Numerical Design of an Extremely High Temperature Thermochemical Reactor for Converting Biochar to Hard Carbon

Abstract: Hard carbon is now a popular choice for the anode material in sodium-ion batteries. Converting biochar to produce hard carbon is considered carbon neutral and of great interest since it reduces the environmental impacts of biomass waste. This procedure requires high temperatures, and induction heating provides several advantages over other heating methods and is, therefore, widely used. In this thesis, a thermochemical reactor based on the principle of induction heating is designed, and CFD simulations of fluid-thermal coupling are performed. According to the simulation results, the total energy use efficiency of the induction heating reactor is calculated and compared with that of the thermal conduction heating reactor, which is found to be much higher than that of the thermal conduction heating reactor. Furthermore, the temperature of the tube wall of the reactor and the power losses of the inlet and outlet are observed, and design improvements are suggested. Simulation results indicate that adding a layer of protector to the exterior of the workpiece effectively reduces the wall temperature and the effect would be greater as the thickness of the protector increases. Meanwhile, the change in efficiency and energy losses are essentially negligible.