Chemical and Biomolecular Engineering, Department of
Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research
First Advisor
Yaşar Demirel
Date of this Version
12-2019
Document Type
Thesis
Citation
A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science
Major: Chemical Engineering
Under the supervision of Professor Yaşar Demirel
Lincoln, Nebraska, December 2019
Abstract
Adipic acid is an essential intermediate chemical feedstock for the production of nylon-6,6; hence it is valuable from an industrial perspective. Currently, commercial adipic acid production includes a combination of two stages. The first stage produces a mixture of cyclohexanone and cyclohexanol called ‘’KA oil” derived from cyclohexane. In the second stage, KA oil is reacted with nitric acid to produce adipic acid. The second stage generates excess N2O emission, which is considered as 310 times more potent than CO2. Renewable feedstocks that can be converted to value-added chemicals offer significant potential for the necessary transition away from petroleum-based products. To date, biochemical conversion processes of biomass to adipic acid are of great interest to displace the current petroleum-based process. Although several renewable routes are possible for the biobased adipic acid production, it is not yet commercialized. The major obstacle to achieving commercial-scale production is economic viability. target the potential commercial-scale adipic acid production, the following research objectives were pursued: (1) Case 1 is the conversion of biorefinery lignin residue (BLR) to adipic acid. The process undergoes base-catalyzed depolymerization of lignin to its low molecular weight monomers, and subsequent microbial conversion of monomers to cis,cis-muconic acid by Pseudomonas Putida, separation and purification of muconic acid, and catalytic upgrading to adipic acid.
Case 2 is the biocatalytic production of adipic acid from glucose. Within the plant, firstly, glucose and water are sent to an oxidation reactor to produce glucaric acid, and then glucaric acid is converted to adipic acid in a hydrodeoxygenation reactor in the acidic environment and presence of a metal catalyst. These two case studies are simulated, analyzed, and optimized by Aspen Plus, (2) Sensitivity analyses of the processes were applied using the Model Analysis Tool of Aspen Plus. The results of the sensitivity analyses revealed that optimization was necessary to achieve higher product yield and reduce the cost of utilities, and (3) Sustainability metrics, economic analysis, and life cycle assessment are applied to both of the case studies. The results of biobased adipic acid productions are compared with the base case of that commercial adipic acid production, with the aid of the Multi-Criteria Decision Matrix consisting of economic indicators, as well as the sustainability metrics. Overall, the goal of this work is to evaluate the feasibility analysis of both study cases and investigate the adipic acid production with the lowest environmental impact. Additionally, the bottlenecks and uncertainties towards sustainability are identified for future work.
Advisor: Yaşar Demirel
Comments
Copyright 2019, Serpil Unlu. Used by permission