Mass Transfer Characterization of Liquid Hydrocarbon Inside a Polyethylene Particle Based on Laser Scanning Confocal Microscopy Measurement

The collision between liquid droplets and solid particles not only affects the macroscopic flow field characteristics inside a multiphase reactor but also significantly determines the mass transfer rate of gas and liquid reactants into the particle at the microlevel. This study introduces a novel method utilizing laser scanning confocal microscopy to visually analyze the mass transfer process of liquid hydrocarbons within polyethylene particles following the collision of single-component or bicomponent hydrocarbon droplets with the particles. Results indicate that the sliding and covering of the liquid film on particle surfaces during droplet–particle collisions can enhance mass transfer to varying degrees, with energy changes analyzed through a theoretical approach based on energy conservation principles. Specifically, when Marangoni convection occurs on the particle surface in the presence of volatile hydrocarbon components, there is a complex interplay between competition and coordination in the mass transfer intensity of liquid on both the surface and inside the particle postcollision with bicomponent hydrocarbon droplets. A Gr*–MaC phase diagram was developed for the first time to identify the occurrence of Marangoni convection, offering insights into enhancing mass transfer efficiency at the particle level.