Visbreaking reaction of atmospheric residue. (Part 1). Distillate yields and properties of visbroken residue.

Abstract

Atmospheric residues from four representative crude oils were subjected to thermal cracking at 420-460°C in the presence of a diluent such as nitrogen, hydrogen, or tetralin, at 50kg/cm2. The rate of thermal decomposition of the residues increased in the following order: Taching <Arabian Heavy <Khafji <Iranian Heavy. The distillates (343°C), consisting mainly of kerosene and gas oil, were obtained in yields up to 15-25wt% on the feed. Significant changes in the physicochemical properties of the cracked residue such as the lowering of pour point, viscosity and average molecular weight were observed.