EquiTherm – smart deployment of energy flows
The main consumer of energy in a brewery, next to the bottling hall, is the brewhouse. Thermal energy in particular, is required in various steps of the production process, such as mashing and wort boiling. But cleaning, too, and warm water generation/reheating are smaller but not-insignificant consumers of energy. In the brewhouse, this opens up a potential for substantial savings in terms of thermal and electrical energy.
During the brewing process, mash liquor, malt and hops are used to create the beer wort, which in the fermentation cellar is fermented into beer by the action of the yeast. For this purpose, in the first step of the production process, malt is milled, and mixed with water. The mash thus created is gradually heated up to various temperature levels, on each of which different enzymes of the malt operate, with the aid of which the starch contained in the malt grains is broken down into fermentable sugar. Once mashing has been completed, and the mash has been “saccharafied”, in the lauter tun the solid constituents are separated from the liquid phase, known as the wort. This is now fed into the wort copper, and boiled while hops are added. The boiling process enables the bitter aromatics of the hops to unfold their true potency. Unwanted aromatics are also removed by evaporation. After being boiled, the wort is clarified and then cooled down to fermentation temperature. This is followed by fermentation with a subsequent storage phase. Once the beer has finished maturing, it will either be filtered beforehand, or filled directly in bottles or kegs.
Energy-efficient brewing with EquiTherm
The EquiTherm process was developed at Krones’ Steinecker plant, and is designed to ensure multiple use of the heat employed in the brewing operation, for maximised efficiency. For this purpose, an additional stage has been interpolated at the wort cooler, so as to recover energy at approximately boiling temperature and buffer it in an energy storage tank. With this wort, still at a high temperature, warm water can be generated at about 80°C, while simultaneously the wort is cooled down to fermentation temperature. By using an innovative mash kettle with a particularly effective heating surface, the mash can be heated up completely using the heat buffered in the energy storage tank, despite minimised temperatures of the heating agents. This means there are 30-per-cent savings of primary energy in the brewhouse, thus sustainably downsizing the environmental impact while simultaneously reducing the costs involved. Worldwide, more than 10 million hl of beer are meanwhile being brewed each year with EquiTherm, e.g. since 2010 at the Bergquell Brewery in Löbau and since 2012 at the C. & A. Veltins Brewery.