GLOBAL OPTIMIZATION FRAMEWORKS FOR THE PROCESS SYNTHESIS AND SUPPLY CHAIN OF LIQUID FUELS AND AROMATICS PROCESSES

Abstract

Efficient utilization of domestic resources, such as coal, natural gas, biomass, and municipal solid waste, is crucial toward meeting U.S. energy independence targets and addressing concerns regarding energy security, energy affordability, and the generation of lower-carbon energy. This pursuit toward an environmentally sustainable energy landscape requires the development of economically competitive and novel processes. A process systems engineering approach provides an avenue to address these challenges and thus, this thesis develops optimization frameworks for the process synthesis and supply chain of liquid transportation fuels and/or aromatics processes.

On the process scale, the existence of several competing alternatives that can produce liquid transportation fuels and aromatics via a thermochemical pathway make it computationally intractable to consider each process design separately. Therefore, a deterministic global optimization-based process synthesis framework will be presented that consists of several novel, commercial, and/or competing technologies that produce liquid transportation fuels and chemicals from single and hybrid feedstocks. The resulting large-scale, mixed-integer nonlinear (MINLP) optimization model, along with the deterministic global optimization branch-and-bound algorithm used to solve it, are described. The optimal process topologies, together with a detailed analysis of the refineries, are described for several energy systems. In addition, a novel representation of the entire refinery output topography (i.e., the product slate) using a production parameter is also shown.

On the network scale, optimized waste-to-liquids refineries will then serve as candidate facilities in a supply chain analysis that minimizes the total cost of liquid fuels production. The mathematical formulation of the optimization-based supply chain framework, together with solutions providing the strategic locations of waste-to-liquids refineries, will be discussed.