不同方式辅助H_(2)O_(2)脱硫结果的比较

Comparison of Desulfurization by Different Methods with H_(2)O_(2)

分别采用磁力搅拌(J)、超声辅助(U)、超声-微波联合(U-M)三种方式辅助H_(2)O_(2)体系对宁夏宁东煤(YYH)和河南洛阳煤(LY)进行氧化脱硫处理,测定脱硫前后煤样中全硫及形态硫的含量并计算脱硫率。利用扫描电子显微镜(SEM)、比表面及孔隙度分析仪(BET)、傅立叶变换红外光谱仪(FTIR)和X射线光电子能谱仪(XPS)对脱硫前后煤样的表面形貌、孔结构、官能团变化及硫形态的转变进行分析,利用同步热分析仪(TG)对脱硫前后煤样的热解特性进行表征。结果表明:磁力搅拌辅助H_(2)O_(2)脱硫时,脱硫率相对较低,而单独超声辅助和超声-微波联合辅助H_(2)O_(2)作用于煤样时,脱硫率及形态硫的变化比磁力搅拌更明显,尤其是超声-微波联合脱硫的作用效果最强,对全硫和有机硫的脱除率最高。这主要归因于,超声波的空化效应使煤粒表面和孔结构得到明显改善,促使氧化剂与含硫化合物更充分接触,而微波辐照可以加强含硫化合物发生裂解,加快化学键断裂,对煤炭脱硫有利。

Three desulfurization methods of magnetic stirring(J),ultrasonic(U)and ultrasonic-microwave(U-M)were used to oxidatively desulfurize Ningdong coal(YYH)and Luoyang coal(LY)by using H_(2)O_(2).The desulfurization rates were calculated according to the content of the total sulfur and form sulfurs in the coal samples after the desulfurization.Through the scanning electron microscopy(SEM),the specific surface area and porosity analyzer(BET),the Fourier transform infrared spectroscopy(FTIR)and the X-ray photoelectron spectroscopy(XPS),the surface morphology,functional group changes,and sulfur speciation transformation of the coal samples were analyzed.In addition,the pyrolysis characteristics of the coal samples were analyzed through the thermogravimetric analysis(TG).The experimental results showed that the magnetic stirring has minor effects on the oxidative desulfurization with H_(2)O_(2).The desulfurization effect by using the ultrasonic and ultrasonic-microwave combined with H_(2)O_(2) is obviously better than that under magnetic stirring.And the ultrasonic-microwave assisted desulfurization has the strongest effect and the highest removal rates of the total sulfur and organic sulfur.This is mainly attributed to the cavitation effect of the ultrasonic,which improves the surface and pore structure of coal particles significantly,and the thermal effect of microwave irradiation causes the cracking of the sulfur-containing materials and the fracture of the chemical bonds,which is beneficial to the coal desulfurization.