Catalysts for Catalytic Oxidation
What is a catalyst? A catalyst is a substance that lowers the activation energy for a given reaction. When trying to oxidize hydrocarbons, carbon monoxide or VOC’s, the activation energy required for the combustion reaction is “Heat”. So in the case of catalytic oxidation, the amount of heat (activation energy) required to abate targeted compounds is lowered dramatically, compared to thermal oxidation.
To illustrate the power of catalysts, let’s look at the oxidation of formaldehyde:
CH2O + O2 → CO2 + H2O
Simple on paper, the oxidation of formaldehyde is quite difficult thermally, requiring temperatures in excess of 1500°F. Using a catalyst, this reaction can take place at less than 600°F. So as this example illustrates, the operating costs for a catalytic oxidation system can be 40 – 60% lower than with thermal oxidation.
Important design factors for catalytic oxidation include temperature (an operating temperature high enough to oxidize the target compounds across the catalyst), residence time (sufficient residence time in the catalyst bed for the oxidation reaction to occur – commonly referred to as Space Velocity or GHSV), turbulence or mixing of combustion air with the targeted compounds, the VOC concentration and species, catalyst characteristics, and the presence of masking agents in the effluent stream that can potentially reduce the effectiveness of the catalyst bed.
Many types and styles of oxidation catalyst are used in catalytic oxidation. Depending on the application or style of catalytic oxidizer to be employed, ceramic or metal monolith, spheres, extrusions, or RCO Catalysts may be the best fit for a given application. Contact Applied Catalysts to find out more.