Reactivity of Naphthalene in Pyrolysis of Coal Tar Using the ¹⁴C Tracer Method

Abstract

To trace the behavior of naphthalene in the pyrolysis of coal tar, the pyrolysis of coal tar containing 14 C-labeled naphthalene was carried out at 800-950 °C for 40-50 s. It was found that naphthalene has significant pyrolysis reactivity. The distributions of the radioactivities in compounds with 3-5 rings were 21.6, 30.3, and 18.6% at 800, 900, and 950 °C for 50 s, respectively. Furthermore, the distributions of the recovered radioactivity in THFI at 800, 900, and 950 °C for 50 s were 1.6, 5.3, and 47%, respectively, indicating that about half of the 14 C-naphthalene can be converted into tetrahydrofuran insoluble (THFI) in 50 s at 950 °C. This 14 C tracer method using 14 C-labeled naphthalene is convenient for tracing the reactivity of coal tar and for elucidating the reaction mechanism of coal tar pyrolysis.