The objectives of this research were to develop the best methods for cellulose nanowhiskers (CNWs) preparation from raw biomass materials and the feasibility to perform CNWs as Fe3+ catalyst support in converting syngas to biofuels. Raw kenaf bast and switchgrass were initially pretreated with dilute NaOH followed by dilute H2SO4. High yields of alpha-cellulose were obtained. Hemicellulose, ash, and most lignin were removed during pretreatment. Preparation of CNWs after pretreatment was then conducted via H2SO4 hydrolysis. The most efficient hydrolysis condition was determined as H2SO4 concentration through orthogonal experiments. In contrast with pure cellulose fibers, CNWs supported Fe3+ catalyst applied in converting syngas to biofuels showed shorter stabilization time and higher C4+ product selectivity. With the increase of reaction temperature to 310°C, CO and H2 could reach their peak conversion rates of 83.4% and 72.1%, while the maximum selectivity of CO2 was 41.1%.

Finding materials based on non-rare earth metals is vital for the global transition to a more sustainable economy. Discovering useful properties in common metal oxides is a promising avenue for new materials. In this work we have investigated the properties of Ru(x)CoMo(1-x) to evaluate the feasibility of its use as an electrocatalyst for the oxygen evolution reaction (OER). Herein, the plasma spray deposition on FTO and glass is reported as a method for production of low Ru content-CoMo oxide. The material showed a good performance in an alkaline electrolyte for OER, with no loss on stability and overpotentials to achieve a current density of 10 mA cm-2 of 528, 483, 455, 439 mV for 0, 10, 20, and 30 At% of Ru, respectively. The final material is shown to be composed entirely of Co and Mo oxides, as well as Ru which is present in the crystal structure of these metal oxides as observed using optical characterization techniques, XRD, Raman and SEM. With the aim of maximising performance and decreasing the amount of Ru used, we find a Ru content of 20 At% is most optimal for OER in alkaline. We find therefore Ru(0.2)(CoMo)(0.8) to be an effective electrocatalyst for OER in alkaline, while examples from literature outperforms it in other applications, it is still a good basis for further work and development.

<p> Polymerization of bulk styrene initiated thermally as well as with di-tertiary-butyl peroxide was studied in isothermal batch reactors. Thermal polymerization was carried out at 100, 140, 170 and 200°C while polymerization with di-tertiary butyl peroxide was at 100 and 140°C. A kinetic model was derived therefrom accounting for initiation reactions from a first order decomposition of catalyst and a second order reaction between two monomer molecules to form two monoradicals, propagation, chain transfer to monomer and termination by combination only. Gel effect was allowed by the variation of rate constants with conversion. Both the thermal initiation rate constant and the first order decomposition rate constant of di-tertiary butyl peroxide were found to agree with literature values with the present values slightly higher. The initial rate constants for propagation, chain transfer to monomer, and termination were extrapolated to the range, 100-200°C using literature data. This kinetic model was used in the simulation of polymer reactor systems studying the effect of recycle and operating conditions on the molecular weight distribution and rate of production of polymer products.</p> <p> The main body of this thesis reports the polymerization study and the development of the kinetic model. The details of the kinetic equations and methods of solution, experimental techniques involved, and the simulation of polymer reactor systems are reported in the Appendices.</p> / Thesis / Doctor of Philosophy (PhD)

<p> A quasi-steady state optimization of an adiabatic, fixed bed tubular reactor, with catalyst decay, is considered.</p> <p> The optimal inlet temperature (distribution) To(t), is sought, so as to maximize the total amount of reaction in a fixed given period of time. Upper and lower bounds are placed on the inlet temperature.</p> <p> A single irreversible reaction is considered with a reaction rate expressible as separable functions of inlet temperature, conversion and catalyst activity.</p> <p> The rate of catalyst decay is expressed in an analogous manner and in particular, the conversion dependence is maintained.</p> <p> The optimal policy of choosing the temperature so as to maintain the exit conversion constant in time when catalyst decay is independent of conversion, is examined.</p> <p> The extension of this constant conversion policy to the present system is discounted.</p> <p> New optimum seeking methods are developed and numerical calculations presented to illustrate the optimal profiles.</p> / Thesis / Master of Engineering (MEngr)

<p> The temperature policy with time is sought which maximizes a performance index for a fixed time in a tubular reactor with uniform temperature, decaying catalyst, and two first-order irreversible parallel reactions. </p> <p> For the case where the performance index is the total amount of desired product produced, an analogy between the optimization problems for a first-order reversible reaction and a parallel reaction first-order in both. paths is developed. </p> <p> A numerical procedure together with theoretical developments is used to solve the problem for a more general performance index which takes into account the cost of the reactant as well as the value of the desired product. The problem is· treated in the format of Pontryagin's Maximum Principle. </p> / Thesis / Master of Engineering (MEngr)

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