No abstract

The first part of this paper concerns the thermal cracking of ethane in a pilot plant, under conditions representative for industrial operation, and the second part deals with the cracking of mixtures of ethane and propane. The rate of cracking of ethane is found to be decreased by the addition of propane, while the rate of propane cracking is slightly increased by the presence of ethane. Correlations are given for the rate coefficients of ethane and propane cracking in the mixtures. Global rate coefficients are also given. The product distribution was determined as a function of the reaction conditions and the mixture composition. The deviations from the pure additivity behavior are explained and correlated. A molecular reaction model was derived from the experiments. It permits a successful simulation of the cracking of ethane and mixtures of ethane-propane in industrial reactors.

The kinetics and product distributions of the thermal cracking of binary and ternary mixtures of ethane, propane, nand i-butane were determined in a pilot plant under conditions of residence time, temperature, total pressure, and dilution as close as possible to those prevailing in industrial operation. The kinetics and yields observed with ternary mixtures were compared with those obtained with binary mixtures and with pure components. The experimental selectivities were compared with those which would be obtained from separate cracking and subsequent addition of the product streams. The deviations between the two can be predicted by means of the so-called global kinetics selectivities, which are based upon the selectivities obtained from the pure components cracking and upon the global rates of cracking of the feed components in the mixture.