Destructive Adsorption of Chlorinated Benzene on Ultrafine (Nanoscale) Particlesof Magnesium Oxide and Calcium Oxide

摘要

The exchange of oxide for chloride in the reaction of MgO or CaO with chlorinatedhydrocarbons has been investigated on a fully automatic reactor-GC-MS system. The presence of MgO or CaO allows destruction of chlorinated benzenes at lower temperature than simple pyrolysis or combustion processes. The presence of hydrogen as a carrier gas allows still lower temperatures to be employed. Decomposition have been observed for mono-, di-, and trichlorobenzenes over MgO and CaO of varying surface areas, and using helium, air, and hydrogen as flow gases. CaO induces more coupling of arenes and more carbon formation compared with MgO. A careful search for true toxins as products (particularly dioxins) was carried out. With low surface area CaO and air as a flow gas, dioxin and monochlorodioxin were produced in small amounts. However, nanoscale MgO did not allow formation of these toxic substances. jg p.1.