The findings of the first reported guest centric encapsulation study are presented within. The guests were of interest as petrol and diesel (fuel) additives, with the focus on 2-ethylhexyl nitrate (2-EHN), di-tert-butyl peroxide (DTBP), aniline, N-methylaniline (NMA) and N,Ndimethylaniline CNNDMA). Complexation with 2-EHN and DTBP was achieved with the novel calix[4]arene derivative, 5, 11, 17, 23-tetra-tert-butyl, 25, 27-bis(oxyethylphenylurea), 26, 28-dihydroxycalix[4}arene, CA(III). This was confirmed in solution by the use of NMR techniques. The multi-step procedure to yield a tetrol cavitand. with recent updates to the procedures are fully described. A new carceplex system with aniline encapsulated, carceplex aniline (4, 24- 5,5'- 6,10- 11 , 11'- 12, 16- 17, 17'- 18, 22- 23, 23'- 4', 24'- 6',10'- 12', 16'- 18 ',22' dodecamethylenedioxy, 2, 8, 14,20, 2', 8' ,14', 20'-octapentyl-bis-calix[4]arene aniline) was produced in a pioneering pressure tube encapsulation follwing unsuccessful attempts under reflux conditions. A pyrogallol[4]arene with pentyl pendant group (2, 8, 14, 20-tetrapentylpyrogallol[4]arene) PA(I) was synthesised and successfully employed for self-assembled complex formation with aniline, NMA and NNDMA. These complexes were found to be stable in polar and apolar media at 313 K over a duration of 2 months. The complexes were of stoichiometry 10:1 (aniline: PA(I)), 12:1 (NMA : PA(I)), and 4:1 (NNDMA: PA(l)). Significant variation was observed when complexes were analysed by TGA in air up to 800 °C compared to control. PA(I) . aniline and PA(I) . NMA displayed solubilities in apolar media making them suitable for analysis in test engines as fuel additives. The first report of a (two-step) carcerand synthesised from pyrogallol[4]arene, PA(I) with the introduction of methylene dioxy spanning and bridging groups, yielding the novel carcerand 4,24- 5, 4'.- 6, 5' - 10, 1\ ' - 12, 16- 17, 16'- 18, 17'- 22, 23'- 23, 24' - 6', 10'- 18', 22' dodecamethylenedioxy, 2, 8, 14, 20, 2', 8', 14', 20' -octapentyl-bis-calix[4]arene is also presented.

C02 emissions are one of the main causes of the greenhouse effect. Reactions between C02 and H2, such as methanol synthesis and methanation, could play an important role in reducing these emissions. The low methanol yield, both selectivity and conversion, is the main problem in the methanol synthesis. Methanation could be considered as another alternative process, because recent research showed that the yield in methanation'process is high, the conversion of C02 to C~ was nearly 100%. By using a combination of the Zero Emission Petrol Vehicle (ZEPV) concept, catalytic hydrogenation of CO2 and methanol to gasoline (MTG) process gasoline can be re-synthesised from recycle C02. The objectives of this thesis are to examine the methanol sY!lthesis behaviour in the lab scale tubular catalytic reactor, to investigate the effect of molecular Sieve 4A (MS 4A) on this synthesis and to analyse the feasibility study for a re-syn fuel refinery. First, methanol synthesis experiments were performed on a CuO/ZnO/AhOJ catalyst at 190- 2200 C, 1 bar, 3600 - 7200 h-I and H2/C02 = 3 - 4. The results indicated that methanol was produced from reaction between H2 and CO2 at those conditions. A maximum C02 conversion was reached at 1900 C, 1 bar, 3600 h-I and H2/C02 = 4. The numerical model results predicted that the initial rate of methanol synthesis increase sharply at pressures into 50 atm and is then relativ~ly constant at pressures above 50 atm. At 50 atm, the initial rate ratio is predicted to increase 35 - 45 times than the initial rate at 1 atm. The presence of water is one of the problems affecting the synthesis. Then to investigate the effect of adding a desiccant, methanol synthesis using a CuO/ZnO/AhOJ catalyst and a MS 4A were carried out at the conditions with the maximum CO2 conversion. The results showed that MS 4A adsorbed water hence the conversion of C02 increased from 1.13% to 2.12%. According to the numerical model, these conversions are predicted 35 - 45 times at pressure around 50 atm. Finally, material and energy balances were calculated for four possible chemical pathways for this re-synthesis (the direct CO2 hydrogenation, the Camere process, the methane to methanol process and the electrolysis process) to determine energy requirements in the re-syn fuel refineries. By using the ZEPV concept, some 70 MT/year of C02 from the combustion of about 22 MT/year of gasoline in around 30 million vehicles in UK can be liquefied at 70 bar and stored on board. This liquid C02 is available to be converted back to gasoline via methanol. The 30% conversion, which was obtained from combination of experiment and numerical model results, was applied for direct hydrogenation of CO2. For the other chemical pathways, the conversion used was based on previous studies. Carrying out this recycling in a set of geographically distributed 're-syn fuel' refineries using offshore wind energy has no further requirement for exploration of crude oil, no limitation of raw material and furthermore no cost penalty for the emitted carbon value. The economic analysis shows that the present (2008) forecourt price for the typical oil refinery (98 p/l) is lower than this forecourt price for the 're-syn fuel' refinery using the offshore wind energy (l09 p/l). By predicting that the wind energy cost will be reduced to as Iowa 2.5 plkWh in the future (2020), it is estimated that the forecourt price of gasoli~e from this futuristic sustainable resynthesis refinery would be decreased to 89 p/l. This forecourt price is cheaper than the current gasoline forecourt price from a typical conventional oil refinery. Based on this preliminary economic assessment, gasoline re-synthesis from recycled CO2 using offshore wind energy is both perfectly sustainable and almost competitive for today and will be cheaper than gasoline from crude oil in the future.

Membrane technology is a potential method for upgrading gasoline quality, with respect to its tendency to promote fouling of engine inlet-systems. This thesis investigates the transport and separation mechanisms of dense polydimethylsiloxane (PDMS) membranes in nanofiltration applications relating to the filtration of gasoline fuels. Simulated fuels were created which comprised representative organic solvents with organometallic and poly-nuclear aromatic solutes. The flux and separation behaviour of the solvent-solute systems were studied using several apparatus and a range of operating regimes. Tests were performed with real fuels and refinery components to verify the mechanisms observed with the model solvent-solute systems, and several strategies were developed by which the process could be optimised or improved. Parallel to this work, a project was undertaken to assess the suitability of the technology on an industrial scale and to identify any scale-up issues. The key factors influencing flux were found to be the viscosity and swelling-effect of the solvent or solvent mixture. The dense membrane was shown to exhibit many characteristics of a porous structure when swollen with solvents, with the separation of low-polarity solutes governed principally by size-exclusion. It is postulated that swelling causes expansion of the polymer network such that convective and diffusive flow can take place between polymer chains. In general terms, a higher degree of swelling resulted in a higher flux and lower solute rejection. The separation potential of the membrane could be partly controlled by changing the swelling-effect of the solvent and the degree of membrane crosslinking. The transport of polar/non-polar solvent mixtures through PDMS was influenced by swelling equilibria, with separations occurring upon swelling the membrane. Separation of the more polar solvent occurred in this manner, and the solute rejection in multicomponent polar/non-polar mixtures deviated significantly from the behaviour in binary mixtures. The results obtained from a pilot-plant scale apparatus were largely consistent with those from laboratory-scale equipment, and engine tests showed that fuel filtration with PDMS is a technically-viable means of upgrading gasoline quality.