PYROLYSIS OF THE LOWER PARAFFINS: IV. THE CONVERSION OF GASEOUS PARAFFINS TO AROMATIC HYDROCARBONS IN BAFFLED QUARTZ TUBES

The polymerization of gaseous olefine mixtures, such as are obtained by the pyrolysis of the lower paraffins, has been studied by passing the gases through heated quartz tubes under conditions of streamline and of turbulent gas flow. It is shown that the observed rate of polymerization of the gaseous olefines to liquid hydrocarbons is appreciably higher, at a given wall temperature, under conditions of turbulent flow. By subjecting propane to two thermal treatments at a maximum temperature of 950 °C., 29% by weight of the gas is converted to liquids of which 70% boil in the gasoline range, and over 30% by weight of the propane is recoverable in the gaseous by-products as olefines, the total conversion into useful products being consequently about 60%. Substantially the same results have been obtained in single-stage recycling experiments.