Optimal Planning of Feedstock for Butanol Production Considering Economic and Environmental Aspects

This paper presents a multiobjective optimization to obtain the optimal planning of butanol production, considering the optimal selection of feedstock and the correct was applied during both the fermentation and purification ratio of fermentable sugars. This multiobjective methodology process of butanol. The multiobjective optimization problem considers minimizing the total annual cost and environmental impact as objective function. The economic objective function takes into account the availability of bioresources, the cost of feedstocks, the fermentation conditions, and the separation units. On the other hand, the environmental assessment includes the overall impact measured through the eco-indicator 99 which is based on a life cycle analysis methodology. Both objective functions were applied to a case study for the optimal planning to produce biobutanol in Mexico. After the optimization process, we generated a set of solutions represented by a Pareto curve that identifies a group of optimal solutions for both objectives. Considering the best compromise of both targets, the best solution involves initially a raw material with a moderate content of sugars followed by a separation unit designed as a hybrid separation process. This hybrid process considers the inclusion of a liquid liquid extraction column followed by three thermally coupled distillation columns.