THE FORMATION OF PROPENE OXIDE FROM THE COOXIDATION OF PROPENE AND ACETALDEHYDE

Experiments have been conducted to seek ways to enhance the selectivit y of propene oxide in the autoxidation of propene in the gas phase. Th e experiments were carried out in two systems, one static and the othe r a continuously stirred tank reactor, in order to obtain a wide range of conditions. The results reported in this paper have been obtained between 505 and 549K and pressures of 0.9 to 55 bar. Monitoring the pe rturbation in the product distribution shows that the selectivity of p ropene oxide is increased markedly on decreasing the temperature. Addi tion of acetaldehyde to propene: oxygen mixtures, by providing an addi tional source of peroxy radicals, enhances further the yield of epoxid e to the extent that the process could be made commercially viable. Ad dition of formaldehyde was found not to increase the epoxide selectivi ty, as its oxidation does not provide an additional source of peroxy r adicals. A previously published reaction scheme, constructed to model propene oxidation at low pressures (<4 bar) was tested by simulation o f the co-oxidation and high pressure experiments reported here.