邯郸-峰峰矿区不同变质程度煤中有机氮的赋存形态

氮是煤中的常见元素之一，煤中氮的赋存形态多样且随煤阶发生变化。以邯郸-峰峰矿区为例，利用X射线光电子能谱（XPS）实验，研究不同变质程度煤（R_ran=1.08%~3.67%）中有机氮的赋存形态，探讨煤中各形态有机氮相对含量随煤阶的变化规律。结果表明:按N 1s XPS谱图分峰峰值的结合能可将煤中氮的形态归为N-6、N-5、N-Q和N-X四种；研究区煤中N-5的相对含量最高，且随着煤阶的增高而降低；N-Q的相对含量随着煤阶的增高而增高；煤中N-6的相对含量随煤阶呈“增-减-稳”的变化规律；N-X的相对含量为9.1%~35.1%，其与煤阶关系不明显；在煤阶R_ran=1.08%~1.47%的范围内，煤的N 1s XPS谱图中缺失N-Q分峰，表明褐煤中相对含量最高的质子化吡啶氮在此阶段已几乎全部去质子化而转化为吡啶氮。不同变质阶段氮的赋存形态变化特征对燃煤发电及煤化工领域煤化学参数选取提供参考。 

Organic nitrogen forms of different rank coals in Handan-Fengfeng mining area,China

Nitrogen is one of the common elements in coal.The occurrence forms of nitrogen in coal are various and vary with coal rank.Based on X-ray photoelectron spectroscopy(XPS),taking Handan-Fengfeng mining area as an example,organic nitrogen forms of different rank coals(Rran=1.08%–3.67%)were studied,and the variation of the relative abundance of each organic nitrogen with rank was further discussed.The results show that four kinds of nitrogen forms are considered for the coals according to binding energies of N 1s XPS sub-peaks,corresponding to N-6,N-5,N-Q and N-X.N-5 is the most abundant organic nitrogen and its relative abundance decreases as coal rank increases,while N-Q shows opposite trend.The variation of the relative abundance of N-6 with rank shows“increasing-decreasing-stable”trend,and N-X accounts for 9.1%–35.1%of the total organic nitrogen,whose changing with coal rank is not obvious.Protonated pyridinic nitrogen,a type of N-Q,which dominates in lignite,almost disappears at a coal rank range from Rran 1.08% to Rran 1.47% due to the loss of oxygen groups and deprotonation,resulting in the absence of N-Q sub-peaks in the XPS spectra.