Study on the Synergistic Mechanism and Char Structural Evolution during Cogasification of Oil Sludge and Petroleum Coke Slurry

To investigate the synergistic mechanism of co-gasification of oily sludge (OS) and petroleum coke (PC), the effects of OS addition on the CO2 gasification reactivity of PC slurry and the structural evolution of the resulting gasification char were systematically examined using thermogravimetric analysis and high-frequency furnace gasification experiments, combined with characterization techniques including X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, and specific surface area analysis.

The results showed that OS addition exerted a significant catalytic effect on PC gasification, reducing the activation energy of the gasification reaction by up to 9.34% and enhancing the hydrogen yield. The co-gasification synergistic effect was closely related to the structural evolution of the gasification char. With increasing OS addition, the disorder degree of the carbon crystallite structure in the gasification char showed a trend of first increasing and then decreasing, whereas the specific surface area and average pore size exhibited opposite trends, confirming the competition mechanism between pore blockage by ash residues and mineral-catalyzed pore creation.