Gas Chromatography (GC) Gas Generation And Helium Shortage

Interview conducted by G.P. ThomasMar 11 2013

In this interview, Scott Thompson, Design Engineering Manager at Peak Scientific, talks to AZoM about the new Precision series of gas generators and how these may not only improve GC in many industries, but also mitigate against a global helium shortage.

Peak Scientific has been at the forefront of gas generation for GC for many years now – could you please briefly explain the role of the gas generator in the day-to-day workings of a GC lab?

Gas generators are quite simply an alternative to gas cylinders. They have become increasingly popular over the years for a number of reasons ranging from cost effectiveness, health and safety, logistics to the convenience of having a stable uninterrupted gas supply.

And I believe you have recently released an innovative new series of gas generators. Could you please give an overview of the different models in the Precision series and the specifications of these?

I hope you are sitting comfortably. We have released 18 new generators covering three gases with a range of operating voltages, output flows and purity levels to offer a truly customisable solution. The new Precision range will suit a single GC to a room full! At Peak we also understand that space inside a laboratory can be very precious so we have designed this range to be stackable to minimize the footprint of our total gas solution.

The biggest development is the Precision Hydrogen Trace, this offers Hydrogen with a purity of 99.9999% with flows up to 500cc/min to support GCs as a carrier or flame gas for detection down to trace levels. The generator utilises a pressure swing adsorption drier to achieve this level of purity. This is a much more robust solution than a palladium diffuser.

The other Hydrogen offering is the Precision Hydrogen, utilising a desiccant drier this generator will produce gas with a purity of 99.9995% and is suitable for flame gas or as carrier gas were a lower level of detection is required. This model is available in output flows of 100, 200, 300 and 450cc/min.

There are also two Nitrogen systems available, Precision Nitrogen and Precision Nitrogen Trace. Both systems offer a Nitrogen purity of 99.9995% to support GCs as a carrier or make up gas. The Nitrogen Trace also incorporates a catalyst chamber that guarantees Methane removal to less than 0.05ppm making the gas suitable for trace level analysis. Both generators are available with 250 and 600cc/min outputs with the Nitrogen also available in a 1000cc/min version.

The Zero Air generators produce air with Methane levels less than 0.05ppm making them suitable for use as a makeup gas for analysis down to trace levels. The generator comes in two output flow options of 1500 and 3500cc/min.

To complement the range we also offer an air compressor option for users that do not have compressed air available in their labs. The air compressor is designed to be quiet in operation with an almost unnoticeable level of vibration with enough capacity to supply the most common generator combinations.

All of the units have been designed for high reliability and minimal maintenance to ensure a long trouble free life.

The full Precision product demonstration video from Peak Scientific.

How does the required detection limit influence which of these systems is recommended?

As the level of detection increases so does the purity of the gas required. To ensure that we offer the most cost effective solution we offer different purity levels, there is no point paying for a higher quality gas if you don’t need it.

We typically suggest that if you are detecting to levels lower than 1000ppm then the Trace models would be recommended, however we are happy to speak to the user to fully understand their needs and ensure that they get the gas that they require.

How can the systems be modified to suit specific laboratory needs?

Due to the modular nature coupled with the output and purity ranges we are confident that we can tailor a solution that best fits the customer’s needs. The system can also grow if and when they requirements of the lab grow.

This series eliminates the need for gas cylinders – what are the benefits of this?

There are a number of benefits for replacing gas cylinders. From a logistics point of view the generator produces gas on demand, 24/7 if required, therefore you do not need to plan on changing cylinders or risk a gap in supply.

It also ensures that the gas quality is consistent as there can be a variance in purity or possible contaminants from cylinder to cylinder. From a health and safety point of view it also removes the need to handle the large cylinders. Also as the generators only produce gas when it is required the actual stored volume of gas can be as little as 1/25,000 of that stored in a cylinder.

Safety is of course one of the most important issues in any lab environment. What steps have been taken to ensure that the Precision series is a safe as possible?

As Hydrogen is an explosive gas then certainly the largest risk would be from the Hydrogen generators, however, we have went to great lengths to manage these risks and we can firmly say that a Hydrogen generator is significantly safer than a cylinder for a number of reasons.

The most significant risk with Hydrogen is a leak into the laboratory environment raising the Hydrogen levels to an explosive level. The safety benefit of a generator can be seen by looking at a theoretical example. The lower explosive limit (LEL) for Hydrogen is 4% in air, if you take a small hermetically sealed laboratory, say 500m³_, the LEL can be reached by emptying two 50L cylinders of Hydrogen, with a large enough leak this can be achieved in minutes. As the generators are designed to contain a minimal amount of Hydrogen, less than 400cc, and are limited in the amount of Hydrogen then can produce it would take nearly 12 days to achieve the LEL in the same lab.

Not satisfied with this we also offer a Hydrogen detector that will sample gas from the GC oven and shut down the generator if the Hydrogen concentration starts getting close to the LEL. The Hydrogen detectors can be linked to allow multiple GCs or even the ambient air to be analysed, any one of the detectors sensing an increase in Hydrogen concentration will shut down the generator.

The Zero Air and Nitrogen Trace systems operate a Catalyst chamber that operates at 450°C; this is protected by a thermal fuse to prevent overheating.

What are some of the further financial benefits of the precision series?

The cost benefit will depend on the level of gas usage but typically a busy lab should see a return on investment within a year compared to cylinders. Although the biggest cost benefit could soon be using Hydrogen as an alternative to Helium due to the increasing costs of this gas.

Looking to the future of GC, do you believe there is a shortage of helium available and if so why is this?

Unfortunately we are facing a shortage. Although Helium is the second most abundant element in the universe it is unfortunately very scarce on Earth. The stocks we do have are dwindling and, as yet, it can’t be manufactured in anywhere near the quantities we use it in and once it is released it escapes our gravity and is lost to space.

What are the possible implications of this shortage to GC users and also the wider public?

The shorter term implications for GC users are that the price of Helium will continue to rise; the longer term issues are that supply may be limited or even restricted. For the wider public there have already been calls by some scientists to ban the use of helium for recreational uses, like party balloons, to help preserve the stock for research and medical purposes, a large user of Helium is MRI and MEG scanners.

How does the new Precision series mitigate against this shortage?

Hydrogen is a suitable replacement to Helium as a carrier gas. Historically Helium has been favoured as it is non-flammable however with the safety features of the Peak generators along with other advantages that Hydrogen offers the GC user then the new Precision series negates the Helium supply issue.

Ultimately, what industries will benefit from these systems?

GCs are used in all manner of industries including; Environmental, Petrochemical, Chemical, Food and Beverage, Pharmaceutical, Clinical and Forensics and the list within these industries is endless.

Where can people find out more about Peak Scientific?

More information about Peak and our products can be found on our website www.peakscientific.com we’re also happy to answer any questions that you may have regarding our products, just call one of our offices worldwide.

About Scott Thomson

Scott started his career as an Apprentice Mechatronics Technician with IBMs PCB manufacturing site in Greenock, Scotland.

After completing his apprenticeship Scott moved to Solectron, soon after they acquired the PCB manufacturing business from IBM, as a Production Engineer before moving into Design Engineering.

When Solectron closed their doors Scott found his way to Peak, initially as a Design Engineer but is now proud to Head the Design Engineering department.