Investigation of the waste heat recovery and pollutant emission reduction potential in graphitization furnace

The graphite furnaces, which are extensively used for high-purity graphite production, inevitably discharges a large amount of waste heat that requires significant recovery for purpose of the improved energy efficiency. The paper numerically analyzed the heat transfer performance of a graphitization furnace under the electrical-heating and natural-cooling period. The temperature-dependent properties and heat transfer coefficients were used to predict the waste heat recovery potential along with on-site measurements. The results show that during the graphitization production, the core furnace temperature can reach 3000 °C while the petroleum coke surface reaches 368 °C without the combustion of the volatiles in the coke. The heat dissipation on the top coke surface accounts for 48.5% of the total electricity input and 66.9% of the total heat dissipation from the furnace, respectively. The equivalent emission reduction of CO2, SO2 and NOx are 47.5 t, 7.4 t and 3.6 t respectively per annum. The investigation of the waste heat recovery potential for graphitization furnaces can provide a reference for the heat recovery equipment and operation for graphitization furnaces.