Craft breweries use CO2 in a surprising number of applications in the brewing, packaging and serving process: moving beer or product from tank to tank, carbonizing a product, purifying oxygen before packaging, packaging beer in the process, pre-flushing brit tanks after cleaning and sanitizing, bottling draft beer in a restaurant or bar. This is just for starters.
“We use CO2 throughout the brewery and bar,” says Max McKenna, senior marketing manager at Boston-based Dorchester Brewing Co. Serving beer – at every stage of the process. ”
Like many craft breweries, Dorchester Brewing is facing a shortage of the commercial quality CO2 it needs to operate (read about all the reasons for this shortage here).
“Because of our contracts, our current CO2 suppliers have not raised their prices despite price increases in other parts of the market,” McKenna said. “So far, the impact has been mainly on limited distribution.”
To compensate for the lack of CO2, Dorchester Brewing uses nitrogen instead of CO2 in some cases.
“We were able to move many operations to nitrogen,” McKenna continued. “Some of the most important ones were cleaning the cans and covering the gas during the canning and sealing process. This is by far the biggest addition for us because these processes require a lot of CO2. For a long time we had a special nitro plant. We use a special a nitrogen generator to produce all the nitrogen for the bar – for a dedicated nitro line and our beer blend.”
N2 is the most economical inert gas to produce and can be used in craft brewery basements, bottle shops and bars. N2 is cheaper than CO2 for drinks and often more available, depending on availability in your area.
N2 can be purchased as a gas in high pressure cylinders or as a liquid in Dewars or large storage tanks. Nitrogen can also be produced on site using a nitrogen generator. Nitrogen generators work by removing oxygen molecules from the air.
Nitrogen is the most abundant element (78%) in the Earth’s atmosphere, the rest is oxygen and trace gases. It also makes it more environmentally friendly as you emit less CO2.
In brewing and packaging, N2 can be used to keep oxygen out of the beer. When used properly (most people mix CO2 with N2 when working with carbonated beer) N2 can be used to clean tanks, transfer beer from tank to tank, pressurize kegs before storage, while aerating under caps. ingredient for taste and mouthfeel. In bars, nitro is used in tap water lines for nitropiv as well as high pressure/long distance applications where nitrogen is mixed with a certain percentage of CO2 to prevent the beer from foaming on tap. N2 can even be used as a boil off gas for water degassing if this is part of your process.
Now, as we mentioned in our previous article on CO2 deficiency, nitrogen is not an exact replacement for CO2 in all brewing applications. These gases behave differently. They have different molecular weights and different densities.
For example, CO2 is more soluble in liquids than N2. This is why nitrogen gives smaller bubbles and a different mouthfeel in beer. This is why brewers use liquid nitrogen drops instead of gaseous nitrogen to nitrate beer. Carbon dioxide also adds a hint of bitterness or sourness that nitrogen does not, which can change the flavor profile, people say. Switching to nitrogen will not solve all carbon dioxide problems.
“There is potential,” says Chuck Skepek, director of technical brewing programs at the Brewers Institute, “but nitrogen is not a panacea or a quick fix. CO2 and nitrogen behave quite differently. You will get more nitrogen mixed with the air in the tank than if you purge the CO2. So it will require more nitrogen. I hear this over and over again.
“One brewer I know was really smart and started replacing carbon dioxide with nitrogen, and their beer had a lot more oxygen in it, so now they use a mixture of nitrogen and carbon dioxide, with a little more luck. not just, “Hey, we’re going to start using nitrogen to solve all of our problems. It’s nice to see a lot more about this in the literature, we’re starting to see more people actually doing some research, and, you know, to come up with best practices for this replacement.
The delivery of these gases will be different as they have different densities which may result in some engineering or storage changes. Hear Jason Perkins, master brewer at Allagash Brewing Co., discuss upgrading his bottling line and gas manifold to use CO2 for pressurized bowl filling and N2 for sealant and bubble breaker. Storage may vary.
“There are definitely some differences, partly because of how we get nitrogen,” McKenna said. “We get pure liquid nitrogen in dewars, so storing it is very different from our CO2 tanks: they are smaller, on rollers and stored in a freezer. We have taken it to the next level. carbon dioxide to nitrogen, but again, we are very careful about how to make the transition efficiently and responsibly to make sure the beer is at its highest level every step of the way. key, in some cases it was a very simple plug and play replacement, while in other cases it required significant improvements in materials, infrastructure, manufacturing, etc.”
According to this excellent article from The Titus Co. (a supplier of air compressors, air dryers, and air compressor services outside of Pennsylvania), nitrogen generators operate in one of two ways:
Pressure swing adsorption: Pressure swing adsorption (PSA) works using carbon molecular sieves to separate molecules. The sieve has pores the same size as the oxygen molecules, trapping those molecules as they pass through and allowing the larger nitrogen molecules through. The generator then releases oxygen through another chamber. The result of this process is that nitrogen purity can reach 99.999%.
Membrane generation of nitrogen. Membrane nitrogen generation works by separating molecules using polymer fibers. These fibers are hollow, with surface pores small enough to allow oxygen to pass through, but too small for nitrogen molecules to remove oxygen from the gas stream. Generators using this method can produce nitrogen up to 99.5% pure.
Well, the PSA nitrogen generator produces ultra-pure nitrogen in large volumes and at high flow rates, the purest form of nitrogen that many breweries require. Ultrapure means 99.9995% to 99%. Membrane nitrogen generators are ideal for small breweries that require a low volume, low flow alternative where 99% to 99.9% purity is acceptable.
Using the latest technology, the Atlas Copco nitrogen generator is a compact industrial air compressor with a special diaphragm that separates the nitrogen from the compressed air stream. Craft breweries are a big target audience for Atlas Copo. According to an Atlas Copco white paper, brewers typically pay between $0.10 and $0.15 per cubic foot to produce nitrogen on site. How does this compare to your CO2 costs?
“We offer six standard packages that cover 80% of all breweries – from a few thousand to hundreds of thousands of barrels per year,” says Peter Askini, business development manager for industrial gases at Atlas Copco. “A brewery can increase the capacity of its nitrogen generators to enable growth while maintaining efficiency. In addition, the modular design allows a second generator to be added if the brewery’s operations expand significantly.”
“Using nitrogen is not intended to completely replace CO2,” explains Asquini, “but we think that winemakers can reduce their consumption by about 70%. The main driving force is sustainability. It’s very easy for any winemaker to produce nitrogen on their own. Don’t use more greenhouse gases.” which is better for the environment It will pay off from the first month, which will directly affect the bottom line, if it doesn’t show up before you buy, don’t buy it.Here are our simple rules.The demand for CO2 is skyrocketing to produce such products, like dry ice, which uses large amounts of CO2 and is needed to transport vaccines. Breweries in the US are expressing concern about the level of supply and wondering if they can keep the price level consistent with the needs of the brewery.”
As mentioned earlier, nitrogen purity will be a major concern for craft brewers. Just like CO2, nitrogen will interact with the beer or wort and carry impurities along with it. This is why many food and beverage nitrogen generators will be advertised as oil-free units (learn about the cleanliness benefits of oil-free compressors in the last sentence in the sidebar below).
“When we receive CO2, we check its quality and contamination, which is another very important part of working with a good supplier,” said McKenna. “Nitrogen is a little different, which is why we still buy pure liquid nitrogen. Another thing we’re looking at is finding and pricing an internal nitrogen generator – again, with a focus on the nitrogen it produces with Purity to limit oxygen uptake. We see this as a potential investment, so the only processes in the brewery that are completely dependent on CO2 will be beer carbonation and tap water maintenance.
“But one really important thing to keep in mind – again, something that seems picky to overlook but is critical to maintaining beer quality – is that any nitrogen generator needs to produce nitrogen to the second decimal place [i.e. 99.99% purity] to limit oxygen uptake and the risk of oxidation. This level of accuracy and purity requires more nitrogen generator costs, but ensures the quality of the nitrogen and therefore the quality of the beer.”
Brewers require a lot of data and quality control when using nitrogen. For example, if a brewer uses N2 to move beer between tanks, the stability of the CO2 in the tank and in the tank or bottle must be monitored throughout the process. In some cases, pure N2 may not work properly (for example, when filling containers) because pure N2 will remove CO2 from the solution. As a result, some brewers will use a 50/50 mixture of CO2 and N2 to fill the bowl, while others will avoid it entirely.
N2 Pro Tip: Let’s talk maintenance. Nitrogen generators really are as close to “set it and forget it” as you can get, but some consumables, such as filters, require semi-regular replacement. Typically, this service is required approximately every 4000 hours. The same team that takes care of your air compressor will also take care of your generator. Most generators come with a simple controller similar to your iPhone and offer full app remote monitoring capabilities.
Tank purge differs from nitrogen purge for a number of reasons. N2 mixes well with air, so it doesn’t interact with O2 like CO2 does. N2 is also lighter than air, so it fills the tank from top to bottom, while CO2 fills it from bottom to top. It takes more N2 than CO2 to purge a storage tank and often requires more shot blasting. Are you still saving money?
New safety issues also arise with the new industrial gas. A brewery should definitely install O2 sensors so employees can visualize indoor air quality – just like you have N2 dewars stored in refrigerators these days.
But profitability can easily outweigh CO2 recovery plants. In this webinar, Dion Quinn of Foth Production Solutions (an engineering firm) states that N2 production costs between $8 and $20 per ton, while capturing CO2 with a recovery plant costs between $50 and $200 per ton.
The benefits of nitrogen generators include eliminating or at least reducing dependence on contracts and supplies of CO2 and nitrogen. This saves storage space as breweries can produce and store as much as they need, eliminating the need to store and transport nitrogen bottles. As with CO2, shipping and handling of nitrogen is paid by the customer. With nitrogenerators, this is no longer a problem.
Nitrogen generators are often easy to integrate into a brewery environment. Smaller nitrogen generators can be wall-mounted so they don’t take up floor space and operate quietly. These bags handle changing ambient temperatures well and are very resistant to temperature fluctuations. Can be installed outdoors, but not recommended for extreme high and low climates.
There are many manufacturers of nitrogen generators including Atlas Copco, Parker Hannifin, South-Tek Systems, Milcarb and Holtec Gas Systems. A small nitrogen generator could cost about $800 a month under a five-year lease-to-own program, Asquini said.
“At the end of the day, if nitrogen is right for you, you have a variety of suppliers and technologies to choose from,” Asquini said. “Find which one is right for you and make sure you have a good understanding of total cost of ownership [total cost of ownership] and compare power and maintenance costs between devices. You will often find that buying the cheapest is not right for your job .”
Nitrogen generator systems use an air compressor, and most craft breweries already have one, which is handy.
What air compressors are used in craft breweries? Pushes fluid through pipes and tanks. Energy for pneumatic conveying and control. Aeration of wort, yeast or water. control valve. Purge gas to force mud out of tanks during cleaning and to assist in hole cleaning.
Many brewery applications require the special use of 100% oil-free air compressors. If the oil comes into contact with the beer, it kills the yeast and flattens the foam, which spoils the drink and makes the beer bad.
It’s also a security risk. Because the food and beverage industry is very sensitive, there are strict quality and purity standards in place, and rightfully so. Example: Sullair SRL series oil-free air compressors from 10 to 15 hp. (from 7.5 to 11 kW) are well suited for craft breweries. Breweries enjoy the quietness of these types of machines. The SRL series offers low noise levels down to 48dBA, making the compressor suitable for indoor use without a separate soundproof room.
When clean air is critical, such as in breweries and craft breweries, oil-free air is essential. Oil particles in compressed air can contaminate downstream processes and production. Since many breweries produce thousands of barrels or several cases of beer a year, no one can afford to take that risk. Oil-free compressors are especially suitable for applications where the air is in direct contact with the feedstock. Even in applications where there is no direct contact between ingredients and air, such as in packaging lines, an oil-free compressor helps keep the final product clean for peace of mind.