Liquid for Compressing a Gaseous Medium and Use of the Same

A method for compressing a gaseous medium, which method comprises contacting the gaseous medium with a liquid adapted to transfer a compressing force directly to said gaseous medium and applying a compressing force to said gaseous medium through said liquid, said liquid comprising a liquid ionic compound or a mixture of a plurality of said liquid ionic compounds, each said liquid ionic compound having the general formula [Q+]n[Zn−],

• wherein the cation [Q+] is a quarternated or protonated ammonium [R1R2R3R4N+], phosphonium [R1R2R3R4P+] or sulfonium [R1R2R3S+] cation or a similar quaternated or protonated nitrogen, phosphorus or sulphur heteroaromatic compound,
• wherein the groups R1, R2, R3, R4 are all the same, partly the same or different,
• wherein the groups R1, R2, R3, R4 are protons (hydrogen atoms), linear, cyclic, branched, saturated or unsaturated alkyl groups, mono- or polycyclic aromatic or heteroaromatic groups or derivatives of these groups substituted with other functional groups,
• wherein R1, R2, R3, R4 can also be connected to one another (multibond groups),
• wherein [Zn−] is an anion having a negative valence number n− or also
• is at least one of an anion protonated with m hydrogen atoms [HmZ(n−m)−], and a molecular liquid for compression of a gaseous medium wherein the respective liquid transfers the force required for compression directly to the gas and has a vapour pressure of less than 10−3 mbar.