Brauwelt - Nitrogen replaces carbon dioxide

Article BRAUWELT 46-47/18

Inertisation gas produced by yourself directly onsite

Nitrogen is used in many areas of the food industry. The gas is also being increasingly used in breweries to prevent the spoilage of beer and to keep it fresh for a prolonged period. The Bavarian company BrauKon, as a brewing equipment manufacturer and brewery, has gained intensive experience with the use of nitrogen and is familiar with the areas in which nitrogen offers breweries advantages over the use of carbon dioxide.

Several process steps in the brewing process take place in the absence of oxygen and using inert gases. After storage of the beer, any contact with oxygen must be avoided, as microbial infections and oxidative enzymatic reactions lead to loss of quality, reduced storage stability, and spoilage of the beer. That is why, after it is stored, the nished beer is subjected to further processing under an inert gas such as fermentation carbonic acid. However, often, and especially in smaller breweries, not enough carbon dioxide is recovered during fermentation for further use as an inert gas and expensive CO2 often has to be bought in as a result. Nitrogen (N2) is an alternative. Nitrogen offers breweries many advantages. For example, on-site nitrogen extraction from the ambient air using a generator allows the brewery to produce the required quantity of inert gas itself. This is more cost-effective and environmentally friendly, as there is no need for any tanker delivery. In addition, CO2 supply shortages, which occurred in summer 2018 in particular, can be avoided and production losses avoided. The employees of Braukon GmbH know how and in which processes nitrogen can be used in the brewery.
BrauKon, based at Chiemsee in Bavaria, is a brewery equipment manufacturer supplying breweries and brewery start-ups worldwide with turnkey brewery equipment, brewhouse technology as well as raw materials for the brewing process. In their „laboratory“, the BrauKon Technikum, more than 30 master brewers and engineers perfect all products up to industrial maturity and, time and again, they test new processes for practical use. The brewing processes are also tested and optimised using various raw materials and mixed gas combinations. In particular, the use of nitrogen was tested here in various process steps during the brewing process. The results are also being included in the beer production of Camba Bavaria, a subsidiary of BrauKon, which brews and distributes 16 different types of beer under the name Camba.

Nitrogen is used at various stages of the process chain within the brewery. In addition to carbon dioxide, Camba also uses nitrogen for pretensioning in its beer tanks. In each of the sixteen 160 hectolitre tanks, a different type of beer is brewed. They include traditional dark, light, Märzen, wheat beer, international pale ale and cherry ale bourbon beer aged in oak barrels. The tanks are used as Unitanks and, after the one-week fermentation time and secondary fermentation, the tank is cooled down to 0 degrees Celsius for storage, which takes another four to six weeks. Following fermentation, the beer is transferred directly into transport tanks for trucks or into filling tanks for intermediate storage. „During decanting, it comes down to whether the tank is emptied completely in one operation or whether it is emptied over the course of several fillings. If the tank is emptied over the course of several fillings, we use CO2 to create defined conditions for the carbon dioxide content of the beer in the tank. If, on the other hand, the tank is emptied completely, nitrogen is let into it from above under pressure in order to make it absolutely oxygen-free“, explains master brewer Christoph Lippert-Pagany.

In this context, the carbon dioxide used is fed into the system via small tanks housed in the utility room. The tanks are delivered to Camba by truck on a weekly basis, a total of approx. 20 tons per year. The requisite nitrogen is produced directly on-site. An INMATEC generator, the market-leading manufacturer of nitrogen generators from Germany, can produce up to 37 m3 of nitrogen per hour depending on demand. The nitrogen generator of type IMT PN 1450 PAN features pressure swing adsorption (PSA) technology, in which sterile compressed air ows through two adsorption vessels lled with a carbon molecular sieve. Oxygen and carbon dioxide molecules from the ambient air are bound in the sieve, while the free nitrogen molecules ow into the product tank and a further storage tank with a volume of 1500 m3 in order to catch peaks. The dry nitrogen has a food-compliant purity of at least 99.5% and can now be used by Camba in a wide range of applications. According to master brewer Lippert-Pagany, the nitrogen produced in-house offers several advantages: „This year we had some difficulties with the supply of CO2. We obtain our CO2 solely from natural, underground deposits that promise the highest purity. Nevertheless, the CO2 shortage from the currently reduced fertiliser production on the world market has created a demand overhang. If a delivery arrives too late, we’re stuck in terms of production. That’s why we’re very happy to be able to produce alternative nitrogen ourselves in our brewery. In addition, we save up to 60% on costs through our in-house production.“

When the fermentation or cooling tanks are emptied, 15 m3 of space per tank is lled at 1.2 bar pressure. The generator therefore needs to provide 18 m3 of nitrogen within a very short space of time. The transport and filling tanks are cleaned prior to filling. To this end, they are rst steamed for sterilisation and then lled with nitrogen in several stages to avoid any contact between the beer and oxygen. During emptying, the tanks are pressurised with nitrogen once again. Bottling is another field of application for N2 in breweries. In this process step, no further CO2 is required for the carbonation of the beer, and, consequently, bought-in carbon dioxide can be completely replaced by nitrogen. Only in very large breweries does the recovery of CO2 from the fermentation process make economic sense. At Camba, each bottle is lled with gas via an elongated tube in a carousel bottling plant. Then, in the course of isobaric filling, beer ows into the bottle, the CO2 escapes, and the oxygen remains outside. In the final stage, the crown cork and the label are placed on the bottle. The product is now ready. „At the moment, we‘re still using bought-in CO2 for filling. However, we will soon be switching completely to nitrogen for both bottling and keg filling, not least to improve our CO2 balance”, Lippert-Pagany remarks.

Nitrogen can therefore be used in many areas of breweries. How and to what extent depends predominantly on the brewery‘s processes. „We supply INMATEC nitrogen generators with much of our turnkey brewery equipment. This trend is on the increase. In this regard, dimensioning is not primarily dependent on the size of the brewery. The processes of the respective brewery are more important. We take a close look at these together with our customers and install the appropriate generator“, explains Lippert- Pagany. In addition, the nitrogen requirement can also depend on the beers that are brewed. „With some types of beer, what is referred to as cold hopping (dry hopping) is used. BrauKon offers the pecially developed and patented HopGun for this purpose. The HopGun is lled with hop pellets and then ushed with the young beer from the storage tank. The dissolving aromas and essential oils from the hops give beer varieties such as Camba Ho Gun, Camba IPA or Camba Hopla a special hop avour. Like all other tanks, the Braukon HopGun is charged with 100% nitrogen for cleaning and inerting. Another very special and individual application for nitrogen in the brewery. Furthermore, different countries have different brewing cultures. In southern countries, for example, beer often binds less CO2. English breweries like to use carbonation stones to carbonate beer. CO2 and cost savings are also playing an increasingly important role in many countries. All this has an impact on the use of nitrogen in the brewing process.

„We can clearly see the advantages of using nitrogen in the brewery. We are less dependent on suppliers and we reduce costs every year. By saving CO2 in production and reducing CO2 deliveries by truck, we are able to produce our beer in a more climate-neutral manner and conserve the region. The consistently positive results we gain from the use of self-generated nitrogen in our brewery have convinced us. This allows us to make the right recommendations to our customers, whom we supply with brewing technologies across the globe, and to support them in their processes and in saving CO2. The reliable and robust INMATEC nitrogen generators, which we are easily able to offer in the right dimensions, are an important component in this regard”, says master brewer Chris- toph Lippert-Pagany.

published in BRAUWELT 46-47/18