Date of Award

Spring 1986

Document Type

Dissertation

Degree Name

Doctor of Engineering Science in Chemical Engineering

Department

Chemical Engineering

First Advisor

Joseph W. Bozzelli

Second Advisor

Edward Charles Roche, Jr.

Third Advisor

Gordon Lewandowski

Fourth Advisor

Wing T. Wong

Fifth Advisor

E. S. Geskin

Abstract

Four catalytic dechlorination reactions were studied experimentally using a fixed-bed reactor at atmosphere pressure. Reaction mechanisms were proposed, and the kinetics modelled.

The first reaction is 1,2-dichloroethane with hydrogen over zeolite catalyst. Catalyst deactivation models were examined.

The second reaction was between 1,2-dichloroethane and hydrogen over palladium catalyst on alumina support. Formation of two intermediates on the catalyst surface is proposed, which then produced ethane, ethylene, and ethyl chloride. Higher conversion to ethane and ethylene was observed at temperatures above 218°C while conversion to chloroethane is higher at temperatures below 218°C. The activation energy was found to be 15 Kcal/gm-mole.

The third reaction was between chloroform and hydrogen over palladium on alumina. Once again, a free radical mechanism was also proposed to interpret the product formation of methylene chloride and methane. The activation energy is 19 Kcal/gm-mole, and conversions up to 12 % were observed.

The fourth reaction was between chlorobenzene and hydrogen over palladium on alumina catalyst. Benzene and biphenyl were the main products at temperatures between 35 and 70°C. An absorbed resonance mechanism is suggested for interpreting the production of benzene and biphenyl. A simple first order reaction model for chlorobenzene was used to obtain kinetic parameters. The activation energy was found to be 13 Kcal/gm-mole.

The relatively low temperature requirements, and low activation energies, indicate that these catalyst systems could be used in an effective process for conversion of aromatic chlorinated species into hydrocarbons plus hydrogen chloride.

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