Comparative evaluation for catalytic gasification of petroleum coke and asphaltene in subcritical and supercritical water

Subcritical and supercritical water gasification of petroleum coke and asphaltene was performed at variable temperatures (350–650 °C), feed concentrations (15–30 wt%) and reaction times (15–60 min). Nickel-impregnated activated carbon (Ni/AC) was synthesized as a catalyst for enhancing syngas yields at optimal gasification conditions (650 °C, 15 wt% and 60 min). Structural chemistry of precursors and chars developed at different gasification...