PURPOSE: Polyurethane recycling: Unifying molecular dynamics and process flow simulation for optimized separations
Abstract
Polyurethanes (PU) are widely used in mattresses, upholstery, furniture, automotive, construction, and insulation. They are mostly thermoset foams, made by reacting isocyanates with polyols. Their thermoset nature limits mechanical recycling, making chemical recycling crucial for circularity. The resulting aromatic molecules, ureas, amines and polyols from depolymerization have varied physicochemical characteristics, impacting separation during recycling. This doctorate aims to expand recycling rates and enhance the recyclability of PU foam materials by creating a radically new workflow for assessment of separability of polyols and aromatic fractions from depolymerized PU mixtures. This framework leverages molecular dynamics to determine unknown thermodynamic and physicochemical properties (binary interactions, heat of vaporization/capacity, density, vapor pressure, critical parameters) to create a bridge between micro- and macro-scale modelling. Macro-scale modelling results can be used to assess separability of specific waste streams based on process and economic indicators. The emphasis is first put on the polyol and aromatic fraction, as they are most abundant in the industry. Later, additives are also studied to completely understand the physical phenomena during separation. Machine learning is used to increase the chemical space that can be studied as well as to accelerate and increase the comprehensibility of the workflow.Researcher(s)
- Promoter: Billen Pieter
- Co-promoter: Nimmegeers Philippe
- Fellow: de Graaf Christophe
Research team(s)
Project type(s)
- Research Project
Polyurethane recycling: Unifying molecular dynamics and process flow simulation for efficient separation and optimization.
Abstract
Polyurethanes (PU) are widely used in mattresses, upholstery, furniture, automotive, construction, and insulation. They are mostly thermoset foams, made by reacting isocyanates (MDI, TDI, or HDI) with polyols. Their thermoset nature limits mechanical recycling, making chemical recycling crucial for circularity. The resulting aromatic molecules, ureas, amines and polyols from depolymerization have varied physicochemical characteristics, impacting separation during recycling. This doctorate aims to use thermodynamic modeling tools to predict the ease of separating depolymerized PU mixtures. Methods include activity coefficient based models (NRTL, UNIFAC, HANSEN) that are accompanied by computational chemistry methods to optimize the models and fill in unknown gaps. Modeling results will inform engineering software for process design, optimizing recycling for recyclers and informing circular design for PU formulators and recyclers. The focus is primarily on predicting interactions between different polyols used in PU, considering monomer composition, degree of branching, molecular weight distribution, and functionality, to facilitate efficient separations. Later, other constituents are covered in more detail as well. The goal is to provide recyclers and formulators with insights for process optimization and improved circularity of PU materials.Researcher(s)
- Promoter: Billen Pieter
- Co-promoter: Cunha Ana
- Co-promoter: Nimmegeers Philippe
- Fellow: de Graaf Christophe
Research team(s)
Project type(s)
- Research Project