The PI will explore hydrothermal carbonization (HTC) as a treatment process that sustainably promotes carbon sequestration and value-added product production from waste streams. The specific objectives of this work are to: (1) understand how the interaction between compounds (e.g., cellulose and lignin) and catalyst addition influences the HTC process, (2) elucidate the mechanisms associated with emerging contaminant fate in the HTC processes, and (3) integrate research and education to increase student and practitioner awareness of HTC and the sustainability of waste utilization. A series of laboratory experiments will be conducted to understand how reaction conditions and mixtures of compounds influence HTC processes. HTC reaction rates, activation energies, end-product characteristics, and process energetics (i.e., heat of reaction), as well as the capacity of the process to effectively treat emerging contaminants, are important when considering its use as a waste treatment technique. This research will identify how mixtures of compounds influence HTC reaction characteristics for feedstocks representing common waste streams. Correlations between feedstock, process conditions, carbon sequestration, process water quality, and hydrochar quality will be established. This research is transformative in that it is the first study evaluating HTC (reaction kinetics, process energetic, etc.) of waste materials and will result in an extensive data set for evaluating a technology that has global implications.
Integration of research and education is a critical component of this work. Significant efforts will be made to introduce HTC and waste sustainability issues to students (K-12, undergraduate, and graduate students) and practitioners. Specific activities include: (1) development of an undergraduate level problem-based laboratory course in environmental engineering, (2) development and implementation of a program that can be applied to middle school classrooms to increase student and teacher awareness to environmental engineering issues and careers, (3) conduct workshops to educate practitioners about HTC, and (3) continue mentoring of underrepresented students and involving them in research and educational activities.
In terms of the broader impacts, results from this work will aid in current policy discussions with respect to climate change, clean and renewable energy, and environmental impact of our waste-related processes. The PI will promote teaching, training, and learning while conducting this research, particularly with respect to underrepresented groups. The PI will continue to mentor young students through collaborations with an HBCU college located in Columbia, SC. A large population of potential future engineers and scientists will be reached via the K-12 education/outreach activities.
