Conversion of Alkyl Aromatics in Supercritical Water: Observations Beyond Model Predictions

Heavy oils are much less valuable than cleaner burning lighter fuels. Thermal cracking (pyrolysis) is a conventional way to convert heavy oils into lighter fuels, with the downside of producing a considerable amount of coke. Here, we study the cracking of heavy oil and model alkyl aromatics in supercritical water experimentally and with computer-generated kinetic models based on quantum chemistry calculations. The model accurately predicts many of the experimental observations. Here we focus on several mysteries and discrepancies between the model and the experiments, including: mispredicted yields between alkanes and alkenes, the formation of a dark colored product as well as multi ring aromatics not predicted by the kinetic model, as well as a contradicting conversion between the model compound and heavy oil distillate.