Performance characteristics of a regenerative catalytic oxidizer for treating VOC-contaminated airstreams

A pilot apparatus of a regenerative catalytic oxidizer (RCO) equipped with two electrical heaters and two 20-cm i.d. x 200-cm height regenerative beds was used to treat methyl ethyl ketone (MEK) and toluene, respectively, in an airstream. The regenerative beds were packed with gravel (approximate particle size 1.25 cm, specific area 205 m2/m3, and specific heat capacity 840 J/kg degree C) as a solid regenerative material and K-type thermal couples for measuring solid and gas temperatures, respectively. The catalyst bed temperature was kept around 400 degrees C and the gas superficial velocity was operated at 0.234 m/sec. This investigation measured and analyzed distributions of solid and gas temperatures with operating time and variations of volatile organic compound (VOC) concentrations in the regenerative beds. The overall VOC removal efficiency exceeded 98% for MEK and 95% for toluene. Degradation of VOCs will exist for MEK on the surface of solid material (gravel) in the temperature range of 330-400 degrees C, but toluene does not exhibit this phenomenon.