In a nutshell, industrial drying plants are mainly operated by burning fossil energy sources and product waste. The moisture (e.g. water) extracted from the material to be dried is in most cases released into the environment in pure gaseous form or with a drying medium such as air, steam. This exhaust air contains high amounts of energy, which could easily be reused, but is rarely done due to inefficient systems.
By using a heat pump in the drying process where there is a combined heating and cooling load, residual heat is recovered and delivered back into the drying process in the form of de-humidified and re-heated air. This not only improves the overall efficiency of the system, it also reduces the need for of fossil fuels as the primary energy source and contributes to reduced operation cost, lower local emissions and better control of the temperature in the drying process, often times leading to enhanced quality of the products.
More detailed information about heat pumps in industrial drying processes is available in the Knowledge Hub and on the following links: