Ionic liquid piston compressor

Principle

An ionic liquid compressor takes advantage of two properties of ionic liquids—their virtually non-measurable vapor pressures and large temperature window for the liquid phase—in combination with the low solubility of some gases (e.g. hydrogen) in them. This insolubility is exploited by using the body of an ionic liquid to compress hydrogen up to 1000bar (14,500psi) in hydrogen filling stations. Linde's ionic liquid compressor reduced the number of moving parts from about 500 in a conventional reciprocating compressor down to 8.

Many seals and bearings were removed in the design as the ionic liquid does not mix with the gas. Service life is about 10 times longer than a regular reciprocating compressor with reduced maintenance during use, energy costs are reduced by as much as 20%. The heat exchangers that are used in a normal piston compressor are removed as the heat is removed in the cylinder itself where it is generated. Almost 100% of the energy going into the process is being used with little energy wasted as reject heat.

Not to be confused with the ion pump or the ionic liquid ring pump.

History

After the renewed interest in ionic liquids, research was done by proionic, an enterprise in the spin-off center "ZAT Center for applied Technology" of the University of Leoben. The system was demonstrated at Zemships.

References

References

1. [http://www.intermediates.basf.com/chemicals/web/en/function/conversions:/publish/images/products-and-industries/ionic-liquids/Achema_News_01_08.pdf New developments in pumps and compressors using Ionic Liquids]{{Dead link. (January 2020)
2. [https://online.wsj.com/article/PR-CO-20140714-903222.html Linde AG: Linde starts small-series production for hydrogen fuelling stations]
3. [http://www.greencarcongress.com/2008/08/flowserve-and-l.html Ionic liquid compressor]
4. "Linde Develops Ionic Compressor for More Efficient Compressed Hydrogen Storage".
5. [http://www.proionic.at/EN/Portals/3/Download/Gasverdichtung%20e.pdf University of Leoben: Spin-off creates innovation for compression of gas]{{Dead link. (November 2025)
6. [http://www.the-linde-group.com/en/images/Linde_Technology_1_2006_EN14-10188.pdf Mobility under high pressure Pag-38]
7. [http://www.zemships.eu/de/DateienDownloadbereich/Conference/P8_Zemships_conference.pdf Construction and design of hydrogen filling stations] {{webarchive. link. (2009-12-21)
8. [http://www.zemships.eu/en/DateienDownload/Zemships_Newsletter_Juli_08_english.pdf Zemships - Ionic liquid compression] {{webarchive. link. (2009-12-21)