Microstructural evolution of petroleum coke during CO2 and H2O gasification in a micro-fluidized-bed reactor with online particle sampling

This study compares the apparent gasification reactivity and conversion-dependent microstructural evolution of petroleum coke (PC) under CO 2 and H 2 O-containing atmospheres at 1000 °C using a micro fluidized-bed reactor with online particle sampling system. Under the investigated conditions, the H 2 O-containing case reached complete conversion within approximately 80 min, whereas the CO 2 case reached about 40% over the same period; this rate difference is condition-dependent because reactant partial pressures were not matched. N 2 adsorption showed rapid early development of accessible porosity followed by surface-area loss at higher conversion, with larger BET areas under H 2 O at equivalent conversion. FTIR indicated progressive relative changes in oxygen- and hydrogen-containing functionalities. XRD and Raman showed increasing carbon ordering in both atmospheres, but the increase was more pronounced under CO 2 , while H 2 O-gasified residues retained a larger contribution of disordered carbon. These results establish atmosphere-dependent links among apparent reactivity, pore evolution, surface functionalities, and carbon ordering in PC.