Method of use of an ionic liquid and device for sorption of a gas

Abstract

A method of use of an ionic liquid for sorption of a gas having an electric multipole moment is provided, wherein the ionic liquid comprises an anion and a non-aromatic cation. In particular, the electric multipole moment may be an electric dipole moment and / or an electric quadrupole moment. The sorption may be an adsorption or an absorption. The ionic liquid may be a pure ionic liquid, i.e. a liquid substantially only containing anions and cations, while not containing other components, e.g. water. Alternatively a solution containing the ionic liquid and a solvent or further compound, e.g. water, may be used.

Description

FIELD OF THE INVENTION[0001]The invention relates to a method of use of an ionic liquid, in particular for sorption of a gas or vapor having an electric multipole moment.[0002]Further, the invention relates to a device for sorption of a gas or vapor.BACKGROUND OF THE INVENTION[0003]Carbon dioxide (CO2) is an undesired diluent that is present in many gas sources. In order to improve the quality of the gases the CO2 should be removed to acceptable specifications. In gas processing industry, various technologies have been employed for CO2 removal including chemical solvents, physical solvents, and membranes. By far, chemical solvents that reversibly react with CO2 are most commonly used for CO2 removal.[0004]Furthermore, processes for removal of CO2 from gaseous streams are known, which comprise the contacting a CO2 containing gaseous stream with an absorbent comprising from 1 to 20 wt % water and an ionic liquid comprising pyridines or imidazole cations and an anion, wherein said cont...

AI Technical Summary

Benefits of technology

[0006]It may be an objective of the invention to provide a method of removal of a gaseous or vaporous component and a device for removal of a gaseous or vaporous component which may be save to use or less expensive than known methods.

[0011]In particular, the device may comprise an inlet, a container including the ionic liquid, and optionally an outlet. The device may be used to sorb gas having an electric multipole moment, e.g. CO2, from a medium which is selected out of the group consisting of recovery gas, synthesis gas, water gas, natural gas, inhaled air, and exhaled air. In particular, the device may be a heat pump. The heat pump may comprise a circuit including CO2 and the ionic liquid which comprises an anion and a non-aromatic cation as working media. In particular, the usage of a pair of working media containing CO2 and an ionic liquid in a heat pump may be advantageous since CO2 is not toxic is of less concern with respect to environmental effect compared to other vaporizable working substances.

[0013]The use of non-aromatic cations of the ionic liquid may provide for an ionic liquid which may be cheaper and more secure than the use of aromatic cations. Such ionic liquids may be a suitable medium to sorb specific gases, e.g. CO2, or vapor out of a mixture of gases and may also be suitable to release these specific gases or vapor again. The specific gases and the ionic liquid may form a complex, i.e. the specific gases may be complex bound. According to some exemplary embodiments it may even be possible to remove the complex bound in the form of a solid compound. The uses of such ionic liquids for sorption of gases may be advantageous since ionic liquids may be used showing no or at least substantially no vapor pressure, e.g. a non measureable vapor pressure or even a vapor pressure in the same magnitude of order of steel. Thus, the gases or mixture of gases may not be contaminated by vapor of the ionic liquid. Furthermore, the use of non-aromatic ionic liquids may increase the performance of the sorption process compared to the case in which aromatic ionic liquids are used. For example, the removal of CO2 by using non-aromatic ionic liquids may exhibit an improved performance even in cases where the vapor pressure of CO2 is low.

[0017]Aliphatic cations may be suitable non-aromatic cations for an ionic liquid which are less expensive and / or less toxic than typical aromatic cations.

Problems solved by technology

However, the known processes of removal CO2 may be costly.

Images