Catalytic Thermal Oxidizer (CTO)

In catalytic thermal oxidizer (CTO) the exhaust gas is initially pre-heated in the special recuperating heat exchanger and then achieves the necessary reaction temperature in the burner chamber working either on natural gas/propane or on electrical energy. Onward the exhaust air flows into the packed bed reactor filled by effective catalyst, which accelerates the reaction and dramatically decreases the temperature of VOC decomposition in water and carbon dioxide. The excess of heat is used for the pre-heating of inlet air flow and the auto-thermal operation can be simply obtained at sufficient concentrations of VOC.

During the reaction the chemical interactions occur between reactants (VOC) and active elements on the catalytic surface while the chemical composition of catalyst remains unchanged. Thus the catalyst keeps its efficiency for many years of operation.

Catalytic thermal oxidizer (CTO)
Schematic illustration of the process in CTO
Exhaust air flow 10.000 Nm3/h
Pollutant type, VOC Acetone/EtOH
Pollutant  heating value 30.000 kJ/kg
Pollutant concentration  0 – 12 g/Nm3
Exhaust air temperature 50 °C
Fuel type back-up burner Natural gas
Gas flow pressure 60 – 200 mbar
Oxidation temperature approx. 300 °C
Heat exchanger degree of efficiency 65  %
Gas consumption with 0/2/4 g/Nm³ solvent 35/24/13 Nm³/h
Gas consumption with 6 g/Nm³ solvent <2  Nm³/h
Average clean gas temperature ~130 °C
Remaining pollutant concentration total C < 20  mg/Nm3
Remaining pollutant concentration CO < 100  mg/Nm3
Remaining pollutant concentration NOx < 100  mg/Nm3
Electrical connection 380-410 V / 50 Hz / 3 Ph +N
Electric power requirement exhaust air fan 25 kW
Total installed power consumption 32 kW
Length x Width  x Height approx. [m] 5,0 x 2,3 x 2,2
Weight approx. 8 t


Company name / City
Gußstahl Lienen
Germany Germany
Germany Germany
St. Petersburg
Russian Federation Russian Federation
IPC Dresden
Germany Germany
Hüttlin / Apogepha
Germany Germany
Hüttlin / Apogepha
Germany Germany
Ask a question