离子液体/H_2O_2体系脱硫实验研究

选取四种不同种类离子液体(ILs),1-丁基-3-甲基咪唑溴化物(Bmim]Br)、1-丁基-3-甲基咪唑四氟硼酸盐(Bmim]BF_4)、1-丁基-3-甲基咪唑硫酸氢盐(Bmim]HSO_4)、1-丁基-3-甲基咪唑磷酸二氢盐(Bmim]H_2PO_4)与30%H_2O_2溶液在温和条件下对两种高硫脱灰煤样(LS、QX)进行脱硫实验研究。用化学法测定脱硫前后煤样形态硫含量,并利用傅里叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)及热重(TG)对脱硫前后的煤样进行表征。结果表明,离子液体的加入使H_2O_2氧化脱硫能力增强,煤中硫铁矿硫和有机硫化物硫被显著脱除;经ILs/H_2O_2体系作用后的煤样中小粒径的颗粒减少,颗粒间的缝隙增大,煤表面的凹坑明显,热重实验结果表明,ILs/H_2O_2体系作用后的煤样相对于原煤热失重增大,部分挥发性物质释放峰温提前。

Experimental study on desulfurization by ionic liquids/H2O2 system

Four different kinds of ionic liquids(ILs), namely,1-butyl-3-methylimidazolium bromide(Bmim]Br), 1-butyl-3-methylimidazolium tetrafluoroborate(Bmim]BF₄), 1-butyl-3-methylimidazolium hydro-sulfate(Bmim]HSO₄), and 1-butyl-3-methylimidazolium dihydrophosphate(Bmim]H₂PO₄) were selected to add to the H₂O₂ solution (30%), respectively, to obtain four mixed solutions. Then, two kinds of deashed high-sulfur coal (LS, QX) desulfurization experiments were tested with above mixed solutions under mild conditions, respectively. The contents of different sulfur forms in coal samples before and after desulfurization were determined by wet chemical method, and the coal samples before and after desulfurization were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and thermogravimetric (TG). The results show that the addition of ionic liquids can make the H₂O₂ oxidation desulfurization ability enhance, and pyrite sulfur and organic sulfide sulfur in coal are obviously removed. After treated by the ILs/H₂O₂ system, the small size particle decreases, the space among the particles increases, and the pits on the coal surface become obvious. Moreover, the thermogravimetric test results show that the total weight loss of the coal sample treated by the ILs/H₂O₂ system increases and the peak temperature of some volatile substances lowers.