ABB’s state-of-the-art solution is based on the ORC (Organic Rankine Cycle) technology that enables turning exhaust gas heat into clean electricity. Thanks to the re-use of wasted heat as operating power, no fossil energy is required to run the power plant. Consequently, 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 has the know-how to fully integrate 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, states: “ABB’s heat recovery system will allow us to produce 10.5 gigawatt hours of electrical energy per year. This corresponds to the demand for energy of approximately 2000 households in Switzerland.”
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.
Cement production typically has an enormous demand for energy. The clinker burning kiln requires temperatures of up to 1500˚C. Despite the fact that the modern plant re-uses 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 solution is a new integrated system for the efficient utilization of low temperature waste heat in industrial plants. Waste air or stack gases with temperatures starting from only 150˚C can be economically used to generate power from 500kW up to double-digit megawatts.
Plant owners using ABB’s heat recovery system will benefit from lower operation costs thanks to an on-site, CO2-free power generation source, making them less dependent from rising energy prices. End users benefit from lower capital expenditures by using standard components that are installed quickly and effectively by ABB’s professional planning and project execution teams.