Life cycle assessment of nine representative agroindustrial systems of sugar production in Mexico

Abstract

Mexico is the sixth-largest producer of sucrose worldwide. Therefore, evaluating the environmental impacts of Mexican sugar and proposing impact mitigation strategies is of high importance since this would support better environmental performance and foster competition within the sector. However, the technological variability that occurs between farms and sugar mills, together with the different types of sugar that are produced, makes it difficult to identify a single agro-industrial production system for sugar production, that represents the entire sector. Environmental improvement strategies identified for one system are specific and have a low level of applicability to others. Therefore, the aim of this study is to develop a life cycle assessment study of nine representative sugar production systems in Mexico, considering 1 ton of sugar as a functional unit while also considering the types of sugar and technological level. The nine sugar life cycle systems analyzed were classified as follows: standard conventional (SC), standard semimechanized (SSM), standard mechanized (SM), refined conventional (RC), refined semimechanized (RSM), refined mechanized (RM), muscovado conventional (MC), muscovado semimechanized (MSM) and muscovado mechanized (MM). The results showed that conventional systems demonstrated a better environmental performance for all the impact categories analyzed, primarily because they have a lower energy requirement in cultivation and irrigation, require less fertilizers and applied pesticides, and in the industrial stage, require less chemicals for clarification. Regarding the types of sugar, Muscovado presented the lowest environmental impacts in all the categories analyzed, since it only requires one crystallization and centrifugation process, followed by drying, which is associated with lower requirements for electricity, heat, and steams. The results would suggest that the strategic avenues for further improving the environmental profile of sugarcane production and processing could include (a) continued pursuit of high yields, which is an important determinant of the environmental impacts of agricultural products, (b) precision application of fertilizers to reduce the potential for losses to the environment and (c) maximizing the utilization of coproducts to increase environmental credits.