Rate Analysis of Oxidation Stabilization Reaction of Spun Mesophase Pitch Fiber

Mesophase petroleum pitch fiber oxidation reaction in a gas phase continuous flow isothermal tank reactor was analyzed by a mathematical reaction model which includes the effect of diffusional resistance of oxygen molecule within a fiber as well as autoxidation reaction of oxygen with active site in the fiber. By fitting the calculated oxygen concentration in the reactor with experimental ones, optimal reaction rate constant, effective diffusion coefficient and gassolid distribution coefficient, which were introduced as parameters, could be estimated. Temperature dependence of these parameters was also elucidated. Radial distributions of oxygen and active site in the fiber were obtained by calculations. It can be concluded that stabilization is completed even the reaction does not proceed to the center of the fiber.