(446b) Applications for Microfibrous Entrapped Catalysts: VOC Oxidation at Microsecond Residence Times

Microstructured heterogeneous catalyst structures, prepared by the wet-lay paper making techniques, entrap small (150-200 μm dia.) catalyst particlulates of Pd/γ-Al2O3 into sinter-locked networks of metal (e.g., Ni) microfibers (4 and 8 μm dia.). These microfibrous entrapped catalysts (MFEC) with pleated configurations (W-structure) provide significant improvements in terms of pressure drop reduction and catalyst effectiveness. MFEC also improves interphase and intraparticle mass transport rates, as it can entrap small particles as well as eliminate flow maldistribution. Volatile organic compounds (VOCs) are harmful to humans. To provide controlled and improved air quality in aircraft cabins, VOC removal, by catalytic combustion is of strong interest. The abatement of VOC (i.e., n-hexane model compound) from a prototype aircraft cabin catalytic converter was investigated at typical face velocities (ca. 10 to 30 m/s) resulting intrabed/intralayer residence times from 67-200 µsec. This research focuses on unique structures of matter which attain high levels of VOC removal at correspondingly low levels of pressure drop. Pleated MFECs (1-2 mm) containing 0.5% Pd/ γ-Al2O3 are tested at operating conditions similar to those used in aircraft cabin air beneficiation. Pressure drop and n-hexane conversion at various flow rates (10-30 m/s) and temperatures (100-200ºC) are presented and a comparison is made with commercial monolith reactors of equivalent volume at various cpsi (100-900 cells per square inch). Also a conversion comparison has been made between noble metal (0.5% Pd) and transition metal (1% Mn) at the same operating condition.