煤精制软沥青中氮硫的分布和热稳定性的分析

Analysis of thermal stability and distribution of nitrogen and sulfur in coal tar refined soft pitch

以高温煤焦油沥青为原料制备两种精制软沥青(A,B),采用索氏抽提方法获得族组成后,分别炭化成半焦。通过元素分析研究了精制软沥青、族组成及炭化产物的的含量及分布情况,利用红外光谱鉴别精制软沥青中不稳定性氮基团的结构。研究结果表明:两种精制软沥青中,氮、硫质量分数都小于0.7%;氮的分布,按庚烷可溶族(HS)、庚烷不溶甲苯可溶族(HI-TS)、甲苯不溶喹啉可溶族(TI-QS)顺序递增;精制软沥青B中硫的分布按HS,HI-TS,TI-QS顺序减小,精制软沥青A中硫在HI-TS族中的分布最多;炭化过程中,—N=形式的氮不易逸出,而-NH-中的氮易逸出,精制软沥青B中氮的逸出率高于精制软沥青A,硫的逸出率二者相近;精制软沥青B中氮、硫的热稳定性较差,对炭化产物性能的影响较小。

Both coal tar refined soft pitch A and B were fabricated with high-temperature coal tar as raw material：Their group compositions were obtained by Soxhlet solvent extraction and they were carbonized to the state of semicoke, respectively. The contents and distributions of nitrogen and sulfur in the coal tar refined soft pitch, group compositions and semi-coke were researched thraugh element analysis. The unstability structure of nitrogen group was verified by infrared spectroscopy. The results showed that the contents of nitrogen and sulfur in both coal tar refined soft pitch were all less than 0.7 % （m/m） ; the distribution of nitrogen increased in the order of heptane soluble （HS）, heptane insoluble-toluene soluble（HI-TS）,and toluene insoluble-quinoline soluble （TI-QS） ; the distribution of sulfur in coal tar refined soft pitch B decreased in the orde of HS, HI-TS,and TI-QS;however, most sulfur in coal tar refined soft pitch A belonged to the family of HI-TS; nitrogen existing in form of-- N;was not easy to escape wheras--NH-- was just the opposite in the carbonization process; the escape rate of nitrogen in the coal tar refined soft pitch B was higher than that in the coal tar refined soft pitch A; the escape rate of sulfur in both was close; it was found experimentally that the thermal stability of nitrogen and sulfur in the coal tar refined soft pitch B was poor, which had little effect on the performance of carbonization products.