阅读说明：本技术 一种用于离子液体的深度干燥除水方法 (Deep drying and water removing method for ionic liquid ) 是由 李啊林 卢世刚 李国华 常增花 王建涛 权威 邵泽超 张刚宁 韩富娟 王晶 张一 于 2020-06-29 设计创作，主要内容包括：本发明涉及离子液体的干燥方法,尤其涉及一种用于离子液体的深度干燥除水方法。所述方法为：将待干燥的离子液体与除水剂混合后进行共沸带水；其中,所述除水剂为乙酸正丁酯、乙酸异戊酯、丙酸乙酯、丙酸正丙酯中的一种。本发明通过选择特定的除水剂、特定的除水工艺,实现了降低离子液体含水量的目的,并且所得低含水量的离子液体纯度高、收率高。所述深度干燥除水方法不仅可以最大程度上降低离子液体的含水量,还能够最大程度上避免除水剂的残留,保障了离子液体的纯度；同时所得低含水量的离子液体的收率极高。本发明的深度干燥除水方法工艺简便、设备简单、干燥效率高、成本低,具有很好的应用前景。(The invention relates to a drying method of ionic liquid, in particular to a deep drying and water removing method for ionic liquid. The method comprises the following steps: mixing the ionic liquid to be dried with a water removal agent, and carrying out azeotropic water carrying; wherein the water removing agent is one of n-butyl acetate, isoamyl acetate, ethyl propionate and n-propyl propionate. According to the invention, the purpose of reducing the water content of the ionic liquid is realized by selecting the specific water removal agent and the specific water removal process, and the obtained ionic liquid with low water content has high purity and high yield. The deep drying and water removing method can reduce the water content of the ionic liquid to the maximum extent, can avoid the residue of a water removing agent to the maximum extent, and ensures the purity of the ionic liquid; meanwhile, the yield of the obtained ionic liquid with low water content is extremely high. The deep drying and dewatering method has the advantages of simple and convenient process, simple equipment, high drying efficiency, low cost and good application prospect.)

1. The deep drying and water removing method for the ionic liquid is characterized in that the ionic liquid to be dried and a water removing agent are mixed and then subjected to azeotropic water carrying;

wherein the water removing agent is one of n-butyl acetate, isoamyl acetate, ethyl propionate and n-propyl propionate.

2. The method of claim 1, wherein the ionic liquid has a water content of no more than 1 wt%; preferably, the water content of the ionic liquid is 0.3-1 wt%.

3. The deep drying and water removing method according to claim 1 or 2, wherein the ionic liquid is one of imidazole ionic liquid, pyridine ionic liquid, piperidine ionic liquid and pyrrolidine ionic liquid;

preferably, the ionic liquid is one of 1-ethyl-3-methylimidazole trifluoromethanesulfonate, N-butyl-N-methylpiperidine bis (trifluoromethanesulfonyl) imide salt, N-butyl-N-methylpyrrolidine bis (trifluoromethanesulfonyl) imide salt and N-ethylpyridine bis (trifluoromethanesulfonyl) imide salt.

4. The deep drying water removal method according to claim 3, wherein when the ionic liquid is 1-ethyl-3-methylimidazole trifluoromethanesulfonate, the water removal agent is n-butyl acetate, isoamyl acetate, ethyl propionate or n-propyl propionate;

or, when the ionic liquid is N-butyl-N-methylpyrrolidine bis (trifluoromethanesulfonyl) imide salt, the water removal agent is N-butyl acetate, isoamyl acetate, ethyl propionate or N-propyl propionate;

or, when the ionic liquid is N-butyl-N-methylpiperidine bis (trifluoromethanesulfonyl) imide salt, the water removal agent is N-butyl acetate, isoamyl acetate, ethyl propionate or N-propyl propionate;

or when the ionic liquid is N-ethylpyridine bis (trifluoromethanesulfonyl) imide salt, the water removal agent is N-butyl acetate, isoamyl acetate, ethyl propionate or N-propyl propionate.

5. The deep drying and water removal method according to any one of claims 1 to 4, wherein the mass ratio of the ionic liquid to the water removal agent is 20 to 100: 1; preferably 20-50: 1.

6. the deep drying and water removal method of any one of claims 1 to 5, comprising the following steps:

1) adding an ionic liquid to be dried and a water removing agent into a reactor, heating under an inert atmosphere condition, and collecting the water removing agent and an azeotrope thereof by a condensing tube after the temperature of the top of the reactor is stabilized at 50-90 ℃; when no obvious liquid falls in the condensation pipe and the gas phase temperature begins to drop, reducing the pressure to the relative vacuum degree of 80000-100000 Pa, and continuously collecting the water removal agent and the azeotrope thereof until the water content of the ionic liquid is lower than 100 ppm;

2) and continuously introducing inert gas into the ionic liquid, heating until the temperature at the top of the reactor is stabilized at 50-90 ℃, then decompressing and discharging the inert gas in the reactor, and continuously collecting the water removing agent and the azeotrope thereof until the water content of the ionic liquid is lower than 20 ppm.

7. The method for deep drying and water removal as claimed in claim 6, wherein the inert atmosphere and the inert gas are the same or different and are each independently selected from one or more of nitrogen, helium and argon.

8. The method for deeply drying and removing water as claimed in claim 6, wherein in the step 1), when no liquid is dropped down obviously in the condensing tube within 1 minute and the temperature of the gas phase begins to drop, the relative vacuum degree is reduced to 80000-100000 Pa.

9. The method of claim 6, wherein the inert gas is introduced at a rate of 0.5 to 2.0L/min per 1 kg of the ionic liquid in step 2).

10. The method of deep drying water removal as set forth in claim 1, comprising the steps of:

1) adding an ionic liquid with the water content of not more than 1 wt% and a water removal agent into a reactor, heating under the inert atmosphere condition, and collecting the water removal agent and an azeotrope thereof by a condensation pipe after the temperature at the top of the reactor is stabilized at 50-90 ℃; when no obvious liquid falls in the condensation pipe within 1 minute and the gas phase temperature begins to drop, reducing the pressure to the relative vacuum degree of 80000-100000 Pa, and continuously collecting the water removal agent and the azeotrope thereof until the water content of the ionic liquid is lower than 100 ppm;

wherein the ionic liquid is one of 1-ethyl-3-methylimidazole trifluoromethanesulfonate, N-butyl-N-methylpiperidine bis (trifluoromethanesulfonyl) imide salt, N-butyl-N-methylpyrrolidine bis (trifluoromethanesulfonyl) imide salt and N-ethylpyridine bis (trifluoromethanesulfonyl) imide salt;

the water removing agent is one of n-butyl acetate, isoamyl acetate, ethyl propionate and n-propyl propionate;

the mass ratio of the ionic liquid to the water removing agent is 20-50: 1;

2) and continuously introducing inert gas into the ionic liquid according to the ratio of 0.5-2.0L/min by taking 1 kg of the ionic liquid, heating until the temperature at the top of the reactor is stabilized at 50-90 ℃, reducing the pressure to the relative vacuum degree of 80000-100000 Pa, discharging the inert gas in the reactor by adopting a vacuumizing mode, and continuously collecting the water removing agent and the azeotrope thereof until the water content of the ionic liquid is lower than 20 ppm.

Technical Field

The invention relates to a drying method of ionic liquid, in particular to a deep drying and water removing method for ionic liquid.

Background

Disclosure of Invention

The invention provides a deep drying and water removing method for ionic liquid, which aims to solve the problems of low purity and low yield of the ionic liquid.

Specifically, the deep drying and water removing method comprises the following steps: mixing the ionic liquid to be dried with a water removal agent, and carrying out azeotropic water carrying;

wherein the water removing agent is one of n-butyl acetate, isoamyl acetate, ethyl propionate and n-propyl propionate.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.