Low-Temperature Catalytic Oxidation of Airborne Organic Materials

摘要

Eltron Research Inc. has developed multi-component metal oxide catalysts for destruction of volatile organic compounds (VOCs) in air at low temperatures. The goal for this work is to produce a simple, cost-effective technology for reducing the concentration of VOCs in air to acceptable levels before the air is released into the atmosphere or recirculated. Specific applications include ventilated work spaces for spray painting and engine maintenance (degreasing and fuel line repair), indoor air decontamination, dry cleaning, food processing (grills and deep fryers), fume hoods, residential use, and solvent-intensive industrial processes. The components of the catalysts were chosen based on their anticipated oxygen surface mobility, moisture tolerance, multiple oxidation states, and documented activity for oxidation reactions. Catalyst powders and monolith- supported catalysts were screened for conversion of 1 -butanol, toluene, and MEK to carbon dioxide and water. The concentrations of VOCs in the feedstream were maintained at (caret)100 ppm, and the space velocity was (caret)6,000 hr(-1). Catalysts highlighted in this document generated complete conversion of 1-butanol to CO2 at l50C, 69% conversion at lOOC, and 15% conversion at 80C. For toluene, complete conversion was achieved at 200C, and greater than 30% conversion at 150C. Catalysts deposited onto cordierite monoliths retained their composition and activity, and were stable in humid air. However, sulfur- and phosphorous-containing compounds quickly poisoned these catalysts through formation of sulfates and phosphates.