Investigation on gas and particle emission characterization of carbon black oxidation process promoted by catalyst/ash

Abstract

The study of the gas and particle emission characteristics during the oxidation of carbon black particles is the basis for exploring the particle emission characteristics during diesel particulate filter (DPF/CDPF) regeneration process. The gas and particle emission of Printex U (PU) particles oxidation under different oxidation temperatures and sample masses are investigated based on fixed bed and thermogravimetric analysis, and the oxidation processes are conducted under the cooperative effect of catalyst (CeO2)/ash (ZnO). The experimental results show that, with the increase of oxidation temperature, the CO/CO2 concentration, the extent of oxidation (η) and the total emitted solid particulate number (PN) increase, but the average particulate diameter (Da) range reduces from 60 to 100 nm to 20–40 nm. On the other hand, with the increase of PU mass, the CO/CO2 concentration and the total PN increase together, and the Da rises from about 30 nm to 40–160 nm, while the η decreases markedly. Both the CeO2 and ZnO nanoparticles can promote the PU oxidation process, and then reduce CO emissions, which lead to the rise the CO2 emissions. Beneficially, the η and the Da increase under the effect of CeO2 and ZnO, and the total PN decreases sharply. Adding catalyst (CeO2) and ash (ZnO) can effectively reduce the emission of small particle size (<23 nm) during oxidation process, which provides a research basis for controlling the emission of particles below 23 nm during DPF regeneration process.