Date of Award
Doctor of Philosophy (PhD)
As the demand for direct petroleum substitutes increases, biorefineries are poised to become centers for conversion of biomass into fuels, energy, and biomaterials. A distributed model offers reduced transportation, tailored process technology to available feedstock, and increased local resilience. Oilseeds are capable of producing a wide variety of useful products additive to food, feed, and fuel needs. Biodiesel manufacturing technology lends itself to smaller-scale distributed facilities able to process diverse feedstocks and meet demand of critical diesel fuel for basic municipal services, safety, sanitation, infrastructure repair, and food production. Integrating biodiesel refining facilities as tenants of eco-industrial parks presents a novel approach for synergistic energy and material exchanges whereby environmental and economic metrics can be significantly improved upon compared to stand alone models. This research is based on the Catawba County NC EcoComplex and the oilseed crushing and biodiesel processing facilities (capacity-433 tons biodiesel per year) located within. Technical and environmental analyses of the biorefinery components as well as agronomic and economic models are presented. The life cycle assessment for the two optimal biodiesel feedstocks, soybeans and used cooking oil, resulted in fossil energy ratios of 7.19 and 12.1 with carbon intensity values of 12.51 gCO2-eq/MJ and 7.93 gCO2-eq/MJ, respectively within the industrial ecology system. Economic modeling resulted in a biodiesel conversion cost of $1.43 per liter of fuel produced with used cooking oil, requiring a subsidy of $0.58 per liter to reach the break-even point. As subsidies continue significant fluctuation, metrics other than operating costs are required to justify small-scale biofuel projects.
Ferrell, Jeremy C., "A Distributed Model Of Oilseed Biorefining, Via Integrated Industrial Ecology Exchanges" (2014). Dissertations. 65.