利用真空热解炉—质谱联用仪研究不同电子电离能量下淮南烟煤和无烟煤热解产物的分子组成分布特征（英文）

Molecular distribution of coal pyrolysis products of bituminous and anthracite from Huainan coalfield by vacuum pyrolysis furnace coupled with mass spectrometer under different electron ionization energies

采用真空热解炉-质谱联用仪研究了不同电子轰击能量下,来自淮南煤田的烟煤、无烟煤和天然焦的热解产物的分子组成分布特征.结果表明,烟煤热解产物的离子种类数量(TNI)、数均分子量(Mn)和重均分子量(Mw)与无烟煤热解产物相似,与天然焦热解产物有很大不同,但是烟煤热解产物的总离子量(TII)多于无烟煤热解产物,这表明烟煤热解产物的分子组成分布与无烟煤热解产物是相似的,与天然焦热解产物有很大不同;在三种煤热解产物中,通过对代表烷基苯的特征碎片离子C7H7+的量与代表苯的分子离子C6H6^·+的量的比值C7H7+/C6H6^·+,以及代表脂肪烃的特征碎片离子C4H9^+的量与C6H6^·+的量的比值C4H9^+/C6H6^·+进行分析,得到三种煤热解产物中的C7H7^+/C6H6^·+的值比较接近,但是天然焦的C4H9^+/C6H6^·+值却大于无烟煤和天然焦,这表明三种煤热解产物中的烷基苯相对于苯的含量相似,但是天然焦热解产物中脂肪烃相对于苯的含量却比烟煤和无烟煤的相应含量高.通过对不同电子电离能量下获得的三种煤热解产物质谱数据进行分析,得到适宜的电子电离能量范围是65~75eV.研究显示,利用真空热解炉-质谱联用仪可以快速获得煤热解产物的分子组成分布信息,为煤的非燃料用途提供指导.

Bituminous,anthracite and natural coke from Huainan coalfield were investigated by a vacuum pyrolysis furnace coupled with mass spectrometer (MS) directly under different electron ionization (EI) energies.Through total intensity of ions (TII),total number of ion species (TNI),number average molecular weight ( M n),and weight average molecular weight ( M w) of the three coals pyrolysis products,it can be obtained that TNI,M n and M w of bituminous pyrolysis products are similar to those of anthracite pyrolysis products,which indicates that the molecular distribution of the bituminous pyrolysis products is similar to anthracite pyrolysis products,but is much different to natural coke pyrolysis products.Through the ratios of specific mass fragment ions of C 7H 7^+/C 6H 6^+ and C 4H 9^+/C 6H 6^·+ in the three coals pyrolysis products,it can be obtained that the ratios of C 7H 7^+/C 6H 6^·+ in the three coals pyrolysis products are similar,but that of C 4H 9^+/C 6H 6^·+ in natural coke pyrolysis products is more than the ratio of C 4H 9^+/C 6H 6^·+ in the pyrolysis products of bituminous and anthracite,which indicates that the relative content of alkylbenzene to benzene in the three coals pyrolysis products is similar,and that the relative content of aliphatic compounds to benzene in natural coke pyrolysis products is more than that in bituminous and in anthracite.And through all MS data,the proper range of EI energy for coal pyrolysis is from 65 eV to 75 eV.The vacuum pyrolysis furnace coupled with mass spectrometer fleetly can be useful to the quick investigation of molecular distribution characteristics of coal pyrolysis products for coal non-fuel utilization.