2025 AIChE Annual Meeting

(258e) Solvent-Based Polymer Recovery and Bioethanol Production from Municipal Solid Waste: Economic and Environmental Feasibility

Authors

Yoel Cortes-Pena - Presenter, University of Illinois at Urbana-Champaign
Ezra Bar-Ziv, Michigan Technological University
Fei Long, Michigan Technological University
George W. Huber, University of Wisconsin – Madison
Victor M. Zavala, University of Wisconsin-Madison
Brian G. Fox, Great Lakes Bioenergy Research Center
Municipal solid waste (MSW) continues to accumulate at an unprecedented rate due to rapid urbanization, increasing consumer demand, and global population growth. According to the World Bank, approximately 2.24 billion metric tons of MSW were generated in 2020, and this figure is expected to rise to 3.4 billion tons by 2050 if current trends persist.1 While some progress has been made in recycling and waste diversion, a significant portion of MSW still ends up in landfills or is incinerated. A fundamental obstacle to the effective recycling of MSW lies in its extraordinary complexity. Unlike homogeneous waste streams such as industrial plastic scrap or agricultural residues, MSW is a highly heterogeneous mixture that includes a wide range of organic and inorganic materials.2 These components include food waste, paper and cardboard, yard trimmings, metals, textiles, glass, and plastics. Polyolefins such as polyethylene (PE) and polypropylene (PP) are especially prevalent in MSW but are typically unrecyclable through mechanical processes once mixed and soiled. These factors render conventional recycling techniques inefficient or even infeasible, necessitating innovative approaches that can handle the full heterogeneity of MSW and selectively recover valuable fractions with minimal pre-sorting or purification.

To address the limitations of conventional recycling methods, the Solvent-Targeted Recovery and Precipitation (STRAP) process was introduced in 2020 by Walker et al. as a selective, solvent-based approach for polymer separation.3 STRAP exploits the thermodynamic solubility differences between polymers in organic solvents to achieve targeted dissolution and subsequent recovery by temperature-driven precipitation. Previous studies have shown that STRAP could not only selectively isolate polymers like PE, PP, PET, and EVOH for a variety of industrial wastes, but could also do so with high chemical purity and minimal degradation.4–6 Given STRAP’s robustness, it may be possible to recover the most prevalent polymers, PE and PP, from MSW. Preprocessing of MSW may result in a feedstock mainly composed of biogenic material and polymers, with little to no metals and glass that would interfere with the STRAP process. The remaining nonsoluble co-product of the STRAP process will be enriched in biogenic material that can be readily converted to bioethanol. Altogether, we envision a chemical process that selectively recovers key polyolefins from MSW and produces bioethanol from the biogenic fraction.

In this study, we conducted a techno-economic analysis (TEA) and life cycle assessment (LCA) to evaluate the potential market feasibility and environmental impact of this conceptual STRAP-MSW process. Furthermore, to address the large uncertainty in MSW availability and composition, bioethanol market prices, and potential technological performance at scale, TEA/LCA was coupled with rigorous uncertainty and sensitivity analyses in BioSTEAM—an open-source simulation platform7,8—to elucidate the most salient drivers of sustainability and establish critical targets for research and development. All simulated scenarios demonstrated that the ethanol produced from the STRAP-MSW process resulted in lower carbon intensities than cellulosic ethanol production. The minimum selling price of the recovered polymer resin may be market competitive under optimistic assumptions on the tipping fee credited for MSW, the processing capacity, and the technological performance of bioethanol production.

(1) Solid Waste Management. World Bank Group. February 11, 2022. https://www.worldbank.org/en/topic/urbandevelopment/brief/solid-waste-m….

(2) Diaz, M. A. H.; Lin, Y.; Burli, P. H.; Hossain, T.; Hartley, D. S.; Thompson, V. S. Evaluation of Sustainable Waste Management: An Analysis of Techno-Economic and Life Cycle Assessments of Municipal Solid Waste Sorting and Decontamination. Resour. Conserv. Recycl. 2025, 212, 107970. https://doi.org/10.1016/j.resconrec.2024.107970.

(3) Walker, T. W.; Frelka, N.; Shen, Z.; Chew, A. K.; Banick, J.; Grey, S.; Kim, M. S.; Dumesic, J. A.; Van Lehn, R. C.; Huber, G. W. Recycling of Multilayer Plastic Packaging Materials by Solvent-Targeted Recovery and Precipitation. Sci. Adv. 2020, 6 (47), eaba7599. https://doi.org/10.1126/sciadv.aba7599.

(4) Yan, T.; Granger, C.; Sánchez-Rivera, K. L.; Zhou, P.; Grey, S.; Nelson, K.; Long, F.; Bar-Ziv, E.; Van Lehn, R. C.; Avraamidou, S.; Huber, G. W. Pigment Removal from Reverse-Printed Laminated Flexible Films by Solvent-Targeted Recovery and Precipitation. Sci. Adv. 2025, 11 (11), eadt5841. https://doi.org/10.1126/sciadv.adt5841.

(5) Yu, J.; Munguía-López, A. D. C.; Cecon, V. S.; Sánchez-Rivera, K. L.; Nelson, K.; Wu, J.; Kolapkar, S.; Zavala, V. M.; Curtzwiler, G. W.; Vorst, K. L.; Bar-Ziv, E.; Huber, G. W. High-Purity Polypropylene from Disposable Face Masks via Solvent-Targeted Recovery and Precipitation. Green Chem. 2023, 25 (12), 4723–4734. https://doi.org/10.1039/D3GC00205E.

(6) Sánchez‐Rivera, K. L.; Zhou, P.; Kim, M. S.; González Chávez, L. D.; Grey, S.; Nelson, K.; Wang, S.; Hermans, I.; Zavala, V. M.; Van Lehn, R. C.; Huber, G. W. Reducing Antisolvent Use in the STRAP Process by Enabling a Temperature‐Controlled Polymer Dissolution and Precipitation for the Recycling of Multilayer Plastic Films. ChemSusChem 2021, 14 (19), 4317–4329. https://doi.org/10.1002/cssc.202101128.

(7) Cortes-Peña, Y.; Kumar, D.; Singh, V.; Guest, J. S. BioSTEAM: A Fast and Flexible Platform for the Design, Simulation, and Techno-Economic Analysis of Biorefineries under Uncertainty. ACS Sustain. Chem. Eng. 2020, 8 (8), 3302–3310. https://doi.org/10.1021/acssuschemeng.9b07040.

(8) Cortés-Peña, Y. Thermosteam: BioSTEAM’s Premier Thermodynamic Engine. J. Open Source Softw. 2020, 5 (56), 2814. https://doi.org/10.21105/joss.02814.