Hydrodesulfurization of Petroleum Coke Deposited on Iron Ores

Hydrodesulfurization of the coke deposited on iron ores was studied at 650-950 °C to find procedures to reduce the sulfur content acceptable for the direct reduction of iron ores. The desulfurization of as-received coke took place at 950 °C and achieved desulfurization level of 83%. The lower temperature decreased not only the rate of desulfurization but also the level achieved within a definite time (10 h). The many cracks found in the coke desulfurized at 950 °C suggest the importance of the accessibility of sulfur to hydogen molecules. The grinding and heat treatment at 1000 °C prior to the hydrodesulfurization enhanced the removal at 750 °C to achieve the same desulfurization level as that at 950 °C with the as-received coke. The structure and reactivity of the coke in terms of its sulfur contaminants are discussed from the view of their physical location in the lump coke.