Electricity: how to take advantage of the heat generated by industrial processes?

Approach used by POWHER project based on Organic Rankine Cycles

The current need to reduce pollutant emissions and mitigate the effects of climate change calls for innovative avenues in the field of electricity production. Paradoxically, in industry, significant amounts of heat are lost to the environment by energy-intensive processes such as those in glass, cement, metals, paper and food. This neglected resource could instead represent a significant contribution to decarbonisation, with an estimated potential of 5% of the EU’s total electricity needs. This is equivalent to the electricity consumption of 20,000,000 households or the production of 19 large power plants.

Exploiting this possible energy source is the objective of the POWHER project, coordinated by Prof. Andrea Spinelli and Prof. Alessandro Romei of the Department of Energy at Politecnico di Milano and financed by the European Union (Next Generation Europe) within the framework of the Research Projects of Significant National Interest (PRIN – MUR).

Exploiting waste heat from industry is crucial for a sustainable energy future. POWHER aims to turn this potential into reality with innovative solutions.

The approach used by the POWHER project is based on Organic Rankine Cycles (ORCs), a technology similar to traditional steam cycles which uses the vaporisation of an organic fluid instead of water. This choice allows the construction of simpler and cheaper systems with good conversion efficiencies.

The focus of researchers at Politecnico di Milano and the University of Bologna is the implementation of Partial Evaporation Organic Rankine Cycles (PE-ORCs), an innovative version of ORCs. This solution could increaseefficiency by up to 30% through incomplete evaporation of the organic fluid. Both theoretical and experimental studies will focus on overcoming the challenges that have so far hindered the adoption of this technology: the development of efficient turbines for two-phase (liquid-vapour) fluids and the optimisation of plant control strategies.

The experimental activities will take place at the Test Rig for Organic VApors (TROVA) at Politecnico di Milano, one of the few experimental apparatuses in the world suitable for studying the motion of organic fluids at high speed and temperature.

The POWHER project thus promises to be an important step towards a sustainable energy future, making innovative use of an often neglected resource and paving the way for efficient power generation solutions.

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