Volatile organic compounds (VOCs) removal over dual functional adsorbent/catalyst system

This study is focused on the elimination of tetrachloroethylene (PCE) and methylethylketone (MEK) by adsorption/catalytic oxidation in humid conditions using zeolites as adsorbent and catalyst. Adsorption experiments have led to the conclusion that HFAU(17) zeolite was a very efficient adsorbent for the removal of PCE and MEK. Furthermore, complete transformation of PCE into CO2 and HCl was achieved at 500 °C over 1.2%Pt/HFAU(5). MEK was completely converted into CO2 at 220 °C over 1%Pt/NaX, without formation of CO. Formation of coke occurs during MEK oxidation reaction, especially over acid catalyst, and at low reaction temperature. Furthermore, it was pointed out that water has a negative effect on MEK conversion. Lastly, adsorption/catalytic oxidation of PCE and MEK was performed over a dual functional HFAU(17)-Pt/FAU adsorbent/catalyst system. The adsorption step was performed at 30 °C with an HFAU(17) adsorbent, and the oxidation step was carried out at 450 °C for PCE with 1.2%PtHFAU(5), and at 250 °C for MEK transformation with 1%PtNaX. It appeared that the adsorbent-catalyst couple remains efficient for MEK transformation during successive adsorption/oxidation cycles.