The pollution of oceans by plastics has become a major environmental problem worldwide. Marine-borne plastics pose new risks to marine life and ecosystems and their impacts on human health are largely unknown as they enter the food chain. Recently, several projects have been initiated worldwide to collect marine plastics using shipboard harvesting approaches. On-board conversion of marine-borne plastics to useful products is a promising technology that could address the limitations of current shipboard harvesting approaches. With support from the Environmental Engineering Program in the Division of Chemical, Bioengineering, Environmental, and Transport Systems and the NSF 2026 Fund Program in the Office of Integrated Activities, Professors Kazantzis and Timko at Worcester Polytechnic Institute propose to explore the feasibility of designing an on-board hydrothermal liquefaction (HTL) system that could harvest and convert marine-borne plastics into useful products including oil, gas or solvents. To achieve this goal, the investigators propose to first develop a modeling framework to simulate the performance of an on-board HTL plastic conversion system. The successful completion of this project will benefit society through helping advance the design and implementation of next-generation technologies to address the global problem of marine plastic pollution. Further benefits to society will be achieved through student education and training, and public outreach including the mentoring of a female doctoral student.
Every year between 4.8 and 12.7 million tons of plastics are released into oceans and marine ecosystems. Hydrothermal liquefaction (HTL) is a promising technology that could convert marine-borne plastics into useful products. The HTL process utilizes a high-temperature and high-pressure reactor to break down plastics into monomers and/or smaller organic compounds, which are then mixed with water to produce oil, gas or solvents. The overarching goal of this EAGER project is to explore the design of an on-board system with the capability to draw in desalinated water and plastics into a HTL reactor to generate useful products. Because the conversion of plastic wastes is not yet practiced commercially, the development of an on-board HTL system is an ambitious and inherently risky undertaking. Thus, the PIs propose to develop a new probabilistic modeling and assessment framework to characterize the technical feasibility, the sustainability profiles as well as the economic viability prospects of an on-board plastic conversion HTL process system by combining thermodynamic modeling (exergy analysis) with TEA and LCA. To account for the uncertainties and related technology risks, the investigators propose to use Monte Carlo simulations to stochastically model and propagate the sources of uncertainties in the model input parameters. This could enable the PIs to generate performance outcome zones and risk-reward distribution profiles rather than single-point estimates of the relevant performance parameters of the proposed on-board HTL plastic conversion system. Thus, the successful completion of this project has potential for transformative impact through the development a new system-modeling framework to advance the design of integrated shipboard collection and reactor systems that could capture and convert marine-borne plastics into useful products.
The supported project further expands the concept from one of the top 33 NSF 2026 Idea Machine entries: Repurposing, Recycling, Renewable Energy.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
