This master thesis is based on a real project for an industrial client of SENER that works in the field of metallurgy. The main objective is to provide initial recommendations and feasibility study on how to best utilize the waste heat that is available in the exhaust gasses from the production processes of the client. This would be done by improving the energy efficiency of the site by means of Waste Heat Recovery (WHR). The recovered heat would be used to drive a steam turbine that produces electricity, as no thermal uses of this heat are available in the installation. Furthermore, this thesis also aims to quantify the positive environmental impact of the WHR system, and how many tons of CO2 emissions would be avoided. Additionally, due to large fluctuations in the mass flow rate of the exhaust gasses, a thermal energy storage might be introduced in order to balance the supply. Two different energy storage systems will be analyzed: steam accumulation and molten salts. The scientific fundamentals of this thesis are based on the science of thermodynamics, or more precisely, mass and energy balances. They would have to be done on each individual component, as well as a global balance. This is done mainly with the help of the “Thermoflex” software, which is used to model the system. However, for some equipment, in-house tools have been developed, in order to understand their behavior and temporal evolution. In order to obtain the properties of the fluids, the open source library CoolProp has been used. The obtained results from the analysis suggest that there is a potential for the implementation of a WHR system. Such a system could yield more than 160000 MWh of yearly production of electricity. Depending on the electricity prices, this amount of electricity produced could be valued at more than 10 million euros. Furthermore, by using waste heat as source of energy, essentially a carbon-free electricity would be produced, which would save approximately 8600 tCO2 emissions. To conclude, it has been decided that such a project is worthwhile pursuing into more detail. This would imply contacting manufacturers of components, basic and detailed engineering, as well as giving a firm offer to the client. However, it should be noted that other factors have to be taken into consideration, such as the treatment of exhaust gasses and to which degree they can be used. This could be a limiting factor, for maximizing the energy efficiency of the entire site
