Method for preparing morpholine ethanol by morpholine ethylene oxide method

Abstract

The invention belongs to the field of chemical production, and provides a method for preparing morpholine ethanol by a morpholine ethylene oxide method, which comprises the following steps: adding morpholine, a catalyst and a phase change microcapsule into a reaction kettle, uniformly stirring to form a stable suspension, adding ethylene oxide in a stirring state at a constant speed, reacting, and separating and purifying after the reaction is finished to obtain morpholine ethanol, the catalyst is selected from water or sodium hydroxide; the phase change microcapsule is formed by coating the surface of a core material with a shell material, and the core material is an organic phase change material with the phase change temperature of 60-70 DEG C; the shell material comprises a first shell layer covering the surface of the core material and a second shell layer covering the surface of the first shell layer; the first shell layer is an organic coating material modified by an inorganic heat-conducting material; and the second shell layer is an inorganic coating material modified by an inorganic heat-conducting material. The method provided by the invention can ensure that the preparation process is safe and stable, can reduce side reactions, and can prepare morpholine ethanol with high yield.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and particularly relates to a method for preparing morpholine ethanol by a morpholine ethylene oxide method. Background Art

[0002] Morpholine ethanol, also known as hydroxyethyl morpholine, 2-morpholine ethanol, N-hydroxyethyl morpholine, etc., is a chemical, pesticide, and pharmaceutical intermediate. It is mainly used in the synthesis of metal surface treatment agents, plant growth regulators, etc. In the pharmaceutical field, it is mainly used to synthesize drugs such as mycophenolate mofetil, pholcodine, and pinaverium bromide.

[0003] There are several main methods for preparing morpholine ethanol:

[0004] (1) Triethanolamine dehydration method: The literature (Zhurnal ObshcheiKhimii, 32, 3176-9; 1962) reported a method for generating 2-morpholinoethanol by dehydration using triethanolamine and sulfuric acid, with a yield of 76%. This method consumes sulfuric acid during the reaction, which will corrode the equipment, and subsequent treatment will produce a large amount of waste salt and wastewater, which is not friendly to the environment. Patent CN108187697A discloses a method for synthesizing 2-morpholinoethanol and the catalyst used. Morpholinoethanol is prepared by dehydration of triethanolamine in the presence of a solid acid catalyst, with a yield of more than 80%. Although this method does not use sulfuric acid and is green and environmentally friendly, it needs to react at a high temperature and has strict requirements on the content of the active component of the catalyst. Improper preparation will greatly reduce the yield.

[0005] (2) 2-bromoethanol-morpholine method: Patent US20140018366A1 discloses the synthesis and use of dibasic muscarinic receptor agonists and antagonists, which discloses a technical solution for preparing morpholineethanol using 2-bromoethanol and morpholine in the presence of sodium carbonate. This method requires the use of halogenated alcohols, and the dehalogenation of halogenated alcohols will produce hydrogen halide wastewater, which also has the problem of being environmentally unfriendly.

[0006] (3) Morpholine ethylene oxide method: Patent WO2014001664A1 discloses a method for preparing morpholine ethane by reacting morpholine and ethylene oxide, which is prepared by adding ethylene oxide to morpholine at a temperature between 0°C and 20°C until the morpholine is completely consumed; the document (Chemical Engineering Journal, 2015, 259: 252-256) discloses a technical solution for preparing morpholine ethanol with a yield of 67% by using morpholine and ethylene oxide as raw materials, 50% sodium hydroxide as a catalyst, and reacting at 40-45°C for 1.5h. This method does not produce salt-containing or acid-containing wastewater during the production process, and does not require a catalyst or only requires low-cost sodium hydroxide as a catalyst. The production process is simple and the cost is low, making it a more ideal preparation method.

[0007] However, since the reaction of ethylene oxide and morpholine is a highly exothermic reaction, the heat released during the reaction cannot be released in time, the reaction temperature is very high, and it is difficult to ensure production safety. Excessively high temperature will increase by-products, seriously affecting its industrial promotion.

[0008] Therefore, how to prepare morpholineethanol safely, stably and in high yield using the morpholine ethylene oxide method remains a problem that needs to be solved. Summary of the invention

[0009] The object of the present invention is to provide a method for preparing morpholine ethanol by a morpholine ethylene oxide method, which can ensure the safety and stability of the preparation process, reduce side reactions, and prepare morpholine ethanol with high yield.

[0010] In order to achieve the above object, the present invention provides the following specific scheme:

[0011] The invention provides a method for preparing morpholine ethanol by a morpholine ethylene oxide method. During the preparation, morpholine, a catalyst and a phase change microcapsule are added into a reaction kettle and stirred evenly to form a stable suspension, ethylene oxide is added at a uniform speed under stirring to react, and after the reaction is completed, the morpholine ethanol is separated and purified to prepare the morpholine ethanol; the catalyst is selected from water or sodium hydroxide; the phase change microcapsule is formed by coating a shell material on the surface of a core material, and the core material is an organic matter with a phase change temperature of 60-70 DEG C; the shell material comprises a first shell layer coated on the surface of the core material, and a second shell layer coated on the surface of the first shell layer; the first shell layer is an organic coating material modified by an inorganic heat conductive material; and the second shell layer is an inorganic coating material modified by an inorganic heat conductive material.

[0012] The main reaction and side reaction of the morpholine ethylene oxide method for preparing morpholine ethanol are:

[0013] Main reaction: C4H9NO+C2H4O→C6H 13 NO2

[0014] Side reaction: C2H4O+H2O→(CH2OH)2C4H9NO+2C2H4O→C8H 17 NO3

[0015] C4H9NO+3C2H4O→C 10 H 21 NO4

[0016] Experimental verification shows that when water is used as a catalyst, the appropriate reaction temperature for the main reaction is 40-60°C. When the system temperature rises, the side reactions increase significantly. The reaction between morpholine and ethylene oxide is a violent exothermic reaction. The inventors found in the previous experiments using a microchannel reactor that after the two are mixed, the outer surface temperature of the coil can rise rapidly to 180°C within one minute, which is sufficient to prove that the exothermic reaction is violent. Even with a microchannel reactor, it is difficult to stably control the temperature.

[0017] When a reactor is used for the reaction, since the volume of an industrial reactor is generally large, even if ethylene oxide is slowly added to morpholine at a certain flow rate, the temperature in the system will rise rapidly due to the violent reaction after the two are mixed. The cooling facilities outside the reactor (generally, the refrigerant is circulated and cooled through the coil outside the reactor) have a slow response to the rapid temperature rise in the system due to the long heat transfer distance and the presence of multiple layers of heat transfer media. It is difficult to control the temperature in the reaction system within a safe range, and it is even more difficult to control the temperature within a temperature range suitable for the main reaction.

[0018] The present invention creatively adds phase change microcapsules into the reaction system, and the phase change microcapsules form a uniform and stable suspension in the reaction system. Thus, when a certain site in the system reacts, the released heat can be quickly transferred to the phase change microcapsules at the site, and the heat transfer distance between the phase change microcapsules and the reaction site can be almost ignored. After the heat is transferred to the phase change microcapsules, the temperature in the phase change microcapsules quickly reaches the phase change temperature of the core material, and the core material absorbs heat to undergo a phase change, thereby allowing the heat in the system to be quickly absorbed, keeping the reaction temperature of the system from being too high, thereby ensuring the safety of the reaction system and avoiding the increase of side reactions at high temperatures.

[0019] The phase change microcapsules of the present invention are to be uniformly dispersed in organic systems such as morpholine and morpholine ethanol to absorb the heat released during the reaction process, and to be easily separated from the reaction system after the reaction is completed. Therefore, the design requirements for the phase change microcapsules of the present invention are as follows: (1) to ensure the integrity of the coating and the strength and flexibility of the coating material to avoid the problem of difficulty in separation from the reaction system caused by leakage of the phase change material; (2) to have a relatively large particle size to facilitate separation from the reaction system by a simple filtering method; (3) to be immiscible with the matrix of the reaction system to avoid contamination of the reaction system; (4) to have a small difference in density from the reaction system to facilitate relatively uniform dispersion under stirring; and (5) to have good thermal conductivity to facilitate rapid transfer of the heat released by the reaction to the phase change material to quickly control the temperature of the reaction system.

[0020] Taking the above requirements into consideration, the present invention designs a phase change microcapsule shell material of which two shell layers are selected, wherein the first shell layer coated on the surface of the core material is an organic coating material modified by an inorganic thermal conductive material, and the second shell layer coated outside the first shell layer is an inorganic coating material modified by an inorganic thermal conductive material.

[0021] (1) Since organic coating materials are easier to achieve coating integrity, while inorganic coating materials are easier to separate from organic reaction systems. Therefore, the present invention ensures the integrity of the coating through the organic coating of the first shell layer to avoid leakage; and ensures immiscibility with the organic reaction system through the inorganic coating of the second shell layer, and is easier to separate, avoiding impurities from polluting the reaction system. (2) The two layers of coating can achieve a larger phase change microcapsule particle size, making filtering and separation easier. (3) By regulating the materials and amounts of the phase change material and the two layers of coating shells, the density of the phase change microcapsules is less different from the density of the reaction system matrix, which can ensure uniform dispersion under stirring. (4) By adding inorganic thermal conductive materials to both layers of shell materials, the problem of poor thermal conductivity caused by organic coating materials is improved, so as to effectively ensure that the heat generated by the reaction system can be quickly transferred to the phase change material.

[0022] In addition, water or sodium hydroxide solution is added as a catalyst in the reaction system of the present invention, and water is preferably used as a catalyst because ethylene oxide is - , H + The OH group can be ionized in the environment of pure morpholine. - Very limited, so water or sodium hydroxide solution is needed as a catalyst to provide more OH - .

[0023] Preferably, the inorganic thermally conductive material is selected from carbon nanotubes, graphene, graphene oxide or silicon carbide; the amount of the inorganic thermally conductive material added to the first shell layer is 5-10% by mass of the first shell layer; the amount of the inorganic thermally conductive material added to the second shell layer is 15-25% by mass of the second shell layer.

[0024] The above materials are all inorganic materials with high thermal conductivity and easy to prepare into micron or nanoparticles. Their addition can establish multiple different heat conduction paths between the core material and the external environment to reduce the interface thermal resistance and thereby increase the heat conduction rate.

[0025] The present invention adds relatively little inorganic thermally conductive material to the first shell layer, which is a choice made after comprehensively evaluating the thermal conductivity and coating integrity. The more inorganic thermally conductive material is added, the worse the integrity of the organic coating material. As for the inorganic coating of the second shell layer, on the one hand, it can supplement the integrity loopholes of the organic coating material, and more importantly, it provides inorganic sites in contact with the organic reaction system, and its requirements for the integrity of the coating are relatively low. Therefore, the present application adds more inorganic thermally conductive material in the second shell layer to ensure that the thermal conductivity of the shell layer reaches a higher level and transfers heat to the phase change material faster.

[0026] Further preferably, the inorganic thermally conductive material is selected from carbon nanotubes, graphene or graphene oxide.

[0027] Among the above materials, the thermal conductivity advantage of carbon-based materials is more obvious. Among them, the thermal conductivity of carbon nanotubes is 3000-6000W / (m·K), the thermal conductivity of graphene is 5000W / (m·K), and the thermal conductivity of graphene oxide is 3000W / (m·K). Under the condition of ensuring the uniformity of dispersion of the precursor, a small amount of addition can greatly improve the thermal conductivity of the shell material.

[0028] More preferably, the inorganic thermally conductive material is graphene oxide. This is because graphene oxide has better affinity with organic coating materials and inorganic coating material precursors and is easier to disperse evenly in the organic coating materials and inorganic coating materials to ensure the establishment of more heat conduction paths.

[0029] Preferably, the organic coating material is selected from melamine formaldehyde resin, urea formaldehyde resin, polyurea resin or polyurethane resin.

[0030] The above materials are selected as organic coating materials because, on the one hand, the above materials have good film-forming properties, coating integrity and flexibility; on the other hand, the above coating materials are easier to prepare capsules using in situ polymerization methods, and it is easier to evenly add inorganic conductive materials to the shell material.

[0031] Preferably, the inorganic coating material is silicon dioxide or titanium dioxide.

[0032] Silicon dioxide or titanium dioxide is selected as the inorganic coating material. The above materials can be coated by a sol-gel method, and even if more thermal conductive materials are added, a stable coating layer can still be formed.

[0033] Preferably, the core material is selected from paraffin or palmitic acid.

[0034] Since the most suitable reaction temperature for the reaction of morpholine and ethylene oxide in the present invention is 40-60°C, when the temperature is higher than the reaction temperature, the system needs to be cooled down. Therefore, the present invention selects a phase change material with a phase change temperature in the range of 60-70°C. In this way, when the system temperature rises, it is quickly transferred to the phase change microcapsule core material. When the temperature of the phase change microcapsule core material reaches 60-70°C, the phase change can be absorbed and cooled down to control the system temperature from being too high to produce more side reactions.

[0035] There are many types of paraffin wax, and the phase transition temperature span is large. Paraffin wax with a phase transition temperature in the range of 60-70°C can be used as the core material of the present invention. The phase transition temperature of palmitic acid is 64°C, which meets the requirements of the present invention, and its phase transition enthalpy is 208 J / g, which has a good heat absorption and heat storage effect.

[0036] Preferably, palmitic acid is selected as the core material of the present invention.

[0037] Since the main components of the reaction product system of the present invention are morpholine ethanol, unreacted morpholine and other impurities, if a small amount of phase change microcapsules are accidentally leaked in the reaction system, due to the large difference in boiling points between palmitic acid and other components in the reaction system, they can be easily separated from the product in the subsequent distillation separation process without causing unnecessary impact on the system.

[0038] Preferably, the mass ratio of the core material, the first shell layer, and the second shell layer satisfies: 1.5:1:1 to 2.0:1:1.

[0039] By controlling the ratio of the core material, the first shell layer and the second shell layer, phase change microcapsules having a density less different from that of the reaction system of the present application can be prepared. At the same time, by adjusting the ratio of each component, the particle size of the prepared phase change microcapsules can also be adjusted to a certain extent, making the particle size larger, and increasing the proportion of available phase change microcapsules with a particle size of more than 50 μm.

[0040] Preferably, the amount of the phase-change microcapsules added is 20% to 40% by mass of the morpholine, preferably 30%.

[0041] Since the reaction of the present invention is a gas-liquid reaction, gaseous ethylene oxide is continuously introduced into liquid morpholine from the bottom of the reactor, and the reaction process is carried out under continuous stirring. If the amount of phase change microcapsules added is too much, it is easy to increase the reaction stirring resistance and affect the mixing uniformity of the reaction raw materials. If the amount of phase change microcapsules added is too little, it cannot cover the various reaction sites in the reaction system well and cannot quickly adsorb the reaction exothermic heat. The present invention comprehensively considers controlling the amount of phase change microcapsules added to 20% to 40% of the mass of morpholine, so as to well achieve the purpose of normal reaction and rapid extraction of reaction exothermic heat.

[0042] Preferably, the method for preparing the phase change microcapsules comprises the following steps:

[0043] S1 uses in-situ polymerization to coat the first shell layer on the surface of the core material to prepare the initial capsule:

[0044] S11: adding the inorganic thermal conductive material to the monomer of the organic coating material in proportion, and preparing the monomer into a prepolymer; S12: preparing the core material into a core material emulsion; S13: dropping the prepolymer into the core material emulsion, stirring for reaction, and preparing an emulsion containing primary capsules; S14: cooling, filtering, and drying the emulsion containing primary capsules obtained in step S13 to obtain primary capsules;

[0045] S2: coating the surface of the primary capsule with a second shell layer by a sol-gel method to prepare the phase change microcapsule;

[0046] S21 dissolves the inorganic coating material precursor to prepare a dispersion, adds an inorganic thermal conductive material to the dispersion and mixes evenly; S22 adds the primary capsule to the dispersion of step S21, adjusts the pH value of the system to react, and prepares a solution containing the phase change microcapsules; S23 cools, filters, and dries the solution containing the phase change microcapsules obtained in step S22 to obtain the phase change microcapsules.

[0047] The primary capsules coated with the first shell layer mainly composed of organic coating materials are prepared by in-situ polymerization, and the phase change microcapsules coated with the second shell layer mainly composed of inorganic coating materials are prepared by the sol-gel method. Both methods are commonly used methods for preparing phase change microcapsules. Double-layer coating can better prepare phase change microcapsules with relatively large particle size.

[0048] Preferably, the molar ratio of the morpholine to the ethylene oxide satisfies: 1:1 to 2:1; and the amount of the catalyst added is 5 to 10% of the total amount of the raw materials.

[0049] Preferably, the initiation temperature of the reaction is 40-50° C., the reaction time is 4-8 h, and the reaction pressure is 0.4 MPa-0.5 MPa.

[0050] The beneficial effects of the present invention are:

[0051] (1) The method of the present invention can well ensure the temperature stability of the reaction system for preparing morpholine ethanol by the morpholine ethylene oxide method, thereby avoiding the safety problems caused by the violent exothermic reaction;

[0052] (2) The method of the present invention can well ensure the temperature stability of the reaction system for preparing morpholine ethanol by the morpholine ethylene oxide method, effectively reduce the occurrence of side reactions, and thus ensure the improvement of the reaction yield.

[0053] (3) The method of the present invention has good temperature control effect of the reaction system, high yield, simple and easy separation of the added phase change microcapsules and the system, and has a good prospect for industrial promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a chromatogram of the system after filtration at the end of the reaction in Example 1 of the present application.

[0055] Figure 2 This is a chromatogram of the system after filtration at the end of the reaction in Example 2 of the present application.

[0056] Figure 3 This is a chromatogram of the system after filtration at the end of the reaction in Example 3 of the present application.

[0057] Figure 4 This is a chromatogram of the system after filtration at the end of the reaction in Example 4 of the present application.

[0058] Figure 5 This is a chromatogram of the system after filtration at the end of the reaction in Example 5 of the present application.

[0059] Figure 6 This is a chromatogram of the system after filtration at the end of the reaction in Example 6 of the present application.

[0060] Figure 7 This is the chromatogram of the system after the reaction of Comparative Example 1 of the present application is completed. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the present invention is further described below in conjunction with specific embodiments. For those without specific conditions in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are followed. The exemplary embodiments can be implemented in various forms and should not be construed as being limited to the examples described herein; on the contrary, these embodiments are provided so that the present invention will be more comprehensive and complete, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art.

[0062] The following Examples 1 to 6 and Comparative Example 1 of the present application all use a 30L laboratory stainless steel reactor as a reaction apparatus, and the reactor is equipped with supporting facilities such as temperature monitoring, pressure monitoring, liquid phase feeding and gas phase feeding.

[0063] Example 1

[0064] This embodiment provides a method for preparing morpholine ethanol by the morpholine ethylene oxide method, comprising the following steps:

[0065] (1) Add 13.05 kg (150 mol) of morpholine and 0.8725 kg of water into a reaction kettle and start stirring at a speed of 450 r / min;

[0066] (2) Weigh 2.61 kg (20% of the weight of morpholine) of phase change microcapsules and slowly add them into the above reaction kettle under stirring;

[0067] (3) The system temperature was raised to 40°C and the pressure was controlled at 0.4 MPa; ethylene oxide was slowly introduced from the bottom of the reactor, and the flow rate of ethylene oxide was controlled to be 100 g / min. The total amount of ethylene oxide added was 4.4 kg (100 mol);

[0068] (4) After the addition of ethylene oxide was completed, the reaction was maintained for 4 hours; during the reaction, the temperature of three points inside the reactor was monitored by temperature, and the highest temperature of the three points inside the reactor was maintained below 91° C. The three points were respectively set at the center of the reactor, below the reactor liquid surface, close to the reactor liquid surface, and close to the bottom of the reactor;

[0069] (5) After the reaction is completed, the machine is turned off, the material is discharged, and the phase change microcapsules are removed by filtration. The chromatogram of the obtained reaction product is measured. Figure 1 The yield of morpholineethanol was calculated to be 88.68%.

[0070] The preparation method of the phase change microcapsules used in this embodiment includes the following steps:

[0071] S1 uses in-situ polymerization to coat the first shell layer on the surface of the core material to prepare the initial capsule:

[0072] S11: 252 g of graphene oxide was weighed, added to 2.15 kg of formaldehyde, and ultrasonically dispersed for 30 min, then 1 kg of melamine was weighed, stirred and heated to 70° C. until the mixture was transparent, the pH value was adjusted to 8-9, and reacted at 70° C. for 3 h to prepare a prepolymer;

[0073] S12 Weigh 6.0 kg palmitic acid, 1.2 kg deionized water, and 5 L SMA-Na solution, and stir the three at high speed at 80 ° C for 2 h to prepare a core material emulsion;

[0074] S13: slowly dropwise adding the prepolymer of step S11 into the core material emulsion of step S12, stirring and reacting for 4 hours, to prepare an emulsion containing primary capsules;

[0075] S14: cooling, filtering, washing, and drying the emulsion containing the primary capsules obtained in step S13 at 40° C. to obtain the primary capsules.

[0076] S2 uses the sol-gel method to coat the second shell layer on the surface of the primary capsule to prepare phase-change microcapsules;

[0077] S21 Weigh 2.8 kg of tetraethyl silicate TEOS and 560 g of graphene oxide GO, add them into a dispersion solution consisting of anhydrous ethanol, deionized water and hexadecyltrimethylammonium bromide, and ultrasonically disperse them at 50°C for 2 h;

[0078] S22: adding the primary capsules prepared in step S1 to the above dispersion, stirring and dispersing at high speed for 30 minutes, adding ammonia water to the system to adjust the pH value of the system to 8-9, and continuing the reaction for 24 hours to obtain a solution containing phase change microcapsules;

[0079] S23: Cool, filter, wash and dry the solution containing the phase change microcapsules obtained in step S22 to obtain 7.825 kg of the phase change microcapsules.

[0080] S3: Pass the phase-change microcapsules through a 300-mesh sieve, and screen the sieve-surface material as the phase-change microcapsules added to the reaction of this embodiment.

[0081] Example 2

[0082] This embodiment provides a method for preparing morpholine ethanol by the morpholine ethylene oxide method, comprising the following steps:

[0083] (1) Add 8.7 kg (100 mol) of morpholine and 1.31 kg of water into a reaction kettle and start stirring at a speed of 450 r / min;

[0084] (2) Weigh 1.74 kg (20% of the weight of morpholine) of phase change microcapsules and slowly add them into the above reaction kettle under stirring;

[0085] (3) The system temperature was raised to 40° C. and the pressure was controlled at 0.4 MPa. Ethylene oxide was slowly introduced from the bottom of the reactor. The flow rate of ethylene oxide was controlled to be 100 g / min. The total amount of ethylene oxide added was 4.4 kg (100 mol).

[0086] (4) After the addition of ethylene oxide was completed, the reaction was maintained for 4 hours; during the reaction, the temperature of three points inside the reactor was monitored by temperature, and the highest temperature of the three points inside the reactor was maintained below 89° C. The three points were respectively set at the center of the reactor, below the reactor liquid surface close to the reactor liquid surface, and close to the bottom of the reactor;

[0087] (5) After the reaction is completed, the machine is shut down, the material is discharged, and the phase change microcapsules are removed by filtration. The chromatogram of the obtained reaction product is measured as follows: Figure 2 As shown. The yield of morpholine ethanol was calculated to be 94.35%;

[0088] The phase change microcapsules used in Example 2 are the same as those used in Example 1.

[0089] Example 3

[0090] This embodiment provides a method for preparing morpholine ethanol by the morpholine ethylene oxide method, comprising the following steps:

[0091] (1) Add 13.05 kg (150 mol) of morpholine and 1.745 kg of water into a reaction kettle and start stirring at a speed of 450 r / min;

[0092] (2) Weigh 2.61 kg (20% of the weight of morpholine) of phase change microcapsules and slowly add them into the above reaction kettle under stirring;

[0093] (3) The system temperature was raised to 40° C. and the pressure was controlled at 0.4 MPa. Ethylene oxide was slowly introduced from the bottom of the reactor. The flow rate of ethylene oxide was controlled to be 100 g / min. The total amount of ethylene oxide added was 4.4 kg (100 mol).

[0094] (4) After the addition of ethylene oxide was completed, the reaction was maintained for 4 hours; during the reaction, the temperature of three points inside the reactor was monitored by temperature, and the highest temperature of the three points inside the reactor was maintained below 89° C. The three points were respectively set at the center of the reactor, below the reactor liquid surface close to the reactor liquid surface, and close to the bottom of the reactor;

[0095] (5) After the reaction is completed, the machine is shut down, the material is discharged, and the phase change microcapsules are removed by filtration. The chromatogram of the obtained reaction product is measured as follows: Figure 3 The yield of morpholineethanol was calculated to be 94.64%.

[0096] The phase change microcapsules used in Example 3 are the same as those used in Example 1.

[0097] Example 4

[0098] This embodiment provides a method for preparing morpholine ethanol by the morpholine ethylene oxide method, comprising the following steps:

[0099] (1) Add 13.05 kg (150 mol) of morpholine and 1.745 kg of water into a reaction kettle and start stirring at a speed of 450 r / min;

[0100] (2) Weigh 3.915 kg (30% of the weight of morpholine) of phase change microcapsules and slowly add them into the above reaction kettle under stirring;

[0101] (3) The system temperature was raised to 40° C. and the pressure was controlled at 0.4 MPa. Ethylene oxide was slowly introduced from the bottom of the reactor. The flow rate of ethylene oxide was controlled to be 100 g / min. The total amount of ethylene oxide added was 4.4 kg (100 mol).

[0102] (4) After the addition of ethylene oxide was completed, the reaction was maintained for 4 hours; during the reaction, the temperature of three points inside the reactor was monitored by temperature, and the highest temperature of the three points inside the reactor was maintained below 74° C. The three points were respectively set at the center of the reactor, below the reactor liquid surface close to the reactor liquid surface, and close to the bottom of the reactor;

[0103] (5) After the reaction is completed, the machine is shut down, the material is discharged, and the phase change microcapsules are removed by filtration. The chromatogram of the obtained reaction product is measured as follows: Figure 4 The yield of morpholineethanol was calculated to be 97.51%.

[0104] The phase change microcapsules used in Example 4 are the same as those used in Example 1.

[0105] Example 5

[0106] This embodiment provides a method for preparing morpholine ethanol by the morpholine ethylene oxide method, comprising the following steps:

[0107] (1) Add 13.05 kg (150 mol) of morpholine and 1.745 kg of water into a reaction kettle and start stirring at a speed of 450 r / min;

[0108] (2) Weigh 5.22 kg (40% of the weight of morpholine) of phase change microcapsules and slowly add them into the above reaction kettle under stirring;

[0109] (3) The system temperature was raised to 40° C. and the pressure was controlled at 0.4 MPa. Ethylene oxide was slowly introduced from the bottom of the reactor. The flow rate of ethylene oxide was controlled to be 100 g / min. The total amount of ethylene oxide added was 4.4 kg (100 mol).

[0110] (4) After the addition of ethylene oxide was completed, the reaction was maintained for 4 hours; during the reaction, the temperature of three points inside the reactor was monitored by temperature, and the highest temperature of the three points inside the reactor was maintained below 68° C. The three points were respectively set at the center of the reactor, below the reactor liquid surface close to the reactor liquid surface, and close to the bottom of the reactor;

[0111] (5) After the reaction is completed, the machine is shut down, the material is discharged, and the phase change microcapsules are removed by filtration. The chromatogram of the obtained reaction product is measured as follows: Figure 5 The yield of morpholineethanol was calculated to be 97.47%.

[0112] The phase change microcapsules used in Example 5 are the same as those used in Example 1.

[0113] Example 6

[0114] This embodiment provides a method for preparing morpholine ethanol by the morpholine ethylene oxide method, comprising the following steps:

[0115] (1) Add 13.05 kg (150 mol) of morpholine and 1.745 kg of water into a reaction kettle and start stirring at a speed of 450 r / min;

[0116] (2) Weigh 3.915 kg (30% of the weight of morpholine) of phase change microcapsules and slowly add them into the above reaction kettle under stirring;

[0117] (3) The system temperature was raised to 40° C. and the pressure was controlled at 0.4 MPa. Ethylene oxide was slowly introduced from the bottom of the reactor. The flow rate of ethylene oxide was controlled to be 100 g / min. The total amount of ethylene oxide added was 4.4 kg (100 mol).

[0118] (4) After the addition of ethylene oxide was completed, the reaction was maintained for 4 hours; during the reaction, the temperature of three points inside the reactor was monitored by temperature, and the highest temperature of the three points inside the reactor was maintained below 92° C. The three points were respectively set at the center of the reactor, below the reactor liquid surface close to the reactor liquid surface, and close to the bottom of the reactor;

[0119] (5) After the reaction is completed, the machine is shut down, the material is discharged, and the phase change microcapsules are removed by filtration. The chromatogram of the obtained reaction product is measured as follows: Figure 6 The yield of morpholineethanol was calculated to be 94.72%.

[0120] The difference between the phase change microcapsules used in Example 6 and the phase change microcapsules used in Example 1 is that 3 kg of tetraethyl silicate TEOS and 450 g of graphene oxide are weighed in step S21.

[0121] Comparative Example 1

[0122] This comparative example provides a method for preparing morpholine ethanol by a morpholine ethylene oxide method, comprising the following steps:

[0123] (1) Add 13.05 kg (150 mol) of morpholine and 1.745 kg of water into a reaction kettle and start stirring at a speed of 450 r / min;

[0124] (2) The system temperature was raised to 40° C. and the pressure was controlled at 0.4 MPa; ethylene oxide was slowly introduced from the bottom of the reactor, and the flow rate of ethylene oxide was controlled to be 100 g / min. The total amount of ethylene oxide added was 4.4 kg (100 mol);

[0125] (3) After the addition of ethylene oxide was completed, the reaction was maintained for 4 hours; the outer wall of the reactor was cooled by circulating water, and the temperature of three points inside the reactor was monitored during the reaction; the three points were respectively set at the center of the reactor, below the reactor liquid surface close to the reactor liquid surface, and close to the bottom of the reactor;

[0126] Among the three points, the temperature at the center of the reactor is the highest, reaching 580°C and continuously maintained at around 400°C.

[0127] (4) After the reaction is completed, the machine is shut down, the material is discharged, and the phase change microcapsules are filtered out. The chromatogram of the obtained reaction product is measured as follows: Figure 7 The yield of morpholineethanol was calculated to be 43.12%.

[0128] From the results of the above embodiments, it can be known that:

[0129] (1) The above embodiments are all experiments carried out in a large reactor of 30L. The heat transfer conditions of the materials in the experiments are slightly different from those in actual industrialization. The experiments in each embodiment show that the method of the present invention can effectively control the temperature of the reaction system, thereby improving the reaction safety and increasing the yield of the reaction product morpholine ethanol. By comparing the results of Comparative Example 1, it can be seen that it is difficult to control the violent exothermic reaction of morpholine ethylene oxide by cooling the outer wall of the traditional reactor, thereby making it difficult to ensure the reaction safety and increasing the side reactions.

[0130] (2) By comparing the results of Examples 3, 4, and 5, it can be seen that as the amount of phase change microcapsules increases, the temperature of the reaction system can be controlled within a lower temperature range. However, when the amount of phase change microcapsules added is 40%, although the temperature of the reaction system can continue to be controlled to a lower level to a certain extent, the yield of the product morpholine ethanol after the reaction does not change much or even decreases compared to when the amount is 30%. This is because as the amount of phase change microcapsules added increases, the stirring and mixing of the reaction system is affected to a certain extent, which affects the reaction to a certain extent.

[0131] (3) By comparing Example 4 and Example 6, it can be seen that when the amount of inorganic thermal conductive material added in the second shell layer of the phase change microcapsule is reduced, it has a certain impact on the thermal conduction of the system. The heat generated by the system cannot be better transferred to the phase change material of the core material, resulting in a relatively high maximum temperature of the system. However, the effect of this temperature difference on the reaction yield is relatively small.

[0132] In summary, it can be seen that by adopting the method of the present invention, the temperature of the reaction center will not be too high during the entire reaction process, sufficient safety can be guaranteed, and the yield of the reaction product is effectively improved. The entire method has a good prospect for industrial application.

[0133] The present invention is not limited to the above-mentioned embodiments, and anyone should be aware that any structural changes made under the enlightenment of the present invention, and any technical solutions that are the same or similar to the present invention, fall within the protection scope of the present invention.

Claims

1. A method for preparing morpholine ethanol by a morpholine ethylene oxide method, characterized in that: Add morpholine, catalyst and phase change microcapsules into a reaction kettle and stir evenly to form a stable suspension, add ethylene oxide at a uniform speed under stirring to react, and separate and purify to prepare morpholine ethanol after the reaction is completed; The catalyst is selected from water or sodium hydroxide; The phase change microcapsule is formed by coating a shell material on the surface of a core material, wherein the core material is an organic phase change material with a phase change temperature of 60 to 70°C; the shell material comprises a first shell layer coated on the surface of the core material, and a second shell layer coated on the surface of the first shell layer; The first shell layer is an organic coating material modified by an inorganic thermal conductive material; The second shell layer is an inorganic coating material modified by an inorganic thermal conductive material.

2. The method for preparing morpholineethanol by the morpholine ethylene oxide method according to claim 1, characterized in that: The core material is selected from paraffin or palmitic acid.

3. The method for preparing morpholineethanol by the morpholine ethylene oxide method according to claim 1, characterized in that: The inorganic thermally conductive material is selected from carbon nanotubes, graphene, graphene oxide or silicon carbide; The amount of the inorganic thermally conductive material added to the first shell layer is 5 to 10% by mass of the first shell layer; The amount of the inorganic thermally conductive material added to the second shell layer is 15-25% by mass of the second shell layer.

4. The method for preparing morpholineethanol by the morpholine ethylene oxide method according to claim 3, characterized in that: The organic coating material is selected from melamine formaldehyde resin, urea formaldehyde resin, polyurea resin or polyurethane resin.

5. The method for preparing morpholineethanol by the morpholine ethylene oxide method according to claim 3, characterized in that: The inorganic coating material is selected from silicon dioxide or titanium dioxide.

6. The method for preparing morpholineethanol by the morpholine ethylene oxide method according to claim 1, characterized in that: The mass ratio of the core material, the first shell layer, and the second shell layer satisfies: 1.5:1：1～2.0：1:1。 7. The method for preparing morpholine ethanol by the morpholine ethylene oxide method according to any one of claims 1 to 6, characterized in that: The preparation method of the phase change microcapsule comprises the following steps: S1 uses in-situ polymerization to coat the first shell layer on the surface of the core material to prepare the initial capsule: S11: adding the inorganic thermal conductive material to the monomer of the organic coating material in proportion, and preparing the monomer into a prepolymer; S12: preparing the core material into a core material emulsion; S13: dropping the prepolymer into the core material emulsion, stirring for reaction, and preparing an emulsion containing the primary capsule; S14: cooling, filtering, and drying the emulsion containing the primary capsule obtained in step S13 to obtain the primary capsule; S2: coating the surface of the primary capsule with a second shell layer by a sol-gel method to prepare the phase change microcapsule; S21 dissolves the precursor of the inorganic coating material to prepare a dispersion, adds an inorganic thermal conductive material to the dispersion and mixes them evenly; S22 adds the initial capsules to the dispersion of step S21, adjusts the pH value of the system to react, and prepares a solution containing the phase change microcapsules; S23 cools, filters, and dries the solution containing the phase change microcapsules obtained in step S22 to obtain the phase change microcapsules.

8. The method for preparing morpholineethanol by the morpholine ethylene oxide method according to any one of claims 1 to 6, characterized in that: The added amount of the phase-change microcapsules is 20% to 40% of the mass of the morpholine.

9. The method for preparing morpholineethanol by the morpholine ethylene oxide method according to any one of claims 1 to 6, characterized in that: The molar ratio of the morpholine to the ethylene oxide satisfies: 1:1-2:1; and the added amount of the catalyst is 5-10% of the total amount of the raw materials.

10. The method for preparing morpholine ethanol by the morpholine ethylene oxide method according to any one of claims 1 to 6, characterized in that: The initiation temperature of the reaction is 40-50°C, the reaction time is 4-8h, and the reaction pressure is 0.4MPa-0.5MPa.

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