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ARS Home » Southeast Area » Florence, South Carolina » Coastal Plain Soil, Water and Plant Conservation Research » Research » Publications at this Location » Publication #312659
Title: Assessing the environmental impact of energy production from hydrochar generated via hydrothermal carbonization of food wastes

Author
item BERGE, NICOLE - University Of South Carolina
item LI, LIANG - University Of South Carolina
item FLORA, JOSEPH R.V. - University Of South Carolina
item Ro, Kyoung

Submitted to: Journal of Waste Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2015
Publication Date: 6/3/2015
Citation: Berge, N.D., Li, L., Flora, J., Ro, K.S. 2015. Assessing the environmental impact of energy production from hydrochar generated via hydrothermal carbonization of food wastes. Journal of Waste Management. 43:203-217.

Interpretive Summary: Hydrothermal carbonization (HTC) is an emerging technology which converts wet biomass material into charcoal called hydrochar. This study evaluated the environmental impacts of producing energy by combusting hydrochar made from wood wastes. It used a life cycle assessment modeling approach to evaluate various environmental impacts associated with the food waste hydrothermal carbonization and subsequent combustion of the hydrochar. The HTC process liquid and hydrochar combustion contribute most significantly to system environmental impact. Sorting efficiencies influence the environmental impact of a food waste carbonization system. Results from this analysis also highlight a need for additional exploration of liquid and gas-phase composition, a better understanding of how changes in carbonization conditions (e.g., reaction time and temperature) influence the fates of metal and nutrients and HTC process liquid treatment.

Technical Abstract: Hydrothermal carbonization (HTC) is a relatively low temperature thermal conversion process that is gaining significant attention as a sustainable and environmentally beneficial approach for the transformation of biomass and waste streams to value-added products. Although there are numerous studies suggesting hydrothermal carbonization is an environmentally advantageous process, a systems level evaluation of the environmental impacts associated with hydrothermal carbonization and subsequent hydrochar combustion has not been conducted. The specific objectives of this work are to use a life cycle assessment approach to evaluate the environmental impacts associated with the HTC of food wastes and the subsequent combustion of the generated solid product (hydrochar) for energy production, and to understand how parameters and/or components associated with food waste carbonization and subsequent hydrochar combustion influence system environmental impact. Results from this analysis indicate that HTC product composition (e.g., liquid and solid) controls system environmental impact. The liquid-phase emissions and hydrochar combustion contribute most significantly to system environmental impact. Results from this analysis also highlight a need for additional exploration of liquid and gas-phase composition, a better understanding of how changes in carbonization conditions (e.g., reaction time and temperature) influence metal and nutrient fate, and the exploration of liquid-phase treatment. Results also indicate that sorting efficiencies influence the environmental impact of a food waste carbonization system.