NSF Award
2400997
This Research Advanced by Interdisciplinary Science and Engineering (RAISE) award is made in response to Dear Colleague Letter 23-109, as part of the NSF-wide Clean Energy Technology initiative. Plastics are ubiquitous, they can be found in products ranging from clothes to food packaging. Both manufacturing them and disposing of them are significant sources of greenhouse gas emissions. Additionally, the majority of plastics are made from fossil fuel-derived feedstocks, which are non-renewable resources. Nearly half of plastics are single-use, and almost 80% of plastic waste ends up in landfills or in the environment. Its presence in the environment further damages ecosystems, and as plastic physically degrades, it is converted into microplastics (microscopic particles) that enter soil, water sources, and the food chain. Recycling can extend the usable life of plastic based on the recycling method, but only a small percentage of plastic is currently recycled, due in part to challenges with mixed materials and energy intense recycling methods. Incineration remains the most prevalent method of degradation because of its ease and tolerance for highly complex input mixtures. Research efforts have focused on decreasing the energy requirements and improving product selectivity of recycling processes, but they remain insufficient to solve the plastic waste problem. This project focuses on the development of low-energy strategies to degrade plastics by combining biological and electrochemical engineering approaches. The principal investigators study new strategies for sustainable recycling of plastics with a net-zero approach. Experiments are combined with techno-economic analysis and life cycle assessments to determine the impacts of these technologies as compared to existing approaches. Educational and workforce training are integrated through programs to bring undergraduate and high school students into the researchers’ laboratories at the Massachusetts Institute of Technology. <br/><br/>This project involves the integration of polymer degradation with microbial bioenergy production to achieve the goals of critical materials recycling and net-zero energy. The team will engineer enzymes to enable polymer deconstruction into monomers, subsequently combine this approach with electroactive microbe engineering and systems optimization to utilize the plastic degradation products as feedstock for bioenergy production. The project represents a unique integration of the disparate fields of microbial and electrochemical engineering to achieve unprecedented efficiency in plastic waste remediation. Importantly, the components of the project’s workflow are modular and based on platform technologies that are readily adapted to other environmental contaminants for conversion into feedstocks for bioenergy production and use. The study is a fundamental shift in approach towards sustainable engineering to achieve environmental remediation and emissions reduction goals and represents an integration of diverse fields of study as well as a novel strategy to integrate microbial and electrochemical engineering to controllably generate bioenergy from polymers via bio-electrochemical degradation. The project aims to develop microbial mixtures to degrade polymers and use the degradation products as carbon sources to generate bio-electricity. Importantly, both the electrochemical and microbial proposed technologies are platforms that can be adapted for the degradation and utilization of additional contaminants. Further, the fundamental insights resulting from coupling genetic engineering with high-throughput screening of electroactive microbes are expected move their utilization into the mainstream.<br/><br/>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.
