Energy flow modeling and life cycle assessment of apple juice production: Recommendations for renewable energies implementation and climate change mitigation

摘要

Due to the growing population and the subsequent need for more food, food production systems have moved towards industrialization. Accordingly, a large amount of energy, particularly fossil fuels, should be supplied annually to this important sector of the industry, thereby increasing environmental hazards for human health and ecosystems. Therefore, the hotspots of energy consumption and environmental impacts of food production systems should be accurately identified in order to improve their efficiency and sustainability. To this end, energy consumption and environmental impacts of apple juice production in West Azarbaijan province of Iran was analyzed in the present study from farm gate to end of packaging of bottled juice using energy flow and life cycle assessment (LCA) approaches. According to the results of energy analysis, the specific energy consumption of apple juice production was found to be 28.33 MJ/ bottle. More specifically, diesel fuel, natural gas, and polyethylene terephthalate bottles had the greatest contributions to the specific energy consumption of apple juice production. Based on the outcomes of the LCA approach, the corresponding life-cycle greenhouse gas emissions of the resources consumed in apple juice production were 1.83 kg CO2 (eq), mainly caused by the combustion of diesel and natural gas. The damages to ecosystem quality due to acidification and eutrophication were respectively found to be 1.69 x 10(-2) kg SO2 (eq) and 4.54 x 10(-3) kg PO4 (-3) eq, mainly because of resources utilization in the agricultural production step. The emissions released due to the consumption of chemical fertilizers and farmyard manure in the agricultural production step had the highest impacts in acidification and eutrophication impact categories. The emissions arisen from the production and consumption of pesticides were the hotspots in abiotic depletion, ozone layer depletion, human toxicity, freshwater aquatic ecotoxicity, and terrestrial ecotoxicity. Overall, it could be concluded that using bio-fertilizers and biological control approaches in the agricultural production step as well as implementing renewable energy technologies in the juicing step could potentially mitigate the environmental burdens of apple juice production. (C) 2019 Published by Elsevier Ltd.