Investigation of the Transformation Behavior of Nickel and Vanadium during Steam Gasification of Petroleum Coke

Abstract

The gasification of petroleum coke (petcoke) can cause fouling and erosion problems. In this study, the evolution of Ni and V during steam gasification is investigated in a fluidized bed from 800 to 1100 °C. The occurrence modes determined by the sequential extraction show that raw petcoke contains diversified Ni forms, whereas V is dominated by organic matter and residual form. The organic matter is rapidly converted to residual form. The Ni in residual form is partially released, whereas the V in residual form is considerably converted to other forms. The volatilization of Ni is positively correlated with the temperature and sulfur content, whereas V has a positive correlation with the exchangeable form. The exchangeable form of V is conducive to forming a well-developed pore structure, whereas carbonates play the opposite role. Under the practical fluidized bed gasification, Ni tends to cause erosion, especially for continental petcoke, whereas V is inclined to cause slagging and fouling.