processes Article Optimization of the Algal Biomass to Biodiesel Supply Chain: Case Studies of the State of Oklahoma and the United States Soumya Yadala 1, Justin D. Smith 1, David Young 2, Daniel W. Crunkleton 1 and Selen Cremaschi 2,* 1 Russell School of Chemical Engineering, The University of Tulsa, Tulsa, OK 74104, USA;
[email protected] (S.Y.);
[email protected] (J.D.S.);
[email protected] (D.W.C.) 2 Department of Chemical Engineering, Auburn University, Auburn, AL 36830, USA;
[email protected] * Correspondence:
[email protected] Received: 29 February 2020; Accepted: 15 April 2020; Published: 18 April 2020 Abstract: The goal of this work is to design a supply chain network that distributes algae biomass from supply locations to meet biodiesel demand at specified demand locations, given a specified algae species, cultivation (i.e., supply) locations, demand locations, and demand requirements. The final supply chain topology includes the optimum sites to grow biomass, to extract algal oil from the biomass, and to convert the algae oil into biodiesel. The objective is to minimize the overall cost of the supply chain, which includes production, operation, and transportation costs over a planning horizon of ten years. Algae production was modeled both within the U.S. State of Oklahoma, as well as the entire contiguous United States. The biodiesel production cost was estimated at $7.07 per U.S. gallon ($1.87 per liter) for the State of Oklahoma case. For the contiguous United States case, a lower bound on costs of $13.68 per U.S.