Membrane-based integrated absorption - Oxidation reactor for destroying VOCs in air

This proof-of-concept research describes a novel membrane-based, integrated absorber-reactor operating at ambient temperature and atmospheric pressure. It degrades volatile organic compounds (VOCs) in a gaseous stream by ozonation in an inert stagnant fluorocarbon (FC) phase having a high ozone solubility. This FC phase acts as a reaction medium and a liquid membrane. The reactor has two sets of nonporous silicone capillaries. The VOC- containing gas flows through one set and supplies the VOC to the FC phase. The O₃-O₂ stream flowing through the other supplies O₃ to the FC phase. There is also a set of microporous Teflon tubules through which water flows removing oxidation products partitioning from the FC phase. With trichloroethylene (TCE), 60% conversion was obtained for 50 000 ppmv TCE in N₂ flowing at 30 cm³/min and 40% for 18 000 ppmv flowing at 50 cm³/min. For 220 ppmv TCE feed, 90% conversion was obtained at 20 cm³/min flow rate and 60% at 60 cm³/min. A conversion in excess of 97% was achieved for a toluene feed of 205 ppmv present in N₂ flowing at 11 cm³/min. No FC phase regeneration is required; it is constantly cleaned by the ozonation reactions. The materials of construction were found to hold up well under repeated experimentation.