Why is Heat Recovery Important?
While electrical energy can come from renewable sources such as solar or wind, much of industrial heat is still generated using fossil fuels, which entails direct CO₂ emissions.
Implementing heat recovery systems reduces the need to produce additional heat, thereby lowering both fuel consumption and associated emissions.
This approach not only improves industrial energy efficiency but also contributes to global climate change mitigation goals.
Benefits of Heat Recovery in Industry
Heat recovery offers concrete advantages for both companies and the environment:
Reduces energy demand and CO₂ emissions.
Lowers operating costs by reusing heat that would otherwise be lost.
Eliminates or minimizes the need for cooling towers, also reducing their energy consumption and maintenance costs.
Frees up physical space and improves operational safety by minimizing hot spots in the plant.
Industrial Applications of Heat Recovery
This concept can be applied across multiple sectors and industrial processes. Some of the most common examples are:
Application Examples:
Air compressors: Recovery of heat generated during compression to preheat intake air or water.
Boiler blowdowns: Use of hot blowdown water to preheat feedwater.
Exhaust gases: Recovery of heat from hot gases from furnaces, engines, or turbines to generate steam or preheat air.
Chillers: Reuse of residual heat for process heating or sanitary hot water.
Cooling towers: Partial heat recovery through heat exchangers for heating or preheating fluids.
Moist drying air: Use of heat from outgoing air to preheat incoming air.
Flash steam: Utilization of heat released during the expansion of steam from high to low pressure.
Available Technologies for Heat Recovery
There are different solutions depending on the process type and characteristics of the residual heat available:
Heat exchangers: Ideal for exhaust gases or hot fluids.
Cogeneration and trigeneration systems: Allow simultaneous generation of electricity, heat, and cooling from a single source.
Flash steam recovery units: Capture heat from steam expansion to reuse it in secondary processes.
These technologies maximize energy utilization and reduce dependence on new heat sources.
Double Savings: Energy + Auxiliary Equipment
One often overlooked benefit of heat recovery is the potential to eliminate or reduce auxiliary equipment such as cooling towers.
By reusing residual heat, the need to dissipate it to the environment is reduced or eliminated, which:
Lowers electrical consumption of pumps and fans.
Decreases maintenance and water treatment costs.
Frees up plant space and simplifies operations.
