Adsorption and Catalysis on Carbonaceous Adsorbents-Electronic Factors.
Abstract
Two carbonaceous adsorbents made from polymeric materials were used in adsorption and catalytic oxidation experiments in the lab and the field. One was a phenolaldehyde based (Novoloid) fiber, Kuractive, used in a cloth or fabric form. The other was a sulfonated polystyrene divinylbenzene cross-linked polymer adsorbent, Ambersorb 572. Catalytic oxidation of trichloroethylene (TCE) at 110-250 deg C and space velocities of 36,000 to 73/hr (Empty Bed Contact Time, EBCT, 0.1 - 49 s) over plain and transition-metal-oxide impregnated Ambersorb 572 demonstrates the potential for this catalyst/support to convert TCE at low temperatures. The first step in the catalytic process appears to be the addition of a proton from the acid catalysis sites to the TCE, followed by non-specific attacks by the resulting carbenium ion or radical. High conversions were maintained at temperatures as low as 110 deg C, although there were numerous by-products. At temperatures above 180 deg C the plain adsorbent/catalyst was superior in performance over the metal-impregnated catalysts under the conditions in this study. Water in the feed stream has an immediate, reversible, poisoning effect on the performance of MTU-CAT, a thermally modified Ambersorb 572, and the transition metal-impregnated catalysts used in this study. However, the water poisoning effect was not noticed when the catalyst was the plain support, Ambersorb 572. Resistive or Joule heating was used to heat both adsorbents. This thermal energy can reduce the local humidity from the incoming gas without heating the entire air stream, regenerate the adsorbent, or provide the activation energy for the oxidation of the desorbing organics on catalyst sites in the adsorbent.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1996
- Accession Number
- ADA309136
Entities
People
- Edward G. Marchand
Organizations
- Air Force Institute of Technology