Studies On Coal/Oil Co-hydroprocessing With Mild Conditions And Peliminary Process Design

In this paper,the coal/oil co-processing under the mild conditions was researched in terms of the influences of reaction temperature,hydrogen pressure,reaction time,coal properties,and ratio of oil and coal on the coal liquefied fraction,and properties of semicoke and liquefied oil.The preliminary design of coal/oil co-processing unit was obtained finally.The coal liquefied fraction shows an upward trend firstly,and drops along with the increase of reaction temperature.In lower temperature range,the volatiles goes up in pace with the increase of reaction temperature,which is totally different with ash.With the reaction temperature increasing,the ash rises constantly,however,volatiles begins to increase and fixed carbon contents decreases.In the meantime,the gasoline contents and n H/n C in oil show a downward trend along with the increase of reaction temperature,however,the contents of diesel,heavy oil,and heteroatom S and N have a distinct trend.The coal liquefied fraction,ash,the heavy oil contents,and H content and n H/n C in oil rise with the increase of hydrogen pressure,during which the volatiles and fixed carbon,gasoline contents,and contents of heteroatom S decrease gradually,while the contents of diesel and heteroatom N remain stable.On the other hand,the coal liquefied fraction and the contents of gasoline and diesel show an upward trend firstly,and drop along with the increase of reaction time,which is different with the n H/n C in oil.In the meantime,the volatiles,fixed carbon,heavy oil contents,and content of heteroatom S decline,and the ash grows.To the lignite which is easily liquefied,the coal liquefied fraction when using FCC slurry as a solvent oil is higher than that of coal tar,which is opposite to the bituminous coal.Comparing with using FCC slurry as a solvent,the contents of light components in oil and n H/n C are higher when using coal tar as a solvent,which is different with the contents of heavy components and heteroatom S and N.The performance of liquefaction improves with the increase of volatile contents and n H/n C.The main component of coal participated in the reaction is volatile,and only a small fraction of fixed carbon participates in the reaction.However,the ash is not involved in the reaction.The preliminary design of a coal/oil co-processing unit was obtained on the basis of experimental data finally.