Brauwelt - The use of nitrogen in the brewery

Latest article in the Magazine BRAUWELT, issue 33/18

BREWERY FOHRENBURG IN VORARLBERG / AUSTRIA

Nitrogen is used as intert gas in order to protect the beer against the ageing process. Nitrogen is used in many sectors of the food industry to prevent goods from spoiling and keep them fresh. In breweries, protective gases are used to protect the beer against the ageing process caused by the introduction of oxygen. The traditional Austrian brewery Fohrenburg previously used carbon dioxide for this purpose in its production and filling plants. After a pilot phase, the company is now opting for nitrogen. A nitrogen generator from INMATEC supplies the required amount of the gas, and in doing so, contributes to a reduction of costs involved in the brewing process.

Beer brewing - time consuming and featuring several processes

On average, each person in Germany and Austria drinks more than 100 litres of beer every year. The production process for this beloved beverage is time consuming and features several process steps, which sometimes involve the exclusion of oxygen and the use of protective gases. Therefore, after the beer is stored, any contact with oxygen must be avoided, since microbial infections and oxidative enzymatic reactions can lead to a decrease in quality, reduced storage stability and even spoiling of the beer. That is why, after it is stored, the finished beer is subjected to further processing under a protective gas. The gas most commonly used for this process is carbon dioxide, which is created during the fermentation process. The carbon dioxide creates the characteristic pearl effect when the beer is poured and gives a well-poured beer its fine foam head. Generally, the fermentation process does not create enough carbon dioxide for subsequent use as a protective gas. This means that companies frequently need to buy in expensive CO2, which is then dissolved in water to form carbonic acid.

Brewery Fohrenburg in Voralberg / Austria

The Fohrenburg brewery based in Vorarlberg has produced carbonated beverages since 1881. 145,000 litres of beer can be brewed per day. The filling plant fills 40,000 beer bottles per hour, and approximately 200,000 beer kegs are filled per year. Maximum levels of quality and the use of the latest brewing techniques are of primary importance for the company. That is why Fohrenburg has decided to test out the use of nitrogen in its plants.

INMATEC, the market-leading manufacturer of nitrogen generators based in Germany, provided the brewery with a type IMT PN 1650 OnTouch nitrogen generator with pressure swing adsorption (PSA) technology. On this generator, the sterile compressed air flows through two adsorption containers filled with a carbon molecular sieve. Oxygen and carbon dioxide molecules from the ambient air are caught in the sieve, while the free nitrogen molecules flow into the product tank. The dry nitrogen, of which around 37 m³ per hour can be retrieved by the plant, features a food-compliant purity of at least 99.5% and can now be used for a wide range of applications at Fohrenburg. Examples include blanketing of mixing tanks, operation of the water deaerating plant and to blow out the saturated steam after sterilisation of the beer kegs and lemonade containers. Fohrenburg now uses nitrogen as the sole protective gas in these areas.

Attempts are currently being made in the bottle filling process to use a mixture of nitrogen and CO2 that is tailored to the beer to rinse the bottles so that they are free from oxygen and to pressurize them. To achieve this, the nitrogen generator can easily be connected to a gas mixer, which automatically provides the gases in the desired mixture ratio.

After a successful test phase spanning several months, Fohrenburg has opted to purchase the INMATEC nitrogen generator.

„The fundamental idea was to be able to support the quality-related processes with carbon dioxide retrieved from our own fermentation process to the greatest extent possible, in order to take one step closer to becoming carbon neutral. In order to achieve this, we must switch over as many processes as possible that previously used carbon dioxide as an protective gas to use nitrogen as a protective gas. The positive results coming from the use of nitrogen in our brewery have convinced us that nitrogen is an excellent replacement for carbon dioxide as a protective gas. The system is working incredibly reliably and helps us to save costs while maintaining the same level of quality."

Dipl.-Ing. Andreas Rosa, Managing Director of Technology and Mater Brewer at Fohrenburg

The INMATEC IMT PN 1650 nitrogen generator is located in the technology room of the brewery and is connected to the building‘s compressed air system and the gas mixer. Thanks to the latest remote control technology, all functions and parameters can be monitored and controlled online.