Effect of ferric chloride addition on soot formation during ethylene pyrolysis in a laminar flow reactor

Abstract

In this work, we investigated the effect of ferric chloride (FeCl) addition on soot formation during ethylene pyrolysis in a laminar flow reactor by characterizing particles sampled at the reactor outlet. To avoid the interference of oxygen atoms on soot formation, we selected FeCl as an iron-based additive and used a diffusion dryer to absorb water in the FeCl solution. By studying particle size distribution, morphology, and chemical composition, we found that iron-containing particles evolved from iron nuclei to core-shell particles and finally to aggregates. These iron-containing particles, which had an overall higher charge fraction, hindered the agglomeration of iron nuclei but promoted the formation of core-shell particles. In addition, ReaxFF molecular dynamics simulations were performed to study the interaction between FeCl and pyrene molecules in the early stages of soot formation. Simulation results show that FeCl would undergo thermal decomposition to form Fe-C sosoloid as the core of the core-shell particles.