An integrated methodology for the economic and environmental assessment of a biorefinery supply chain

A supply chain network MILP model, developed by means of AIMMS software, and a pro-cess plant simulation model, developed by means of Aspen Plus, are combined for theoptimization of a biorefinery network. Optimization of the supply chain network is initiallyaddressed using literature process and economic data. The results are used as input in theAspen Plus model where the technical and economic performance of the biorefineries iscalculated rigorously. The two computational tools are iteratively executed until convergence on number, locations and size of the biorefineries and on process yield to productsand total costs is achieved. The final results are used to perform the Economic Value and Environmental Impact (EVEI) analysis of the overall biorefinery network. The methodologyis applied to a case study concerning the deployment of cereal straw in Germany to pro-duce ethanol, ethyl levulinate and electricity. Optimization results reveal that the wheatstraw supply network with four biorefineries is economically feasible and determines anenvironmental margin in terms of equivalent emissions savings of about 4 Mt of CO2peryear.