霍州和兴和褐煤的热溶解聚及其有机氧的赋存形态

Thermal dissolution of Huozhou and Xinghe lignites and the occurrence forms of organic oxygen in them

依次采用石油醚、二硫化碳、甲醇、丙酮和等体积的丙酮/二硫化碳混合溶剂对霍州(HZ)和兴和(XH)褐煤进行分级萃取得到萃取物(E_1-E_5)和萃取残渣(ER1-ER5),利用甲醇、甲苯、等体积甲醇/甲苯混合溶剂和丙酮等溶剂分别对ER5在320℃进行热溶得到热溶物(SPs)。HZ和XH的累积萃取物产率分别为7.03%和7.86%,其中,E3的产率最高;萃取残渣在甲醇/甲苯混合溶剂中的热溶物产率最高,ER_(5,HZ)和ER_(5,XH)的热溶物产率分别为45.76%和40.14%。E_1-E_5的傅里叶变换红外光谱(FT-IR)谱图中均有较强的脂肪C-H的伸缩振动峰,而SPs的FT-IR谱图中具有较强的C=C、C=O和缔合羟基的吸收峰。气相色谱质谱联用(GC/MS)分析表明,E_1-E_5中含氧化合物(OCOCs)以醇、醚和酮类化合物为主,而SPs中OCOCs以醇、酚和酮类化合物为主,且极性较强的溶剂有利于褐煤中OCOCs的溶出。与原煤FT-IR谱图相比,萃取残渣和热溶残渣的FT-IR谱图中缔合羟基、C=O和C-O-C的伸缩振动峰强度明显减弱。X射线光电子能谱(XPS)分析表明,两种褐煤中不同形态氧的相对含量为C-O>C=O>COO-,并且HZ具有更高的C-O和COO-含量。

Huozhou（ HZ） and Xinghe（ XH） lignites were extracted in turn with petroleum ether,carbon disulfide,methanol, acetone and isometric acetone/carbon disulfide mixed solvent to obtain the extracts（ E1-E5） and the extraction residues（ ER1-ER5）,then ER5 was thermally dissolved at 320 ℃ using methanol,toluene,isometric methanol/toluene mixed solvent and acetone to gain the soluble portions（ SPs）. The total yields of extraction for HZ and XH are 7.03% and 7.86%,respectively,in which the yield of E3 is the highest.The SPs yield of extraction residue with isometric methanol/toluene mixed solvent is the highest,and the SPs of ER（5,HZ） and ER（5,XH） with isometric methanol/toluene mixed solvent reaches 45. 76% and 40. 14%,respectively.There exist strong adsorption peaks ascribed to aliphatic C-H in the Fourier transform infrared（ FT-IR） spectra of E1-E5,while the intensity of adsorption peaks ascribed to C =C,C =O and O-H in the FT-IR spectra of SPs is obviously higher than that of extracts. The gas chromatography/mass spectrometer（ GC/MS） analyses showthat the oxygen containing organic compounds（ OCOCs） in E1-E5 are dominated with alcohols,ethers and ketones,while it is mainly composed of alcohols,phenols and ketones in the SPs,and the strong polar solvents contribute to dissolving the OCOCs in lignites. The adsorption peaks ascribed to associated O-H,C = O and C-O-C in the FT-IR spectra of extraction residues and thermal dissolution residues are weaker than those of rawcoals. The X-ray photoelectron spectroscopy（ XPS） analyses indicate that the relative content of oxygen forms in XH and HZ is C-O C = O COO-,and the relative content of C-O and COO-in HZ is higher than that in XH.