Thermal generation refers to the heat energy generation cycle. There are four combustibles for thermal energy, oil, natural gas, wood, and geothermal waste.
- The main disadvantage is that the thermal oxidation operates at 800-900 C compared with 250-350 C for the catalytic alternative.
- The high operating temperature also means that more energy must be added to the process as a supplemental fuel, compared to a comparable catalytic process. This contributes to a higher operating cost of the unit.
- Another disadvantage of the high operating temperature is that NO2 can be formed in the flame, perhaps requiring additional emission controls.
- For catalytic oxidation, the cost of the catalyst and its replacement due to premature deactivation ass to the cost. If deactivation can be minimized, catalyst replacement costs can be minimized.
- Thermal power depends on coal, oil or natural gas, which are all steady in supply.