Energy from Waste – Frying Fat Generates Electricity

2007-Jun-30 | Household and other waste can be used to produce energy on a large scale. In collaboration with various partners, Siemens has developed three types of plant for converting waste into fuels. As reported in the latest issue of the research magazine Pictures of the Future, the energy generated in this way is sufficient to supply thousands of households with heat and power.

The Berlin-based waste disposal company Alba AG, for example, converts 60 percent of the refuse that arrives at its waste treatment facility in Pankow (160,000 tons annually) into substitute fuels. The waste is dried in a large hot-air drum, ground into fine particles, and separated from nonflammable, recyclable substances. It is then pressed into fuel pellets that the company sells to power plants and other clients. Siemens supplies the software and the measuring technology for the coordination of the many machines involved.

Another energy-production system called Sipaper Reject Power from Siemens Industrial Solutions and Services (I&S) is used at a factory for recycled cardboard in Hirschwang, Austria. Non-recyclable, flammable residual substances with a relatively high moisture content can with the help of this combustion technology (featuring centrifugal wheel loading and grate firing) be combusted immediately. The resulting steam is converted into electrical energy via a turbine. Thanks to a flue-gas cleaning agent, emissions are cut to below the legally permissible threshold.

Also located in Austria is a combined heat and power plant set up by I&S and the energy service provider Wirkungsgrad Energieservice GmbH. The special feature of the plant in Dornbirn-Stöcken is that it converts used frying fat and cooking oil into electricity and heat. Three giant eight-cylinder heavy-oil motors and generators together produce four-and-a-half megawatts of power. Because the fuels originate from plants, the power generated is completely organic.