Document Type

Thesis

Date of Award

5-31-1991

Degree Name

Master of Science in Environmental Science - (M.S.)

Department

Chemical Engineering, Chemistry and Environmental Science

First Advisor

Henry Shaw

Second Advisor

Robert J. Farrauto

Third Advisor

Richard B. Trattner

Abstract

The catalytic oxidation of chlorinated hydrocarbons CH2Cl2 (DCM) and C2HCl3 (TCE) was investigated over a 1.5% Pt on Al2O3/monolith at 150 to 450°C. The studies were conducted at space velocities from 1,000 v/v/hr to 30,000 v/v/hr. Chemical equilibrium calculations showed the potential conversion and products distribution. The reactivity and selectivity for destruction of these compounds with air over Pt catalyst were evaluated experimentally. This research was conducted in a tubular reactor system with associated feed and product flow measuring equipment. Feed and product streams were analyzed using gas chromatography (GC) with ECD, FID and TCD detectors. The conclu-sions from the studies are:

  • The light off temperature is 200°C for CH2Cl2 at 1020 v/v/hr space velocity and 325°C for C2HCl3 at 30,000 v/v/hr space velocity.
  • Over 99% conversion of DCM is achieved at 400°C and 1020 v/v/hr, and 95% conversion of TCE is achieved at 450°C and 30,000 v/v/hr.
  • Temperature and space velocity are the key parameters for oxidation of chlorinated hydrocarbons.
  • The statistics activation energy for oxidizing C2HCl3 is 20 + kcal/mol.
  • Both water and methane strongly influence the selectivity of TCE oxidation to HCl.
  • Carbon and chlorine balances for oxidation of C2HCl3 are within 100+10%.
  • No significant CO formation is observed.

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