This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dingley, J. Articles by Mason, R. S. Search for Related Content PubMed PubMed Citation Articles by Dingley, J. Articles by Mason, R. S. Related Collections Equipment Technology Pharmacology

---

TECHNOLOGY, COMPUTING, AND SIMULATION

A Cryogenic Machine for Selective Recovery of Xenon from Breathing System Waste Gases

John Dingley, MD^*, and Rod S. Mason, PhD

From the *Clinical School, and Department of Chemistry, University of Wales Swansea, Singleton Park, Swansea, UK.

Address correspondence to John Dingley, MD, University of Wales Swansea, The Grove Building, Singleton Park, Swansea SA2 OUL, UK. Address e-mail to john.dingley{at}morrnhst-tr.wales.nhs.uk.

BACKGROUND: Xenon has many characteristics that make it very attractive as an anesthetic and therapeutic drug. Unfortunately, the supply of xenon is fixed, and therefore reclamation and recovery from even the most efficient breathing circuits is desirable. We built and evaluated a cryogenic device to recover xenon from waste anesthetic gases.

METHODS: Xenon was selectively frozen to –139.2°C from test gas mixtures at ambient pressure (STP). The machine ran on standard 240 V 13 A electrical current without refrigerants that required replenishing, e.g., liquid nitrogen. A wide range of xenon/oxygen mixtures were processed over a range of freezing chamber temperatures. Efflux gas and thawed reclaimed xenon were collected separately. Xenon purity and yield (fraction recovered) were measured and calculated on each occasion.

RESULTS: Gas was processed at 300 mL/min, and the operating temperature was –139.2 (0.096)°C [Mean (sd)]. Purity and yield were >90% and >70% for gas mixtures containing 20% xenon, increasing to >95% and >85%, respectively, with an input gas xenon fraction 40%. Efficiency improved linearly with reducing temperature.

CONCLUSIONS: Xenon of high purity (>90%) and yield (>70%) for such a machine was recovered from all gas mixtures containing 20% xenon. The operating temperature of the freezing chamber is a major influence on the efficiency of recovery.

This article has been cited by other articles:

				S. Rawat and J. Dingley Closed-Circuit Xenon Delivery Using a Standard Anesthesia Workstation Anesth. Analg., January 1, 2010; 110(1): 101 - 109. [Abstract] [Full Text] [PDF]