Electrifying process heat – Reducing the use of fossil fuels in the brewery

Substantial amounts of electricity and thermal energy are required for brewing beer. While electricity can already be produced from renewable sources today, generation of process heat is still largely based on fossil fuels. Steinecker(opens external link in a new tab) set out to change that. The specialists for brewing technology within the Krones Processing network are presenting their solution EquiTherm Power(opens external link in a new tab) for the first time.

The system achieves decarbonisation in various parts of the brewing process by capturing process heat that would otherwise be wasted and reusing it, by raising the temperature of the thermal energy available and thus rendering it effectively usable, or by applying the field-proven concept of vapour compression to heating steam as well. That enables breweries to cut their CO₂ emissions and purposefully integrate renewable resources into their thermal energy supply.

Different applications in the brewing process

Making effective use of fermentation heat is one of the key areas here. Heat is continuously generated during fermentation and dissipated via the tank cooling system. The cooling circuit takes this energy to the refrigeration system where it is absorbed by the refrigerant and released again on the condenser side. Until now, this thermal energy has often been dissipated into the hall. Since its temperature is not high enough to serve as process heat, a heat pump raises it to a usable level. As a result, the dissipated fermentation heat can be reused as process heat.

Efficiently combining the production of iced water and hot water constitutes the second field of application. Traditionally, each of the two media is generated in a separate process. While thermal energy is needed to make hot water, electricity is necessary for refrigeration in order to produce iced water. A heat pump now links these two processes: The heat absorbed during iced-water production is no longer dissipated into the hall and wasted. Instead it is purposefully used for making hot water. Thanks to this combined approach to generating heat and cold, a total coefficient of performance (COP) of up to 8 can be achieved.

For higher-temperature applications, such as wort boiling or sterilisation, a heat pump can be used to bring the available thermal energy up to the needed temperature. As an alternative to the heat pump, a compressor can be employed to recover high-temperature energy: Hot water is vaporised in a priming vessel, thus creating a steam-saturated atmosphere. An electrically driven compressor sucks in the steam and raises its pressure and temperature to such an extent that it can be used as heating steam, which can then be fed into the existing steam network and distributed to the various consumers of process heat.

Flexibility for food and beverage production

Thanks to the heat storage tank, provision and consumption of heat do not have to take place at the same time. That means standardised heat pump modules can be efficiently used exactly when they are needed. What’s more, integration of alternative heat sources makes for flexible line operation and provides an option for purposefully responding to fluctuations in energy prices and availability.

Integration into a company’s thermal energy supply system is possible with minimal intervention in the existing infrastructure. So it is not only breweries that can benefit from easy retrofittability, flattening load peaks by buffer tanks and the option for using electricity from a local emission-free energy source – all food and beverage producers do as well. Preventing heat losses and using regenerative energy sources mean less fossil fuels are consumed, which in turn reduces a company’s dependence on volatile energy prices and helps ensure a reliable power supply