Reducing the cost and environmental impact of integrated fixed and mobile bio-oil refinery supply chains

Abstract

The call to decrease reliance on fossil fuels to reduce impacts on the environment and improve energy independence has created new duties and responsibilities within society. As one approach, mobile bio-oil refineries have been developed to facilitate the production of bio-oil near the source of underutilized forest harvest residues. These mobile refineries are expected to improve the robustness of woody biomass to bio-oil supply chains by reducing overall supply chain costs and environmental impacts. The use of mobile refineries in combination with large-scale non-mobile refineries, however, must be examined to better understand the potential economic and environmental benefits and drawbacks of such a supply chain. The research presented herein develops a mathematical model capable of helping decision makers in determining the optimal combination and location of fixed refineries and mobile refineries for a known quantity of woody biomass and a given set of harvesting locations by considering capital, operational, and transportation costs. A hypothetical case for northwest Oregon, USA is applied to verify the mathematical model. The supply chain environmental impacts are assessed by considering the carbon footprint of the transportation activities and the bio-refinery infrastructure. The results indicate that the use of a mobile refinery along with a fixed refinery is more suitable when transportation costs and distances increase. It is also found that the capital intensity of mobile refineries can influence the importance of their role. High capital cost can be detrimental to their application within a mixed-mode bio-oil supply chain.