Thermal Cracking of Kerosene and Heavier Petroleum Fractions by Pneumatic Transport Reactor

Abstract

A bench scale unit of pneumatic transport reactor was tested for thermal cracking of kerosene and heavier petroleum fractions. The reactor consisted of a stainless steel tubing, inside diameter of 16mm and length of 20m, which was housed in a furnace as 20 turnings spiral of 32cm in diameter. Sand was used as the suspending solid. Cracking was carried out at temperatures ranging from 650 to 770°C, sand to oil mass flow ratio ranging from 0 to 0.5, and feed rate ranging from 5 to 12kg/hr. Normal functioning of the transport cracking unit was ensured by a continuous operation for over 30hrs without steam dilution. Inner wall of the reactor tube remained clean from carbonaceous materials, which were carried away out of the system with the suspending solid.Overall gasification as well as the composition of gaseous products from both kerosene and heavier fractions were found to be similar with those reported on naphtha cracking process. Analyses also revealed that, under elevated cracking temperatures, liquid products were composed purely of aromatic hydrocarbons: mainly methyl derivatives of benzene and naphthalene. It was thus concluded that the pneumatic transport reactor deserved further developments as a cracking unit for heavier petroleum fractions.