Biomethane grid injection Leoben
The best-known Austrian beer brand on the international market is Gösser, which belongs to Brau Union. The brewery in Leoben, Styria, can look back on a tradition: the brewing activity that was started by the Göss nunnery and later discontinued was successfully reactivated in 1860 by the beer brewer Max Kober. Today, the color green in the logo also stands for the effort to pursue a climate-friendly corporate policy.
Gösser is making great efforts to reduce fossil fuels in production, procurement, and delivery. The use of self- produced biogas is a core area of the company's sustainability strategy. The supply of biogas is a joint project between Brau Union, the energy supplier Energienetze Steiermark, and the compressor specialist BAUER KOMPRESSOREN. The biogas used for the production process is obtained by Brau Union in an in-house biogas plant from the spent grains, the residues of the brewing process. "Energienetze Steiermark" then converts the raw gas into ready-to-use biomethane. The freshly obtained raw gas must first be processed. It goes through a so-called amine wash, in which the raw gas is freed from undesirable accompanying substances such as carbon dioxide, hydrogen sulphide and other acidic gases. This achieves high purities even at relatively low pressures.
The pressure of the gas when fed into the feed system is only a few millibars. Before compression, the quality of the processed biomethane is measured with a gas analyser for its methane content and its accompanying substances in order to comply with the standards set out in the norms. Since the feed takes place in different networks depending on demand, two technically different compressor systems were planned. Here, the technologically leading compressor technology of the natural gas and biogas specialist BAUER KOMPRESSOREN is used.
The first of the two systems contains a water-cooled screw compressor of the type CNK 9-55, which is characterized by a high delivery capacity at lower pressure. This feeds the fully processed BAUER KOMPRESSOREN Biogas feed-in at the Gösser brewery into a 4-bar network, which is used for the brewing process in the brewery. After compression, the biomethane is cleaned again and cooled down to approx. 20°C. If the consumption in the brewing process is low, the system switches to the second compressor, a water-cooled CS 23.8-37 medium-pressure compressor. This BAUER high-pressure booster can handle high inlet pressure, which significantly reduces energy requirements. The enclosure of the compressors in heated and ventilated containers allows operation even under highly fluctuating external conditions. With the commissioning of the fully installed systems, Gösser Bräu has added another important component to its sustainability strategy.
