A kinetic study on the chlorination reaction of alumina with carbon deposited by thermocatalytic cracking

Abstract

Rates of chlorination reactions of floury and sandy aluminas with carbon deposited by thermocatalytic cracking have been investigated over the temperature range of 500°to 700°C. The experimental results obtained are summarized as follows:
(1) Reactivity for the chlorination of sandy alumina was superior to that of floury alumina.
(2) When the chlorination of sandy alumina was made under the optimum conditions: temperature 600°C, reaction time 60 minutes, amount of chlorine introduced 1.18 chemical equivalent to alumina, the recovery efficiency of aluminum chloride exceeded more than 95%.
(3) The chlorination reaction of sandy alumina sigmoidally proceeded with the prolonged time. The chlorination rate was accelerated by increasing temperature and the partial pressure of chlorine. The apparent activation energy calculated from an Arrhnius plot was 17.3 kcal/mol at the temperature range of 525°to 600°C. The ratedetermining step of the chlorination reaction may be a chemical reaction process rather than mass transport one.
(4) The chlorination rates of floury and sandy aluminas with carbon deposited by thermocatalytic cracking were much faster than those of the mixtures of active carbon and alumina measured by other investigators.