阅读说明：本技术 一种硫代二甘硫醇的制备方法 (Preparation method of thiodiglycol ) 是由 梁万根 张超 崔卫华 孙志利 费潇瑶 许倩倩 周芳晶 靖培培 刘龙飞 于 2019-10-31 设计创作，主要内容包括：本发明属于及有机合成技术领域,具体涉及一种硫代二甘硫醇的制备方法,具体制备方法包括：硫代二甘醇与硫化氢通入混合器中充分混合,其中硫代二甘醇采用泵加压通入,硫化氢采用钢瓶减压进入；混合均匀的原料自下而上通过装有催化剂的固定床反应器,硫代二甘醇与硫化氢反应生成硫代二甘硫醇；反应后的产品与未反应的硫化氢进入分离器,其中硫化氢从分离器上部加压进行重复利用,产品从分离器下部产出。本发明采用硫化氢代替原有工艺中的硫脲,盐酸,碱等化学品,减少了成本,无三废产生,采用固定床反应器,是一种连续性反应装置,操作简单,反应充分,减少副反应的发生。(The invention belongs to the technical field of organic synthesis, and particularly relates to a preparation method of thiodiglycol, which comprises the following steps: introducing thiodiglycol and hydrogen sulfide into a mixer for fully mixing, wherein the thiodiglycol is introduced by adopting a pump for pressurization, and the hydrogen sulfide is introduced by adopting a steel cylinder for decompression; enabling the uniformly mixed raw materials to pass through a fixed bed reactor filled with a catalyst from bottom to top, and enabling thiodiglycol to react with hydrogen sulfide to generate thiodiglycol; and the reacted product and unreacted hydrogen sulfide enter a separator, wherein the hydrogen sulfide is pressurized from the upper part of the separator for recycling, and the product is produced from the lower part of the separator. The invention adopts hydrogen sulfide to replace thiourea, hydrochloric acid, alkali and other chemicals in the prior art, reduces the cost, does not generate three wastes, adopts a fixed bed reactor, is a continuous reaction device, has simple operation and full reaction, and reduces the generation of side reactions.)

1. A preparation method of thiodiglycol is characterized by comprising the following specific processes:

(a) introducing thiodiglycol and hydrogen sulfide into a mixer for fully mixing, wherein the thiodiglycol is introduced into the mixer by adopting a pump for pressurization, and the hydrogen sulfide enters the mixer by adopting a steel cylinder for decompression;

(b) enabling the uniformly mixed raw materials to pass through a fixed bed reactor filled with a catalyst from bottom to top, and enabling thiodiglycol to react with hydrogen sulfide to generate thiodiglycol;

(c) and the reacted product and unreacted hydrogen sulfide enter a separator, the product is produced from the lower part of the separator, and the hydrogen sulfide enters the mixer again from the upper part of the separator through pressurization for recycling.

2. The method of claim 1, wherein the catalyst is a supported cobalt or/and molybdenum catalyst and the support is alumina.

3. The method according to claim 1, wherein the molar ratio of hydrogen sulfide to thiodiglycol is 2-10: 1.

4. The method according to claim 3, wherein the molar ratio of hydrogen sulfide to thiodiglycol is: 4-6:1.

5. The method for preparing thiodiglycol according to claim 1, wherein the reaction pressure in the fixed bed reactor is: 0.2-1.5 MPa.

6. The method for preparing thiodiglycol according to claim 5, wherein the reaction pressure in the fixed bed reactor is: 0.6-1.0 MPa.

7. The method as claimed in claim 1, wherein the reaction temperature in the fixed bed reactor is 100-180 ℃.

8. The method as claimed in claim 7, wherein the reaction temperature in the fixed bed reactor is 120-160 ℃.

9. The method as claimed in claim 1, wherein the volume space velocity of hydrogen sulfide in the fixed bed reactor is 500-2000h^-1。

10. The method of claim 1, wherein the thiodiglycol is pumped into the mixer to 0.2-1.5MPa, and the hydrogen sulfide is pumped into the mixer to 0.2-1.5 MPa.

Technical Field

The invention belongs to the technical field of organic synthesis, and particularly relates to a preparation method of thiodiglycol.

Background

The thiodiglycol thiol is an organic compound containing two sulfydryl groups, is mainly used for preparing optical resin materials, and has a structural formulaThe existing synthesis of thiodiglycol is realized by adopting the following technology: the method comprises the following steps of carrying out reflux reaction on thiodiglycol as a raw material, thiourea and hydrochloric acid in a certain ratio at the temperature of about 110 ℃ for 2-5 hours to generate isothiourea salt of the thiodiglycol, adding alkali liquor into the generated isothiourea salt, carrying out alkaline hydrolysis reaction at the temperature of 40-80 ℃ to generate a target product, separating the product from a water phase through liquid separation, and carrying out water washing, distillation, adsorption, filtration and other processes on the product to prepare a refined product of the thiodiglycol. In the prior art, thiodiglycol is required to be converted into isothiourea salt, then alkaline hydrolysis is carried out on the thiodiglycol to generate a crude product, and the crude product is washed, distilled, adsorbed and filtered to obtain a final product; the production amount of the waste water is large, about 6 tons of waste water are produced in each ton of products, the waste water treatment cost is high, and the environmental protection pressure is large.

Disclosure of Invention

Aiming at the problems, the invention provides a preparation method of thiodiglycol, which adopts thiodiglycol and hydrogen sulfide to directly synthesize thiodiglycol through catalysis, has high atom utilization rate, almost no three wastes and continuous and simple operation.

The technical scheme of the invention is as follows:

a preparation method of thiodiglycol is characterized by comprising the following specific processes:

(a) introducing thiodiglycol and hydrogen sulfide into a mixer for fully mixing, wherein the thiodiglycol is pressurized to 0.2-1.5MPa by a pump and introduced into the mixer, and the hydrogen sulfide is depressurized to 0.2-1.5MPa by a steel cylinder and enters the mixer;

(b) the evenly mixed raw materials pass through a fixed bed reactor filled with a catalyst from bottom to top, thiodiglycol reacts with hydrogen sulfide to generate thiodiglycol, the catalyst needs to be ensured to be in a certain amount to fill a bed layer of the tubular reactor, and the volume space velocity of the hydrogen sulfide is controlled to be 500 plus 2000h^-1；

(c) And the reacted product and unreacted hydrogen sulfide enter a separator, the product is produced from the lower part of the separator, and the hydrogen sulfide enters the mixer again from the upper part of the separator through pressurization for recycling.

The hydrogen sulfide and the thiodiglycol are fully and uniformly mixed in a mixer to form a highly dispersed gas-liquid mixture, and the hydrogen sulfide gas enters the reactor in the form of droplets of the thiodiglycol and reacts under the action of a catalyst.

Preferably, the catalyst is a supported cobalt or/and molybdenum catalyst and the support is alumina.

Preferably, the specific preparation steps of the cobalt catalyst comprise: weighing 3 parts of gamma-Al with the granularity of 40-60 meshes in parts by mass₂O₃Carrier, taking 1.29 parts of Co (NO)₃)₂·6H₂Dissolving O in 3 parts of ultrapure water, slowly dropping the solution into the carrier and stirring uniformly, soaking at room temperature for 8 hours, and drying in an oven at 120 ℃ for 12 hours to obtain Co (NO) as the catalyst precursor₃)₂/Al₂O₃. Placing the mixture into a muffle furnace for calcination at the temperature of 450-650 ℃ for 4-8 hours, and cooling to room temperature after the calcination is finished to obtain the load typeA catalyst. But are not limited to, catalysts prepared by such methods.

Preferably, the molar ratio of hydrogen sulfide to thiodiglycol is: 2-10:1, further preferably: 4-6:1. Too low a ratio will result in insufficient reaction, and too high a ratio will result in insufficient reaction due to short residence time and material loss.

Preferably, the reaction pressure in the fixed bed reactor is: 0.2 to 1.5MPa, and more preferably: the reaction pressure is as follows: 0.6-1.0 MPa. The reaction pressure is too low to be beneficial to the reaction, and the pressure is high, so that the safety risk exists.

Preferably, the reaction temperature in the fixed bed reactor is 100-180 ℃, and further preferably, the reaction temperature is 120-160 ℃. The reaction speed is influenced by low reaction temperature, and side reactions are increased by overhigh reaction temperature.

Preferably, the space velocity of the hydrogen sulfide in the fixed bed reactor is 500-2000h^-1More preferably, 800-^-1. The space velocity is the volume flow (20 ℃, m) of the raw material hydrogen sulfide³.h^-1) Catalyst volume (m)³)。

The invention adopts hydrogen sulfide to replace thiourea, hydrochloric acid, alkali and other chemicals in the prior art, reduces the cost, does not generate three wastes, adopts a fixed bed reactor, is a continuous reaction device, has simple operation and full reaction, and reduces the generation of side reactions. The invention has higher product content and yield, more importantly, the operation is simple and convenient, no three wastes are generated, and the synthesis efficiency is higher.

Drawings

FIG. 1 is a flow chart of the preparation method of the present invention.

Detailed Description

The above-described aspects of the present invention will be described in further detail below with reference to specific embodiments, but it should not be construed that the scope of the above-described subject matter of the present invention is limited to the following examples. All the technologies realized based on the above contents of the present invention belong to the scope of the present invention.