阅读说明：本技术 一种制备牛磺酸的方法 (Method for preparing taurine ) 是由 张静 桂振友 郭斌 蔺海政 钟子太 孔令晓 梁静 王文 李晶 陈来中 张永振 于 2020-06-11 设计创作，主要内容包括：本发明提供一种制备牛磺酸的方法,采用的非均相催化剂体系能够大幅改进羟乙基磺酸钠制备牛磺酸工艺条件,另外高温喷雾干燥器脱出副产乙醇胺、乙二醇和二聚乙二醇,实现母液有效成分的完全套用。与传统的工艺相比,该工艺使羟乙基磺酸钠的氨解反应所需要的反应温度和压力条件更加温和,同时反应时间也缩短。实现母液中有效成分的完全套用,显著提高牛磺酸的总收率,易于工业化生产,降低了产品生产成本。(The invention provides a method for preparing taurine, wherein a heterogeneous catalyst system is adopted, so that the technological conditions for preparing taurine from sodium isethionate can be greatly improved, and in addition, by-products of ethanolamine, ethylene glycol and diethylene glycol are removed by a high-temperature spray dryer, so that the complete application of the effective components of the mother liquor is realized. Compared with the traditional process, the process has the advantages that the reaction temperature and pressure conditions required by the ammonolysis reaction of the hydroxyethyl sodium sulfonate are milder, and the reaction time is shortened. The method realizes complete application of effective components in the mother liquor, obviously improves the total yield of taurine, is easy for industrial production and reduces the production cost of products.)

1. A method for preparing taurine is characterized in that sodium isethionate and liquid ammonia react under the catalysis of a heterogeneous catalyst to obtain sodium taurate, and taurine is obtained through further neutralization reaction.

2. The process of claim 1 wherein the heterogeneous catalyst is BaCaTiO₄、BaCe₂Ti₅O₁₅、BaTi₆Co₆O₁₉Preferably BaTi₆Co₆O₁₉And/or the catalyst is used in an amount of 1 to 15 wt%, preferably 2 to 12 wt%, more preferably 5 to 10 wt% based on the mass of sodium isethionate.

3. Method according to claim 1 or 2, characterized in that it comprises the following steps:

(1) introducing liquid ammonia into the aqueous solution of the solid mixture obtained by spray drying of the aqueous solution of the hydroxyethyl sodium sulfonate and the mother liquor, and adding a heterogeneous catalyst to obtain a raw material solution;

(2) heating the raw material liquid, and introducing the heated raw material liquid into a high-pressure reactor for reaction to obtain a reaction liquid;

(3) after ammonia in the reaction liquid is removed, neutralizing, crystallizing and filtering to obtain crude taurine and primary filtrate;

(4) concentrating the primary filtrate at high temperature to remove most of sodium sulfate and a heterogeneous catalyst to obtain a mother solution;

(5) and (3) after the mother liquor is subjected to secondary product removal containing ethanolamine, ethylene glycol and polyethylene glycol by a high-temperature spray dryer, preparing the obtained solid into an aqueous solution, reusing the aqueous solution as a stock solution in the step (1), and sending a small amount of condensate containing the by-product to biochemical treatment.

4. The method according to claim 3, wherein the concentration of the raw material sodium isethionate aqueous solution in step (1) is 30 to 50 wt.%, preferably 35 to 48 wt.%, more preferably 40 to 45 wt.%; and/or, the concentration of the sodium isethionate in the mixed solution is 5 to 30 wt%, preferably 10 to 25 wt%, more preferably 15 to 20 wt%; the concentration of the aqueous solution of the solid mixture obtained by spray drying the mother liquor is 30-60 wt%, preferably 35-58 wt%, more preferably 45-55 wt%; and/or, liquid ammonia is introduced so that the concentration of ammonia in the aqueous mixture of the aqueous solution of sodium isethionate and the solids obtained by spray drying of the mother liquor is from 10 to 30% by weight, preferably from 15 to 28% by weight, more preferably from 18 to 27% by weight.

5. The method according to any one of claims 3-4, wherein the reaction temperature in step (2) is 200-250 ℃, preferably 210-240 ℃, more preferably 220-235 ℃; the reaction pressure is 17-19MPa, preferably 17.8-18.8MPa, more preferably 18-18.5MPa in terms of gauge pressure; the reaction time is 20-50min, preferably 25-48min, more preferably 30-45 min.

6. The method according to any one of claims 3 to 5, wherein the temperature for removing ammonia from the reaction solution in step (3) is 150-200 ℃, preferably 170-190 ℃, more preferably 175-185 ℃; the concentration of the reaction solution after ammonia removal is 20-50 wt%, preferably 30-48 wt%, and more preferably 35-45 wt%; and/or after ammonia in the reaction liquid is removed, using concentrated sulfuric acid to neutralize the reaction liquid at 50-90 ℃ to adjust the pH value of the system to 7-9; and/or, cooling to 20-40 ℃ for crystallization after neutralization to obtain a taurine crude product and a primary filtrate.

7. The method as claimed in any one of claims 3 to 6, wherein the primary filtrate concentration temperature in step (4) is 90 to 150 ℃, preferably 100-130 ℃, more preferably 110-120 ℃; the concentration of taurine in the concentrate is 20 to 45 wt%, preferably 30 to 40 wt%, more preferably 35 to 40 wt%.

8. The method according to any one of claims 3 to 7, wherein the inlet temperature for the spray drying in step (5) is 185-240 ℃, preferably 190-235 ℃, more preferably 200-230 ℃; the air outlet temperature is 80-125 ℃; operating pressure: 5-10 kPa; the moisture content of the obtained solid matter is 2 wt% or less.

9. The method of any one of claims 2 to 8, wherein BaCaTiO₄The preparation method of the catalyst comprises the following steps: weighing nano-scale BaCO according to the molar ratio of 1:1:1₃、TiO₂And CaCO₃Fully grinding the particles for 30-60min by a ball mill after mixing, transferring the particles to a muffle furnace for calcining, and quickly cooling to room temperature to obtain the required catalyst and/or;

BaCe₂Ti₅O₁₅the preparation method of the catalyst comprises the following steps: weighing nano-scale BaCO according to the molar ratio of 1:5:2₃、TiO₂And CeO₂Fully grinding the particles for 30-50min by a ball mill after mixing, transferring the particles to a muffle furnace for calcining, and cooling to room temperature to obtain the required catalyst and/or;

BaTi₆Co₆O₁₉the preparation method of the catalyst comprises the following steps: weighing nano-scale BaCO according to the molar ratio of 1:6:3₃、TiO₂And Co₂O₃And after the particles are well mixed, fully grinding the particles for 30-60min by a ball mill, transferring the particles to a muffle furnace for calcining, and cooling to room temperature to obtain the required catalyst.

10. The method of claim 9, wherein the BaCaTiO is₄In the preparation method of the catalyst, the calcination process is carried out for 4-6h at 1300-1400 ℃; and/or, BaCe₂Ti₅O₁₅In the preparation method of the catalyst, the calcination process comprises the steps of firstly calcining at 1200-1250 ℃ for 3-4h, then heating to 1260-1300 ℃, and continuing calcining for 3-4 h; and/or, BaTi₆Co₆O₁₉In the preparation method of the catalyst, the calcination process is calcination at 1200-1300 ℃ for 2-4 h.

Technical Field

The invention relates to a method for preparing taurine.

Background

Taurine, also known as taurocholic acid and taurochol, and its chemical name 2-aminoethanesulfonic acid, is a non-protein amino acid essential to the human body and is present in free form in almost all organs of humans and mammals. The taurine has different functions from other amino acids, and can promote the growth and development of nervous system, protect brain, improve memory, improve optic nerve conduction and visual function, protect heart, prevent and treat cardiovascular and cerebrovascular diseases, etc. Taurine has high medicinal value, is an important nutrient substance, is widely applied to the fields of functional beverages, pet foods, health foods, feeds, medicines and the like, can also be used as a biochemical reagent and other organic synthesis intermediates, and is a fine chemical with wide application value.

At present, the synthesis process of taurine is mainly divided into two types: 1) the main disadvantages of the ethanolamine process are long reaction period, low yield, high cost and serious generation of three wastes, and the ethanolamine process is a non-mainstream production process at present; 2) the ethylene oxide process is a mainstream process for producing the taurine at present, and has the advantages of low production cost, high taurine yield and small three-waste yield, but the process has harsh aminolysis reaction conditions of the sodium isethionate, and salt is easy to separate out under high temperature and high pressure, so that equipment and instruments are blocked, the shutdown and maintenance are required regularly, the productivity is improved, and the production cost and the safety risk are increased. In addition, the generated byproducts such as ethylene glycol, ethanolamine, diethylene glycol and the like are accumulated in the process of recycling the mother liquor, and the mother liquor needs to be discharged regularly and quantitatively, so that the total yield of the product is influenced.

In conclusion, the existing taurine preparation process has harsh reaction conditions, high safety risk, accumulated by-products and appropriate discharge of mother liquor containing effective components, thereby reducing the total yield of the product and increasing the production cost.

Disclosure of Invention

The invention aims to provide a method for preparing taurine, which enables ammonolysis reaction conditions to be milder, shortens reaction time, adopts high-temperature spray drying to effectively remove byproducts such as ethanolamine, ethylene glycol, diethylene glycol and the like, realizes full recovery of effective components in mother liquor, and only sends a small amount of condensate to biochemical treatment. The yield of the product is improved, the production cost of the product is reduced, and the industrialization is easy to realize.

In order to achieve the above purpose, the technical scheme provided by the invention is as follows:

a method for preparing taurine comprises the steps of reacting hydroxyethyl sodium sulfonate with liquid ammonia under the catalysis of a heterogeneous catalyst to obtain sodium taurate, and further performing neutralization reaction to obtain the taurine.

The byproducts ethanolamine, glycol and diglycol are removed by adopting a high-temperature spray dryer, so that the complete application of the effective components of the mother liquor is realized. Preferably, the heterogeneous catalyst is BaCaTiO₄、BaCe₂Ti₅O₁₅、BaTi₆Co₆O₁₉Preferably BaTi₆Co₆O₁₉。

As a preferred embodiment, the method for preparing taurine comprises the following steps:

(1) introducing liquid ammonia into the aqueous solution of the solid mixture obtained by spray drying of the aqueous solution of the hydroxyethyl sodium sulfonate and the mother liquor, and adding a heterogeneous catalyst to obtain a raw material solution;

(2) heating the raw material liquid, and introducing the raw material liquid into a high-pressure reactor for reaction to obtain a reaction liquid;

(3) after ammonia in the reaction liquid is removed, neutralizing, crystallizing and filtering to obtain crude taurine and primary filtrate;

(4) concentrating the primary filtrate at high temperature to remove most of sodium sulfate and a heterogeneous catalyst to obtain a mother solution;

(5) and (3) removing byproducts such as ethanolamine, ethylene glycol and polyethylene glycol from the mother liquor through a high-temperature spray dryer, preparing the obtained solid into an aqueous solution, reusing the aqueous solution as a stock solution in the step (1), realizing complete reuse of effective components of the mother liquor, and sending a small amount of condensate containing byproducts to biochemical treatment.

In the present invention, BaCaTiO₄The preparation method of the catalyst comprises the following steps: weighing nano-scale BaCO according to the molar ratio of 1:1:1₃、TiO₂And CaCO₃And after mixing, fully grinding the particles for 30-60min by a ball mill, then transferring the particles into a muffle furnace, preferably calcining the particles at 1300-1400 ℃ for 4-6h, and then quickly cooling the particles to room temperature to obtain the required catalyst.

BaCe₂Ti₅O₁₅The preparation method of the catalyst comprises the following steps: weighing nano-scale BaCO according to the molar ratio of 1:5:2₃、TiO₂And CeO₂And after the particles are well mixed, fully grinding the particles for 30-50min by a ball mill, then transferring the particles into a muffle furnace, preferably calcining the particles for 3-4h at 1250 ℃, then heating the particles to 1260-1300 ℃, continuing calcining for 3-4h, and cooling the particles to room temperature to obtain the required catalyst.

BaTi₆Co₆O₁₉The preparation method of the catalyst comprises the following steps: weighing nano-scale BaCO according to the molar ratio of 1:6:3₃、TiO₂And Co₂O₃And after the particles are well mixed, fully grinding the particles for 30-60min by a ball mill, then transferring the particles into a muffle furnace, preferably calcining the particles at the temperature of 1200-1300 ℃ for 2-4h, and cooling the particles to room temperature to obtain the required catalyst.

In the invention, liquid ammonia is introduced in the step (1) to ensure that the concentration of ammonia in the solid mixed solution obtained by spray drying of the sodium isethionate aqueous solution and the mother liquor is 10-30 wt%, preferably 15-28 wt%, and more preferably 18-27 wt%; the concentration of sodium isethionate in the mixed liquor (comprising liquid ammonia) is 5 to 30 wt.%, preferably 10 to 25 wt.%, more preferably 15 to 20 wt.%. The concentration of the dried solid after dilution with ultrapure water (i.e., an aqueous solution of a solid mixture obtained by spray-drying a mother liquor) is from 30 to 60% by weight, preferably from 35 to 58% by weight, more preferably from 45 to 55% by weight. The amount of the catalyst is 1 to 15 wt%, preferably 2 to 12 wt%, more preferably 5 to 10 wt% based on the mass of the sodium isethionate. The concentration of the raw material sodium isethionate aqueous solution is 30 to 50 wt%, preferably 35 to 48 wt%, more preferably 40 to 45 wt%.

In the invention, the reaction temperature in the step (2) is 200-250 ℃, preferably 210-240 ℃, and more preferably 220-235 ℃; the reaction pressure is 17-19MPa, preferably 17.8-18.8MPa, more preferably 18-18.5MPa in terms of gauge pressure; the reaction time is 20-50min, preferably 25-48min, more preferably 30-45 min.

In the invention, the temperature for removing ammonia from the reaction solution in the step (3) is 150-200 ℃, preferably 170-190 ℃, and more preferably 175-185 ℃; the concentration of the reaction solution after ammonia removal is 20-50 wt%, preferably 30-48 wt%, and more preferably 35-45 wt%; after ammonia in the reaction liquid is removed, concentrated sulfuric acid is used for neutralizing at 50-90 ℃ to adjust the pH value of the system to 7-9. And cooling to 20-40 ℃ for crystallization after neutralization to obtain a crude taurine product and a primary filtrate.

In the invention, the concentration temperature of the primary filtrate in the step (4) is 90-150 ℃, preferably 100-130 ℃, and more preferably 110-120 ℃; the concentration of the concentrated taurine is 20-45 wt%, preferably 30-40 wt%, more preferably 35-40 wt%; then most of sodium sulfate is removed by filtration;

in the invention, the spray drying in the step (5) is to disperse the material to be dried into fine particles like fog by mechanical action, increase the water evaporation area, accelerate the drying process to contact with hot air, and remove most of water instantly to dry the solid matter in the material into powder. The inlet air temperature is 185-240 ℃, preferably 190-235 ℃, and more preferably 200-230 ℃; the air outlet temperature is 80-125 ℃; operating pressure: 5-10 kPa; the moisture content of the solid matter is 2 wt% or less.

The principle that the spray drying can realize the total recycling of the mother liquor to prepare the taurine is as follows: the high-temperature spray drying utilizes heat (the operation temperature is obviously higher than the boiling point of the byproduct) to change the byproducts such as ethylene glycol, ethanolamine and the like into gas phase, so that the byproducts are removed along with water, the solid obtained by drying can be diluted into solution by using ultrapure water, and the solution is applied to an ammonolysis reaction part according to a certain proportion.

The heterogeneous catalyst system of the invention can greatly improve the process conditions for preparing taurine from hydroxyethyl sodium sulfonate according to the following principle: in the ammonolysis reaction of the hydroxyethyl sodium sulfonate, the action mechanism of the conventional alkaline catalyst such as NaOH in the patent is compared by utilizing OH^-Promoting the removal of ammonium ions on hydroxyl groups in the hydroxyethyl sodium sulfonate, thereby promoting the ammonolysis reaction; the heterogeneous catalyst adopted by the invention contains an alkaline catalyst consisting of metal elements such as Ba, Ca, Ti, Ce, Co and the like, the catalyst is calcined into a eutectic body at high temperature, and due to the existence of chemical bonds of metal and oxygen, compared with a mixture catalyst consisting of metal oxides, the catalyst has structural advantages, the alkaline site of the catalyst can activate hydroxyl, so that the nucleophilic attack of ammonia on hydroxyl carbon is promoted better, and a high-energy-state four-membered ring intermediate cannot be formed, so that the required reaction temperature and pressure conditions are milder, and the reaction time is shortened.

The invention has the positive effects that:

(1) the heterogeneous catalyst is adopted, so that the temperature and pressure conditions of the ammonolysis reaction are milder, and the reaction time is shortened.

(2) All by-products in the mother liquor are removed efficiently, and the accumulation of the by-products in the mother liquor recycling process is avoided.

(3) The effective components in the mother liquor are completely reserved, and the complete application of the effective components is realized.

(4) After the mother liquor is completely recycled, the total yield of the taurine in the whole process can reach more than 92 percent.

Detailed Description

The following examples are not intended to limit the scope of the present invention, and modifications and equivalents may be made thereto without departing from the spirit and scope of the present invention, which is defined in the appended claims.

Reagents for preparing the catalyst were purchased from Sigma-Aldrich; sodium isethionate was purchased from Sigma Aldrich (Sigma-Aldric)h) Trade company, Inc.; the taurine and sodium taurate yield is obtained by analyzing and calculating by liquid chromatography equipped with ultraviolet detector, wherein the liquid chromatography is of 1200 series of Agilent company, and is equipped with C18 liquid chromatography column, the column temperature is set at 40 deg.C, acetonitrile and 0.05mol/L NaH₂PO₄The solution is a mobile phase, the flow rate is 1.0mL/min, the detection is carried out at the wavelength of 360nm by an ultraviolet detector, and the quantification is carried out by an external standard method. Before sample introduction, a sample is diluted properly by ultrapure water, added with excessive dinitrofluorobenzene solution for full derivatization, and then subjected to sample introduction analysis; catalyst grinding was carried out by using a Shanghai Procept agitation dispersion mill JSF-500.

Qualitative analysis of the catalyst sample was carried out using an X-ray diffractometer model G670 manufactured by Huber corporation, and Cu K α (incident wavelength thereof) was selected) The instrument is used as a radiation source, the scanning speed is 0.02 degree/S, the scanning range of the instrument is set to 10-80 degrees before scanning is started, the acceleration voltage of the X-ray light tube is set to 40KV, the acceleration current is set to 40mA, and data are collected in a continuous scanning mode in the test analysis process.

Catalyst preparation examples

BaCaTiO₄The preparation method of the catalyst comprises the following steps: weighing nano-scale BaCO according to the molar ratio of 1:1:1₃、TiO₂And CaCO₃And after the particles are well mixed, fully grinding the particles for 45min by a ball mill, transferring the particles into a muffle furnace, calcining the particles for 4.5h at 1300 ℃, and quickly cooling the particles to room temperature to obtain the required catalyst.

BaCe₂Ti₅O₁₅The preparation method of the catalyst comprises the following steps: weighing nano-scale BaCO according to the molar ratio of 1:5:2₃、TiO₂And CeO₂And after the particles are well mixed, fully grinding the particles for 30min by a ball mill, transferring the particles into a muffle furnace, calcining the particles for 3.5h at 1250 ℃, heating the particles to 1300 ℃, continuously calcining the particles for 4h, and cooling the particles to room temperature to obtain the required catalyst.

BaTi₆Co₆O₁₉The preparation method of the catalyst comprises the following steps: according to the formula of the mesogenWeighing nano-scale BaCO at a sub-molar ratio of 1:6:3₃、TiO₂And Co₂O₃And (3) fully grinding the particles for 35min by a ball mill after the particles are well mixed, transferring the particles into a muffle furnace, calcining the particles for 2.4h at 1280 ℃, and cooling to room temperature to obtain the required catalyst.