Light Olefin Production from Shale Oil-Derived Vacuum Gas Oils: Deep Catalytic Cracking-Oriented Approach

The catalytic cracking of shale oil-derived vacuum gas oils was explored following a DCC-oriented approach, aiming to produce petrochemical olefins. Two vacuum gas oils from Argentinian shale oils (VGO NC1 and VGO NC2 ) and one from a conventional extraction crude oil (“Escalante”, VGO C ) were converted over a gasoline type equilibrium FCC catalyst in a fluidized bed CREC Riser Simulator reactor (reaction times: 5–45 s, temperatures: 550 °C (FCC typical) and 600 °C (DCC approximation), cat-to-oil: 5). The raw crude oils exhibited markedly different properties but the resulting VGOs showed very similar distillation curves, shale oil-derived VGOs displaying higher API gravity and significantly lower sulfur content. Conversions were higher at 600 °C, but at a given temperature all the feedstocks exhibited similar conversion behavior, product distributions and coke yields. Increasing reaction temperature favored dry gas and light olefin production, while gasoline yields decreased due to overcracking, accompanied by changes in composition and octane number. Aromaticity in gasoline increased from 37 to 60% and olefinicity in LPG was 20% higher at 600 °C. Overall, the results indicate that shale oil-derived VGOs can be safely processed under FCC/DCC conditions, their performances being comparable to conventional VGOs, while offering advantages in sulfur content. The operation under conditions close to those of DCC significantly improved the production of light olefins, which is encouraging in a global scenario characterized by greater demand for petrochemical raw materials and increasing availability of shale oils.