关键词: 煤焦油, 热裂解, 双外推法, 机理模型

Abstract: Simultaneous thermogravimetry-mass spectrometry (TG-MS) was used to investigate the pyrolysis behavior of coal tar and the instantaneous evolution characteristics of gaseous products, and the pyroletic reaction mechanism of coal tar was inferred by the double extrapolated method. Data processing/fitting was conducted introducing the Costs-Redfern and the Flynn-Wall-Ozawa integration methods, thus giving the two-stage reaction mechanism function of weightlessness and kinetic parameters. The results showed that mainly there are two weight loss stages during coal tar pyrolysis. The first one is a polycondensation process of organic reaction after dehydration, which is mainly affected by the random nucleation mechanism and, as a result, the old phase disappears with new phase generated for nucleation. In the stage the main products are micromolecular gases and macromolecular condensed tar, and the activation energy is 162kJ/mol. In the second stage the pyrolysis occurs once again for the macromolecules of condensed tar under the control of three-dimensional diffusion mechanism, which reflects the mutual transfer mechanism between gaseous products. Moreover, in the second stage the nuclei are growing and diffusing, where the products are mainly the hydrogen and carbon monoxide with an activation energy 76.68kJ/mol.