Nuclear radiation‐induced cracking of n ‐hexadecane

A representative paraffin hydrocarbon in the gas oil range, n ‐hexadecane, has been irradiated in the Industrial Reactor Laboratories' 5 mw. nuclear research reactor. In the vapor phase radiation‐induced cracking proceeded efficiently, and G values for radiation conversion of n ‐hexadecane were 200 to 1,200 at temperatures near 750°F. Total conversions of n ‐hexadecane were less than 3 wt. % and were due only in part to the radiation effect. The distributions of products which were obtained were similar to those which result from thermal cracking of n ‐hexadecane. There were however significant increases in the yields of hydroger., reductions in the yields of very light hydrocarbons and small yields of high molecular weight products. At temperatures above 850°F. extensive thermal cracking obscured the effects of radiation. In liquid phase radiation‐induced cracking at 750°F. conversions of n ‐hexadecane up to 15 wt. % have been obtained at liquid spaces velocities near 4 v./hr./v. In many exposures nearly one‐half of this conversion was attributed to the direct utilization of radiation. The corresponding G values were 30 to 60. The products obtained have been accounted for by adding together the products which would be expected from a radiation‐induced reaction producing primarily dimer, from radiation‐initiated chain propagated cracking, and thermally initiated chain cracking. The product distribution from these reactions can be changed by variation of the cracking temperature and/or radiation dose.