Affiliation:
1. University of Wisconsin-Madison, Department of Chemical and Biological Engineering, Madison, Wisconsin, USA
Abstract
This paper introduces a computational framework for selecting green solvents to separate multilayer plastic films, particularly those challenging to recycle through mechanical means. The framework prioritizes the selective dissolution of polymers while considering solvent toxicity. Initial screening relies on temperature-solubility dependence, utilizing octanol-water partition coefficients (LogP) to identify non-toxic solvents (LogP = 3). Additionally, guidelines from GlaxoSmithKline (GSK), Registration, Evaluation, Authorization, and Restriction of Chemical Regulation (REACH), and the US Environmental Protection Agency (EPA) are employed to screen for green solvents. Molecular-scale models predict temperature-dependent solubilities and LogP values for polymers and solvents. The framework is applied to identify green solvents for separating a multilayer plastic film composed of polyethylene (PE), ethylene vinyl alcohol (EVOH), and polyethylene terephthalate (PET). The case study demonstrates the framework's effectiveness in identifying environmentally friendly solvents and balancing trade-offs between solvent toxicity and solubility. Furthermore, the framework informs process design by screening for suitable green solvents in selective dissolution processes, potentially leading to the development of more sustainable dissolution processes and the identification of easily recyclable polymer blends in multilayer plastic films.