POWRE: Adsorption of Low Concentration Gaseous Mixtures

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

ABSTRACT Proposal No.: CTS-0074667 Proposal Type: POWRE Principal Investigators: Jane H. Davidson Institution: University of Minnesota POWRE: Adsorption of Low Concentration Gaseous Mixtures With the recognition that the air we breathe can adversely affect human health, there is increased interest in removing gaseous contaminants from indoor air by adsorption. Indoor air may contain hundreds of volatile organic compounds (VOCs) as well as inorganic gases, such as ozone, sulfur dioxide, and nitrogen dioxide, in trace (parts-per-billion, ppb) concentrations. The aim of this study is to explore the interactions between organic vapors and chemically reactive gases on an activated carbon adsorbent. The dynamic adsorption of a gas/vapor mixture of two organic compounds from different chemical families (toluene and dichloromethane) and ozone will be measured. Concentrations of the VOCs will be varied from 1 to 10 ppm. The concentration of ozone will be varied from 100 ppb to 1 ppm. Adsorbent capacities and equilibrium isotherms will be quantified for individual adsorbates and for several binary mixtures and one ternary mixture. Scanning electron microscopy and X-ray photoemission spectrometry will be used to analyze the carbon surface before and after adsorption. The presence of by-products will be assessed with mass spectrometry. These experiments will provide new data for mixed-component adsorption in a concentration range for which very few data exist. Breakthrough curves and isotherm data for ozone and for the mixture of ozone and VOCs will be the first available. The efficacy of predicting adsorption of mixtures using data obtained for the individual components will be appraised. The experimental results will be compared with existing dynamic models for mixed-component adsorption. Predictive model comparisons will ultimately aid the development of design guidelines for adsorption systems for indoor air purification and similar applications, as in automobiles and aircraft cabins.