Energy Recovery from Sugarcane-Trash in the Light of 2nd Generation Biofuel. Part 2: Socio-Economic Aspects and Techno-Economic Analysis

Abstract

Since last decade of twentieth century, the change in cane harvesting method from manual harvesting of burned cane to mechanical harvesting of green cane brought the real possibility of sugarcane-trash energy use. The sugarcane-trash, also called Sugarcane Agricultural Residues (SCAR) represents 1/3 of total sugarcane energy content. Despite SCAR is considered today the main unexplored energy reserve in the sugarcane agro-industry a negligible part of this residues is used. Starting from the analysis of the current situation and environmental aspects described in Part1 of the present work (Alonso Pippo et al. in Waste Biomass Valoriz 1), an assessment on socio-economic aspects of SCAR and energy use was carried out. The impact of sugarcane mechanized harvesting on employment was described. The food versus biofuels production from crops was analyzed. SCAR characteristic in face 2nd generation biofuels requirements was treated. The social aspects related to land use were evaluated. A Linear Programming model for profitability maximization was used in order to estimate economical benefits derived from SCAR energy use. The model solution showed that among the variables should be considered in order to maximize profitability special attention deserves: sugarcane production and SCAR transportation cost. It seems to be that sugarcane mechanized harvesting combined with train transport are among the best infrastructure conditions to maximize the profit. When it is delivered to sugar-mill by train SCAR cost can be up to five times cheaper than when it is delivered using articulated lorries. Assuming SCAR energy use for electricity cogeneration as main priority, it was calculated the optimal size for sugarcane factory from techno-economic point of view. An added value/added cost analysis on SCAR energy use at a medium size factory was carried out.