Many research labs make use of equipment or perform experiments that require a regular supply of gases such as hydrogen, helium, and nitrogen, for example. Historically, labs purchase and store these gases in relatively large (roughly 4 feet tall) steel compressed gas cylinders. While there are some benefits to this method, there are also numerous safety concerns that impose limits on the transportation and use of gas cylinders and on the quantity that can be stored in one space. Alternatively, installing a gas generator can circumvent these safety issues and provide a more sustainable option for supplying gas to your lab.
Gas generators can provide long-term cost and time savings by cutting out the need to order gas. Removing this element also helps researchers avoid potential gas supply shortages, such as the most recent helium shortage. Additionally, gas generators tend to be safer than gas cylinders as potentially hazardous gases are only produced on an as-needed basis and are not stored in a compressed form, limiting the potential for dangerous accidents. Generating gas only as it’s needed is also a more sustainable option that can help limit waste, both of the gas itself and of the waste from shipping the cylinders. While gas cylinders do provide users with the ability to order specific gas mixtures, gas generators are quickly rising to become a safer, more sustainable option for research laboratories.
Gas generator versus gas cylinder safety
When using any amount of potentially hazardous gases for research, there are always safety concerns to consider. While gas cylinders have the benefits of being replaceable and of taking up relatively little floor space, storage can be tricky. A given structure has building or fire codes that have maximum allowable quantities (MAQs) of gas cylinders that can be stored at one time within them. This means lab managers need to make special accommodations for cylinder storage or limit the number of cylinders being stored in a building.
“You can order cylinders to whatever specifications you need—combinations with other gases, purities, calibrated to an ASTM or NIST standard, sizes, etc.,” explains Jonathan Klane, MSEd., CIH, CSP, CHMM, CIT, and senior safety editor at Lab Manager. “But the fire and building codes only allow so many cylinders within each hazard classification per fire control zone or area, which is usually the entire floor of the building unless it is divided with full fire stops (such as chemical storage rooms, nano-fabs, etc.).”
Additionally, while it is less common, the compressed nature of gas cylinders can lead to other safety concerns, such as dangerous gas leaks or even explosions. If the gas being stored is flammable, then a leak can cause a fire risk, but even inert gases can be dangerous given the pressure they are kept under. “If any gas cylinder (even with an inert gas) has the stem broken off, it becomes a steel rocket and will smash through concrete and brick walls,” adds Klane.
Gas generators take up more space than cylinders but are in many ways much safer.
“Basically, gas generators create their gas on an as-needed basis. It is ‘consumed’ or used up as it's being created. So, with no flammable gas accumulating, we have no hazards. They are placed in one lab and used there,” explains Klane.
Finally, because gas produced from a gas generator is consumed immediately while its being generated and isn’t stored, gas generators do not count toward a building’s MAQs.
Sustainability and convenience of gas generators
In addition to safety concerns, many lab managers are looking for ways to make their facilities more sustainable. Researchers that regularly use gases for their work will frequently be forced to replace cylinders. This necessitates both the compression and purification of gas into a new cylinder and the shipping of those cylinders—often over long distances. Both requirements are high-energy endeavors that contribute to the lab’s carbon footprint. There are also additional economic costs both in the cost of shipping cylinders and in the potential wasted time during cylinder changeovers. Gas generators, on the other hand, eliminate these concerns by removing the need for shipping cylinders and compressing gas.
Another source of waste is the cylinders themselves. The majority of gas cylinders either get fully used and replaced or only get used until the experiment is completed and are left with varying amounts of gas still in them. Either way, the cylinders become a waste product that needs to be removed from the lab. Since a gas generator only produces what gets used, it eliminates this source of waste generation.
Gas generators are also more consistent and convenient than cylinders. Generators require limited maintenance and produce a consistent purity, unlike cylinders which need to be regularly replaced and can be of varying quality. These conveniences prevent wasted time in the lab and help avoid potential pain points.
As generators become increasingly prevalent and more compact and efficient, many labs will benefit from switching over from cylinders to a central generator. The convenience and consistency make generators a reliable option for labs that need regular supplies. Coupled with the safety benefits of not having to store unused gas in a potentially volatile pressurized container, as well as the added boost to sustainability from decreasing shipping and waste, gas generators represent a promising step forward for the future of research.