Technical Session 17: Mashing Session
Peter Gattermeyer, Krones AG, Freising - Germany
ABSTRACT: Brewing beer is an exceptionally
energy-intensive process, and the brewhouse accounts for about a third
of the energy used, made available as heat in the form of steam or
high-pressure hot water and in the form of electricity for driving pumps
and motors. Increasing priority is being accorded to downsizing the
operating costs involved by significantly reducing the consumption of
energy and media. In view of the lengthy lifetimes now being achieved by
plant components, continually rising energy prices are compelling
breweries to look far into the future when planning their investments.
Moreover, social pressure and legislation relating to climate change
will mean that new installations have to be chosen with a view to their
CO2 emissions. Today’s brewhouses achieve consumption figures
of 6.2 kWhr/hL of cast wort cold for thermal energy, 3.0 kWhr/hL for
electricity, and 1.4 hL/hL (1.4 US bbl/US bbl) for water. This
development status constitutes the yardstick—one where any improvement
seemed well-nigh impossible. The autarchic brewery, then, was thought to
lie far off in the future. Thanks to a revolutionary design
enhancement, the consumption of primary energy in the brewhouse,
however, has been reduced by approximately another 30%. To achieve this,
the production of superfluous hot water at the wort cooler is avoided,
and instead, energy is recovered at a high temperature level in an
additional heat exchanger stage. A pressure, less stratified, storage
tank is used as a buffer between the energy source and the energy sink.
This energy, in the form of hot water, suffices for heating the entire
mashing process. The heating medium temperature here is only slightly
higher that that the mash being heated. But, the requisite heat-up rates
are achieved nonetheless. This is made possible by the specially shaped
heating surfaces, which as pillow plates feature a cushion-shaped
surface on the product side. This means that in mash kettles heat
transfer efficacies hitherto unprecedented are being achieved, up to
100% above those of conventional heating surfaces. This invention
enables alternative forms of energy to be efficiently deployed at a
temperature level of <95°C (203°F). The very low heating medium
temperature creates not only energy-economy gains, but technological
advantages as well. Fouling in the mash kettle is avoided entirely, and
the natural enzymes are treated gently. The thermal stress on the mash
has been significantly reduced. Thanks to the reduced steam consumption
in the brewhouse, new installations in particular can be designed with a
smaller steam boiler and smaller steam and condensate valves. Now that
less cooling output is required in the conventional stages of the wort
cooling process, less iced water is needed too, which means that less
electricity is consumed in producing it. This energy recovery system
brings CO2-neutral, media-friendly beer production within feasible reach.
Peter
Gattermeyer graduated in 1996 as an engineer for brewing and beverages
at TU Munich-Weihenstephan. After that he started his career at
Steinecker. In 2003 he became head of the Brewhouse Technology Section,
and in 2008 he was appointed head of the Technology Center in Krones’
Process Technology Division. In this position he is responsible for
commissioning and developments in beverage technology. He has published
scientific articles and is member of various committees.
VIEW PRESENTATION 59
