The first part of this thesis is concerned with the development of a general synthetic approach to-the bicyclo(3.2.1)octane ring system. This work resulted in the successful synthesis of 1,5-dimethylbicyclo (3.2.1)octan-8-one(54) , 1,5-dimethylbicyclo (3.2.1)oct-6-en-8-one(55) and 1,5-dimethyl-6-isoproxybicyclo (3.2.1)oct-6-en-8-one(56). Alkylation of 2,6-dimethylcyclohexanone with allyl bromide afforded the olefinic ketones (78) and (79). Ozonolysis of the latter gave the keto aldehydes (80) and (81), which underwent a facile intramolecular aldol condensation to afford a mixture of the bicyclic alcohols (68) and (69). The mesylates (94_) and (9_5_) were obtained from the bicyclic alcohols (68J and (69_) . The keto iodide (70) , obtained by treating a mixture of the mesylates (94) and (95) with sodium iodide in refluxing acetone, was dehydrohalogenated to afford the desired bicyclic ketone (55). Hydrogenation of the latter over palladium afforded the desired bicyclic ketone (_54) . Oxidation of a mixture of the keto alcohols (68) and (69) with Collin's reagent afforded the diketone (71) which, under appropriate conditions, underwent O-alkylation to give the desired bicyclic enol ether (56) . In the second part of this thesis, the stereochemistry of nucleophilic addition to the 8-keto group present in the bicyclic ketones (54) , (55) and (56) was briefly investigated. The bicyclic ketones (54), (55) and (56) were reduced with lithium aluminium hydride to afford the bicyclic alcohols (112), (113) and (114) . Hydrogenation of the alcohol (113) yielded the alcohol (112). Hydrolysis of the enol ether (114) gave the ketol (116) . Hydrogenolysis of the dithioketal(117) of the keto alcohol (116) with Raney-nickel afforded alcohol (112). Thus, the bicyclic alcohols (112), (113) and (114) must have the same relative stereochemistry at C-8. The bicyclic ketones (5_4_) , (5_5) and (5_6_) were also treated with one equivalent of methylithium under identical conditions to form the corresponding tertiary alcohols (128), (129) and (130). These alcohols are also formed stereo-selectively and have the same relative stereochemistry as the corresponding secondary alcohols (112) , (113) and (114) . / Science, Faculty of / Chemistry, Department of / Graduate

The utilization of energetic strained molecules may be one way to mitigate carbon emissions or better and more economical fuel blends. To investigate candidate molecules, limonene and dicyclopentadiene, both theoretical and experimental procedures were implemented here. Computational quantum chemistry methods were employed to determine the thermodynamic properties and kinetic parameters for the hydrogen-abstraction reactions of limonene by a hydrogen atom. Geometry optimization and energy calculation was conducted for all stable species and transition states using Gaussian 09. The rate constants of the H-abstraction reactions were calculated using conventional transition state theory, as implemented in ChemRate software. The obtained values were fitted over the temperature range of 298 – 2000 K to obtain the modified Arrhenius parameters. Increasing the anti-knock quality of gasoline fuels can enable higher efficiency in spark ignition engines. This study explores blending the anti-knock quality of dicyclopentadiene (DCPD, a by-product of ethylene production from naphtha cracking), with various gasoline fuels. The blends were tested in an ignition quality tester (IQT) and a modified cooperative fuel research (CFR) engine operating under homogenous charge compression ignition (HCCI) and knock limited spark advance (KLSA) conditions. Ethanol is widely used as a gasoline blending component in many markets, due to current fuel regulations. The test results of DCPD-gasoline blends were compared to those of ethanol-gasoline blends. Furthermore, the anti-knock properties of dicyclopentadiene (DCPD) as an additive to primary reference fuels (PRF) and toluene primary reference fuels (TPRF) have been investigated. The research octane number (RON) and motor octane number (MON) were measured using cooperative fuels research (CFR) engine for four different fuel blends. Moreover, the ignition delay times of these mixtures were measured in a high-pressure shock tube at 40 bar and stoichiometric mixtures over a temperature range of [700-1200 K]. Ignition delay measurements were also conducted using rapid compression machine (RCM) at stoichiometric conditions and 20 bar. An ignition quality tester (IQT) compared ignition delay times of iso-octane and DCPD. Furthermore, a chemical kinetic auto-ignition model was designed to simulate the IDT experiments.

Future internal combustion engines demand higher efficiency but progression towards this is limited by the phenomenon called knock. A possible solution for reaching high efficiency will be to improve the anti-knock quality of the fuels by blending high-octane fuel with a low-octane fuel. In this study, the non-linear blending effect by blending oxygenated/non-oxygenated fuels of high octane number with low octane fuels were studied in three different combustion modes: Spark ignition (SI), Homogeneous Charge Compression ignition (HCCI) and Compression Ignition (CI). For SI combustion, RON and MON was used for the fuel rating, for HCCI combustion, Lund Chevron HCCI fuel number and for rich combustion conditions, Derived Cetane Number (DCN) was used to understand the fuel auto-ignition behavior. A Cooperative Fuel Research (CFR) engine was used for SI and HCCI mode whereas Ignition Quality Tester (IQT) was used for CI mode. The non-linear blending behavior was described using the concept of blending octane number. Five octane additives including ethanol, methanol, 1-butanol, toluene and iso-octane were used in this study, of which ethanol and methanol gave the strongest octane enhancement effect whereas iso-octane resulted in the weakest octane enhancement. The base fuel composition and octane number also had an important role in the blending behavior of the fuels. The non-linear blending of fuels highlighted that some of the blended fuels behaved similarly in both SI and HCCI combustion mode, therefore the study was further extended to understand the pre-spark heat release or Low temperature heat release (LTHR) in both the combustion modes. Knock occurs in SI due to end-gas auto-ignition and for HCCI, the combustion is controlled by auto-igniting of the complete charge inside the cylinder. Therefore fundamentally the combustion process in the end gas region of SI and HCCI combustion modes is controlled by auto-ignition. In this respect, HCCI combustion was used as an alternative path to understand the end-gas auto-ignition in SI engine using the standard CFR engine. Pre-spark heat release or low temperature reactions were detected in both the combustion modes.

A thermodynamic cycle simulation of the four-stroke spark-ignition engine was used to determine the effects of variations in engine design and operating parameters on engine performance and emission characteristics. The overall objective was to use the engine cycle simulation to determine the difference between a propane-fuelled and an iso-octane-fuelled engine for the same operating conditions and engine specifications. A comprehensive parametric investigation was conducted to examine the effects of variations in load, speed, combustion duration, spark timing, equivalence ratio, exhaust gas recycle, and compression ratio for a 3.3 liter, Chrysler Minivan, V 6 engine operating on propane. Parameters were selected for the analysis. Variations in the brake specific fuel consumption, brake specific NOx emissions, and mean exhaust temperature were determined for both the propane-fuelled and the iso-octane-fuelled engines. Brake specific fuel consumption and mean exhaust temperature values for the propane-fuelled engine were consistently lower (3 to 5 %) than the corresponding values for the iso-octane-fuelled engine. Fuel structure did not have a significant effect on brake specific nitric oxide emissions. Predictions made from the simulation were compared with some of the available experimental results. Predicted brake torque and brake power showed acceptable quantitative agreement (less than 10 % variation) in the low engine speed range (1,000 to 3,000 rpm) and similar trends with the available experimental data.

No description available.

The development of an auxiliary power unit (APU) capable of providing climate control and electricity in long haul trucks is of significant interest due to the expected economic and environmental benefits. A potentially efficient and environmentally friendly APU design is one based on the use of an autothermal fuel reformer that converts on-board truck fuel to a hydrogen rich gas that directly fuels a solid oxide fuel cell unit. To assist in the development of such a unit a numerical study of the autothermal reforming of iso-octane in a compact tubular reactor has been undertaken. This was done to determine the reactor performance and the factors that potentially influence its performance. Variations in the wall thermal conductivity, the catalyst thermal conductivity, the catalyst porosity, the conditions of the inlet reactant gas, and the effectiveness factor of the chemical reaction mechanism have been studied to determine their effects on the performance of the reformer. It has been found that higher thermal conductivities of the outer wall and in the catalyst region gave increased dry hydrogen yield and fuel conversion. The study of the effects of inlet species concentration ratios indicated that maximum hydrogen yield was obtained with an oxygen-to-fuel ratio between 1.0 and 1.15 and a steam-to-fuel ratio of approximately 3.0. Results obtained with various inlet species temperatures and bed porosities showed only small changes in the reformer performance. While the results obtained here do provide useful information about the performance of the autothermal reformer, the model used has been re-assessed and it is recommended that an improved model be used in future work. In particular, the assumed effectiveness factors for all of the chemical reactions occurring in the catalyst region need to be improved. This was highlighted by the fact that a brief study indicated a very strong dependence of the reformer product gas composition on the effectiveness factor. This indicates that while the present model is able to predict trends in the reformer performance, it is limited in its accuracy due to the fact that the effectiveness factor used is only approximately known. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2007-08-31 13:22:27.466

This thesis examines the reactions of hydrocarbons exposed to chlorosulfonic acid in order to establish the reaction rate and associated molecular structure of each compound.

The work encompassed by this thesis is partially a reproduction of the results obtained by John A. Marcia in his work on the photo-chemical reactions of branched hydrocarbons. The previous work done on this particular problem was rendered partially valueless because of the loss of the liquid hydrocarbon product when a fractionation column at the Texas Company Laboratory, Beacon, New York, broke during the fractionation run.

Increasing the efficiency of the spark-ignition engine can help to reduce the environmental impact of the transportation sector. Engine knock obstructs the increased efficiency that could be gained by increasing the compression ratio in a spark-ignition (SI) engine. A fuel’s propensity to knock is measured by the research octane number (RON) and the motor octane number (MON) in a co-operative fuel research (CFR) engine. A fuel’s octane sensitivity (OS) is the difference between the RON and MON. Modern downsized and turbocharged engines operate at what is considered to be beyond-RON conditions. Studies have shown that having a fuel with higher OS improves knock resistance at beyond-RON conditions. This study aims to gain a better understanding of the role of intermediate-temperature heat release (ITHR) in defining OS and its subsequent impact on SI operation through the experimental framework. The ITHR of toluene primary reference fuels (TPRFs) fuels with matching RON and varying OS was studied at RON-like and MON-like homogeneous charge compression ignition (HCCI) conditions for two different matching criteria. The first criterion was to control the combustion phasing by matching half of the heat release (CA50) to 3 crank angle degrees after top dead center. The second criterion was to match the compression ratios. Results showed that at RON-like HCCI conditions, TPRF fuels display decreasing ITHR with increasing OS. Furthermore, it was shown that TPRF fuels with low sensitivity displayed a greater increase in ITHR from MON-like conditions to RON-like conditions. Thus, the sensitivity of ITHR to changes in operating conditions was found to be a contributing factor to OS. In the beyond-RON conditions (relevant to current modern engines), there is a potential for improved engine efficiency by using fuels with high OS to allow for higher compression ratios. The experimental results of this work show that OS is negatively correlated with ITHR. Thus, high-sensitivity fuels can be designed by choosing components and additives that reduce the amount of ITHR.

There are numerous numerical and experimental studies to find correlations of octane rating with fuel properties. This thesis was based on the hypothesis that quenching characteristics at ignition locations impact the flame development. Conversely, determination of quenching characteristics might serve as an effective measure to determine the fuel mixture octane number. This hypothesis was tested with premixed flame experiments using primary reference fuels (iso-octane and n-heptane) and commercial grade gasoline. Premixed flame experiments were conducted on a flat flame burner. Primary reference fuels of different ratios were taken and correlated to their respective thermal quenching condition by introducing co-flowing inert gasses at room temperature with fuel-air mixture. The inert gasses that were used in the experiment are nitrogen and helium and the results are analyzed using a camera and an imaging spectrometer. The experimental results support the hypothesis that flame quenching can be correlated to fuel mixture octane number, and holds potential as an alternative method to determine the octane number.