Propylene combustion constants

Meta-4 A process for converting ethylene and 2-butene into propylene by metathesis. The process operates in the liquid phase at low temperatures in the presence of heterogeneous catalyst based on rhenium oxide on alumina. The catalyst is constantly regenerated by coke combustion. Developed by IFP and the Chinese Petroleum Corporation of Taiwan. A demonstration plant was operated from 1988 to 1990 and the process was demonstrated at Kaohsiung, Taiwan, in 1999. Now offered by Axens. 

Problem The standard heat of hydrogenation of gaseous propylene to propane is — 29.6 kcal., and the heat of combustion of propane is — 530.6 kcal. at 25 C. (Unless otherwise stated, constant pressure is to be understood.) Utilizing the... 

Substantial attention has been given in the literature to whether CO2 is formed directly by combustion of propylene (parallel), by oxidation of acrolein (consecutive), or both (parallel-consecutive). Results tend to indicate a parallel route at low temperatures and a consecutive or parallel-consecutive route at high temperatures. In reality the paraUel-consecutive holds, and it is only a question of the relative rate constants and kinetics for the two routes. It should be remembered that parallel effects will dominate at low conversions, and consecutive effects at high conversions, even when the rate constants for the two routes are about the same. 

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