Temperature patterns on a hollow cylindrical catalytic pellet.

Area of Science:

• Chemical Engineering
• Catalysis
• Reaction Engineering

Background:

• Atmospheric oxidation of carbon monoxide (CO) is crucial for pollution control.
• Understanding catalytic reactions on solid supports is vital for process design.
• Hollow cylindrical catalysts offer unique surface area and mass transfer properties.

Purpose of the Study:

• To investigate the atmospheric oxidation of carbon monoxide on a hollow cylindrical catalytic pellet.
• To analyze the resulting temperature patterns and reaction dynamics under varying conditions.
• To understand the influence of catalyst nonuniformity and transport phenomena on reaction stability.

Main Methods:

• Utilized a conical reactor for simultaneous temperature measurement on the pellet's top and side using an IR imager.
• Performed atmospheric oxidation of a 6 vol % carbon monoxide mixture.
• Observed transitions from a high-temperature ignited state to nonuniform states with temperature fronts.

Main Results:

• Observed intricate pulse splitting and extinction phenomena on both the top and side of the pellet.
• Demonstrated that catalyst nonuniformity and transport significantly influence temperature fronts and patterns.
• Reported highly irregular motions and conversions following a decrease in reactor temperature.
• Identified global coupling as a stabilizing factor for temperature fronts and patterns.

Conclusions:

• The atmospheric oxidation of CO on a hollow cylindrical catalyst is characterized by complex, dynamic temperature patterns.
• Catalyst and reactor design, including transport phenomena, critically affect reaction stability and behavior.
• Nonuniformity and global coupling play key roles in stabilizing intricate reaction patterns and fronts.