A better understanding of the chemistry of terphenyls production is required due to its contribution to the petrochemical industry and its usage in the production of useful raw materials. A benzene pyrolysis study was conducted with pure benzene, benzene with biphenyl and acetylene and benzene with CO2 mixed with N2 as diluent. This study aims to provide better insights into the effect of additives on terphenyls through pyrolyzing different fuels which were carried out in a jet-stirred reactor under atmospheric pressure, temperature range of 700-1250 K and residence time of 3s. The experimental data were measured by GC (gas chromatography) and plotted versus the temperature range provided four different kinetic models were simulated to compare with the experimental data of the reactants and products. Numerical analyses were conducted to gain a deep understanding of the main pathways that affect terphenyl isomers. A significant amount of soot was noticed at high temperatures (1200-1250 K) which was considered a soot area where the measurements may have affected. The addition of biphenyl and acetylene to benzene pyrolysis speeds the benzene consumption at high temperatures provided it showed a boost in m-terphenyl formation compared to pure benzene. In addition, acetylene addition increases the production of small hydrocarbons and the production of m-terphenyl was inhibited due to the change in the chemistry that acetylene follows. In the comparison of the experimental data with simulations, a good agreement was noticed for some compounds. Biphenyl addition is less sensitive toward H-abstraction reaction compared to pure benzene. Additionally, kinetic simulations of different residence times and pressures show an increase with increasing both factors and vice versa, based on the selected model. A shift in the speciation profiles was seen where the effect on reactants was noted at lower temperatures for higher residence time and pressure.

<p> The kinetics of the hematite to rnagnetite reduction have been studied in H2-H2O, and H2-H2O-N2 gas mixtures, using natural as well as synthetic specimens. The reactivity of hematite was found to be related to the structural defects formed during the preparation of the specimens. The type of defects formed and their effect on reactivity are discussed. Kinetic studies are performed on the specimens with reproducible properties. Rate expressions based upon suitable reaction mechanisms are derived and their validity checked with the experimental data. Reaction rate parameters for the expressions accurately interpreting the experimental results are evaluated, and the effect of nitrogen is separately established. Values of enthalpies and entropies for the mechanistic steps a.re calculated from the temperature dependence of these parameters, which reasonably support the proposed mechanism. </p> / Thesis / Doctor of Philosophy (PhD)

Biodiesel has come to the forefront of the energy community as a clean-burning, renewable energy that can replace the use of No. 2 Diesel fuel. Tall oil fatty acids, a by-product of the pulp and paper industry, may be utilized as a biodiesel feedstock. This thesis presents an empirical study of the acid-catalyzed esterification of tall oil fatty acids into biodiesel. Under atmospheric conditions, factorial design analysis determined the optimum parameters to be methanol ratio (6:1), sulfuric acid (5%), and temperature (60oC). This reaction was tolerant to water up to 1%. A pseudo-homogeneous second order kinetic model was applied to the reaction at the optimal conditions. The Activation Energy was calculated to be 19.73 kJ/mol with a pre-exponential factor of 23.6. Quality tests were performed under ASTM D 6751-06 to evaluate the final product with tall oil methyl esters having exceptional cold flow properties with a cloud point of -10.7oC.

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Dissolution experiments were conducted on bioapatite at 4°C, 21°C and 38°C and solution pH values between 2 and 8 in a stirred tank reactor. The bioapatite was obtained from modern white-tailed deer (Odocoileus virginianus) scapulae, crushed, and cleaned in 30% hydrogen peroxide to remove organic matter. The average BET specific surface area of the 75-106 and 106-246 μm particles was 255 m2 g-1. During experiments the ratio of Ca:P released became stoichiometric at ca. 1.44. The following dissolution rate law was derived from the experimental results: R = K1(H+)ⁿ+K2 in which R is the dissolution rate (mol bioapatite m-2 s-1) based on the bioapatite stoichiometry, n = 1.01 ± 0.15, k1 = 1.84 x 10-6 ± 1.71 x 10-6 mol m-2 s-1, and k2 = 4.29 x 10-10 ± 1.15 x 10-10 mol m-2 s-1 and H+ is the hydrogen ion activity. From 2 < pH < 4, dissolution rate is dependent on pH and becomes independent of pH from 4 < pH < 8. These results for modern bone may be compared with previous investigations of igneous (FAP) and phosphorite-derived sedimentary carbonate fluorapatites (CFA)(e.g., Guidry and Mackenzie, 2003). At pH = 6, in the pHindependent region, dissolution of the modern bioapatite was ca. 7 times faster than FAP and 100 times faster than CFA. The acid transition pH of the bioapatite (pH = 4) is lower than that for FAP (pH = 6). Bioapatite dissolution rates influence fossil preservation potential, the release rate of nutrients from bone meal fertilizers, the effectiveness of bone as reactive barriers to control pollutants and nuclear waste isolation, and as a feedstock material in CO2 sequestration processes. / Geology

<p> Our work demonstrates the decomposition results obtained using Ti02 coated paper at different pH, ionic strength, UV intensities, temperature and flow rates. A kinetic model ofTi02 photocatalytic decomposition of reactive azo dye (RBS) was developed for the different conditions. </p> <p> Ti02 coated paper was developed by simply spraying Ti02 suspension on the filter paper. The stability of the Ti02 coated paper was studied and the environment where Ti02 coated paper can be used is under pH 7. The stability of Ti02 attached on the paper surface is determined by the property of the polymeric retention aids and the adsorption of reactive azo dye (RB5) is dependent on the electrostatic attraction. </p> <p> Ti02 photocatalytic decomposition mainly occurs at the surface of Ti02. So the adsorption of RBS molecules is considered to be one of the most important factors, which can affect the decomposition rate. Other factors, such as UV intensity and temperature, can also change the decomposition rate by affecting the formation of free radicals. </p> <p> New discovery of intermediate products can make the mechanism of the photocatalytic decomposition more clear, although the specific information about the intermediate products is not available yet. The adsorption and decomposition of intermediate products provide useful information for developing the decomposition kinetic model. </p> <p> Langmuir adsorption model is fit for the adsorption of RB5 and its degradation intermediate products at Ti02 surface. Our kinetics model combines the principles of Langmuir-Hinshelwood model and two-step first order model. It can describe the change of the RB5 concentration in the bulk and predict the desorption of intermediate products. </p> / Thesis / Master of Applied Science (MASc)

Note: Contains three parts.