不同煤岩成分的焦煤萃取后FTIR特征研究

The FTIR Characteristics of Extracted Coking Coal in Different Macrolithotype

为了研究不同煤岩成分煤萃取后的化学组成变化特征,选取平顶山焦煤作为研究对象,采用四氢呋喃(THF)、二硫化碳(CS2)、醋酸(HAc)等有机溶剂对煤样进行索氏萃取;借助于柱层析法、傅里叶变换红外光谱法等手段,对溶剂萃取后煤样的萃取率、族组分及特征官能团进行了计算和分析。研究表明:镜煤的萃取率最高,其次是亮煤、暗煤;相比而言,有机溶剂CS2对煤样的萃取率最高,THF的萃取率高于有机酸HAc;萃取物中,镜煤、亮煤、暗煤的总烃类含量依次减小,非烃类组分含量依次增大,THF溶剂萃取后以沥青质含量最高,CS2溶剂萃取后以饱和烃含量最高;镜煤的脂肪烃及含氧官能团含量最高,脂肪结构参数I4最大,芳构化程度参数I2最小,芳/脂比最小,而暗煤最大。萃取后,脂肪烃及含氧官能团含量较原煤均出现不同程度的减少,以镜煤最为明显,暗煤萃余物的芳烃含量最多,芳构化程度参数I2最大,芳/脂比最大。其中,CS2溶剂萃取后,煤中的富氧程度降低最为明显,而THF对与氢键缔合的—OH,—NH,酚类等官能团及脂肪烃溶解性最好。

To study the chemical composition change of the extracted coal in different macrolithotype,the cocking coal samples were taken from the Pingdingshan coal fields,and the extract solution of tetrahydrofuran(THF),carbon disulfide(CS 2)and acetic acid(HAc)were experimentally conducted on the samples in this paper.Based onthe chromatography and fourier transform infrared spectroscopy(FTIR),coal solution-extraction rate,chemical component and major functional group changes were investigated.The study find extraction yield of organic solvents on the vitrain is the highest,followed by the clarian,the durian,among differentlithotype of coal.Further,the extraction yield of CS 2 is the highest and THF is relatively higher than HAc.The hydrocarbon contents in the extraction decrease in the sequence of the vitrain,the clarian,and the durian,whereas the non-hydrocarbon components increase correspondingly.More bituminic is extracted from the coal sample under THF extraction,but more saturated hydrocarbon is done under CS 2 extraction.Further comparison of function group betweenthe pre-extracted coal and the pro-extracted coal of the same sample,fatty hydrocarbon content and oxygenic functional groups of the vitrain are the highest,the fat structure parameter is the largest,the aromatization of the coalandthe proportion of aromatic to the fatty hydrocarbon are the smallest,while thedurian has the largest proportion of aromatic to the fatty hydrocarbon.In addition,in allthe solutions treated to the coal,the fatty hydrocarbon and oxygenic functional groups in the pro-extracted coal decrease in different degrees,the vitrainis the most obvious,whereas the aromatization of the durian residue and the proportion of aromatic to the fatty hydrocarbon are the largest.In these cases,oxygen-containing functional group can be significantly extracted by CS 2,while the hydrogen-bond hydroxyl,phenols groups and fatty hydrocarbon are dramaticallyextracted by THF.