Analytical Techniques for Evaluation of Oxidation Catalysts for the Abatement of Paint Bake Oven Emissions

Abstract

The abatement of paint bake oven emissions using oxidation catalysts operated at low temperature (500°-600°F) offers significant energy savings relative to traditional incineration. Pilot testing in the field offers the advantage that the actual vapor stream is utilized to evaluate the catalyst. To this end, four low temperature catalysts based on three different substrates have been evaluated onsite for hydrocarbon solvent abatement efficiency. One of these experimental catalysts is effective in our pilot tests at 550°F even on an exhaust stream containing only 100 ppm (v/v-as propane) total hydrocarbons.

In order to evaluate oxidation catalysts, a comprehensive program of vapor stream chemical analysis and catalyst surface analysis was necessary. Vapor stream chemical analysis included methane/nonmethane total hydrocarbon determination, gas chromatography- mass spectrometry and Fourier-transform infrared spectroscopy. Since it would not have been possible to pilot test each catalyst for a full year, methods of projecting effective lifetime after only a few weeks of on-site testing had to be utilized. The techniques employed were electron spectroscopy for chemical analysis, gas chemisorption, scanning electron microscopy, and x-ray fluorescence.

This paper addresses the problems of on-site engineering and analysis, off-site chemical and physical analysis, and the performance of four different catalysts for the low temperature oxidation of enamel paint bake oven emissions.