Harald Raupenstrauch, Graz University of Technology, Inffeldgasse 25, Graz, 8010, Austria, Stefan Radl, Chemical Apparatus Design, Process Engineering and Combustion, Graz University of Technology, Inffeldgasse 25, Graz, 8010, Austria, Helmut Antrekowitsch, Nonferrous Metals, University of Leoben, Franz-Josef-Strasse 18, Leoben, Austria, and Franz Rotter, Austria Metall AG, Ranshofen, Austria.
The production of ferrous and non-ferrous metal products is highly energy intensive. Therefore the annual costs for electricity and fossil fuels like natural gas are remarkable. For ecological and economical reasons (CO2-certificates, fossil fuel supply, etc.) these costs will rise dramatically within the next future. However, the considered branch is in an exceptional position since there exists a high potential for substitution of energy sources, heat recovery and process optimization. However, the main questions are: Can this potential be utilized and what would be the most ecological and economical concept? The basis of developing a new energy concept is an intensive analysis of the actual situation of the considered company. Exemplary the Austria Metall AG (AMAG) was investigated and new concepts were proposed. The AMAG has been a technological orientated company in the aluminium branch for the past 60 years. The content of this contribution will be: o Characterisation of the main heat consumers concerning amount, temperature range and potential of synchronization of waste heat and heat demand. Aggregates covered are for example melting furnaces, pre-heater for pig aluminium as well as scrap aluminium, etc. o Overview of possible concepts, e. g. combined heat and power cycles based on gas engines, gas turbines, the Organic Rankine Cycle (ORC), etc. o Evaluation of these concepts concerning ecological and economical feasibility o Sensitivity analysis of selected concepts with respect to trends of gas and electricity prices. o Effects on the sustainability of the aluminium process