Carbazole, a kind of nitro heterocyclic compound, was the main constituted part of the coal tar fraction.There was about 15% of the carbazoles contained in the high temperature coal tar.

• 摘要咔唑是一种含氮的杂环化合物，是煤焦油馏分中重要的组成部分，高温煤焦油内约含咔唑1.；5%25。