Greenhouse gases have a dramatic and unfavourable impact on worldwide climate change.

PRLog (Press Release) – Apr 24, 2009 – New approaches have been developed to reduce the contribution of these gases to the atmosphere and while the long-term reduction of greenhouse gas will be achieved by broad changes in energy consumption (e.g. transportation), in the short term significant reductions in greenhouse gases can be obtained by analysing energy consumption patterns and implementing alternative techniques that reduce the amount of energy consumed by various processes.

The generation of nitrogen gas for the laboratory is an excellent example of how a significant reduction in the generation of greenhouse gases can be brought about by selecting an alternative process that performs the desired operation while consuming less energy. Nitrogen gas is commonly used in a broad range of applications in the laboratory; typical applications include gas chromatography, liquid chromatography with mass spectroscopy detection, Fourier transform infrared spectroscopy, inductively coupled plasma spectroscopy, glove boxes, and blanketing of reactions that require an inert atmosphere.

High-purity nitrogen gas for laboratory applications is normally obtained by the fractional distillation of air. This process requires a considerable amount of energy since the air must be compressed and chilled to below the vaporisation point of nitrogen (–195.8°C at 1 atm) to liquefy it. The liquid nitrogen is then vaporised to produce nitrogen gas. The process of nitrogen generation requires much more energy and expense than is needed, especially as the gas is usually generated at a site a long way from where it is used. The overall energy that is required to operate the fractional distillation facility and to transport the tank to and from the end user’s site is a significant contributor of greenhouse gases.

An alternative approach to nitrogen generation for the laboratory uses a hollow fibre membrane to separate the desired gas from air with a high degree of purity. The only power that is required by a system that uses a hollow fibre membrane is the electrical power needed to operate a compressor to deliver the air to the membrane. Pure nitrogen for laboratory use can be readily obtained from air using an in-house hollow fibre membrane system.

When a hollow fibre membrane system is used for the generation of nitrogen, the only energy that is required is the energy used to power the compressor that supplies air to the system. Assuming a 3-hp compressor is used with a 50% duty cycle, the equivalent

of five 9000-L tanks of nitrogen can be generated per day at an approximate power expenditure of 25 kWh (kilowatt-hour). Since the nitrogen system is normally directly connected to the instrument, no energy is required for transporting the gas.

An in-house hollow fibre membrane system of gas generation can provide a significant economic benefit compared to the use of bottled gas, in addition to the environmental benefits. The in-house generation of nitrogen gas using a system that employs hollow fibre bundles is environmentally friendly and an effective, energy-efficient approach to providing pure, clean, dry nitrogen gas to laboratory instrumentation. Since considerably less energy is expended to generate the gas, less greenhouse gas is created.

In addition, using in-house generation of nitrogen in the laboratory is a convenient, safe, and cost-effective approach to the problem of supplying the gas. The gas can be readily generated on an as-needed basis at pressures and volumes that meet the needs of typical instrumentation. A significant benefit of the membrane approach is that considerably less energy is required, thereby reducing the generation of greenhouse gases and helping to protect the environment.

About Parker Hannifin: Parker Hannifin are the world leaders in providing a range of technologies, such as climate control, electomechanical solutions, filtration, fluid handling and gas generation. As a global brand Parker Hannifin prides itself on offering complete solutions for motion and control technologies for a wide range of industry applications, such as agriculture, chemical processing, packaging equipment, aerospace and alternative energy uses.