胜利褐煤和小龙潭褐煤在甲醇中的热溶及热溶物分析

研究了胜利褐煤(SL)和小龙潭褐煤(XLT)在甲醇中的热溶行为,并利用傅里叶变换红外光谱、气相色谱/质谱(GC/M S)和大气压固体分析探针/飞行时间质谱(ASAP/TOF-M S)对320℃热溶物的组成和结构特征进行了分析。两种褐煤热溶物产率均随温度升高而增加,但240℃后XLT热溶物(SPXLT)产率明显高于SL热溶物(SPSL)。GC/MS分析表明,两种褐煤热溶物以含氧化合物为主,尤其酚类的相对含量超过49%;与SPXLT相比,SPSL中烯烃、芳烃、醚类、羧酸、酯类和有机硫化合物(OSCs)含量较高,而烷烃、酚类、酮类和有机氮化合物含量较低;SPSL中的OSCs以噻吩为主,而SPXLT中的OSCs以硫醇为主。ASAP/TOF-M S可检测出热溶物中大量GC/M S无法检测出的较强极性和难挥发化合物;与SPXLT相比,SPSL中CHO和CHS族分含量较低,而CHN、CHNO、CHOS、CHNS和CHNOS族分含量较高;两种褐煤热溶物中化合物的碳数和双键数(double bond equivalent,DBE)主要分布在3-15和0-10,SPXLT中化合物的碳数和DBE分布相对集中。

Thermal dissolution of Shengli and Xiaolongtan lignites in methanol and analysis of the soluble portions

Thermal dissolution behaviors of Shengli (SL) and Xiaolongtan (XLT) lignite in methanol were investigated. The composition and structural characteristics of soluble portions (SPs) obtained at 320 ℃ were characterized with Fourier transform infrared spectroscopy, gas chromatograph /mass spectrometer (GC/MS) and atmospheric solid analysis probe/time of flight mass spectrometer (ASAP/TOF-MS). For the two lignites, the yield of SPs increase with temperature increasing, while the yield of SPs from XLT (SP_XLT) is obvious higher than that from SL (SP_SL) above 240 ℃. GC/MS analysis results show that compounds in the SPs are dominated in oxygen-containing organic species, especially the relative content of phenols is higher than 49%. The relative contents of alkenes, arenes, ethers, carboxylic acids, esters, organosulfur compounds (OSCs) in SP_SL are higher, while the relative contents of alkanes, phenols, ketones and organonitrogen compounds in SP_SL are lower than those in SP_XLT. Additionally, the OSCs in SP_SL and SP_XLT are mainly composed of thiophenes and mercaptan, respectively. Many compounds with high polarity and low volatility which could not be identified by GC/MS were identified using ASAP/TOF-MS. The relative contents of CHO and CHS class species in SP_SL are higher, but the relative contents of CHN, CHNO, CHOS, CHNS and CHNOS in SP_SL are lower than those in SP_XLT. The carbon number and double bond equivalent (DBE) of the compounds in SP_SL and SP_XLT mainly distribute in 0-10 and 3-15, respectively, while the distribution of carbon number and DBE of the compound in SP_XLT are more concentrated than those in SP_SL.