by Dalvir Jandu, P.Eng.
Your first conversation with Purity Gas will likely begin with a discussion about how nitrogen gas generation technology works and how much money you’ll save. For most customers, the next question is about the environmental benefits.
Compared to the conventional alternative, in which third-party providers use fractional distillation to produce liquid nitrogen, then transport it to you, generating your own nitrogen gas will significantly reduce your CO2e (carbon dioxide equivalent) emissions.
Eliminate unnecessary emissions related to transportation
Producing nitrogen gas in house removes the need for delivery trucks – powered by non-renewable fuel – to travel back and forth to your location(s). Consider even just one remote industrial location receiving deliveries of liquid nitrogen every couple of weeks. The trucks are travelling thousands of miles annually, yet those emissions are unnecessary and can be eliminated.
On-site generation uses less electricity
Liquid nitrogen providers compress and cool the air, causing it to liquefy. This fractional (or cryogenic) distillation method uses a lot of energy because the process involves repeated cycles of extreme heating and cooling to separate the nitrogen.
Purity Gas’s nitrogen generation technology produces the same volume of nitrogen gas at high purity but uses only about half the amount of electricity it takes to fill liquid nitrogen tanks or cylinders.
It’s also possible that your liquid nitrogen provider is located in a region with a higher-emitting energy grid. Producing your own nitrogen gas in a region with a cleaner energy grid will reduce your carbon footprint.
Understanding the reduction in CO2e emissions
At Purity Gas, we are well accustomed to providing a report to outline potential reduction in CO2e emissions for any customer considering the switch from liquid nitrogen delivery to on-site nitrogen gas generation.
Review the sample scenario below, based on a typical North American facility. We show the greenhouse gas emissions saved in both production and transportation and demonstrate a potential reduction of 24.5 tonnes of CO2e emissions over a one-year period.
It’s an impressive savings – just one tonne of CO2e is equivalent to emissions produced by heating a home with natural gas for six months or driving a car several thousand miles.
| CO₂e from traditional N₂ production methods | 0.64 kWh/m³ |
| CO₂e from onsite N₂ generation (99.5% purity) | 0.31 kWh/m³ |
| Average NA Energy intensity | 325 g CO₂/kWh |
| Distance Traveled for deliveries (approximate average) | 150 miles |
| Delivered Liquid N₂ | Gaseous - Onsite Generated |
|---|---|
| 100,000 m³ annual usage | 100,000 m³ annual usage |
| 0.64 kWh/m³ | 0.31 kWh/m³ |
| 243,470 kWh energy - traditional method | 119,683 kWh energy - onsite N₂ |
| 323 g CO₂/kWh | 323 g CO₂/kWh |
| 20,699,250 total g CO₂e - traditional method | 10,175,165 total g CO₂e - onsite N₂ |
| 20.70 Tonnes CO₂e - traditional method | 10.18 Tonnes CO₂e - onsite N₂ |
| 10.52 Tonnes CO₂e saved in production | |
| Delivery from Fractional Distillation Plant to User | |
|---|---|
| Full Delivery | Empty (return trip) |
| 146.8 per Tonne Mile | 146.8 per Tonne Mile |
| 150 miles | 150 miles |
| 37.62 Tonnes total | 13 Tonnes total |
| 5,643 Ton miles | 1,950 Ton miles |
| 828,392 g CO₂ | 286,260 g CO₂ |
| 0.828 Tonnes CO₂e Per Trip | 0.423 Tonnes CO₂e Per Trip |
| 26 Trips per year | 26 Trips per year |
| 18.22 Tonnes CO₂e per year | 6.30 Tonnes CO₂e per year |
| 24.52 Tonnes CO₂ emissions - Transportation | |
Waste reduction
If you’re storing liquid nitrogen tanks or cylinders, the liquid nitrogen boils off and evaporates to the atmosphere through a pressure relief valve. That’s not environmentally friendly or cost effective – if you use your supply inconsistently, you’re losing nitrogen before you get to use it.
It’s also worth mentioning that liquid nitrogen tanks and cylinders have a lifespan and will eventually have to be properly disposed of. On site generation eliminates this safety risk and negative impact on the environment.
The benefit of modular generation systems
Purity Gas systems are all modular and custom designed to meet your facility’s specific needs. Taking energy consumption into account is part of the design process. For example, if we can design a system that uses a 25-horsepower air compressor instead of a 100-horsepower compressor, you're saving 75 horsepower worth of energy every time you run the system. Sizing the system just right is a key element of preventing unnecessary energy use.
We recently worked with a customer who already generated nitrogen on site from one large central system. Their main reason for switching to a custom Purity Gas system was to improve efficiency to protect the environment.
In this case, we worked directly with the company’s sustainability team, who appreciated the value of having full control over the amount of nitrogen being generated at a given time. During slower periods, they can turn off some of the generator modules to save energy.
A modular system also allows for future growth. If you expand production, you simply add to the existing system, without having to replace it and start over. There’s no waste and no downtime.
Environmental considerations are everybody’s business. At Purity Gas, we’re proud of our contribution to reducing greenhouse gas emissions for our manufacturing customers.
Ready to learn more? Contact us, or start with our free assessment to get a clear picture of your usage and needs, as well as potential ROI and carbon footprint reduction.
