It was the aim of this investigation to prepare derivatives of 1,4-naphthoquinone substituted at the 2- and 3- positions with various amino groups. 2,3-Dichloro-1,4-naphthoquinone was selected as the starting material because of the possibility of replacing the chloro groups in direct substitution reactions with amines.

No description available.

This thesis seeks to improve the economic viability of carbon capture process by reducing the energy requirement of amine scrubbing technology. High steam requirement for solvent regeneration in this technology can be reduced by improvements in the regeneration process. Solvent models based on experimental results have been created by previous researchers and are available for simulation and process modeling in Aspen Plus®. Standard process modeling specifications are developed and multiple regeneration processes are compared for piperazine (a cyclic diamine) in Chapter 2. The configurations were optimized to identify optimal operating conditions for energy performance. These processes utilize methods of better heat recovery and effective separation and show 2 to 8% improvement in energy requirement as compared to conventional absorber-stripper configuration. The best configuration is the interheated stripper which requires equivalent work of 29.9 kJ/mol CO₂ compared to 32.6 kJ/mol CO₂ for the simple stripper. The Fawkes and Independence solvent models were used for modeling and simulation. A new regeneration configuration called the advanced flash stripper (patent pending) was developed and simulated using the Independence model. Multiple complex levels of the process were simulated and results show more than 10% improvement in energy performance. Multiple cases of operating conditions and process specifications were simulated and the best case requires equivalent work of 29 kJ/mol CO₂. This work also includes modeling and simulation of pilot plant campaigns carried out for demonstration of a piperazine with a 2-stage flash on at 1 tpd CO₂. Reconciliation of data was done in Aspen Plus for solvent model validation. The solvent model predicted results consistent with the measured values. A systematic error of approximately +5% was found in the rich CO₂, that can be attributed to laboratory measurement errors, instrument measurement errors, and standard deviation in solvent model data. Stripper Modeling for CO₂ capture from natural gas combustion was done under a project by TOTAL through the Process Science and Technology Center. Two configurations were simulated for each of three flue gas conditions (corresponding to 3%, 6% and 9% CO₂). Best cases for the three conditions of flue gas require 34.9, 33.1 and 31.6 kJ/mol CO₂. / text

With the ever increasing environmental concerns in terms of the need for a vast improvement in clean energy and clean air technologies, this thesis focuses on analyzing the underlying principles that determine the activity of catalysts/sorbents for fuel cell applications and CO₂ capture using first principles based simulations with a view point to help fabricate efficient catalysts. We attempt to clarify the fuzzy concepts of existing surface-nearsurface interactions in Pd based electrocatalysts with particular attention to Pd₃Co alloy catalysts by presenting a thorough inter and intra-layer orbital analysis and bring forth the crucial role played by the surface-subsurface binding driven by the out of plane d-state interactions in determining the surface reactivity. We first decouple the effects induced by the different Pd-Pd and Pd-Co lattice parameters (lattice strain effect) from the hetero atom induced surface-subsurface interaction (we call it "interlayer ligand effect") and clearly demonstrate how enhanced surface-subsurface d [subscript xz+yz] interaction leads to an increased oxygen hydrogenation to H₂O in Pd₃Co based electrocatalysts. We then extend the concept of hetero atom induced surface-subsurface binding to a series of 3d transition metals and provide guidelines for the right choice of metals that may be potential ORR candidates. Finally, we describe the facet dependence and the effect of surface Au alloying on the surface reactivity of Pd₃Co electrocatalysts. In the second section of the thesis, we emphasize on the underlying principles of CO₂ capture by MEA and study the synergetic interplay of various factors that may lead to better CO₂ capture , also enabling efficient solvent regeneration. Though extensive studies are carried out on the most traditionally used alkanol amine MEA for CO₂ capture, there are several less studied aspects like the molecular orbital redistribution on CO₂ binding that decides the fate of the intermediate species and the role of water arrangement in assisting/hindering the progress of the reaction. We study the fundamental CO₂-amine interactions and highlight the crucial importance of alkanol-amine configuration, water arrangement and protonation/de-protonation tendencies at various basic sites in the development of the reaction. We then analyze the synergetic interplay between the inductive effect, the steric hindrance and the resonance in enhancing efficient CO₂ binding and allowing an alternative O-driven mechanism resulting into easy solvent regeneration. We believe that our efforts may help fabricate better catalysts and sorbents and help improve the existing clean energy and clean air technologies. / text

No description available.

No description available.

Amine functionalized silicas are promising chemisorbent materials for post-combustion CO₂ capture due to the high density of active sites per unit mass of adsorbent that can be obtained by tuning the synthesis protocol, thus resulting in high equilibrium CO₂ adsorption capacities. However, when compared to physisorbents, they have a few disadvantages. Firstly, oxidative degradation of the amine groups reduces the lifetime of these adsorbent materials. Furthermore, rapid heat release following the reaction between amines and CO₂ results in large local temperature spikes which may adversely affect adsorption equilibria and kinetics. Thirdly, there is a lack of fundamental understanding of CO₂-amine adsorption thermodynamics, which is key to scaling up these materials to an industrial-scale adsorption process. In this dissertation the qualitative and quantitative understanding of these three critical aspects of aminosilica adsorbents have been furthered so these materials can be better evaluated and further tuned as adsorbents for post-combustion CO₂ capture applications.

Polymeric hollow fiber sorbents were functionalized with amine moieties for improving the carbon dioxide sorption capacity from flue gas to reduce the greenhouse gas emissions from coal-fired power plants. Three different experimental pathways were studied to form the amine-functionalized hollow fiber sorbents. Aminosilane functionalized cellulose acetate (CA) fibers, polyethyleneimine (PEI) functionalized polyamide-imide (PAI, Torlon® fibers and PEI post-infused and functionalized Torlon®-silica fibers were formed. CO₂ equilibrium sorption capacity data were collected by using the pressure decay sorption cell and thermal gravimetric analyzer. Other physio-chemical properties of the amine-functionalized fiber sorbents were characterized by using fourier-transform infrared spectroscopy, elemental analysis, and scanning electronic microscopy. Different reaction conditions were studied on the effect of sorption isotherms. Aminosilane-CA fibers were the first proof-of-concept for forming the amine functionalized polymer hollow fibers. PEI-PAI fibers were designed as a new method to reach enhanced sorption capacities than Aminosilane-functionalized CA fibers. PEI post-infused and functionalized Torlon®-silica fibers have further enhanced sorption capacity; however they easily degrade with similar reaction for forming PEI-PAI fibers. Lumen-side barrier layers were created successfully via post-treatment technique of using the crosslinked Neoprene® polymer onto PEI-functionalized PAI fibers. PEI-functionalized PAI fibers also have good cyclic stability and low heat of sorption.

In the first part of this dissertation, we study the aging of soot, a representative type of primary aerosols, in the presence of OH-initiated oxidation products of toluene. Monodisperse soot particles are introduced into an environmental chamber where toluene is oxidized by OH radicals. The variations in soot particle properties are simultaneously monitored, including particle size, mass, organic mass faction, hygroscopicity, and optical properties. The changes in particle properties are found to be largely governed by the thickness of the organic coating that is closely related to reaction time and initial reactant concentrations. Derived from particle size and mass, the effective density increases while dynamic shape factor decreases as the organic coating grows, suggesting a compaction of the soot morphology. As the organic coating grows, the particles become more hygroscopic and have enhanced light scattering and absorption. The second part discusses the potential reactions between amines and some aerosol constituents and alteration of aerosol properties. The reactions between alkylamines and ammonium sulfate/bisulfate have been studied using a low-pressure fast flow reactor coupled to a mass spectrometer at 293 K. Alkylamines react with ammonium sulfate/bisulfate to form alkylaminium sulfates, suggesting the existence of alkylaminium salts in particle phase. We have extended our study to characterize the physicochemical properties of alkylaminium sulfates. The hygroscopicity, thermostability, and density of five representative alkylaminium sulfates have been measured by an integrated aerosol analytical system. All alkylaminium sulfate aerosols show monotonic size growth when exposed to increasing relative humidity. Mixing ammonium sulfate with alkylaminium sulfates lowers the deliquescence point corresponding to ammonium sulfate. Alkylaminium sulfates are thermally comparable to or more stable than ammonium sulfate. The densities of alkylaminium sulfate particles are lower than that of ammonium sulfate. Our results suggest that the organic compounds can effectively alter the composition and properties of atmospheric aerosols, considerably influencing the impacts of aerosols on air quality, climate forcing, and human health.

Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.