Steam cracking of coal-derived oils and model compounds: 2. Cracking of hydrogenated coal-derived oils

Coal-derived oils of different degrees of hydrogenation and of different boiling ranges as well as a petrol-based gas oil (for comparison) have been thermally cracked at 830 °C with a residence time of 0.14s. Hydrogenated coal-derived middle oil yields less light olefins than gas oil (32 versus 40 wt%) but substantially more BTX aromatics (21 versus 7 wt%). The amount of olefins (42 wt%) from hydrogenated coal-derived light oil is higher and that of BTX aromatics (16 wt%) is slightly less than obtained from middle oil. Perhydrogenated coal-derived middle oil (> 99% saturated compounds) has been cracked within a wide temperature- and residence time range to verify the applicability of two crack severity functions designed to represent the product distribution. The latter are compared with that of t-decalin and naphtha.