A Concrete Example Of Waste Heat
ABB Switzerland supplies heat recovery and electrical power production system to Swiss cement plant
ABB Switzerland and Holcim have reached an agreement for the installation of ABB’s newly developed heat recovery and electrical power production system at Holcim’s cement plant in Untervaz, Switzerland. Cement production is an energyintensive process, for example the clinker burning kiln requires temperatures of up to 1500°C. Despite the fact that the modern Holcim plant was already reusing most of the process exhaust heat for material drying, a significant amount of low-temperature gas is vented through the stack.
ABB’s heat recovery is a new, integrated system for the efficient utilization of low-temperature waste heat in industrial plants. The company said that waste air or stack gases with temperatures starting from only 150°C can be economically used to generate CO2-free power from 500 kW up to double-digit megawatts. ABB’s system is based on Organic Rankine Cycle (ORC) technology, which turns exhaust gas heat into clean electricity. With the reuse of fossil energy is required to run the power plant. Holcim’s Untervaz operation will be able to considerably reduce its energy costs and operate the plant more efficiently.
The contract comprises engineering, project planning, delivery, installation and commissioning of the complete turnkey package consisting of all power plant components such as turbine, generator and heat exchangers. ABB will be in charge of the full integration of the power plant into the entire cement production process, including electricity supply and the complete control system. The system is expected to be in operation at the end of 2011.
Markus Hepberger, plant manager at Holcim’s Untervaz operation, said, “ABB’s heat recovery system will allow us to produce 10.5 GWh of electrical energy per year. This corresponds to the demand for energy of approximately 2000 households in Switzerland.” The companies also reported that a future replacement of the existing planetary cooler will increase the power production up to 50%. Then the plant will need 20% less electricity to operate and will boost its productivity even further.