor, where the ethylene oxide and aqueous ammonia react under a pressure of 0.1 MPa and a temperature of 20° C.;

[0050] (3) Product collection: After the reaction is completed, the reaction product is collected. The product is a mixture, mainly containing monoethanolamine, diethanolamine, triethanolamine, free ammonia and water;

[0051] S2, further reaction stage with propylene oxide:

[0052] (1) Raw material mixing: the mixture obtained in the previous step is directly introduced into the reaction system containing propylene oxide without the need for ammonia removal or distillation treatment;

[0053] (2) Control of reaction conditions: Propylene oxide reacts with the alcohol amine in the mixture at a temperature of 50°C and a pressure of normal pressure;

[0054] (3) Product formation: During the reaction, propylene oxide reacts with alcohol amines to form a variety of products, including EDIPA, DEIPA, TIPA, propylene glycol, some residual triethanolamine, some ethers, and a small amount of free ammonia and water;

[0055] (4) Product collection and treatment: After the reaction is completed, the reaction products are collected.

[0056] Embodiment 3

[0057] S1, reaction stage of ethylene oxide and ammonia:

[0058] (1) Raw material preparation: prepare ethylene oxide and ammonia water that meet the process requirements;

[0059] (2) Mixing and reacting: mixing ethylene oxide and aqueous ammonia in a molar ratio of (1-99):(99-1), and feeding the mixture into a reactor, where the ethylene oxide and aqueous ammonia react under a pressure of 10 MPa and a temperature of 150° C.;

[0060] (3) Product collection: After the reaction is completed, the reaction product is collected. The product is a mixture, mainly containing monoethanolamine, diethanolamine, triethanolamine, free ammonia and water;

[0061] S2, further reaction stage with propylene oxide:

[0062] (1) Raw material mixing: the mixture obtained in the previous step is directly introduced into the reaction system containing propylene oxide without the need for ammonia removal or distillation treatment;

[0063] (2) Control of reaction conditions: Propylene oxide reacts with the alcohol amine in the mixture at a temperature of 120°C and a pressure of normal pressure;

[0064] (3) Product formation: During the reaction, propylene oxide reacts with alcohol amines to form a variety of products, including EDIPA, DEIPA, TIPA, propylene glycol, some residual triethanolamine, some ethers, and a small amount of free ammonia and water;

[0065] (4) Product collection and treatment: After the reaction is completed, the reaction products are collected.

[0066] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0067] Effect Example

[0068] The mixed alcohol amines obtained in the above examples 1-3 were compared with products on the market, and the reinforcing effect of the mixed alcohol amines prepared in each example was verified by a comparative test on cement mortar. The test adopted a laboratory module test, specifically referring to GB / T17671-1999 "Test Method for Cement Mortar Strength", and selected 2 different cements for compressive strength comparison test with and without the prepared mixed alcohol amines. The specific results are shown in the following table:

[0069]

[0070] In summary, by adopting a method for producing ethanolamines and isopropanolamines without distillation and recovery of free ammonia, the steps of distillation and recovery of free amine are eliminated, and the cost is greatly saved. The method is simple and convenient, and a water-absorbing molecular sieve is used as a catalyst, which greatly reduces the amount of water used for catalysis, thereby reducing energy consumption, and directly uses liquid ammonia as a raw material, which reduces material cost and operating cost. At the same time, the method also improves the reaction rate, reduces the generation of impurities and avoids the decomposition of the product, improves the purity of isopropanolamine (more than 99%), is suitable for large-scale production, simplifies the production process, eliminates the steps of distillation and ammonia recovery, significantly reduces production cost and energy consumption, improves reaction efficiency and product yield, and reduces waste discharge and environmental pollution. The obtained mixed product has broad application prospects, especially in the field of building materials, showing good performance advantages.

[0071] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0072] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for producing mixed alcohol amines without rectification and recovery of ammonia, characterized in that: The specific steps include: S1, reaction stage of ethylene oxide and ammonia: (1) Raw material preparation: prepare ethylene oxide and ammonia water that meet the process requirements; (2) mixing and reacting: mixing ethylene oxide and aqueous ammonia in a molar ratio of (1-99):(99-1), and feeding the mixture into a reactor, wherein the ethylene oxide and aqueous ammonia react under a pressure of 0.1 MPa to 10 MPa and a temperature of 20° C. to 150° C. in the reactor; (3) Product collection: After the reaction is completed, the reaction product is collected. The product is a mixture, mainly containing monoethanolamine, diethanolamine, triethanolamine, free ammonia and water; S2, further reaction stage with propylene oxide: (1) Raw material mixing: the mixture obtained in the previous step is directly introduced into the reaction system containing propylene oxide without the need for ammonia removal or distillation treatment; (2) Control of reaction conditions: Propylene oxide reacts with the alcohol amine in the mixture at a temperature of 50°C to 120°C and a pressure of normal pressure; (3) Product formation: During the reaction, propylene oxide reacts with alcohol amines to form a variety of products, including EDIPA, DEIPA, TIPA, propylene glycol, some residual triethanolamine, some ethers, and a small amount of free ammonia and water; (4) Product collection and treatment: After the reaction is completed, the reaction products are collected.

2. The method for producing a mixed alcohol amine without distillation and recovery of ammonia according to claim 1, characterized in that: In S1(1), the ammonia water can be prepared in advance to a desired concentration, usually 95% to 99% concentrated ammonia water. In S1(2), the reactor can be a tower reactor or a tubular reactor.

3. The method for producing a mixed alcohol amine without distillation and recovery of ammonia according to claim 1, characterized in that: In S1(3), the mixture comprises monoethanolamine (10%-50%), diethanolamine (10%-50%), triethanolamine (1%-30%), free ammonia (10%-30%) and water (10%-40%).

4. The method for producing a mixed alcohol amine without distillation and recovery of ammonia according to claim 1, characterized in that: In said S2(3), the content of the product includes EDIPA (N-ethyldiisopropanolamine, 10%-50%), DEIPA (N,N-diethylisopropanolamine, 10%-50%), TIPA (triisopropanolamine, 10%-30%), propylene glycol (1%-10%), some residual triethanolamine, some ethers and a small amount of free ammonia (<5%) and water (10%-20%).

5. The method for producing a mixed alcohol amine without distillation and recovery of ammonia according to claim 1, characterized in that: In S2(2), these reaction conditions also need to be optimized according to the design of the reactor and the properties of the raw materials to ensure the generation of the target product.

6. The method for producing a mixed alcohol amine without distillation and ammonia recovery according to claim 1, characterized in that: In S1(3), in the process of producing ethanolamine by ammonolysis of ethylene oxide, the product collection step generally includes the following key stages: (1) Post-reaction treatment: Flash deamination: After the reaction is completed, the reaction mixture is first flashed through a high-pressure flash tower to remove more than 90% of the ammonia in the mixture; Dehydration: After flash deammoniation, the mixed ethanolamine enters the atmospheric pressure dehydration tower to further remove most of the water in the material. The remaining water is evaporated in the dehydration tower to ensure the smooth progress of subsequent refining; (2) Refining process: Continuous distillation: Mixed ethanolamines are separated and purified by continuous distillation technology; Monoethanolamine (MEA) refining: mixed ethanolamine is fed from the middle of the MEA tower, and high-purity MEA is evaporated from the top of the tower under high vacuum conditions; Refining of diethanolamine (DEA) and triethanolamine (TEA): The mixed liquid after removing MEA enters the DEA and TEA towers, DEA is refined from the top of the tower, and TEA is obtained through the side line and the bottom of the tower respectively; Product classification and collection: various ethanolamine products obtained through distillation are classified and collected according to purity requirements to meet different market demands; (3) Quality control and testing: During the entire collection process, quality control and testing of products at each stage are required to ensure that the purity and quality of the products meet the standard requirements.

7. The method for producing a mixed alcohol amine without distillation and ammonia recovery according to claim 6, characterized in that: In the product collection step, (1) flash deamination in the post-reaction treatment is the key to reducing the difficulty of subsequent treatment and improving the purity of the product; (2) continuous distillation in the refining process is usually carried out in multiple distillation towers to ensure the purity of different ethanolamine products.

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