Factors Affecting Sulfur Reactions in High Sulfur Oil Shale Pyrolysis

Abstract

Oil shale samples from the Ellajjun area south of Jordan were pyrolyzed in different conditions and environments. Sulfur of shale oil was determined using x-ray fluorescence (XRF). Generated products swept from the retort by several sweeping media; they include nitrogen, water vapor, hydrogen, and mixture of nitrogen and water vapor. Other conditions are 2–11 mm particle size, 1 atm operating pressure, and 410–550°C temperature range. The sulfur content of shale oil was found to be 12 wt % for hydrogen pyrolysis, while water vapor at 1 atm decreased this value to 7 wt %. Hydrogenation of oil shale resulted in 12 wt %. the sulfur content of shale oil being at 420°C, and then reduced to 10.3 wt % at temperatures higher than 470°C. When water vapor is added to nitrogen, the sulfur in the oil shale is increased by 4 wt %. Water vapor sweeping gas increased the sulfur of the shale oil from 6.5 wt % to 8.1 wt % compared with a nitrogen pyrolyzing medium. Retorted shale analysis showed 44 wt %, and 31 wt % is left in the retorted shale of the original 4.5 wt %. Sulfur found in the raw oil shale is unretorted for nitrogen and hydrogen sweeping gases. On the other hand, increasing particle size from 2 mm to 11 mm did not have any significant influence on the sulfur content of the produced shale oil.