Conversion of Arabian Light Crude Oil to Light Olefins via Catalytic and Thermal Cracking

Abstract

The thermal and catalytic cracking of Arabian Light crude oil, which has a density of 34° API, were evaluated in a fixed-bed microactivity test (MAT) unit between 550 and 650 °C. For the catalytic cracking, two catalysts were used, a steamed commercial MFI catalyst (M-cat) and an equilibrium FCC catalyst (E-cat). Thermal and catalytic cracking were compared at the same conversion, 34%, at 650 °C. For both, as the temperature increased, the yields of light olefins, LPG, dry gas, and coke increased, associated with a consistent decrease in heavy ends (LCO and HCO). The naphtha yield for catalytic cracking decreased as temperature increased; however, for thermal cracking, it was nearly constant. The superiority of catalytic cracking over thermal cracking for the propylene yield was interpreted in terms of mechanisms of free radicals and carbenium ions. Thermal cracking gave a higher yield of ethylene. At high temperature (650 °C) and catalyst to oil (C/O) ratio of 4, the olefins yield decreased in the order ...