Design of bioethanol green supply chain: Comparison between first and second generation biomass concerning economic, environmental and social criteria

This contribution addresses the optimal design of the biomass supply chain as it is crucial to ensure long term viability of such a project. This work is focused on the multi objective optimization by considering all the dimension of the sustainable development, namely economic, environmental, and social. The environmental dimension is quantified through life cycle assessment, and more particularly the Ecocosts method. The social aspect is measured through two indicators: the competition between energy and food, and the total number of local accrued jobs. For the latter a new method based on financial accounting analysis is proposed to estimate the direct, indirect and induced jobs created. Once the superstructure described, the optimization problem is formulated as a mixed integer linear program (MILP) that accounts for biomass seasonality, geographical availability, biomass degradation, process conversion technologies and final product demand. The output results of the model propose the optimal network design, facilities location, process selection and inventory policy. Since multiple conflicting objectives are involved when optimizing the sustainability of the biomass supply chain and the binary variables have an important influence on the resolution, the MILP problem is solved with the goal programming method to reach the trade-off. The approach is illustrated through a bioethanol supply chain case study in France, for the comparison between agricultural and forest residues biomass