Detailed kinetic analysis of the impact of nucleation behavior and particle size distribution on the configurations of carbon black

Abstract

The impact of nucleation behavior and particle size distribution on the morphology of carbon black, which is a type of carbon nanoparticle, is investigated using a fixed sectional approach by applying the detailed chemical kinetic reaction for our previous experimental work: the pyrolysis of benzene in an inert atmosphere. By comparing the numerical behavior of polycyclic aromatic hydrocarbons (PAHs) formation and nucleation with experimental configurations of carbon black, the impacts of the behavior of PAHs formation and nucleation on the configurations are discussed. The development rate of the particle size distribution increases with an increase in temperature, and the size of small particles (size below 10 nm) decreases with an increase in residence time. The sensitivity of the furnace temperature on the particle size distribution and morphology of carbon black were further investigated by performing the calculation with the temperature being constant. Although the nucleation rate is nearly identical between 1,850 and 2,000 K, the rate decreases below 1,750 K. The mole fraction decreases with an increase in temperature, especially at 2,000 K, although the differences are small below 1,850 K. To form the complex aggregate shapes, three requirements should be fulfilled: (i) large particle number concentration, (ii) high nucleation rate, and (iii) quench before small particles of size below 10 nm collide with large particles consisting of a log-normal distribution. With these requirements fulfilled, the aggregate shapes would become the most complex at 1,850 K with a residence time of around 40 ms for the current benzene pyrolysis.