β Scribed by J.H. Choi; H. Kumagai; T. Chiba; Y. Sanada
No coin nor oath required. For personal study only.
Carbonization of petroleum and coal tar pitches to toluene insoluble fraction (77) was investigated under air and nitrogen gas blowing systems. The TIyield was evaluated on the basis of the weight of pitch loaded. Changes of the yield with the reaction time were analyzed by a kinetic model of carbonization. The model assumes that pitch as a reactant contains a reactive component, P, , which converts to active thermal fragment, P*, and gas and tar, G, more quickly than the residual component, P2, exhibiting a nonlinear decrease of pitch in semi-logarithmic plot against the reaction time in an early stage of the reaction. The activation energies for P, and P2 conversions depended on pitch and gas atmosphere.
In particular, activation energies for PI conversion in the air blowing system was found to be appreciably smaller than those in the nitrogen blowing system. This less temperature-sensitive carbonization in the former system may be attributed to pitch reactivity improved by oxygen in air.
π SIMILAR VOLUMES
A QI-free coal tar pitch with a softening point around 80Β°C was air blown in an autoclave at 330", 360", and 38O"C, respectively, for various periods in order to prepare a pitch precursor for GPCF. Air blowing markedly increased the softening point and contents of solvent insoluble fractions such as