Sustainability assessment of orange peel waste valorization pathways from juice industries

A wide variety of products such as high value-added bioactive materials, biofuels, biochemicals and bioplastics can be obtained by the valorization of waste streams in a comprehensive and holistic biorefinery concept. In this study a meta-analysis of the available technologies utilizing organic waste derived from the juice industry is conducted. Initially, a mass flow analysis is performed to quantitatively illustrate the available orange peel waste volumes in the EU followed by a geographic distribution. The overall sustainability of the available valorization scenarios is then analyzed by considering critical environmental, economic and energy indicators and comparing innovative and conventional valorization technologies. Innovative technologies are better in terms of energy requirements and extraction time and also, in product yield and environmental performance than the conventional ones (85.1%, 9.5% and 47.9% lower CO₂ eq values for the extraction of essential oils, pectin and phenolic compounds respectively). In terms of orange peel waste valorization scenarios, landfilling shares the largest environmental impact, followed by thermochemical and biological conversion alternatives. Complex biorefinery schemes are proportionate to environmental performance and energy consumption, but inversely proportionate to production cost. Finally, a trade-off analysis illustrates a positive correlation between environmental indicators of the most under study valorization scenarios.