Compressed gases such as zero air, nitrogen and hydrogen are commonly used in the laboratory for a broad range of instrumentation such as GC with FID, LC-MS and FTIR. In many laboratories, the compressed gas source is a high pressure gas cylinder. These cylinders are filled to a high pressure, typically, 2000 psi. The primary disadvantages of gas supply in the form of high pressure cylinders are safety, cost, and delivery and service inconveniences.
Precautions must be taken when transporting and handling high pressure compressed gas cylinders. If the individual loses control of the tank, it is possible that serious property damage and/or injury could occur. In the same vein, if a leak occurs, it is possible that the air in the laboratory could be displaced by the nitrogen or hydrogen, leading to asphyxiation. Users of high pressure compressed gas cylinders invariably will experience unplanned downtime resulting from an empty cylinder. This may occur in the middle of analysis, overnight, or during a weekend. Other inconveniences might include delayed delivery, inflexible delivery schedules, price increases, rental fees, and long term contracts.
These safety hazards and inconveniences can be eliminated by the use of an in-house gas generator. An in-house gas generator can be connected directly to the instrument and provides the necessary gas at the pressure and flow required by the application on a 24 hour/7 day a week basis with minimum user interaction. This paper describes how high purity gases can be generated in the laboratory and outlines the safety benefits that the generator provides.