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Thesis (Ph. D.)--University of Wisconsin--Madison, 1943. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 75-76).

Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references.

Thesis (Ph. D.)--Washington State University, May 2010. / Title from PDF title page (viewed on June 3, 2010). "Department of Biological Systems Engineering." Includes bibliographical references.

Thesis (Ph.D.)--Aberdeen University, 2009. / Title from web page (viewed on Feb. 18, 2010). Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 135-141).

Thesis (M.S.)--University of Wisconsin--Madison, 1984. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 60-72).

Thesis (Ph.D.)--OGI School of Science & Engineering at OHSU, July 2006. / Includes bibliographical references (leaves 97-114).

Doctor of Philosophy / Department of Chemical Engineering / Peter H. Pfromm / Since its inception, the Haber-Bosch (HB) process for ammonia (NH3) synthesis has allowed for a significant increase in global food production as well as a simultaneous decrease in global hunger and malnutrition. The HB process is estimated to be responsible for the subsistence of 40% of the world population as approximately 85% of the over 182 metric tons of NH3 produced in 2017 was used as fertilizer for crop production. The natural gas consumed (mostly to generate H2) represents approximately 2% of the global energy budget, while the CO2 produced is about 2.5% of all global fossil CO2 emissions. Approximately 40% of food consumed is essentially natural gas transformed by the HB process into agricultural products. However global food production will need to double due to expected increase in world population to 9.6 billion by 2050 and rising demand for protein among developing nations. A novel thermochemical reaction cycle for sustainable NH3 synthesis at atmospheric pressure is explored herein. Both thermochemical and kinetic rationales are discussed regarding choice of Mn as the cycled reactant. The energetic driving force for these reactions is conceptually derived from concentrated solar energy. Mn was reacted with N2 forming Mn-nitride, corrosion of Mn-nitride with steam at 500 °C formed MnO and NH3, and lastly MnO was reduced at 1150 °C in a 4 vol % CH4 – 96 vol % N2 stream to Mn-nitride closing the cycle. Optimum nitridation at 800 °C and 120 min produced a Mn6N2.58-rich Mn-nitride mixture containing 8.7 ± 0.9 wt. % nitrogen. NH3 yield was limited to 0.04 after 120 min during nitride corrosion but addition of a NaOH promotor improved NH3 yield to 0.54. Mn6N2.58 yield was 0.381 ± 0.083 after MnO reduction for 30 min with CO and H2 but no CO2 detected in the product. Mn-nitridation kinetics were investigated at temperatures between 600 and 900 °C for 10 and 44 μm reactant powder particle sizes. That equilibrium conversion decreased with increasing temperature was confirmed. Jander’s rate law, which assumes gaseous reactant diffusion through a solid product layer, described the experimental data reasonably well. The rate constants and initial rates were as much as an order of magnitude greater for the 10 μm Mn reactant particle size. Additionally the activation energy was found to be 44.1 kJ mol-1 less for the 10 μm reactant particle size. Reducing the particle size had a small but positive effect on Mn-nitridation kinetics. Further reducing particle size will likely have a greater impact. A review of relevant classical thermodynamics is discussed with special attention paid to open systems. Confidence issues regarding over-reliance on x-ray diffraction are considered with options suggested for mitigation. Opportunities for future work are assessed.

Application of microwave (MW) radiation followed by aeration (A) for the purpose of ammonia removal from both synthetic solutions and landfill leachate was investigated in this study. Four sets of experiments: water bath (WB), microwave (MW), sequential microwave/aeration process (MW+A), and sequential water bath/aeration process (WB+A) were conducted using synthetic solution. MW and MW+A tests were applied on the landfill leachate as well. For each test, either 100 mL of synthetic solution or landfill leachate was used. All the tests were conducted with three replicates in batch scale. For both economic and safety concerns, the samples’ temperature were maintained below the boiling point. One-way ANOVA tests and T-tests were conducted to analyze the differences of ammonia removal efficiencies among different methods. Both thermal and non-thermal effects for the sequential microwave/aeration process were investigated. Factorial design and response surface methodology (RSM) were applied to evaluate and optimize the effects of pH, MW energy level and microwave power output. Results confirmed that the sequential microwave/aeration process was an effective approach for removal of ammonia from aqueous systems. Maximum ammonia removal of 81.7 % for synthetic solution and 70% for landfill leachate was achieved by applying 7.8 KJ MW energy output/L sample and 10 minutes aeration. When apply the sequential microwave/aeration process to synthetic solution, at optimum condition of pH 10.5, 7.8 KJ MW energy output/L sample and 10 minutes aeration time, the contribution of thermal process was 39%, while 61% for non-thermal processes (33% for aeration and 28% for EMF). Statistical analysis of synthetic solution tests data using RSM showed that ammonia removal efficiency strongly depended on pH and MW energy output. R square of 0.941 indicates that observed results fitted well with the model prediction. Optimum pH and MW energy output level for ammonia removal was 11 and 7.8 KJ MW energy output/L sample respectively, and under this condition, maximum ammonia removal efficiency predicted for synthetic solution was 76.3%.