Valorizing petroleum coke into hydrogen-rich syngas through K-promoted catalytic steam gasification

Hydrogen-rich syngas was successfully produced from catalytic steam gasification of petroleum coke. This work studied the steam gasification of petroleum coke over KOH, K₂CO₃, KNO₃, CaO, Fe₂O₃, K₂CO₃–CaO and K₂CO₃–Fe₂O₃ in a pressurized fixed bed. KOH and K₂CO₃ demonstrated good catalytic activity compared with other catalysts. The carbon conversion efficiency (CCE) increased from 14.7 wt% to 61.4 wt% and 87.9 wt% after adding 10 wt% K₂CO₃ and 10 wt% KOH, respectively, and H₂ content increased from 60.9 vol% to 66.7 vol% and 64.2 vol%. The increase of gasification temperature and pressure resulted in the increase of CCE. However, raising temperature was beneficial to the increase of H₂ and CO contents, while the elevated pressure was in favor of the formation of CH₄. In addition, the K-catalytic steam gasification of petroleum coke accorded with the oxygen transfer and intermediate hybrid mechanism.