5.7 Exhaust Gas for Combustion Air
Combustion reactions are highly exothermic. However, their reactants (fuel and oxidant) continuously absorb considerable energy to reach proper combustion temperatures. Exhaust gases from a prime mover, particularly from a gas turbine (because of its high oxygen content), provide an excellent preheated oxidant. These gases can be considered as an oxidant source for combustion of fossil fuels used in most heating applications including steam generators or boilers. This is shown in a schematic in Figure 5-9.
Figure 5-9 – Exhaust Gas for Combustion Air for a Boiler System
5.7.1 Processes Uses
Applications for using exhaust gases as an oxidant include:
- Central boiler systems
- Waste VOC incineration systems
- Kilns
- Calciners
- Large ovens
- Large heat treating operations
- Large furnaces
- Forging operations
- Tempering operations
- Annealing operations
- Cupolas.