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 pa rticle size 1.25 cm, specific area 205 m(2)/m(3), and specific heat capacit y 840 J/kg degreesC) as a solid regenerative material and K-type thermal co uples for measuring solid and gas temperatures, respectively. The catalyst bed temperature was kept around 400 degreesC and the gas superficial veloci ty was operated at 0.234 m/sec. This investigation measured and analyzed di stributions of solid and gas temperatures with operating time and variation s of volatile organic compound (VOC) concentrations in the regenerative bed s. The overall VOC removal efficiency exceeded 98% for MEK and 95% for tolu ene. Degradation of VOCs will exist for MEK on the surface of solid materia l (gravel) in the temperature range of 330-400 degreesC, but toluene does n ot exhibit this phenomenon.