Life cycle assessment of the Argentine lemon and its derivatives in a circular economy context

Abstract

Over the last few years, a paradigm shift has emerged towards a circular economy that seeks to return to the process as many material/energy flows as possible to increase the sustainability of products, reducing waste and pollution. The citrus industry is not an exception hence one way to apply this approach is through the re-use of certain outflows to produce bioproducts and bioenergy. The objectives of this work are, first, to present the environmental profile of lemons and derivatives in Argentina through the Life Cycle Assessment methodology, and second, to unveil environmental implications of shifting from traditional industries to biorefineries which apply circular economy principles. To do that, the current production scheme for manufacturing essential oil, concentrated juices and dehydrated peel is studied (baseline), to then consider new products, i.e., ethanol, limonene and biogas, through several scenarios with different degrees of biogas recirculation. We find that for lemon production, agrochemicals represent more than 60% in eleven of the twelve impact categories. For processed products, agriculture contributes with more than 50% in all the categories, followed by natural gas and electricity consumption. It also results that adding value to wastes and implementing circular economy strategies do not ensure a better environmental performance of the system. When comparing the current situation with biorefinery schemes, the most promising scenario is the one in which all the biogas is used to produce electricity, causing the least impact in eight of the twelve categories analyzed.