Method for removing water from ionic liquid alcoholic solution

Abstract

The invention relates to a method for removing water from an ionic liquid alcoholic solution. The method comprises the following steps: S1, adding an additive into an ionic liquid alcoholic solution for adjustment to obtain an adjusted ionic liquid alcoholic solution; S2, enabling the adjusted ionic liquid alcoholic solution to pass through a pervaporation unit to obtain a dehydrated ionic liquid alcoholic solution; and S3, heating the dehydrated ionic liquid alcoholic solution, and recovering the additive in the ionic liquid alcoholic solution. According to the method disclosed by the invention, the acidity in the system is greatly reduced by adding the additive into the acidic ionic liquid alcoholic solution, so that the system does not damage the pervaporation membrane, and the operation conditions of the conventional pervaporation membrane are met; the whole water removal process can be completed at low temperature, so that the energy consumption of the whole process is greatly reduced; and the whole process is simple and easy to be continuous, and the obtained treated final product can directly enter esterification, ester exchange and other reaction units to realize direct reuse of the ionic liquid.

Description

technical field [0001] The invention belongs to the field of water removal of ionic liquid alcohol solution, in particular to a water removal method of ionic liquid alcohol solution. Background technique [0002] Ionic liquids, also known as low-temperature molten salts, generally refer to substances that are in a liquid state at or near room temperature and are composed of organic cations and inorganic anions with large volume differences. Ionic liquids are different from ordinary molten salts in that their melting points are different. The size of the electrostatic potential between anions and cations determines the melting point. Ionic liquids cannot attract each other in an orderly manner due to the large difference in volume between anions and cations, thereby reducing the two. The electrostatic potential between them leads to its lower melting point. However, the electrostatic potential still dominates the interior of ionic liquids, making ionic liquids have almost no...

AI Technical Summary

Problems solved by technology

Although pervaporation has been widely used in the dehydration process, and compared with traditional rectification, pervaporation can save energy by more than 30%, but for pervaporation in acidic systems (especially strong acidic systems, PH<2), it is still difficulty

[0009] As can be seen from the above analysis, there are still various difficulties in the removal of water in the ionic liquid, alcohol and water system: (1) adopting rectification method, it is difficult to apply to the low boiling point alcohol system, the energy consumption is huge and the operability is poor; (2) Adopting the adsorption method, it is easy to make the ionic liquid in the system adsorb on the adsorbent; (3) Using the pervaporation method, due to the strong acidity of the acidic ionic liquid, it is difficult to find a suitable pervaporation membrane

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