Desulfuration of electrolyzed coal water slurry in HCl system with ionic liquid addition

Effects of ionic liquid-assisted on electrolyzed desulfuration of coal water slurry (CWS) in HCl system were investigated by constant-current electrolysis. The results indicated that the desulfuration effects from CWS electrolysis in the HCl system were improved, and the removal effects of organic sulfur in coal were improved as ionic liquids increased. On the other hand, reduction of electrolysis on cathode showed that hydro-desulfuration ratio with 1-butyl-3-methylimidazolium bromide (C8H15N2Br) was higher than that with 1-butyl-3-methylimidazolium chloride (C8H15N2Cl), and hydro-desulfuration ratio with pyridine ring ionic liquids was higher than that with imidazole ring. The results of ash composition showed Fe-containing mineral matters were removed by electrolysis on anode. However, they were not removed by electrolysis on cathode. In addition, the desulfuration ratio of CWS electrolysis without membrane was between anode and cathode electrolysis ratio. Finally, the mechanism of ionic liquid-assisted on electrolyzed desulfuration of CWS in HCl system was proposed.

Fig. 2 Effects of ionic liquids on desulfuration of electrolysis on anodeFigure optionsDownload as PowerPoint slideHighlights
► Ionic liquids improved desulfuration ratio from CWS electrolysis in HCl system.
► Ionic liquids boosted the removal ratio of organic sulfur from electrolysis.
► The inorganic sulfur was not removed nearly from electrolysis on cathode.
► Hydrodesulfurization capability of ionic liquids with hexatomic ring was higher.
► Electrolysis without membrane cannot achieve accumulation effects.