Ammonia keeps your beer ice cold while saving brewers energy costs

One of the first ammonia systems in a brewery was installed as early as in 1876, enabling a Bavarian brewery to produce beer throughout the year. Since these humble beginnings breweries have had a significant impact on the development of refrigeration systems. While nowadays ammonia is a standard for a large number of breweries, some have shifted in this direction only recently. The examples below from Germany and England show that in the long term the decision to install ammonia cooling system results not only in lower electricity bills, but also in a better cooling output and environmental performance.

Reducing energy consumption, increasing capacity

The Daniel Thwaites brewery founded in 1807 in Blackburn, Lancashire, England supplies over 350 pubs in the Northern England with its beer. In order to improve the efficiency of refrigeration, which is an important element in the brewing process, the brewery installed a new reciprocating compressor by GEA that uses ammonia as a working fluid. Installed by specialists from Star Refrigeration, the new system has resulted in increased output of 400 kW as compared to the 310 kW supplied by the previous installation. In addition, the energy efficiency has improved, saving the owners approximately £2,000 (around €2,500) a week in electricity costs, which means that the investment will be paid back in less than 18 months.

Heat pump connected to ammonia refrigeration system provides heat for local pub

An ammonia refrigeration system for chilling brewing water has substituted the old traditional ice bank system in one of the oldest Bavarian breweries “Herzoglich Bayerische Brauhaus Tegernsee”. To cool 190 liters of brewing water from +16°C to +2°C in 180 minutes, a gravity-type system using 100kg of ammonia has been introduced. With a cooling capacity of 124 kW, the main features of the installation include:

• A separator
• An air-cooled condenser for condensing the refrigerant
• A secondary plate heat exchanger operating with glycol
• Two reciprocating compressors to supply constant cooling
• A connection to a heat pump that then supplies heat to a nearby pub and restaurant

Beer cooled with the natural refrigerant blend R723

Another old brewery in Bavaria, the Ottenbräu Brewery, has recently installed a completely new state-of-art brewing plant, with a brewing capacity of 4,000 litres of beer per day, using the natural refrigerant blend R723. The blend comprising of 60% ammonia and 40% dimethylether reaches a 3% better energy efficiency than pure ammonia.

The brewery has achieved energy savings of around 40% as a result of:

• Switching from bricked-in fermentation vats to free-standing directly cooled stainless steel fermentation tanks;
• Changing the space cooling of the storage tanks to direct jacket cooling by glycol;
• Replacing ice bank storage systems with single-stage plate heat exchangers with pre-cooled brewing water;
• Using the natural refrigerant R723.