Turning off the oil
Hitherto, the Brauerei Murau eGen Brewery in Austria had been consuming 700,000 litres of heating oil a year for producing its beers. Since early 2014, it has reduced its consumption of fossil fuel to zero: no more invoices for heating oil. This has been made possible by a complete change-over to low-temperature process heat in the form of hot water. This heat comes from a biomass cogeneration plant built by Murau Municipal Utilities Ltd. in 2011, and fired solely with wood from the surrounding region. To enable this heat to be utilised for the brewhouse as well, Krones modified the latter to incorporate the EquiTherm system. For the first time, beer is now being brewed and bottled entirely with district heat from the surrounding region: so the cooperative Murau Brewery, together the Murau municipal utilities and Krones AG, have written a brand new chapter in the history of brewing technology.
Since the end of April 2014, the cooperative brewery, with an annual beer output of around 280,000 hectolitres, has been producing its beer 100-per-cent with heat from the biomass cogeneration plant of Murau Municipal Utilities. This means that in the brewery fossil fuels are no longer being burned for making the beer. A milestone. And: hitherto unknown options are opened up for saving energy in the brewing process using “low-temperature process heat”. In view of this measure’s manifest importance for the country’s energy policy, the Austrian Minister for Agriculture and the Environment, Andrä Rupprechter, attended the official inauguration ceremony for the Low-Temperature Brewery Murau held in May 2014.
This change-over to regional, regeneratively produced, CO2-neutral thermal energy has been made possible not least by the modification of the brewhouse to incorporate Steinecker’s EquiTherm system, where the entire energy required for mashing is provided by the wort cooling process. Since the brewery wanted to preserve the traditional character of the existing brewhouse with its copper hoods, Krones integrated this state-of-the-art technology into the extant copper vessels. The entire interiors of the mash tuns and the essential part of the wort boiling equipment were modified to feature the very latest Steinecker technology, and the existing wort cooler was expanded to incorporate the EquiTherm system. The two mash tuns were given the interior and the substructure of the ShakesBeer EcoPlus in an energy-economical design. At the same time, Krones built a new mash mixer made of copper for each mash tun. The wort copper was modified to include the Stromboli wort boiling system with an external boiler, and fitted with additional heat exchangers. Moreover, the wort is now no longer heated using the external boiler, but with a lautered-wort heater during recirculation pumping, which means the wort is already at boiling temperature when it reaches the copper.
The heart of the system is the stratified energy storage tank with a capacity of 110,000 litres, where firstly the heat from the EquiTherm is stored, and secondly the thermal energy required in each case for the various heat consumers can be taken from the different heat layer levels. “The big advantage here is that thanks to the buffer storage tank we can start up the consumers at precisely the temperatures that are actually needed there. We used to do everything with steam at 160 degrees Celsius”, explains Technical Director and Brewmaster Günter Kecht. “Nowadays we are using three temperatures: we need water at 115 degrees in the brewhouse only for boiling, 105 degrees for the bottle washer and 95 degrees for the rest.”
The local-heat cogeneration plant flagship project
“Our new local-heat cogeneration plant, which was commissioned in November 2011 after a record construction time of only ten months, may safely be described as a definite flagship project”, emphasises the municipal utilities’ CEO Kurt Woitischek. “Alternative energy generation is beneficial in terms of climate protection, it is good for the economy and for our region”, is his firm conviction. In its final stage of completion, the heating plant will supply thermal energy amounting to 20 million kilowatt-hours per year, thus obviating the need for two million litres of heating oil, which in turn prevents 5,700 tons of CO2 emissions. The Murau-Stolzalpe biomass cogeneration plant is fully automated throughout. The chopped wood comes from timber thinnings and residues from logging. It is delivered solely by domestic forestry firms, and unloaded into the two 13-metre-high silos.
Energy recirculation optimised to perfection
“This energy recirculation system has been consummately perfected by Krones, and it works so brilliantly that every technician’s heart beats faster”, is the verdict from Municipal Utilities Director Kurt Woitischek. He has made an intensive study of the system, since it was he who placed the order for the modification job in the brewery. His deal was this: the municipal utilities have financed the modification job in advance and in return, for the next 15 years the brewery will be paying the amount that it spent on average for thermal energy in the past five years. A win-win situation.
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