This PhD project aimed to study the separation of carbon dioxide from high pressure gas mixtures as it is directly applicable to pre-combustion carbon dioxide capture. Adsorption isotherms were produced and best fit by the Langmuir-Freundlich and dual-site Langmuir (DSL) isotherms. Breakthrough experiments investigated the separation under dynamic conditions. These showed that adsorption capacities need to be studied on a volumetric basis. The multicomponent DSL isotherm model was the most suitable for predicting breakthrough capacities. An axial dispersed plug flow model was validated against the experimental data with a reasonable accuracy. Cyclic experiments were validated, which were found to be restricted by the surrounding pipework and instruments. A parameter sensitivity analysis indicated the particle diameter, bed voidage and particle voidage had the greatest effect on the breakthrough curve. Pressure swing adsorption systems were also simulated. Simple cycles and counter-current operation were proven to not produce high quality heavy or light product. A novel purge recycle step was introduced and improved the carbon dioxide purity. A carbon dioxide purity of 93.8% was achieved by using a rinse step after pressure equalisation steps, but required a compressor and resulted in a significant reduction in carbon dioxide capture rate.

Most granular laundry detergents are manufactured through spray drying. One drawback of this process is wall build-up, which negatively effects process operation, safety and product quality. Macro and micro-scale observations showed the amount and micro-structure of deposits changed significantly across the dryer. These changes were linked to changes in particle properties during drying. Measurements of deposition ranged from 1 - 10 kgm-2, or 2 - 10% of the total slurry sprayed, depending on location, operating conditions and slurry/powder properties. Wall deposition appeared to be time dependent. Wall deposition was broken down into two critical steps; collision frequency, describing how many and how often particles hit the wall and, collision success rate which describes particle’s behaviour upon contact with the wall. Collision frequency was investigated using Particle Imagine Velocimetry (PIV) to measure both fluid and particle dynamics. Finding both to be time dependent, and to vary with position and operating conditions. To investigate collision success rate, particle physical and mechanical properties were studied, revealing mutual dependence of all properties on both formulation and particle size. Impacting these particles at a range of velocities and angles found that the fraction of particles that broke ranged from 0 - 100% and restitution coefficients from 0.1 - 0.8.

The mixing of multiphase turbulent flow within a column is investigated using Positron-Emission Particle-Tracking (PEPT) to understand the controlling phenomena of convection of heat towards the inside surface of its wall in the measurement of the inside-wall heat transfer coefficient by inverse analysis. This is part of a design options study initiated by Rolls-Royce for a key process in the reclamation of uranium from uranium bearing materials. The column contains water and electrolyte and loose metallic swarf. Compressed air is distributed into the column from a perforated plate and hence the multiphase flow is gravity driven. A dynamic assessment of mixing is provided through the framework of the Reynolds-Avergaed Navier-Stokes (RANS) equation in the evaluation of stresses within the multiphase flow. Inverse analysis of heat conduction across the wall of the column provides measurement of the inside-wall heat transfer coefficient. The mixing of swarf coincides with the convergence of the stationary dynamics of the multiphase turbulent flow measured using PEPT. Tikhonov regularisation affords the resolution of the inside-wall heat transfer coefficient of the inverse analysis. A common global gas hold-up between different flows segregates the controlling phenomena of momentum transfer and convection of heat towards the inside surface of the column wall.

Dry powder inhalers (DPIs) are widely used for the therapy of respiratory and pulmonary diseases. In this study, a coupled discrete element method and computational fluid dynamics (DEM-CFD) is employed to investigate the micromechanics of carrier-based DPIs. The effects of van der Waals forces and electrostatic forces on the mixing process, and the influences of air flow and particle-wall impact on the dispersion process are examined. For the mixing of carrier and active pharmaceutical ingredient (API) particles in a vibrating container, it is found that vibration conditions affect the mixing performance. While there is an optimal mixing condition to maximise the number of API particles attaching to the carrier (i.e. contact number) for van der Waals cases, the contact number decreases with increasing vibration velocity amplitude and frequency for electrostatic force cases. It is also revealed that van der Waals forces (short range) and electrostatic forces (long range) result in different mixing behaviours. For the air flow induced and impact induced dispersion, it is found that the dispersion performance improves with increasing air velocity, impact velocity and impact angle, and reduces with increasing work of adhesion. The dispersion performance can be approximated using the cumulative Weibull distribution function governed by the ratio of air drag force to adhesive force or the ratio of impact energy to adhesion energy.

There is a clear need for the development of novel materials for bone regeneration. There is, however, with the exception of poly-(methyl methacrylate) a lack of mouldable polymeric fillers for irregular bone defects. In this thesis, we investigate the production of a new bone graft replacement combining magnetite nanoparticles with polycaprolactone (PCL) to produce a material that can soften in response to the application of an alternating magnetic field. The magnetite nanoparticles were synthesized by a non-surfactant method and then emulsified with PCL. Particle size analysis using light scattering showed that the size distributions of magnetite nanoparticles were influenced by acid concentration and mixing conditions. In contrast, the size of the PCL particles were not strongly related to the mixing conditions, but was influence by the stabilizer used during emulsification. The magnetite nanoparticles showed superparamagnetic behaviour when analysed using SQUID. In the thermal test, magnetite nanoparticles display smooth curves both in the heating and cooling processes and do not shows significant heat loss. Scanning electron microscopy and chemical analysis showed that the magnetite nanoparticles were evenly distributed through the polymer matrix and could be caused to melt following an appropriate external magnetic stimulus. It was demonstrated that magnetite containing microspheres could successful be used for the encapsulation and delivery of antibiotics at a dose which was sufficient to be lethal to E. coli.

The selective oxidation of alcohols is one of the most challenging reactions in green chemistry. While the current chemical industry uses organic and inorganic oxidants to produce carbonyl compounds, it is highly desirable to use a heterogeneous catalyst for the efficient oxidation of alcohols. The present research is focused on increasing the activity and selectivity towards the corresponding carbonyl of the heterogeneous oxidation for alcohols. The low activity of 5 wt.%Pt-1 wt. %Bi/Carbon for the oxidation of 2-octanol was investigated in a 500ml stirred tank reactor. The fast reaction rate drops dramatically from 0.23 M/hr to 0.006 M/hr after 15 minutes reaction time when heptane was used as solvent. Different possible causes such as overoxidation, leaching and poisoning were examined. It was found that the loss of high conversion rate was due to product adsorption and hence, different solvents were investigated. A mixture of 16-18% v/v dioxane in heptane was able to effectively regenerate active sites and allow a constant reaction rate of 0.07M/hr. The effects of temperature and pressure were also studied. Gas-liquid, liquid-solid and internal mass transfer effects were determined experimentally and semi-empirically. Six different Langmuir-Hinshelwood rate models were examined where a modified model based on Schuurman et al. (1992) was found to adequately describe the experimental data. The novel 2.5%Au-2.5%Pd/titania catalyst was investigated for the oxidation of benzyl alcohol. Different parameters such as catalyst oxidation state, pressure and stirrer design were studied to increase the activity and selectivity of the catalyst. The selectivity was shown to be highly dependent on the oxygen concentration. Therefore, the pressure, temperature, catalyst treatment were optimised and the reactor configuration was re-designed to enhance oxygen transport to the catalyst. While the conversion rate was unaffected by the oxygen concentration, the catalyst pre-treatment significantly increased the reaction rate. Eventually, the use of a Rushton Turbine at 20 rps with a shower disc sparger and a treated catalyst allowed the selectivity to reach 93%. The reaction could be described with a Power Law model satisfactorily. Transition Metal Oxide catalysts such as \(AgO/ SiO_2, Fe_2O_3/SiO_2, CuO/SiO_2\) and \(CuO/Al_2O_3\) were investigated as an alternative to the expensive noble metal based catalyst. However, it was shown that such catalysts are ineffective for the oxidation of different alcohols by studying the effects of different engineering parameters. The maximum conversion reached was 15% with calcined copper oxide catalyst for 1-octanol oxidation.

The application of High Throughput Experimentation (HTE) stirred vessels in the catalyst and pharmaceutical industries enable the parallel screening of potential formulations. Such tasks only require a fraction of the raw material and experimental time that are needed in conventional lab scale reactors. However their small sizes (~ 15-250 ml) contribute to a low Reynolds Number, Re, which results in poor mixing efficiencies. Together with unconventional geometries, i.e. lack of baffles and simple impeller designs, their fundamentals are not fully understood. The present study applies Particle Image Velocimetry (2-D PIV) and Planar Laser Induced Fluorescence (PLIF) techniques to a HTE scale stirred vessel (T = 45 mm, V = 72 ml) to determine the mixing behaviour. Three mixing strategies: centreline unbaffled (U), conventional baffled (B) and off-centre eccentric agitator (E) configurations, were investigated using a pitched blade turbine (PBT). Experiments were performed in the high transitional regime (Re \( \approx\) 6000) using distilled water as the working fluid. A uniform power input of P/V = 168Wm\(^{-3}\) was applied. A method based on multiple horizontal and vertical 2-D PIV measurements was used to reconstruct the 3-D flow field in each of these configurations, since the conventional 3-D PIV is unusable at this scale. It was found that the determination of turbulent kinetic energy (TKE) using the isotropic assumption was perfectly valid for (B), but will lead to a considerable underestimation in both (U) and (E). In addition to the three configurations, a square section vessel (S) (T = 41.5 mm, V = 72 ml) and regular vessel with a tilted impeller axis (T) were also studied. With a modified experimental procedure a log variance method for mixing time was applied using PLIF where all the usable pixels in an image were accounted for. Not only was (U) found to be highly inefficient, (B) also registered a slower mixing time due to a small amount of tracer being trapped behind the baffles, which makes the (E), (S) and (T) an even better choice in turbulent mixing. The use of (S) enabled the formation of a more compact HTE unit, also its trailing vortices were able to reach a height of y/H = 0.6, bringing more energy to the upper reaches of vessel, as visualised by angle resolved PIV measurements. The flow number of impeller and the amount of pseudo-turbulence were also determined and they agreed well with literature values. However in the laminar mixing regime using Polypropylene Glycol (PPG) as the Newtonian working fluid (μ = 0.4–0.8 Pa s, P/V = 0.6–5.5 kWm\(^{-3}\), Re = 5–35), at low Re values, (S) only managed a mixing performance comparable to the (U) configuration as the baffling effect of its four corners are less pronounced. However, mixing performance improves in (S) at higher Re values. (B) and (E) gave a comparable mixing performance, suggesting (E) should always be adopted for its viability in both turbulent and laminar mixing regimes. For gas-liquid mixing using air and water (P\(_G\)/V = 168 Wm\(^{-3}\), Q\(_G\) = 0.5–1.0 vvm), an image analysis algorithm was developed which enabled measurement of gas and liquid phase velocities separately. In addition to the PBT, a Rushton Disk Turbine (RDT) was also used (C = D = 0.33T). The power input required for the small mixing vessel to achieve complete gas dispersion was not achievable at the required gas flow rate; hence the experiments are carried out in the flooding regime. This had the advantage of clearly discernible differences between gas and liquid flow pattern for validation purposes. A new image algorithm was written to separate out bubbles in the imaging plane which transforms the in-plane bubbles into tracer particles. The local velocities of the gas phase are then obtained using the conventional cross-correlation technique. The results showed qualitative agreement with experimental observations of global gas phase flow patterns in literature.

This aim of this work is to determine carbon formation when methane is reformed directly inside the SOFC anodes, from thermodynamic equilibrium and kinetic approaches. Two carbon formation determination approaches - carbon-steam equilibrium and carbon activity approaches were then presented, compared and discussed. The consideration of the reversed syngas formation reaction is important to the carbon activity approach, which is expected to be a useful tool for determining carbon formation in the anode recirculation system. The investigation of the combined steam and dry methane reforming, both thermodynamic equilibrium computational modelling approach and kinetic experimental validation were presented in this work. Different ratios among methane, steam and carbon dioxide, leading to different oxygen to carbon atomic were used to examine the methane reforming and the carbon formation prevention abilities. Finally, a kinetic modelling for a methane fed SOFC with anode recirculation system was built based on the integration of different functions for a more detailed investigation. The combination of different fuel current densities (i.e.0.5, 1.0 and 1.4), steam to methane ratios (i.e. 0.25-4.0) in the fuel and different recycling rate (i.e.10%-90%) were given to the model to investigate the effects of fuel conditions on the system operation.

The sensing of biological compounds is of vital importance to the screening and diagnosis of disease. The importance of such assays is due to the correlation observed between the observed levels of biological compounds and diseases such as cancer and diabetes mellitus. Compounds such as sugars and proteins are included in this useful class of molecules which can be used to detect pathology. Currently the detection of these compounds is achieved through the use of other biologically derived molecules- typically antibodies and enzymes. However, sensors based on these compounds can be limited in terms of their stability and suitability. Therefore there is a constant drive for novel detection methods for such molecules. In this context, the aims of the work described herein, are to produce synthetic sensing systems for the selective detection of saccharides and glycoproteins. This work will use principles of nanotechnology and self-assembly to produce surface sensors which exploit the revisable interactions of boronic acids to bind compounds of interest, and which employ surface plasmon resonance spectroscopy to enable the label free reporting of these binding events.

Suspensions of micron sized air cells, Air Filled Emulsions (AFEs), represent a new colloidal material with outstanding physical properties. They have the potential for technological applications in very different fields such as biomedical, environmental sciences and the food industry. This thesis focuses on the construction of AFEs and their use as ingredients to construct reduced fat and calorie emulsion-based products. These microstructurally complex materials have been termed triphasic A/O/W emulsions. A sonochemical templating process has allowed for the construction of air cells (the majority around 0.5-10 μm) in the size range of oil droplets found in emulsion based foods. Air cells were stabilised with either hydrophobins, obtained from submerged fermentation and extraction, or other cysteine rich but more common proteins such as bovine serum albumin (BSA) and egg albumen (EWP). The air cells were stable against disproportionation and ripening for substantial periods of time. They resisted destabilisation effect of oil droplets and could survive unit operations involving mild vacuum treatment and centrifugal forces, relatively high shear forces, temperatures and pressures. Triphasic A/O/W emulsions were created with up to 60% included phase of air and oil in an aqueous continuous phase. This gave a greater than 50% reduction in lipid content. Comparative rheology and tribology showed that the triphasic A/O/W emulsions could have similar if not better lubrication properties than a full O/W version. The molecular properties of the protein used for the AFEs played a crucial role in the determination of lubrication properties (mouth-feel). Moreover, AFEs and triphasic emulsions offer the potential for new structures and textures for the food industry due to their self interaction to give a weak gel