Regenerative thermal oxidizers minimize fuel consumption by regenerating, or reusing, heat generated by the system. Prior to being exhausted to the atmosphere, the hot, purified air passes through a media bed to capture heat energy that will be used to pre-heat incoming air. RTOs can operate at thermal efficiencies of 85 to 99 percent, reducing or eliminating the need to burn natural gas in the combustion chamber. Once the system is sufficiently heated, the natural gas burners can be turned off if enough flammable gas is present in the exhaust stream.
A regenerative catalytic oxidizer (RCO) is similar in design to an RTO, except that the ceramic heat exchange media closest to the combustion zone is coated or impregnated with precious metals that function as a catalyst. The metals enable oxidation at significantly lower temperatures (600°F to 1,000°F). A catalytic system requires the presence of the type of VOCs that will oxidize at these lower temperatures.
By Paul Sims, Global Market Manager - Environmental at Koch Knight LLC. (Pollution Engineering, March 2009)