阅读说明：本技术 一种从工业废四氢呋喃中精馏回收四氢呋喃的方法 (Method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran ) 是由 王培文 于 2020-07-22 设计创作，主要内容包括：本发明属于四氢呋喃回收技术领域,具体涉及一种从工业废四氢呋喃中精馏回收四氢呋喃的方法,是将工业废四氢呋喃母液粗蒸馏得到四氢呋喃粗品,然后通入惰性气体后通过加压精馏分离低沸点物质,继续加压进行精馏脱水,直到得到含水率低于0.1％的四氢呋喃。本发明方法有效利用了低沸点可以脱大部分水,避免了使用其他有机萃取剂再二次回收,降低了成本,操作简便,产品质量好,提高了产品质量和收率。(The invention belongs to the technical field of tetrahydrofuran recovery, and particularly relates to a method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran, which comprises the steps of carrying out crude distillation on industrial waste tetrahydrofuran mother liquor to obtain a tetrahydrofuran crude product, then introducing inert gas, separating low-boiling-point substances through pressure rectification, and continuing pressurization to carry out rectification dehydration until tetrahydrofuran with the water content of less than 0.1% is obtained. The method effectively utilizes the low boiling point to remove most of water, avoids using other organic extracting agents for secondary recovery, reduces the cost, has simple and convenient operation and good product quality, and improves the product quality and the yield.)

1. A method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran is characterized by comprising the following steps: and (3) carrying out crude distillation on the industrial waste tetrahydrofuran mother liquor to obtain a tetrahydrofuran crude product, then introducing inert gas, separating low boiling point substances by pressure rectification, and continuously pressurizing to carry out rectification dehydration until tetrahydrofuran with the water content of less than 0.1% is obtained.

2. The method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran according to claim 1, comprising the following steps:

(1) crude tetrahydrofuran is obtained by crude distillation:

putting industrial waste tetrahydrofuran mother liquor into a rough distillation kettle, and heating and distilling to obtain a tetrahydrofuran crude product;

(2) introducing inert gas to separate low-boiling-point raw materials:

introducing inert gas into a rectifying tower kettle, pumping the tetrahydrofuran crude product obtained in the step (1) into a rectifying tower, controlling the pressure in the kettle to be 0.1-0.6 MPa through pressurization, and heating, rectifying and separating a low-boiling-point raw material;

(3) introducing inert gas for pressure dehydration:

continuously introducing inert gas into the rectifying tower kettle, controlling the pressure in the kettle to be 0.1-0.6 MPa, and heating, rectifying and dehydrating to obtain tetrahydrofuran mixed liquor with the water content of less than 6%;

(4) keeping the pressure, heating and rectifying to obtain a tetrahydrofuran finished product:

and continuously introducing inert gas, controlling the pressure in the kettle to be 0.1-0.6 MPa, and heating and rectifying to obtain a tetrahydrofuran finished product with the water content of less than 0.1%.

3. The method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran according to claim 2, wherein: the industrial waste tetrahydrofuran mother liquor in the step (1) is a mixed liquor containing tetrahydrofuran, low-boiling-point raw materials and water.

4. The method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran according to claim 2, wherein: in the step (1), the distillation temperature is 80-90 ℃.

5. The method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran according to claim 2, wherein: in the step (2), the temperature of the top of the rectifying tower is 40-50 ℃ when the low boiling point raw material is separated by heating and rectifying.

6. The method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran according to claim 2, wherein: in the step (3), the temperature of the top of the rectifying tower is 80-100 ℃ when the heating, rectifying and dehydrating are carried out.

7. The method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran according to claim 2, wherein: in the step (4), the temperature of the top of the rectifying tower is 100-120 ℃ when the rectifying tower is heated and rectified.

8. The method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran according to claim 2, wherein: in the step (1), the step (2), the step (3) and the step (4), steam is used for heating.

9. The method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran according to claim 2, wherein: in the step (2), the step (3) and the step (4), the inert gas is nitrogen or argon.

Technical Field

The invention belongs to the technical field of tetrahydrofuran recovery, and particularly relates to a method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran.

Background

Tetrahydrofuran is also called 1, 4-ethylene oxide and tetramethyleneoxide (T h F for short), is a common organic solvent, has strong toxicity, can be poisoned when being inhaled by steam or contacted with skin, has the explosion limit of 2.3-11.8 in air, can generate peroxide like diethyl ether, and is extremely easy to explode. Tetrahydrofuran is generally used to dissolve and react in organic materials, but does not participate in the reaction itself. The product is separated after the reaction, and the residual tetrahydrofuran can not be used due to the impurity, which causes great economic loss and pollutes the environment if directly discarded. At present, the recovery and purification of tetrahydrofuran has great difficulty in purification due to extraction by using an extraction solvent and rectification, and no domestic report exists for directly recovering and extracting pure tetrahydrofuran from industrial waste tetrahydrofuran.

Disclosure of Invention

The invention aims to provide a method for recovering tetrahydrofuran from industrial waste tetrahydrofuran by rectification, which solves the problem that the existing recovery and purification of tetrahydrofuran is more difficult due to extraction by using an extraction solvent and rectification.

The realization process of the invention is as follows:

a method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran comprises the steps of carrying out crude distillation on industrial waste tetrahydrofuran mother liquor to obtain a tetrahydrofuran crude product, then introducing inert gas, carrying out pressure rectification to separate low-boiling-point substances, and continuing pressurization to carry out rectification dehydration until tetrahydrofuran with the water content of less than 0.1% is obtained.

The method for rectifying and recovering tetrahydrofuran from industrial waste tetrahydrofuran specifically comprises the following steps:

(1) crude tetrahydrofuran is obtained by crude distillation:

putting industrial waste tetrahydrofuran mother liquor into a rough distillation kettle, and heating and distilling to obtain a tetrahydrofuran crude product;

(2) introducing inert gas to separate low-boiling-point raw materials:

introducing inert gas into a rectifying tower kettle, pumping the tetrahydrofuran crude product obtained in the step (1) into a rectifying tower, controlling the pressure in the kettle to be 0.1-0.6 MPa through pressurization, and heating, rectifying and separating a low-boiling-point raw material;

(3) introducing inert gas for pressure dehydration:

continuously introducing inert gas into the rectifying tower kettle, controlling the pressure in the kettle to be 0.1-0.6 MPa, and heating, rectifying and dehydrating to obtain tetrahydrofuran mixed liquor with the water content of less than 6%;

(4) keeping the pressure, heating and rectifying to obtain a tetrahydrofuran finished product:

and continuously introducing inert gas, controlling the pressure in the kettle to be 0.1-0.6 MPa, and heating and rectifying to obtain a tetrahydrofuran finished product with the water content of less than 0.1%.

Further, the industrial waste tetrahydrofuran mother liquor in the step (1) is a mixed liquor containing tetrahydrofuran, low-boiling-point raw materials and water.

Further, in the step (1), the distillation temperature is 80-90 ℃.

Further, in the step (2), the temperature of the top of the rectifying tower is 40-50 ℃ when the low boiling point raw material is separated by heating and rectifying.

Further, in the step (3), the temperature of the top of the rectifying tower is 80-100 ℃ when the rectifying tower is heated, rectified and dehydrated.

Further, in the step (4), the temperature of the top of the rectifying tower is 100-120 ℃ when the rectifying tower is heated and rectified.

Further, in the step (1), the step (2), the step (3) and the step (4), steam is used for heating.

Further, in the step (2), the step (3) and the step (4), the inert gas is nitrogen or argon.

The invention has the following positive effects:

the method effectively utilizes the low boiling point to remove most of water, avoids using other organic extracting agents for secondary recovery, reduces the cost, has simple and convenient operation and good product quality, and improves the product quality and the yield.

Detailed Description

The present invention will be further described with reference to the following examples.

The low boiling point raw material contained in the industrial waste tetrahydrofuran is dichloromethane with a boiling point of 39.75.