WO2018039848A1 - Recovery process for tetrahydrofuran - Google Patents

Abstract

Provided is a recovery process for tetrahydrofuran, comprising: firstly testing the concentration of tetrahydrofuran prepared, and pouring the tetrahydrofuran, when the water content thereof is greater than 10%, into an oil-free vacuum pump and carrying out a vacuum-pumping treatment on same; then adding potassium permanganate to the oil-free vacuum pump, and carrying out an oxidation treatment with stirring; then adding a catalyst to the solution after the oxidation is finished, reacting at a temperature of 50ºC for 50 min; and finally pouring the solution into a reduced pressure distiller and carrying out reduced pressure distillation, collecting 90% of a fraction, and finally obtaining tetrahydrofuran with a water content of less than 5%. The advantages of the process lie in: by adding a special oxidizing agent, the oxidability index of tetrahydrofuran meets the quality standard, the number of distillations is decreased, and energy consumption is reduced; and by the use of an oil-free vacuum pump for vacuum-pumping, a clean tail gas is obtained.

Description

[Name of invention established by ISA according to Rule 37.2] Recovery process of tetrahydrofuran Compound herbicide

Technical field

The invention relates to a compound herbicide, belonging to the field of chemical substance recovery and treatment.

Background technique

Tetrahydrofuran is an organic solvent with excellent performance and is widely used in pharmaceutical and chemical production. The industrial waste liquid produced by the pharmaceutical and chemical production of tetrahydrofuran is processed by atmospheric distillation. Since tetrahydrofuran is difficult to be separated from water by azeotropy, it cannot be directly used for production; if the waste liquid is directly discharged into the sewage treatment system, It has increased the difficulty of sewage treatment, polluting the environment, and causing waste of resources. A variety of tetrahydrofuran recovery treatment processes have been developed in the prior art, but these processes are complicated in process, long in time and low in efficiency. Therefore, it is urgent to develop a compound herbicide with simple process, short time and high efficiency. Upon search, no technical solutions identical or similar to the present invention were found.

Summary of the invention

The technical problem to be solved by the present invention is to provide a compound herbicide which is simple in process, short in time and high in efficiency.

In order to solve the above technical problem, the technical solution of the present invention is: a compounding herbicide, and the innovation is that the recycling process is as follows:

(1) testing the concentration of the prepared tetrahydrofuran, when the water content is greater than 10%, the tetrahydrofuran is poured into an oil-free vacuum pump for vacuum treatment;

(2) adding potassium permanganate to the oil-free vacuum pump, and performing oxidation treatment while stirring, the stirring time is controlled to 5 min;

(3) adding a catalyst to the oxidized solution, and reacting at a temperature of 50 ° C for 30 min;

(4) The solution was poured into a vacuum distiller for distillation under reduced pressure, and 90% of the fraction was collected to finally obtain tetrahydrofuran having a water content of less than 5%.

The advantages of the invention are:

(1) Adding a special oxidant to make the oxidizing index in tetrahydrofuran meet the quality standard, reducing the number of distillations and reducing the energy consumption; using an oil-free vacuum pump to vacuum, obtaining clean exhaust gas, and increasing the tail gas recovery system to recover and recover tetrahydrofuran, reducing The pollution discharge, the aforementioned operations cooperate with each other, and finally improve the recovery yield of tetrahydrofuran.

(2) Adding a catalyst to the solution accelerates the distillation speed of the solution and improves the efficiency of the recovery treatment.

(3) A liquid moisture detector is arranged in the vacuum distiller to detect the water content in the solution, and when the moisture is less than 5%, the operation can be stopped.

detailed description

Example 1

The invention discloses a compound herbicide, and the recycling process is as follows:

(1) testing the concentration of the prepared tetrahydrofuran, when the water content is greater than 10%, the tetrahydrofuran is poured into an oil-free vacuum pump for vacuum treatment;

(2) adding potassium permanganate to the oil-free vacuum pump, wherein the potassium permanganate is added in an amount of 0.02% by mass of tetrahydrofuran, and is oxidized while stirring, and the stirring time is controlled to be 1 to 5 minutes;

(3) adding manganese dioxide to the oxidized solution, and reacting at a temperature of 20 ° C for 30 to 50 minutes;

(4) The solution was poured into a vacuum distiller equipped with a liquid moisture detector for vacuum distillation, and 90% of the fraction was collected to finally obtain tetrahydrofuran having a water content of less than 5%.

The recovery time of tetrahydrofuran in this example requires a total of 55 minutes.

Claims (1)

1. A compound herbicide characterized in that the recycling process is as follows:

   (1) testing the concentration of the prepared tetrahydrofuran, when the water content is greater than 10%, the tetrahydrofuran is poured into an oil-free vacuum pump for vacuum treatment;

   (2) adding potassium permanganate to the oil-free vacuum pump, and performing oxidation treatment while stirring, the stirring time is controlled to 5 min;

   (3) adding a catalyst to the oxidized solution, and reacting at a temperature of 50 ° C for 30 to 50 minutes;

   (4) The solution was poured into a vacuum distillation apparatus for distillation under reduced pressure, and 20% of the fraction was collected to finally obtain tetrahydrofuran having a water content of less than 5%.