Regenerative catalytic oxidizers (RCOs) combine the recovery characteristics and heat storage of regenerative thermal oxidizers (RTOs) with the low operating temperature of catalytic oxidizers. This combination provides the lowest operating cost volatile organic compound (VOC) oxidation technology available for applications with low VOC concentrations.
Schematic of Recuperative Catalytic Oxidizer
A catalytic oxidizer is a type of oxidation system that is similar to thermal oxidizers. This type of oxidation system is also known as a catalytic incinerator.
A catalytic oxidizer promotes oxidation using a catalyst. Catalytic oxidation is a chemical reaction between a precious metal catalyst bed internal to the oxidizer system and VOC hydrocarbon molecules. Catalysts accelerate rates of chemical reactions. The acceleration allows reactions to occur normally between 644 °F (340 °C) and 1,004 °F (540 °C).
Regenerative Catalytic Oxidizers Allow Lower Operating Temperatures
The catalyst can be used in a regenerative thermal oxidizer (RTO) to allow lower operating temperatures. This is also called regenerative catalytic oxidizer or RCO. For example, the thermal ignition temperature of carbon monoxide is normally 609 °C (1,128 °F). By utilizing a suitable oxidation catalyst, the ignition temperature can be reduced to around 200 °C (392 °F). This can result in lower operating costs than an RTO. Most systems operate at the 500 °F (260 °C) to 1,830 °F (1,000 °C) degree range. Some systems are designed to operate both as RCOs and RTOs. When these systems are used, special design considerations are utilized to reduce the probability of overheating (dilution of inlet gas or recycling), as these high temperatures would deactivate the catalyst, e.g. by sintering of the active material.
Recuperative Catalytic Oxidizers Lower Fuel Requirement
Catalytic oxidizers also work as a form of heat recovery that effectively lowers fuel requirement. The recuperative catalytic oxidizer passes hot exhaust gases from the catalytic oxidizer through a heat exchanger. This heats incoming new air to the catalytic oxidizer.