Cracking of Residual Oil in the Presence of Iron Ore

Abstract

Cracking of vacuum residual oil for production of low sulfur fuel oil has been carried out in the presence of iron ore particles in a fixed bed reactor. Steam was used as a diluent and the experimental conditions covered the temperature range 400-600°C.
The results indicated that the yields of the liquid and gaseous products were 80-90 and 2-7 wt%, respectively. The sulfur contents of the liquid product of lower gravity were 2-3 wt%. The value is considerably lower than those obtained by thermal cracking operations in the presence of mullite or sand particles. The distribution of total sulfur contained in the feed in the products was as follows: 30-55 wt% in the liquid product, 2-5 wt% in the gas, 15-25 wt% in the coke and 20-30 wt% in the iron ore. This suggests that the iron ore has a capability of capturing sulfur in the course of carcking of the residual oil.
The reactions of some iron oxides with hydrogen sulfide were investigated by use of a DTA equipment. The iron ore appeared to react with sulfur compounds in the reduced state of magnetite as well as of metallic iron to desulfurize the residual oil, since the desulfurization of the residual oil was obserbed at above 400°C at which temperature hydrogen is recognized in the gas produced by cracking of the oil. Iron ores are thus expected to be an effective solid medium for production of low sulfur fuel oil in the cracking process of residual oils.