What is the Difference Between a Regenerative Thermal Oxidizer and a Recuperative Thermal Oxidizer?August 17, 2019
While both are a type of Thermal Oxidizer, the difference between a Regenerative Thermal Oxidizer (RTO) and Recuperative Thermal Oxidizer is how these machines recover heat during the oxidation process. Each technology destroys pollutants by heating the dirty airstream to very high temperatures to destroy the hydrocarbons (VOC) in the airstream. Each utilizes heat recovery to reduce the gas use needed to heat the airstream. The method of recovering heat is significantly different between the two systems. Let’s compare the two type.….
|Characteristic:||Recuperative Thermal Oxidizer||Regenerative Thermal Oxidizer|
|Typical Heat Recovery||70%||95%|
|Flow Direction change||No||Yes|
|Heat exchange material||Metal- Stainless or exotic||Ceramic|
|Operating Temp (F)||1400||1600|
|VOC Destruction efficiency (VOC DRE)||99-99.99%||99+%|
What is a Recuperative Thermal Oxidizer?
A recuperative thermal oxidizer uses a familiar air-to-air metal heat exchanger to recover heat from the hot, cleaned air before it is exhausted to atmosphere. The recovered heat is utilized to pre-heat incoming, dirty air. The heat recovery is typically around 70%. Airflow is in one direction.
The benefit of using a Recuperative Thermal Oxidizer is the very high VOC destruction it offers; as high as 99.99%.
What is a Regenerative Thermal Oxidizer?
A regenerative oxidizer is much more complicated. A regenerative heat exchanger, by design, is much more energy efficient than a recuperative. It utilizes valves to create airflow reversals, two ceramic heat sinks (beds) to absorb and give off heat, and control logic to make it all work- achieving very high thermal efficiency. The exiting bed of the RTO absorbs heat from hot, cleaned air before it exhausts to atmosphere. The heat stored in this bed releases to the dirty cool air passing over it in the next half cycle, pre-heating this air before it enters the combustion chamber. Air is passed through the combustion chamber and VOCs are oxidized before exhausting to the atmosphere.
Recuperative Thermal Oxidizer or Regenerative Thermal Oxidizer – Which is Better?
Regenerative Thermal Oxidizers are by far the oxidizer technology of choice for most industrial air emission control applications. RTOs achieve very high VOC destruction, with the lowest operating cost. They also have the longest life and the highest reliability when compared to other thermal oxidizer technologies. However, for applications needing 99.99% VOC destruction a thermal recuperative oxidizer would be the better choice. Also, when heat recovery can be utilized to for heating a process (i.e. oven) running at 300 F or higher, a thermal recuperative oxidizer can sometimes rival RTOs in energy efficiency.