Influence of temperature and pressure on carbon black size distribution during allothermal cracking of methane

摘要

Allothermal cracking of methane is a suitable and eco-friendly way to simultaneously produce hydrogen and carbon black. The economic viability of the process relies on the ability to produce carbon black having well-defined characteristics, particularly concerning the particle size. A model for the study of the carbon particle size distribution during thermal cracking of methane has been developed. The model takes into account: heat transfer by conduction, convection, particle and gas radiation, homogenous and heterogenous reactions of methane dissociation, nucleation, and growth of solid carbon particle formed. The model alleges nanoparticles are in thermal equilibrium and do not impact the flow. A parametric study is made on operating pressure and temperature. As a result, the increase of the pressure and temperature increases the yield of thermal methane cracking. Moreover, results show a particle size distribution becoming narrower with increasing temperature and/or pressure. In these conditions, the particles population tends to be monodispersed.