How Breweries Use Compressed Nitrogen
At its most basic form, the brewing process occurs in four steps — malting, mashing, boiling and fermenting. Compressed gases such as nitrogen are used in many of these steps. Here are some of the key uses of compressed nitrogen in brewing:
- Tank cleaning: Nitrogen gas is used to purge tanks and ensure they are clean between uses. By using compressed nitrogen for cleaning, brewers can ensure residual mash, wort and beer is removed. Leftover beer and ingredients can oxidize, polluting the next batch that goes in the tank with a sour flavor.
- Beer movement: Nitrogen can be pushed into a tank to displace the carbon dioxide and oxygen inside, helping to push the beer out of one tank and into the next.
- Pressurization: Nitrogen is often injected into kegs as a way to pressurize them before they undergo shipping or go into storage.
- Infusion: Nitrogen can be infused into the beer during the brewing process to add to the flavor complexity and mouthfeel of the beverage.
Many breweries use nitrogen in these ways, often relying on nitrogen gas cylinders as a source for compressed nitrogen. However, many breweries are turning to a nitrogen generator as their source of compressed nitrogen.
How Nitrogen Generation Works
Nitrogen generators are becoming an increasingly attractive option for breweries. In fact, the global market size for nitrogen generators is expected to grow at a compound annual growth rate of 4.9% through 2026. How do these nitrogen generators work? Nitrogen generators use the ambient air as a primary source of nitrogen. Air is composed of about 78% nitrogen, with the rest of the composition containing oxygen and trace gases. Nitrogen generators work by removing the oxygen molecules in the air. Generators can do this via one of two methods:
- Pressure swing adsorption: Pressure swing adsorption (PSA) works by separating molecules using a carbon molecular sieve. This sieve has pores the same size as oxygen molecules, catching these molecules as they pass while letting larger nitrogen molecules by. The generator then releases oxygen through another chamber. The result of this process is nitrogen with a 99.999% purity level.
- Membrane nitrogen generation: Membrane nitrogen generation works by separating molecules using polymer fibers. The fibers are hollow with surface holes small enough for oxygen to pass through, but too small for nitrogen molecules, removing oxygen from the gas stream. Generators using this method can produce nitrogen with up to a 99.5% purity level.
Generators are often paired with air compressors, which take ambient air and compress it to feed into the nitrogen generator. Oil-free air compressors are the best choice for this purpose, as they are not lubricated by oil that could contaminate the beer or surrounding equipment.
The Benefits of Nitrogen Generation for Breweries
So why should brewery operations use a nitrogen generator over nitrogen cylinders or bottles? While useful in smaller operations, nitrogen bottles can quickly become a drag on production for breweries of all sizes. Below are some of the most significant benefits of nitrogen generation over nitrogen cylinders.
1. Improved Efficiency
Breweries that use nitrogen bottles utilize a cycle. They order the bottles, receive and store the bottles, hook up and replace the bottles, then reorder when supplies are running low. This process introduces several inefficiencies in brewery production, which can be solved with a nitrogen generator. Some of the key ways nitrogen generators can improve efficiency in your brewery include the following:
- Eliminate reliance on deliveries: Breweries that utilize nitrogen bottles rely on deliveries of these bottles. This presents a key problem — what happens when someone forgets to place a new order, or there is a delay in the delivery schedule? In these cases, your brewery will have to scramble to put in an emergency order and rely on current supplies until they run out. In a worst-case scenario, the brewery will have to halt production until the new delivery comes in, resulting in massive losses in productivity. With a nitrogen generator, breweries supply their own nitrogen, maximizing reliability and eliminating the need for deliveries and the potential for costly delays and downtime.
- Reduce storage needs: In a brewery, space is precious. If you're using nitrogen bottles, you need to dedicate some of this space to nitrogen storage. A nitrogen generator eliminates this wasted storage space with a freestanding piece of equipment. This means your brewery can utilize storage space more efficiently.
- Minimize waste: When a brewery purchases liquid nitrogen in bulk, they don't use it all at once. As a result, nitrogen sits in its tank until it's used. During this time, ambient heat causes the nitrogen to expand, which can cause leaks or even tank explosions if the pressure isn't released. Because of this, the tanks must be regularly opened to release the pressure, which wastes nitrogen. To add to the waste, cylinders become unusable even when there is still some nitrogen left in the bottle. Nitrogen generators eliminate this waste by sourcing nitrogen in-house and allowing breweries to only use what they need when they need it.
- Maximize labor efficiency: Breweries that rely on nitrogen bottles must replace these bottles regularly during production and open tanks regularly to release excess pressure. This means your staff must take time out of their day solely for the maintenance of nitrogen bottles. This issue is eliminated with a nitrogen generator, which produces a continuous supply of nitrogen to your operations. As a result, your staff is freed up to spend their time on more important tasks in the brewery.
All these benefits of nitrogen generators mean more uptime for your brewery and improved utilization of your labor and storage resources.
2. Reduced Costs
Utilizing nitrogen bottles in breweries can incur significant costs in various ways. Some of the upfront and hidden costs of using nitrogen cylinders include the following:
- Price variations: Purchasing nitrogen costs an average of $0.25 to $0.40 per cubic foot, though the price increases depending on how far the gas supplier is from the brewery site. By simply switching to a nitrogen generator, the cost per cubic foot decreases by 40% to 75%, averaging around $0.10 to $0.15 per cubic foot.
- Delivery costs: Delivery costs are usually included in the price of nitrogen cylinders. However, emergency deliveries can incur increased costs when you're running low on supplies and need immediate resources to keep production moving.
- Gas waste: Nitrogen cylinders incur waste through regular maintenance, and the last 15% of the bottle often goes unused. This means you're paying for nitrogen you can't even use in the brewery.
- Labor cost: One of the significant hidden costs of nitrogen cylinders is the internal labor expense. Brewery staff must spend time ordering, receiving, maintaining and switching out nitrogen bottles on an ongoing basis, incurring continuous labor costs that could be going toward more critical brewery functions.
- Lost production time: In the event of a delivery or replacement delay, breweries must temporarily halt production until their supplies are replenished, costing them money in lost production time.
Even though the purchase of a nitrogen generator and its peripheral systems and hookups can cost breweries money upfront, the cost savings of a nitrogen generator more than offset the upfront costs. Most breweries see an ROI within a couple of years of purchase.
3. Improved Safety
In addition to reducing costs and maximizing efficiency, switching from a nitrogen cylinder system to a nitrogen generator is a safer option. Compressed gas cylinders pose two significant safety concerns:
- Explosion: The internal pressure of compressed gas cylinders can be up to 2,500 pounds per square inch. Exposing cylinders to heat, knocking them over or dropping them can cause their shell to weaken or crack. If the weakness is significant, this can cause the canister to explode, sending shrapnel flying at a high speed. This shrapnel can damage surrounding equipment and severely injure any staff in the area.
- Air quality: In addition to the explosion risk, nitrogen cylinders can quickly release large amounts of nitrogen into the air, depleting the local oxygen content of the air. This can pose a significant risk to workers in the area.
Nitrogen generators pose a solution. Instead of storing compressed gas cylinders and managing their safe storage to avoid explosions and leaks, a brewery can switch to a nitrogen generator. These generators are hooked up directly to supply lines, releasing nitrogen directly where it needs to go. While precautions should still be taken to avoid leaks, switching to a nitrogen generator eliminates the risk of explosions in breweries.
4. Reduced Carbon Footprint
Using a nitrogen generator also presents ecological benefits for breweries, especially when using a nitrogen generator to replace carbon dioxide usage in production. The two key benefits in this area are as follows:
- Replacing CO2 usage: Many breweries use CO2 for cleaning tanks and transferring beer between vessels. Nitrogen can be used for the same purpose. By switching from CO2 to nitrogen in these uses, breweries can cut their CO2 usage significantly, reducing their environmental footprint.
- Reducing delivery needs: Even if you are switching from nitrogen cylinders to an in-house nitrogen generator, the switch makes a positive impact on the environment. Utilizing an in-house generator eliminates the need for regular deliveries, reducing your brewery's impact on the environment through automobile usage.
What's the Difference Between Nitrogen and Carbon Dioxide for Breweries?
Both nitrogen and carbon dioxide are often used in breweries for pressurization and carbonation purposes. Currently, carbon dioxide is still the most common choice for carbonating beer. However, the two gases are slightly different from one another in various respects. Some of the key differences include the following:
- Solubility: Carbon dioxide is much more soluble in water and water-based liquids compared to nitrogen. As a result, a container that uses pressurized carbon dioxide will have more dissolved CO2 in the beverage compared to a container pressurized with nitrogen.
- Mouthfeel: Carbon dioxide produces large bubbles in beers, while nitrogen produces smaller, yet more abundant bubbles. The smaller bubbles produced using nitrogen create a creamier mouthfeel, along with a thick, foamy head and a pleasant cascade in the glass. In both cases, the effervescence of the beer creates a pleasurable sensation on the tongue, highlighting the sweeter notes of the beer.
- Taste: Carbon dioxide is an acid, and when combined with beer, it lends the beer a hint of tartness. Nitro, on the other hand, does not add the same bitter flavor since it is less soluble, but helps suppress the bitterness of hops in a beverage.
For breweries, these factors most strongly affect which type of gas to use for pressurizing long tap lines. Most beers are pressurized using CO2, but the solubility and bitterness of CO2 can negatively affect the taste of sweet, malty beers. While CO2 is still a good option for more bitter beers, nitrogen is a better solution for malty beers. Typically, a brewery will use a mix of nitrogen and carbon dioxide in a 75:25 or 70:30 ratio to push beers without negatively affecting taste.
Considerations for Implementing Nitrogen Generators at Your Brewery
The benefits of nitrogen generators make them an excellent choice for breweries of any size. If you're interested in implementing a nitrogen generator system in your brewery, PneuTech has plenty of options available. Before taking the dive, it's essential to consider some factors about your brewery. These include:
- What are the sizes of your fermenting vessels and brite tanks?
- Do you perform tasks like inserting tanks, transferring products and packaging at the same time?
- What is your transfer rate for packaging?
- What is the volume of CO2 or nitrogen that you currently use on an annual basis?
- How do you expect to use nitrogen in your system?
Knowing the answers to these questions will help your supplier determine the best type of system for your brewery. Once you have your answers, reach out to PneuTech and we can discuss your options with you.
Choose PneuTech for Nitrogen Generators
If you're interested in making the switch to a nitrogen generator system, PneuTech is here to help. Founded in 1983, PneuTech has been helping customers meet their compressed air needs for over 40 years. With superior expertise and quality supplies, we serve companies of all sizes nationwide with locations in Illinois, Wisconsin, Minnesota, Texas, Michigan and Pennsylvania.
We have experience working with various industries, including breweries, food and beverage producers, pharmaceutical and chemical companies, the petroleum industry and more! Across our range of products and services, we are focused on the satisfaction of our customers.
Contact PneuTech today to learn more about our nitrogen generator systems.