Michael Ryder

Date of Award

January 2023

Document Type


Degree Name

Doctor of Philosophy (PhD)


Energy Engineering

First Advisor

Michael Mann

Second Advisor

Olusegun Tomomewo


Rare earth elements are critical materials for many technologies driving the energy industry forward. However, there is increasingly low security and lack of sustainability of current supplies. New sources and processing methods are needed and are being intensely investigated among U.S. energy leaders such as rare earth extraction from lignite coal in North Dakota. A critical need is to confirm the technological and economic viability of these approaches, aspects which are inherently interconnected, would benefit from a dynamic approach. The current approach is Techno-Economic Assessments (TEAs). TEAs evaluate the economics of the process and commercialization of the technology for viability before substantial investment is made. Standard TEAs are high-effort endeavors, and most often performed in a spreadsheet format, with hundreds to thousands of built-in equations and assumptions. Due to these features, standard TEAs have a high potential for errors and can be difficult to effectively communicate with stakeholders. Standard TEAs also do not allow for evaluation of critical dynamic variables or feedback loops within the system. TEAs drive decision making; errors in them may either limit the potential of processes if the economic results are understated or may mislead investors if the economic potential is overstated. An alternative methodology is system dynamics (SD) modeling. SD models are developed and presented in a clear visual format with explicit assumptions. SD models also readily incorporate and utilize dynamic variables. Based on these factors, SD is proposed to be a more comprehensive, less error prone, and more accessible approach than the current, standard approach to TEAs. This research effort utilized systematic literature review and application of SD modeling to an existing rare earth TEA to evaluate if the benefits of SD could enhance the outcome of a standard TEA. The findings suggest that a generic TEA structure can be applied to real projects resulting in the discovery and correction of errors and inclusion of more realistic aspects of the project resulting in more likely outcomes. In the cases analyzed, the corrections and improvements result in substantial increase in the economic potential of the process.