Formation of highly graphitic char derived from phenolic resin carbonization by Ni-Zn-B alloy.

The formation of highly graphitic phenolic resin chars (GPFCs) during catalytic carbonization at relatively low reaction temperature (1200-1600 °C) using novel Ni-Zn-B alloy catalyst with small amount of addition (5-15%) was systematically studied. Only two kinds of graphites (turbostratic graphite and ordered graphite) can be found in GPFCs after catalytic carbonization with Ni-Zn-B and their proportions were changed with reaction conditions. When Ni-Zn-B was involved at 1200-1600 °C, the phenolic resin char was fully transformed to be graphite, and ordered graphite content increased to 28.42% at 1400 °C, which was also almost twice of ordered graphite content in the char catalyzed by pure Ni. But the order graphite content would decrease due to sintering at higher reaction temperature. The addition of Zn and B can promote nickel-based alloy catalytic action by reducing melt point and accelerating graphitization respectively. It was also found that ordered graphite content could be used as a key evaluation parameter to directly reflect the quality of GPFCs based on detailed characteristics analysis. The model between three reaction conditions (reaction temperature, retention time, catalyst content) and ordered graphite content was built with artificial neural network (ANN), and the prediction accuracy of ANN was high up to 91.48%.