Kinetic Model of Stabilized Pan Fiber Mass Loss During Carbonization
The carbonization process converts stabilized precursor (or PAN) fiber into carbon fiber and takes place within two high temperature furnaces, namely the LT (Low Temperature) and HT (High Temperature) furnaces. The largest fiber mass loss occurs within the LT furnace which typically operates with a temperature between 500 and 800°C. The volatiles released from the fiber are generally not uniform throughout the carbonization process and are strongly depend on operating conditions such as temperature, heating rate, residence time, and even extent of oxidation from the previous step. Since its inherent complex nature, little research works has focused on the mass loss kinetics within the carbonization process in spite of significant impacts on the quality of final product. We have developed continuous model for carbonization process including mass loss rate as a lumped kinetics using two-zone model for the fiber and pseudo-pure off-gas. The kinetic coefficients used in this model have been estimated by reviewing existing literature data and extending it to real operating conditions. Fiber conversion (i.e. linear density change) predictions over the fiber travel direction are obtained from the model by applying realistic operating conditions. A parametric study on fiber conversion with different time and temperature conditions was also performed.
Author: Tae-Seok Lee
Conference: SAMPE Seattle 2017