supply chain design

This paper analyzes the impact that an intermodal facility has on location and transportation decisions for biofuel production plants. Location decisions impact the management of the in bound and out-bound logistics of a plant. We model this supply chain design and management problem as a mixed integer program. Input data for this model are location of intermodal facilities and available transportation modes; cost and cargo capacity for each transportation mode; geographical distribution of biomass feedstock, and production yields; and biomass processing, and inventory costs. Outputs from this model are the number, location and capacity of biofuel production plants. For each plant, the transportation mode used, timing of shipments, shipments size, inventory size, and production schedule that minimize the delivery cost of biofuel are determined. The model proposed in this research can be used as a decision making tool for investors in the biofuels industry as it estimates the real cost of the business. The state of Mississippi is considered as the testing grounds for our model.

The objective of this study is to design and evaluate the performance of the supply chain for biocrude production from activated sewage sludge in wastewater treatment facilities. Experimental results indicate that feeding wastewater activated sludge with high sugar load and establishing a high carbon-to-nitrogen ratio in the wastewater can enhance biocrude yield and quality from the sludge. The biocrude will be further refined and converted to biodiesel. The optimization part, of the optimization-simulation framework that we propose, uses a mixed integer program to identify locations for sugar plants as well as the assignment of wastewater treatment plants to sugar plants and refineries. The objective is to minimize total supply chain related costs. We use the solution from the optimization model (the structure of the supply chain) to build a discrete-event simulation model. The simulation captures the seasonal and random nature of biomass supply. We use a case study that designs the supply chain for biocrude in Mississippi given the availability of lignocellulosic biomass, the locations of harvesting sites, location of wastewater treatment plants, and location of refineries