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Carbon and Energy Footprinting across Archetypes for U.S. Maple Syrup Production
Spencer M Checkoway1, Geoffrey M Lewis1, Gregory A Keoleian1
1Center for Sustainable Systems, School for Environment and Sustainability, University of Michigan, Dana Building, 440 Church Street, Ann Arbor, Michigan 48109-1041, United States.
Abstract:
The production of maple syrup from sap requires extensive processing, which has traditionally led to significant energy inputs and greenhouse gas (GHG) emissions per gallon produced. Technology advancements, e.g., vacuum tubing sap collection systems, reverse osmosis (RO), and electric evaporators have changed the way syrup is produced, resulting in widespread variability in processing equipment and sugar-making operational decisions. This paper evaluates these complex operations through a cradle-to-retail gate carbon footprinting model and by capturing variability in a series of producer archetypes. By isolating energy and emissions impacts, we find that implementing RO has the largest reduction effect on energy (54-77%) and emissions (57-82%), depending on both production size and evaporator fuel (wood, fuel-oil, or electricity). Results also demonstrate the effect of production scale on cumulative energy demand (CED) and emissions per gallon of syrup, with small producers ranging from 333-1,425 MJ/gal and 27-118 kg CO2e/gal (61-90% biogenic on-site) for wood-fired operations and 18-65 kg CO2e/gal for oil-fired operations. Large producers ranged from 90-131 MJ and 3.5-7 kg CO2e/gal (electricity to oil-fired operations). Producers of all scales with the highest rates of electrification in their operations have the lowest GHG emissions and energy use per gallon of syrup produced.
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