Preparation method of trihydroxymethyl aminomethane

Abstract

The invention discloses a preparation method of tris (hydroxymethyl) aminomethane, which comprises the following steps: preserving heat at 15-80 DEG C for 4 hours in a condensation reaction, and after the reaction is finished, putting a condensation liquid into a storage tank for later use; then 10% of a silver catalyst is added into a hydrogenation kettle, the temperature is controlled to be 15-180 DEG C, and the hydrogen pressure is controlled to be 20-30 kg; then pumping the hydrogenation liquid into a crystallization kettle by using a pump, controlling the temperature to be reduced to-5 DEG C, separating out crystals, keeping the temperature at-5 DEG C for 2 hours, centrifuging to obtain a trihydroxymethyl aminomethane solid, and putting the trihydroxymethyl aminomethane solid into a recrystallization kettle; the method comprises the following steps: adding trihydroxymethyl aminomethane into a recrystallization kettle, recycling the mother liquor, recovering methanol or ethanol to avoid the waste of the mother liquor, finally, adding trihydroxymethyl aminomethane solid and water into the recrystallization kettle according to the ratio of 1: 0.3-1: 0.5, and centrifuging to obtain crystals, namely the product. The silver catalyst is adopted, the safety is high, the condensation reaction temperature is controlled to be 15-80 DEG C, the reduction hydrogenation pressure is controlled to be 20-30 kg, the product yield can be increased, and the method is suitable for industrial production.

Description

Technical Field

[0001] The present application relates to the technical field of preparation and application of tris(hydroxymethyl)aminomethane, and in particular to a method for preparing tris(hydroxymethyl)aminomethane. Background Art

[0002] Tris(hydroxymethyl)aminomethane is an organic compound with the chemical formula C4H 11 NO3, white crystalline particles. It can be used as a biological buffer for preparing buffer for gel electrophoresis. As an alkaline drug, it is used to correct acidosis without causing increased carbon dioxide retention. 7.28% tris(hydroxymethylaminomethane) 2-3ml / kg each time (isotonic solution is 3.64%), diluted with an equal amount of 5%-10% glucose solution and slowly dripped. The English abbreviation THAM is commonly used in clinical practice.

[0003] However, the current preparation process of tris(hydroxymethyl)aminomethane has a low product yield, high condensation reaction temperature, and high reduction hydrogenation reaction pressure, which is not suitable for industrial production. Summary of the invention

[0004] The present application provides a method for preparing tris(hydroxymethyl)aminomethane, which solves the problems in the prior art of low product yield, high condensation reaction temperature, high reduction hydrogenation reaction pressure, and unsuitability for industrial production during the preparation of tris(hydroxymethyl)aminomethane.

[0005] In order to solve the above technical problems, the present application provides a method for preparing trishydroxymethylaminomethane, comprising:

[0006] Put methanol or ethanol, paraformaldehyde or formaldehyde, and a catalytic amount of base into a condensation kettle, add nitromethane dropwise, keep warm at 15-80°C for 4 hours, and after the reaction is completed, put the condensation liquid into a storage tank for later use;

[0007] The condensation liquid is pumped into a hydrogenation kettle, and 10% of a silver catalyst is added, the temperature is controlled at 15-180° C., the air is replaced with nitrogen until the air in the hydrogenation kettle is completely replaced, hydrogen is introduced while stirring, and the hydrogen pressure is controlled to be 20-30 kg. After 3-5 hours, the reaction is completed, and the hydrogenation liquid is placed in a storage tank for standby use without any treatment;

[0008] The hydrogenation liquid is pumped into a crystallization kettle, and the temperature is controlled to drop to -5°C to precipitate crystals, which are kept at -5°C for 2 hours, and the solid tris(hydroxymethyl)aminomethane is obtained by centrifugation and then put into a recrystallization kettle;

[0009] The mother liquor obtained by centrifugation is returned to the condensation kettle for reuse, and the mother liquor after reuse is distilled to recover methanol or ethanol;

[0010] The tris(hydroxymethyl)aminomethane) solid and water are put into the recrystallization kettle at a ratio of 1:0.3 to 1:0.5, and crystals are precipitated after cooling down. The crystals are centrifuged after keeping warm for 2 hours, and the crystals obtained by centrifugation are the tris(hydroxymethyl)aminomethane product.

[0011] Based on the above examples, as a preferred implementation, the catalytic amount of base is any one of flake caustic soda, potassium hydroxide, sodium methoxide, sodium ethoxide, and sodium tert-butoxide.

[0012] Based on the above embodiment, as a preferred implementation mode, after obtaining the tris(hydroxymethyl)aminomethane product, the method further comprises:

[0013] The tris(hydroxymethyl)aminomethane product is dried and then packaged and stored.

[0014] Based on the above embodiment, as a preferred implementation mode, after the crystals obtained by centrifugation are tris(hydroxymethyl)aminomethane products, the method further comprises:

[0015] The mother liquor obtained by centrifugation is returned to the recrystallization kettle for reuse, and the mother liquor after 3-10 times of reuse is used for wastewater treatment.

[0016] It should be further explained that the air was replaced by the nitrogen three times.

[0017] Compared with the prior art, the present application provides a method for preparing trishydroxymethylaminomethane, firstly, methanol or ethanol, paraformaldehyde or formaldehyde, and a catalytic amount of a base are put into a condensation kettle, nitromethane is added dropwise, and the mixture is kept warm at 15-80° C. for 4 hours. After the reaction is completed, the condensation liquid is placed in a storage tank for standby use; then, the condensation liquid is pumped into a hydrogenation kettle, and a 10% silver catalyst is added. The temperature is controlled at 15-180° C., and the air is replaced with nitrogen until the air in the hydrogenation kettle is completely replaced. Then, hydrogen is introduced while stirring, and the hydrogen pressure is controlled to be 20-30 kg. After 3-5 hours, the reaction is continued. The hydrogenation liquid is put into a storage tank for standby without any treatment; the hydrogenation liquid is pumped into the crystallization kettle, and the temperature is controlled to drop to -5°C, crystals are precipitated, and the mixture is kept at -5°C for 2 hours, and the solid tris(hydroxymethyl)aminomethane is obtained by centrifugation and then put into the recrystallization kettle; the mother liquor obtained by centrifugation is returned to the condensation kettle for application, and the mother liquor after application is distilled to recover methanol or ethanol; to avoid the waste of mother liquor, the solid tris(hydroxymethyl)aminomethane and water are put into the recrystallization kettle at a ratio of 1:0.3 to 1:0.5, and crystals are precipitated after cooling, and the mixture is kept for 2 hours and then centrifuged, and the crystals obtained by centrifugation are the tris(hydroxymethyl)aminomethane products. The silver catalyst is used, which is safer, and the condensation reaction temperature is controlled at 15-80°C, and the reduction hydrogenation pressure is controlled at 20-30kg, which can improve the product yield and is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without inventiveness.

[0019] Figure 1 A schematic diagram of a method for preparing trishydroxymethylaminomethane provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0021] The core of the present application is to provide a method for preparing tris(hydroxymethyl)aminomethane, which can solve the problems in the prior art of tris(hydroxymethyl)aminomethane in the preparation process, such as low product yield, high condensation reaction temperature, high reduction hydrogenation reaction pressure, and unsuitability for industrial production.

[0022] Figure 1 A schematic diagram of a method for preparing tris(hydroxymethyl)aminomethane provided in an embodiment of the present invention is shown in FIG. Figure 1 shown.

[0023] A method for preparing trishydroxymethylaminomethane comprises the following steps:

[0024] In the first step, methanol or ethanol, paraformaldehyde or formaldehyde, and a catalytic amount of base are added to a condensation kettle, and the catalytic amount of base is preferably any one of caustic soda flakes, potassium hydroxide, sodium methoxide, sodium ethoxide, and sodium tert-butoxide. Nitromethane is then added dropwise, and the mixture is kept warm at 15-80° C. for 4 hours. After the reaction is completed, the condensation liquid is placed in a storage tank for standby use. In this step, the amount of methanol or ethanol, paraformaldehyde or formaldehyde, the catalytic amount of base, and the amount of nitromethane can be adjusted according to actual conditions.

[0025] In the second step, the condensation liquid obtained in the first step is pumped into a hydrogenation kettle, and 10% of a silver catalyst is added. The use of a silver catalyst can improve the safety of the reaction. The temperature is controlled at 15-180° C. The air is replaced with nitrogen until the air in the hydrogenation kettle is completely replaced. The number of times the nitrogen replaces the air is preferably 3 times. Hydrogen is introduced while stirring, and the hydrogen pressure is controlled to be 20-30 kg. The reaction is completed after 3-5 hours, and the hydrogenation liquid is placed in a storage tank for standby use without any treatment.

[0026] The third step is to pump the hydrogenation liquid into a crystallization kettle, control the temperature to drop to -5°C, precipitate crystals, keep the temperature at -5°C for 2 hours, centrifuge to obtain tris(hydroxymethyl)aminomethane solid, and then put it into a recrystallization kettle; and in order to avoid the waste of mother liquor, the mother liquor obtained by centrifugation is returned to the condensation kettle for application, and the mother liquor after application is distilled to recover methanol or ethanol, thereby improving the recovery rate of methanol or ethanol.

[0027] The fourth step is to put the tris(hydroxymethyl)aminomethane) solid and water into the recrystallization kettle at a ratio of 1:0.3 to 1:0.5, cool to room temperature to precipitate crystals, keep warm for 2 hours and then centrifuge to obtain the tris(hydroxymethyl)aminomethane product.

[0028] In order to store the product, based on the above embodiment, preferably, after obtaining the tris(hydroxymethyl)aminomethane product, the method further comprises: drying the tris(hydroxymethyl)aminomethane product and then packaging and storing it.

[0029] In order to improve the recycling of mother liquor, based on the above embodiment, preferably, after the crystals obtained by centrifugation are the tris(hydroxymethyl)aminomethane product, the process further includes: returning the mother liquor obtained by centrifugation to the recrystallization kettle for reuse, and subjecting the mother liquor after 3-10 times of reuse to wastewater treatment.

[0030] Example

[0031] Add 960kg of paraformaldehyde, 2kg of potassium hydroxide and 1000kg of methanol into a 5000L three-necked flask, turn on stirring, heat to about 35 degrees and stir until completely dissolved, then start adding 610kg of nitromethane dropwise for a total of 2h. After 4h of reaction, the conversion rate is greater than 98%, and the raw material is less than 1%. Stop the reaction and wait for hydrogenation reaction.

[0032] The above-mentioned tris(hydroxymethyl)aminomethane condensation liquid (dry), 150kg thallium nickel, 133kg methanol and 12kg dichloromethane were added to a 3000L hydrogenation kettle. After the gas replacement was qualified, the pressure was increased to 3.0Mpa, stirring was turned on, and the temperature was controlled at 40-45 degrees for reaction. After hydrogen absorption, the pressure was controlled at 2.2-3.0MPa and stirring was continued for 4h. After waiting for the pressure to stop dropping, the temperature was raised to 55-60 degrees and the temperature was controlled for 1h, and the reaction was stopped.

[0033] The reaction solution was poured into a crystallization kettle while hot, cooled to -10°C, and kept at -10°C for 2 hours to precipitate solid. After centrifugation, 800 kg of white solid was obtained, which was trihydroxyaminomethane.

[0034] The present application provides a method for preparing tris(hydroxymethyl)aminomethane, wherein the condensation reaction is kept at 15-80°C for 4 hours, and after the reaction is completed, the condensation liquid is placed in a storage tank for standby use; then, 10% of a silver catalyst is added to the hydrogenation kettle, the temperature is controlled to be 15-180°C, and the hydrogen pressure is controlled to be 20-30kg; then, the hydrogenation liquid is pumped into a crystallization kettle, the temperature is controlled to drop to -5°C, crystals are precipitated, and the mixture is kept at -5°C for 2 hours, and the tris(hydroxymethyl)aminomethane solid is obtained by centrifugation and then put into a recrystallization kettle; and methanol or ethanol is recovered after being applied to the wood industry to avoid waste of mother liquor, and finally, the tris(hydroxymethyl)aminomethane solid and water are put into a recrystallization kettle at a ratio of 1:0.3 to 1:0.5, and the crystals obtained by centrifugation are the product. The silver catalyst is used, which is safer, the condensation reaction temperature is controlled at 15-80°C, and the reduction hydrogenation pressure is controlled at 20-30kg, which can improve the product yield and is suitable for industrial production.

[0035] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art disclosed in the present application. The specification and examples are to be regarded as exemplary only, and the true scope of the present application is indicated by the claims.

[0036] It should be understood that the present application is not limited to the precise structure described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The above-described embodiments of the present application do not constitute a limitation on the scope of protection of the present application.

Claims

1. A method for preparing tris(hydroxymethyl)aminomethane, characterized in that: include: Put methanol or ethanol, paraformaldehyde or formaldehyde, and a catalytic amount of base into a condensation kettle, add nitromethane dropwise, keep warm at 15-80°C for 4 hours, and after the reaction is completed, put the condensation liquid into a storage tank for later use; The condensation liquid is pumped into a hydrogenation kettle, and 10% of a silver catalyst is added, the temperature is controlled at 15-180° C., the air is replaced with nitrogen until the air in the hydrogenation kettle is completely replaced, hydrogen is introduced while stirring, and the hydrogen pressure is controlled to be 20-30 kg. After 3-5 hours, the reaction is completed, and the hydrogenation liquid is placed in a storage tank for standby use without any treatment; The hydrogenation liquid is pumped into a crystallization kettle, and the temperature is controlled to drop to -5°C to precipitate crystals, which are kept at -5°C for 2 hours, and the solid tris(hydroxymethyl)aminomethane is obtained by centrifugation and then put into a recrystallization kettle; The mother liquor obtained by centrifugation is returned to the condensation kettle for reuse, and the mother liquor after reuse is distilled to recover methanol or ethanol; The tris(hydroxymethyl)aminomethane) solid and water are put into the recrystallization kettle at a ratio of 1:0.3 to 1:0.5, and crystals are precipitated after cooling down. The crystals are centrifuged after keeping warm for 2 hours, and the crystals obtained by centrifugation are the tris(hydroxymethyl)aminomethane product.

2. The method for preparing tris(hydroxymethyl)aminomethane according to claim 1, characterized in that: The catalytic amount of base is any one of flake caustic soda, potassium hydroxide, sodium methoxide, sodium ethoxide, and sodium tert-butoxide.

3. The method for preparing tris(hydroxymethyl)aminomethane according to claim 1, characterized in that: After obtaining the tris(hydroxymethyl)aminomethane product, the method further comprises: The tris(hydroxymethyl)aminomethane product is dried and then packaged and stored.

4. The method for preparing tris(hydroxymethyl)aminomethane according to claim 1, characterized in that: After the crystals obtained by centrifugation are tris(hydroxymethyl)aminomethane products, the method further comprises: The mother liquor obtained by centrifugation is returned to the recrystallization kettle for reuse, and the mother liquor after reuse 3-10 times is subjected to solvent recovery treatment.

5. The method for preparing tris(hydroxymethyl)aminomethane according to claim 1, characterized in that: The air was replaced with the nitrogen gas three times.

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