Economic, environmental, and social impacts of different sugarcane production systems

Abstract

Mechanization in the sugarcane agriculture has increased over the last few years, especially in harvesting and planting operations, in the Brazilian Center-South region. The consequences of such a technological shift, however, are not fully comprehended when multiple perspectives are considered such as economic aspects, environmental regulations, and social context. The main goal of this study is to generate comprehensive information to subsidize decision-making processes not only in Brazil but also in other countries where sugarcane production is still under development. Manual and mechanical technologies for planting and harvesting were evaluated (with and without pre-harvest burning), as well as straw recovery, seeking to identify their advantages and disadvantages, considering economic, environmental, and social aspects. Considering vertically integrated production systems (agricultural and industrial phases), sugarcane production scenarios were compared under the metrics from engineering economics, life cycle assessment (LCA), and social LCA. Manual technologies were related to the highest job creation levels; however, lower internal rates of return and higher ethanol production costs were also observed. In general, mechanized scenarios were associated with lower ethanol production costs and higher internal rates of return due to lower biomass production cost, higher ethanol yield, and higher electricity surplus. Considering the restrictions for sugarcane burning and practical diffi culties of manual harvesting of green cane, environmental analysis showed that mechanical harvesting of green cane with straw recovery presents, in general, the best comparative balance of of the sustainability aspects. Th e aims were to analyze the economic, social, and environmental aspects of manualand mechanical-based sugarcane production systems in Brazil, as well as their eff ects on the ethanol production system when a vertically integrated production model is considered. Th is work identifi es strengths and weaknesses of these technologies and enlightens decision making processes in other countries with substantial potential for sugarcane production expansion for bioenergy, such as South Africa, Mozambique, Colombia, Guatemala, among others. Materials and methodsIn this paper, the Virtual Sugarcane Biorefi nery (VSB) was used to perform the simulations which give support to the technology assessments. Th e VSB has been developed by the Brazilian Bioethanol Science and Technology Laboratory (CTBE/CNPEM), which is an integrated computer simulation platform that evaluates technologies in use or under development, estimating the economic, environmental, and social impacts of the entire sugarcane production chain.22 Th e computational model for simulation and quantification of important parameters for technical, economic, environmental, and social assessment of the agricultural practices in the sugarcane production system are performed in CanaSoft . Th is model, which is one of the tools within VSB, is based on spre...

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Critique of selected peer-reviewed publications on applied social life cycle assessment: focus on cases from developing countries

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Electricity Production from Sugarcane Straw Recovered Through Bale System: Assessment of Retrofit Projects

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