The northern slopes of the Uinta Mountains, Utah were previously glaciated and contain many landslides. The Tokewanna Landslide is very large and lacks Quaternary faults. Presumably, increased moisture was the failure trigger. A Quaternary climate record from a cored fen, developed in a small basin between hummocks, was reconstructed using sediment pyrolysis, biomass balance, and magnetic susceptibility. Pyrolysis is used to define Hydrogen Indices that are used to delineate wetter and drier conditions based on the kerogen type - Type III being drier, and Type II wetter. The data were matched to a time/depth curve and compared to other Uinta Mountains climate studies. Pyrolysis, biomass balance, and magnetic susceptibility results indicate drier to wetter conditions from ~11,027 to ~8,800 cal yr BP. This was followed by an increase in precipitation, peaking ~8,060 cal yr BP, and then decreasing. Drying conditions ensued after ~4,800 cal yr BP, and from ~1,700 cal yr BP to modern. Regional studies suggest mid-Holocene Epoch warming; some also indicate increased precipitation during those periods. A study at nearby Little Lyman Lake (Tingstad et al., 2011) displays a plankton percent record similar to the wetness record of the study fen. The fen core record does not indicate wet conditions at its base as expected. The record begins ~11,000 cal yr BP and likely represents an incomplete history of this Holocene fen, as the base of the wetland deposits was not reached.

The overuse of antibiotics in agriculture is an emerging concern, due to their potential detrimental impact to the environment. This study focuses on exploring antimicrobial properties of lignin derived compounds. Lignin is of interest as a feedstock to replacing some petroleum-based chemicals and products because it is the most abundant source of renewable aromatic compounds on the planet. Two lignin rich streams, residues from the enzymatic hydrolysis of dilute acid and alkaline pretreated corn stover, were decomposed via pyrolysis and hydrogenolysis, respectively. The resulting liquid oils were subjected to sequential extractions using a series of solvents with different polarities. Chemical compositions of the extracted fractions were characterized through HPLC and GC/MS. These extracted compounds were screened against Saccharomyces cerevisiae (S. cerevisiae), Escherichia coli, and Lactobacillus amylovorus for antimicrobial properties. Six lignin model monomers: guaiacol, vanillin, vanillic acid, syringaldehyde, 2,6-dimethoxyphenol, and syringic acid were compared to the oils and extracted fractions for antimicrobial properties. Development of lignin-derived chemicals with antimicrobial properties could provide a novel use for this underutilized natural resource.

An important step in the more efficient use of PICA (Phenolic Impregnated Carbon Ablator) as a Thermal Protection System (TPS) material for spacecraft is the understanding of its pyrolysis mechanics. The gases released during pyrolysis and their subsequent interaction with the reactive plasma environment is not yet well understood. The surface recession of PICA as it ablates during testing only makes the study and characterization of the chemical reactions more difficult. To this end, a probe has been designed for this study to simulate, in steady state, the pyrolysis gases within the UVM 30kW Inductively Coupled Plasma (ICP) Torch Facility. This probe, which is an extension of previous work done at UVM, has been used to inject Carbon Dioxide, Hydrogen, and a mixture of the two into pure Argon and dilute Nitrogen, Oxygen, and air plasmas. During testing, spatially resolved, pointwise, line of sight emission measurements were taken in the boundary layer region. These results were then compared to temporally resolved PICA emission data taken in a previous study. After the correct temporal PICA scan was found the data sets closely matched. This indicates that the gas-injection probe is a viable method to simulate pyrolysis in a steady state environment. The key pyrolysis species of CN, NH, OH, Hydrogen Alpha (Hα), and Hydrogen Beta (Hβ) were spatially traced along the stagnation line for the pure Hydrogen and mixture injection cases. These measurements show evidence of spatial relationships between NH and Hα as well as between OH and Hβ. They also show that all of the molecules tend to follow the same general trend spatially. The work done for this study has both reintegrated gas-injection capability into the UVM facility as well as laid the groundwork for future gas-injection testing within the facility. Spatial emission analysis techniques currently being developed at UVM will provide a more resolved picture of the interactions occurring in the boundary layer once completed.

Two reaction classes have been studied computationally including the pyrolysis of various components of airplane fuels, such as decane, dodecane, butylbenzene isomers, and JP-10 (exo-tetrahydrodicyclopentadiene), and oxidation of a group of molecules belonging to the class of Polycyclic Aromatic Hydrocarbons (PAHs). Investigation of both reaction classes have been performed using ab initio quantum chemistry methods with the Gaussian 09 and MOLPRO programs at various levels of theory. Initially, Potential Energy Surfaces (PES) were generated at the G3(MP2,CC)/B3LYP/6-311G** level of theory for various radicals involved in the reactions as reactants, intermediates, transition states, and products. The next step was to perform RiceRamsperger-Kassel-Marcus (RRKM) / Master Equation calculations in order to calculate rate constants and branching ratios of different products at various temperatures and pressures characteristic for combustion flames. All calculations were then compared with previous works on similar systems available in the literature. The results of these simulations along with previous data were then used to formulate guidelines for the pyrolysis and oxidation patterns of larger and more complex systems, in order to achieve a better understanding of the pathways to the end products in airplane jet engines.

Reports indicate that the worldwide energy consumption and fossil fuel energy production level will have an opposite trend in the coming two decades. The former will continue to increase while the later will decrease. Therefore, additional sources of energy need to be developed. Field pennycress (Thlaspi, arvense L.) has been found to be an ideal source of energy because it has prolific yield and has no value as food. We demonstrated conventional and catalytic fast pyrolysis of whole pennycress biomass in a fluidized bed reactor. Characterization studies on field pennycress showed that the biomass had a potential to be converted to energy-rich bio-fuel. Thermogravimetric and kinetic study on field pennycress provided vital information on the degradation behavior of the feedstock. A parametric study was conducted on conventional rapid pyrolysis by using the effects model. The optimum experimental condition that gave maximum liquid yield was found to be at a temperature of 500 °C and a gas flow rate of 24 l/min. The catalysts used for catalytic fast pyrolysis were HZSM-5, a commercial catalyst, and red mud, an alumina industry waste material. The liquid products obtained from pennycress were found to have better qualities compared to a typical lignocellulosic feedstocks pyrolysis bio-oil. The bio-oil from the red mud catalyzed experiment had almost neutral pH of 6.5 and the pH in the case of HZSM-5 was 5.7. In comparison to bio-oil from conventional rapid pyrolysis, HZSM-5 and red mud reduced the viscosity of the bio-oil by 3 and 5 times, respectively. However, red mud was only found to be effective in improving the higher heating value (HHV) of the bio-oil from 33.18 MJ/kg (dry basis) in conventional pyrolysis to 35.7 MJ/Kg (dry basis). The HHV of HZSM-5 catalyzed bio-oil was 33.63 MJ/kg. The composition of non-condensable gases and the chemical makeup of the bio-oil from the two catalysts were different, suggesting that the reaction pathways could be different. HZSM-5 had higher selectivity for aromatics whereas red mud produced longer aliphatic chains. The bio-oil obtained from red mud catalytic pyrolysis of field pennycress is a promising alternative energy source that could replace petroleum fuels after some upgrading.

Magnetic nanoparticles attract increasing attention because of their current and potential biomedical applications, such as, magnetically targeted and controlled drug delivery, magnetic hyperthermia and magnetic extraction. Increased magnetization can lead to improved performance in targeting and retention in drug delivery and a higher efficiency in biomaterials extraction. We reported an approach to synthesize iron contained magnetic nanoparticles with high magnetization and good oxidation resistibility by pyrolysis of iron pentacarbonyl (Fe(CO)[subscript 5]) in methane (CH[subscript 4]). Using the high reactivity of Fe nanoparticles, decomposition of CH[subscript 4] on the Fe nanoparticles leads to the formation of nanocrystalline iron carbides at a temperature below 260°C. Structural investigation indicated that the as-synthesized nanoparticles contained crystalline bcc Fe, iron carbides and spinel iron oxide. The Mössbauer and DSC results testified that the as-synthesized nanoparticle contained three crystalline iron carbide phases, which converted to Fe[subscript 3]C after a heat treatment. Surface analysis suggested that the as-synthesized and subsequently heated iron-iron carbide particles were coated by iron oxide, which originated from oxidization of surface Fe atoms. The heat-treated nanoparticles exhibited a magnetization of 160 emu/g, which is two times of that of currently used spinel iron oxide nanoparticles. After heating in an acidic solution with a pH value of 5 at 60°C for 20 h, the nanoparticles retained 90 percentage of the magnetization. / Singapore-MIT Alliance (SMA)

Thesis (Ph. D.)--University of Washington, 1983. / Vita. Bibliography: leaves 169-182.

Wood is an interesting alternative to fossil fuels. It is CO2-neutral and widely available. However it is a difficult fuel to handle which features a low energy content. Thus technologies for wood thermal conversion need to be improved. This work concerns the development of a comprehensive two-dimensional mathematical model describing the pyrolysis of large wood particles and its implementation in a Fortran program. The model has been continuously tested and improved by experimental results obtained in a reactor for single particle pyrolysis (SPAR) at the Division of Physical Chemistry at Göteborg University. The first part of the thesis (Paper I) presents a kinetic study of the pyrolysis of large wood particles, based on experiments carried out in the SPAR. Three pyrolysis kinetic schemes were selected for later inclusion in a model featuring heat and mass transfer. Paper II concerns the addition of a sub-model for heat and mass transfer to the three kinetic schemes. The resulting model for large wood particles has been tested against experiments in the SPAR. A scheme based on two competing reactions developed from experiments at low temperature pyrolysis in the SPAR was found to perform well but its empirical nature limits its validity to the experimental conditions of the SPAR. A scheme from the literature based on TGA experiments appeared promising, especially when planning to enhance it with secondary reactions. Paper III deals with the development of shrinkage models for 2D cylindrical particles. The predicted mass loss, size variation and surface temperature were tested against experiments carried out in the SPAR. The shrinkage does not a?ect the pyrolysis rate or the surface temperature in the conditions prevailing in the SPAR. Paper IV investigates the influence of different shrinkage models and the geometry on the heating rate of a shrinking particle. Shrinkage influences the heating rate positively by increasing the conductive heat flow and negatively by decreasing the surface area of the particle. Therefore the net effect of shrinkage on the heating rate depends on the particle geometry and the location of shrinkage. Paper V studies three di?erent models for wood drying under pyrolysis conditions. The predicted surface temperature and global drying rate were compared with experimental results from pyrolysis experiments of wet particles in the SPAR. A model based on a first order kinetic evaporation rate was found to be the most interesting because of the quality of the prediction of the drying rate and the ease of implementation. / QC 20100624

Fossil fuels dominate the world energy supply today and the transport sector is no exception. Renewable alternatives must therefore be introduced to replace fossil fuels and their emissions, without sacrificing our standard of living. There is a good potential for biofuels but process improvements are essential, to ensure efficient use of a limited amount of biomass and better compete with fossil alternatives. The general aim of this research is therefore to investigate how to improve efficiency in biofuel production by process development and co-generation of heat and electricity. The work has been divided into three parts; power cycles in biofuel production, methane production via pyrolysis and biofuels from renewable electricity. The studies of bio-based methanol plants showed that steam power generation has a key role in the large-scale biofuel production process. However, a large portion of the steam from the recovered reaction heat is needed in the fuel production process. One measure to increase steam power generation, evaluated in this thesis, is to lower the steam demand by humidification of the gasification agent. Pinch analysis indicated synergies from gas turbine integration and our studies concluded that the electrical efficiency for natural gas fired gas turbines amounts to 56-58%, in the same range as for large combined cycle plants. The use of the off-gas from the biofuel production is also a potential integration option but difficult for modern high-efficient gas turbines. Furthermore, gasification with oxygen and extensive syngas cleaning might be too energy-consuming for efficient power generation. Methane production via pyrolysis showed improved efficiency compared with the competing route via gasification. The total biomass to methane efficiency, including additional biomass to fulfil the power demand, was calculated to 73-74%. The process benefits from lower thermal losses and less reaction heat when syngas is avoided as an intermediate step and can handle high-alkali fuels such as annual crops. Several synergies were discovered when integrating conventional biofuel production with addition of hydrogen. Introducing hydrogen would also greatly increase the biofuel production potential for regions with limited biomass resources. It was also concluded that methane produced from electrolysis of water could be economically feasible if the product was priced in parity with petrol. / <p>QC 20121127</p>

Glycerol is a waste by-product obtained during the production of biodiesel. Biodiesel is one of the alternative fuels used to meet our energy requirements and also carbon dioxide emission is much lesser when compared to regular diesel fuel. Biodiesel and glycerol are produced from the transesterification of vegetable oils and fats with alcohol in the presence of a catalyst. About 10 wt% of vegetable oil is converted into glycerol during the transesterification process. An increase in biodiesel production would decrease the world market price of glycerol. The objective of this work is to produce value added products such as hydrogen or syn gas and medium heating value gas from waste glycerol using pyrolysis and steam gasification processes. <p> Pyrolysis and steam gasification of glycerol reactions was carried out in an Inconel®, tubular, fixed bed down-flow reactor at atmospheric pressure. The effects of carrier gas flow rate (30mL/min-70mL/min), temperature (650oC-800oC) and different particle diameter of different packing material (quartz - 0.21-0.35mm to 3-4mm; silicon carbide 0.15 to 1mm; Ottawa sand 0.21-0.35mm to 1.0-1.15mm) on the product yield, product gas volume, composition and calorific value were studied for the pyrolysis reactions. An increase in carrier gas flow rate did not have a significant effect on syn gas production at 800oC with quartz chips diameter of 3-4mm. However, total gas yield increased from 65 to 72wt% and liquid yield decreased from 30.7 to 19.3wt% when carrier gas flow rate decreased from 70 to 30mL/min. An increase in reaction temperature, increased the gas product yield from 27.5 to 68wt% and hydrogen yield from 17 to 48.6mol%. Also, syn gas production increased from 70 to 93 mol%. A change in particle size of the packing material had a significant increase in the gas yield and hydrogen gas composition. Therefore, pyrolysis reaction at 800oC, 50mL/min of nitrogen and quartz particle diameter of 0.21-0.35mm were optimum reaction parameter values that maximise the gas product yield (71wt%), hydrogen yield (55.4mol%), syn gas yield (93mol%) and volume of product gas (1.32L/g of glycerol). The net energy recovered at this condition was 111.18 kJ/mol of glycerol fed. However, the maximum heating value of product gas (21.35 MJ/m3) was obtained at 650oC, 50mL/min of nitrogen and with a quartz packing with particle diameter of 3-4mm. <p>The steam gasification of glycerol was carried out at 800oC, with two different packing materials (0.21-0.35mm diameter of quartz and 0.15mm of silicon carbide) by changing the steam to glycerol weight ratio from 0:100 to 50:50. The addition of steam to glycerol increased the hydrogen yield from 55.4 to 64mol% and volume of the product gas from 1.32L/g for pyrolysis to 1.71L/g of glycerol. When a steam to glycerol weight ratio of 50:50 used for the gasification reaction, the glycerol was completely converted to gas and char. Optimum conditions to maximize the volume of the product gas (1.71L/g), gas yield of 94wt% and hydrogen yield of 58mol% were 800oC, 0.21-0.35mm diameter of quartz as a packing material and steam to glycerol weight ratio of 50:50. Syn gas yield and calorific value of the product gas at this condition was 92mol% and 13.5MJ/m3, respectively. The net energy recovered at this condition was 117.19 kJ/mol of glycerol fed. <p>The steam gasification of crude glycerol was carried out at 800oC, quartz size of 0.21-0.35mm as a packing material over the range of steam to crude glycerol weight ratio from 7.5:92.5 to 50:50. Gasification reaction with steam to glycerol weight ratio of 50:50 was the optimum condition to produce high yield of product gas (91.1wt%), volume of gas (1.57L/g of glycerol and methanol), hydrogen (59.1mol%) and syn gas (79.1mol%). However, the calorific value of the product gas did not change significantly by increasing the steam to glycerol weight ratio.