NSF Award
2305252
Over one-third of the food produced in the United States goes to waste. About 94% of this wasted food ends up in landfills, incinerators, and municipal sewage systems. In landfills, the decomposition of food waste generates greenhouse gases (methane and carbon dioxide) and other by-products that can cause soil, air, and water pollution. Because food waste is a renewable source of organic carbon that can support a circular economy, there is a critical need for novel and cost-effective processes for converting food waste to high value products. The overarching goal of this project is to explore the conversion of boneless/ homogenized food waste into mesoporous carbon which could be used to fabricate electrodes for supercapacitors and energy storage applications. To advance this goal, the Principal Investigators (PIs) propose to design, evaluate, and optimize a novel 2-stage process which consists of a surfactant assisted hydrothermal carbonization (HTC) of food waste to produce a hydrochar precursor material followed thermal treatment to produce an electrode-grade mesoporous carbon material for preparing supercapacitors with high specific surface area (>2000 m2/g) and electrical capacitance (>275/F/g). The successful completion of this project will benefit society through the generation of new data and fundamental knowledge to advance the conversion of food waste to mesoporous carbon for supercapacitors and energy storage applications. Additional benefits to society will be achieved through student education and training including the mentoring of one graduate student at Old Dominion University and one graduate student at the South Dakota School of Mines and Technology.<br/><br/>Food waste is a promising resource and feedstock for advancing a circular economy. However, there are several challenges associated with the processing and conversion of food waste to valuable organic compounds including its high moisture content, variable composition, and the presence of inorganic impurities. Hydrothermal carbonization (HTC), which can utilize water as a reaction medium, has emerged as promising process for the conversion of food waste to high-value organic products. In this project, the Principal Investigators (PIs) will explore the ulization of surfactant assisted HTC to convert homogenized and boneless food waste to hydrochar followed by the thermal treatment of the produced hydrochar to generate an electrode-grade mesoporous carbon for supercapacitors and energy storage applications. The guiding hypotheses of the proposed research are that 1) the self-assembly of surfactant micelles in hydrothermal media will provide nucleation and growth sites for the dispersed hydrochar that forms during the HTC of food waste and 2) the use of a surfactant will open the pores of the hydrochar during thermal treatment to improve mesoporosity, specific surface area, and ion intercalation. The specific objectives of the research are to 1) conduct mechanistic investigations of hydrochar formation during surfactant assisted HTC; 2) develop and validate treatment processes to remove metallic impurities from hydrochar; 3) investigate the chemical-thermal treatment of the synthesized and purified hydrochar to generate mesoporous carbon; and 4) carry out a life cycle assessment (LCA) and techno-economic analysis (TEA) to evaluate the environmental impact and economic feasibility of producing mesoporous carbon from food waste for supercapacitor manufacturing and energy storage applications. To implement the education and training goals of the project, the PIs propose to leverage existing programs at Old Dominion University (ODU) and the South Dakota School of Mines and Technology (SDSMT) to 1) recruit and mentor graduate and undergraduate students from underrepresented groups to work on the project and 2) develop and implement outreach activities to advance diversity, equity, and inclusion in STEM education including annual workshops at ODU and SDSMT that focus on the science and engineering of food waste conversion to high value products.<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.
