Chlorination and dehydrochlorination reactions relevant to the manufacture of trichloroethene and tetrachloroethene. Part 1: Reaction pathways

Sutherland, I. W., Hamilton, N. G., Dudman, C. C., Jones, P., Lennon, D. and Winfield, J. M. (2011) Chlorination and dehydrochlorination reactions relevant to the manufacture of trichloroethene and tetrachloroethene. Part 1: Reaction pathways. Applied Catalysis A: General, 399(1-2), pp. 1-11. (doi: 10.1016/j.apcata.2011.02.035)

Abstract

Factors which affect the selectivity of the chlorination of 1,2-dichloroethane and the associated dehydrochlorination reactions have been examined using approximate thermodynamic calculations, equilibrium measurements, and a continuous flow micro-reactor. There is a balance between surface and gas-phase chemistry within the system. Heterogeneous catalysis is not necessary to effect dehydrochlorination of 1,1,2,2-tetrachloroethane to trichloroethene but an attapulgite-supported copper(II) chloride catalyst favours formation of pentachloroethane and its dehydrochlorination product, tetrachloroethene. The latter is the thermodynamic minimum of the system. Below 473 K and with long reaction times (2 h, batch reactor), radical chlorination to form pentachloroethane is dominant. Above 573 K and under flow conditions, free radical dehydrochlorination to form trichloroethene becomes dominant. Heterogeneous chlorination under flow conditions provides a route to pentachloroethane and thence tetrachloroethene. High conversions favour the formation of oligomeric products.

• Item Type: Articles
• Keywords: Chlorination, dehydrochlorination, attapulgite, copper(II) chloride, homogeneous catalysis, heterogeneous catalysis
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Winfield, Professor John and Lennon, Professor David
• Authors: Sutherland, I. W., Hamilton, N. G., Dudman, C. C., Jones, P., Lennon, D., and Winfield, J. M.
• Subjects: Q Science > QD Chemistry
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Applied Catalysis A: General
• Publisher: Elsevier BV
• ISSN: 0926-860X
• ISSN (Online): 1873-3875
• Published Online: 08 March 2011