German engineers have found a greener way of brewing amber nectar.
Scientists at the Technische Universitaet in Munich (home of the Oktoberfest beer festival) are creating a new brewing process that could cut down on the amount of energy needed to produce beer.
For more than a hundred years, the brewing process has involved boiling giant kettles to temperatures of upto 160C to boil down 'crude beer' or wort. The scientists say that about 45 per cent of the energy consumed by breweries is used for this process.
Instead the Bavarian team have adapted an approach using combined heat and power stations, which harness the heat produced during power generation. The technique had already been tried, but on its own it couldn't heat the kettles to the necessary temperature. The new system combines the CHP station with what the TU München scientists call a ‘zeolite storage system’.
This consists of thousands of zeolite spheres, two to three millimetersp in diameter. "These porous pellets are made of silicate minerals and have excellent heat storage properties," the team reports. "One gram of zeolite has an internal surface of about 500 square meters."
When zeolite that has been soaked in water is heated, the spheres dry up, charging up the system. Once water is added again, the zeolite spheres release heat of up to 250C, according to the researchers.
On its own, the combined heat and power (CHP) station can achieve temperatures of 90C, but this thermal-chemical process boosts it to the levels needed for brewing.
Dr Winfried Russ, the project leader, says: "At night a medium-sized brewery needs little energy. In this time we can feed unused heat from the CHP station into the zeolite storage system." When the heat is needed the next day, the brewers can just hit a button and get the heat boost they need."
The system has been tested using simulations and now real-world tests are underway. Russ is eager to see the results: "We already know that it will work. What we don’t know is just how much energy can be saved."
The technology will be on display at the Drinktec 2009 trade fair in Munich from September 14 to 19.