高硫煤与生物质共热解时有机硫的迁移规律

Characteristics of Organic Sulfur Migration During Co-pyrolysis of Coal/Biomass Blends

选取晋南和宁东地区的两种高硫煤作为研究对象,用HCl-HF-CrCl2对煤样进行脱矿物质处理。将脱矿物质煤与稻壳和木屑两种生物质分别按不同质量比进行混合,在不同温度下共热解,研究了混合半焦收率的实验值与计算值的差异,以及脱矿物质煤与生物质共热解对煤中有机硫逸出的促进作用,并对有机硫逸出率最大的样品进行了FTIR,XPS,BET表征,探讨了生物质促进煤热解过程中有机硫逸出的机理。结果表明:当升温速率为15℃/min,温度低于700℃时,脱矿物质煤与生物质共热解存在明显的协同效应,使得混合样热解的有机硫逸出率高于煤单独热解时的有机硫逸出率。FTIR分析表明脱矿物质晋南煤与生物质共热解过程中—S=O键消失,说明协同效应促进亚砜的分解;XPS分析表明最大有机硫逸出率下有机硫的种类及含量都减少,变化最明显的是脂肪族硫化物和砜类。

Two kinds of high sulfur coal in Jinnan and Ningdong area were selected,and after treated by HCl-HF-CrCl 2 system to remove mineral,two kinds of biomass of rice husk and sawdust were mixed respectively at different mass ratio,and co-pyrolysis was carried out at different temperatures.By comparing the experimental and calculated value of the yield of mixed char,the conditions for the existence of the synergistic effect were analyzed,the effect of the synergistic effect on promoting sulfur migration was discussed,and the mixed char which have maximum organic sulfur migration rate were characterized by FTIR,XPS and BET.The results show that when the co-pyrolysis heating rate is 15℃/min and the temperature is less than 700℃,there is a synergistic effect between demineralized coal and biomass,which leads to a higher sulfur migration rate of co-pyrolysis than that of individual coal pyrolysis.FTIR analysis indicates that the—S O functional group disappears during co-pyrolysis of demineralized Jinnan coal and biomass,indicating that the synergistic effect promotes the decomposition of the sulfoxide functional groups;XPS results show that the type and content of organic sulfur decrease during co-pyrolysis,and the most visible changes are aliphatic sulfide and sulfoxide.