The term energy recovery, or energy recuperation, describes the recovery of energy that occurs as a waste product of various production processes and would otherwise remain unused. This energy can be thermal (e.g. heat), mechanical (e.g. movement or pressure) or electrical (e.g. electricity). Such energy represents an important resource, causing companies to implement specific recovery systems. Energy recovery contributes significantly to the energy efficiency of production plants. Throughout most energy-intensive industries, the production processes create thermal energy as a waste product. To reuse this otherwise unused thermal energy, companies implement heat exchangers or thermal heat pumps to recuperate this energy.

The recovery of thermal energy is based on the principle of transferring heat from one medium to another based on temperature gradient. These two media are usually air, gas or a thermally conductive liquid. One medium, the so-called carrier medium, is located in the recuperation system. In a heat exchanger this is usually a liqui or air. The carrier medium runs through piping, which are arranged in a snake-like pattern inside the heat exchanger. The second medium carrying thermal energy, e.g. the process exhaust air, then flows in between the piping in a set angle. During this process the thermal energy of the exhaust air is transferred to the carrier medium inside the piping. Afterwards, the energy is released into the environment or incoming fresh air. This system of energy recuperation runs in a continuous cycle.

The most common types of heat exchangers are based on the co-flow, cross-flow or counter-flow principles. Which type offers the most efficient solution for the individual production plant depends on different requirements. However, to prevent exhaust air from igniting or deflagrating due to contained gases, the exhaust air passes through a high-performance precipitator first before entering the heat recovery system. This way only the purified exhaust air enters the recuperation system.

By recovering heat, production plants sustainably reduce their the energy consumption. Recovered energy can be used for subsequent processes or, in the case of thermal energy, to heat the production hall and other buildings. This lowers the consumption of fossil fuels – which in turn improves the life cycle assessment of a company.