The oxidation of propane on nonstoichiometric calcium hydroxyapatites in the presence and absence of tetrachloromethane

The oxidation of propane on nonstoichiometric calcium hydroxyapatites has b een investigated in the presence and absence of tetrachloromethane (TCM) at 723 K. In the absence of TCM, the principal products were CO and CO2 and t he selectivity to propylene was found to depend on the stoichiometry. On ad dition of TCM to the feedstream, it was generally observed that the convers ion of propane and the selectivity to CO2 decreased with increasing time-on -stream, while the selectivity to propylene increased. Both the conversion and selectivities were dependent upon the partial pressure of TCM in the fe edstream, the stoichiometry and time-on-stream. The role of chlorinated spe cies is discussed. (C) 2000 Elsevier Science B.V. All rights reserved.