title: Assessing the environmental impact of energy production from hydrochar generated via hydrothermal carbonization of food wastes.
abstract: Although there are numerous studies suggesting hydrothermal carbonization is an environmentally advantageous process for transformation of wastes to value-added products, 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 process water emissions and hydrochar combustion most significantly influence system environmental impact, with a net negative GWP impact resulting for all evaluated substituted energy-sources except biomass. These results illustrate the importance of electricity production from hydrochar particularly when it is used to offset coal-based energy sources. HTC process water emissions result in a net impact to the environment, indicating a need for developing appropriate management strategies. 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.
authors.affiliation: Department of Civil and Environmental Engineering, University of South Carolina, 300 Main Street, Columbia, SC 29208, United States. Electronic address: berge@cec.sc.edu.
authors.forename: Nicole D
authors.initials: ND
authors.lastname: Berge
authors.affiliation: Department of Civil and Environmental Engineering, University of South Carolina, 300 Main Street, Columbia, SC 29208, United States.
authors.forename: Liang
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Civil and Environmental Engineering, University of South Carolina, 300 Main Street, Columbia, SC 29208, United States.
authors.forename: Joseph R V
authors.initials: JR
authors.lastname: Flora
authors.affiliation: Coastal Plains Soil, Water, and Plant Research Center, Agricultural Research Service (ARS), United States Department of Agriculture (USDA), 2611 West Lucas Street, Florence, SC 29501, United States.
authors.forename: Kyoung S
authors.initials: KS
authors.lastname: Ro
mesh_terms: D002244:Carbon; D002606:Charcoal; D003198:Computer Simulation; D004560:Electricity; D004777:Environment; D005502:Food; D018857:Food Packaging; D006358:Hot Temperature; D008670:Metals / Q000737:chemistry; D008962:Models, Theoretical; D012037:Refuse Disposal / Q000379:methods*; D059205:Renewable Energy; D013022:South Carolina
chemical_list: D008670:Metals; C540010:biochar; D002606:Charcoal; D002244:Carbon
keywords: Environmental impact; Food waste; Hydrothermal carbonization; Life cycle assessment