Single Particle Growth, Fragmentation and Morphology Modelling: A DEM Approach

Abstract

In this work, the development of a 3D discrete element method (DEM) modeling concept and application that can describe and explain the catalyst particle growth and fragmentation mechanism and follow the morphology developments is presented. The proposed unified modeling methodology is able to predict the expected particle morphology in terms of exact shape, size, and porosity, taking into account the major contributing effects, including reaction kinetics, thermodynamics as well as mechanical considerations. The developed DEM model is validated based on indicative particle morphology patterns as captured experimentally via the SEM technique, managing to qualitatively predict the observed particle morphology. These results indicate the potential of DEM approach in polymer reaction engineering (PRE), expanding the simulation capabilities and range of application.

What Can Industrial Catalytic Olefin Polymerization Plants Tell Us About Reaction Kinetics? From Production Rate and Residence Time to Catalyst Reaction Performance.

“…In low‐pressure polymerization processes with heterogeneous catalysts, the catalyst particles can be seen as a multitude of semi‐batch micro‐reactors operating in parallel. [ 21 ] Therefore, what actually matters from a mathematical modeling perspective, are the local conditions surrounding the catalyst active sites ‐temperature and local (absorbed) concentrations‐ and the polymerization time. When referring to well‐mixed (ideal) batch processes, one may assume homogenous conditions and equal polymerization time for all catalyst particles, but for continuous processes (such as in continuous stirred tank reactors, CSTRs) new catalyst particles constantly enter the reactor while a fraction of the existing particles exit it, leading to the development of a broad residence time distribution (RTD).…”

Polymerization in the Borstar Polypropylene Hybrid Process: Combining Technology and Catalyst for Optimized Product Performance

“…The catalyst is then fed into the pre-polymerization loop reactor, acting as a preconditioning reactor under milder conditions (e.g., the typical operating temperature ranges from 10 °C to 45 °C). This process step ensures controlled catalyst fragmentation, resulting in smooth operation in the upcoming reaction stages [ 19 ].…”

A Thermodynamic Simulation Package for Catalytic Polyolefin Reactors: Development and Applications

“…Thus, the polymer particle keeps expanding until it exits the reactor. [8,9] Based on this conceptual model, the polymerization rate and properties of polyolefins made in slurry and gas-phase reactors must depend on the concentration of reactants in the amorphous polymer phase surrounding the active sites. Solution reactors are simpler because the active sites and polymer chains are dissolved in a solvent; to analyze their polymerization kinetics, we only need to calculate the concentration of reactive species in the liquid phase.…”