Staged condensation of oil shale pyrolysis volatiles for preliminary dedust and fractionation of shale oil

Publication date: Available online 6 March 2019Source: Journal of Analytical and Applied PyrolysisAuthor(s): Hua Zhang, Ze Wang, Jingdong He, Ermei Liu, Wenli Song, Songgeng LiABSTRACTHigh dust content in shale oil is a big trouble for fluidized bed pyrolysis process. The staged condensation is proposed for on-line preliminary dedust of shale oil with coarse fractionation of oil components. Oil shale powders are continuously pyrolyzed using a lab-scale fluidized bed and the produced volatiles are condensed in three stages with reducing temperatures. The effect of the first stage condensing unit (U1) temperature on the distributions of oil components and dust is investigated. It is found that the amount of shale oil in U1 decreases monotonously with U1 temperature, while the amount of dust in U1 is generally stable at low temperatures and then decreases sharply at high temperatures. The amount of heavy components changes very little at low U1 temperatures and then decreases rapidly at higher temperature. At the optimal U1 temperature of 150 °C, the content of dust in oil of U1 is 6.99%, which accounts for 45.60% of total dust. Mechanism study shows that a lower U1 temperature favors a simultaneous heterogeneous and homogeneous condensation, which produce liquid-covered particles and liquid droplets respectively, and induce the formation of agglomerates by adhesion of the particles and droplets.

Source: Journal of Analytical and Applied Pyrolysis - March 7, 2019 Category: Chemistry Source Type: research