There are a number of reasons why breweries should invest in energy saving measures. Energy prices will rise in the medium term, which will further reduce the amortization period. And even if climate change is, according to some, a natural phenomenon, it cannot hurt to be more economical with our resources, explains Alexander Hinds, process specialist engineer at Krones.
There is no doubt about it that beer is energizing mind and body of those who are enjoying this masterpiece of natural beverage production. But before this can happen a lot of technological knowledge and energy is required to accomplish the brewing process. The energy consumption of beer production is comparable high.
Heat in the brew house and refrigeration for the cellar are the major consumptions which are defining the CO2 foot print of the brewery. But furthermore, the production costs and not least the quality of the beer are linked to the energy consumption. With the reduction of energy consumption, each brewery can realize several advantages at the same time and commercialize this commitment successfully.
Because the awareness of consumers for healthy and sustainably produced products is becoming an increasingly important aspect for the success of a company. In order to reduce energy consumption, breweries have two options: to reduce demand by technological measures or to recover the energy already used in the best possible way.
There is no question that a modification of the technology inevitably changes the beer character. So the recovery remains as the only real alternative.
The thermal energy in the brewhouse is needed for the mashing process and wort boiling. The simplest form of energy recovery is already realized by all breweries in wort cooling. The cooling water is heated up by the wort to about 80 – 85 °C and reused for mashing in, sparging and for cleaning. However, far more warm brewing water is gained than is needed. Not infrequently, the hot water tank overflows already in the middle of the production week and water and energy disappear into the drain.
This can be avoided by the EquiTherm system. It recovers the surplus energy of the wort at a separate stage of the wort cooler and supplies the mash kettle with this energy. Depending on the mashing program up to 100 % of the required thermal energy can be covered by the recuperated energy. In addition, the hot water surplus is eliminated and neither energy nor water will be lost in the future.
EquiTherm can be retrofitted into existing brewhouses. For this purpose, the heating surfaces of the mash kettle are replaced by pillow plates, which allow a high heating capacity at low heating medium temperature. Furthermore, the wort cooler is supplemented with a separate stage. The recovered energy is buffered in the form of hot water at 96 °C in an energy storage tank.
From here, the kettle is then supplied during mashing. Since an energy storage tank is required for EquiTherm, the energy of the vapors of the wort boiling can now also be recuperated. For this purpose, a vapor condenser is needed, which condenses the vapor with water from the energy storage tank.
This water is also heated to 96 °C and is stored in the energy storage tank. With this energy, the lauter wort is preheated to about 92 °C before the boiling process. A holding vessel is needed at a high brewing rate, but is not absolutely necessary. The following figure shows the combination of both systems in a brewhouse.
Based on a standard brewing process with mashing in temperature of 50 °C, a total evaporation of 4 % and a cast gravity of 15 °P the thermal energy consumption in the brewhouse is around 8,0 kWh/hl cold wort. With EquiTherm, the demand can already be significantly reduced to 6,0 kWh/hl of cold wort. In combination with the vapor condenser, only 4,0 kWh/hl of cold wort is required. At current energy prices, the return on investment of retrofitting is in the range of 3 to 6 years. In addition to the financial aspect, there are also a number of technological advantages through retrofitting.
When mashing, the thermal load is significantly reduced in the heating processes, since instead of steam with temperatures of 130 – 150 °C hot water of maximum 96 °C is used. This causes a significant decrease in the fouling of the heating surfaces, which is why the heating power remains constant over the entire week.
The heating of the lauter wort with reduced temperature in the heating medium improves the wort quality significantly. Lighter beer colors, longer flavor stability and more stable foam (of course only in countries where beer is also tapped with foam) are mentioned here in the first place. These were just three examples of how energy in the brewing process can be recycled.
But there are certainly in each brewery far more individual ways to reduce consumption. Energy consultants specializing in breweries can help find these potentials and develop solutions for their implementation.
So there are a number of reasons why breweries should invest in energy saving measures. Energy prices will rise in the medium term, which will further reduce the amortization period. And even if climate change is, according to some, a natural phenomenon, it cannot hurt to be more economical with our resources.
