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When appropriately sourced, bioethanol and biodiesel fuels provide an opportunity for nations to increase their energy independence or to reduce greenhouse gas emissions by supplying energy-dense fuels which are miscible with fossilderived gasoline and diesel. These fuels can be used in low concentrations in vehicles with no modifications; in the case of ethanol, only minor changes in the fuel system materials together with a low-cost alcohol sensor are necessary for compatibility with a high concentration. Ethanol provides the beneficial property of having a high research octane number which can be exploited at the high-load operating conditions in modern pressure-charged spark ignition engines. However, the availability of sustainable feedstocks constrains the supply of biofuels, and this limits the level at which they are able to displace fossil fuels. The miscibility of methanol with both ethanol and gasoline enables the penetration of alcohols in the fuel pool to be increased. The present work describes the properties of specific mixtures of gasoline, ethanol and methanol which are blended to be iso-stoichiometric and iso-energetic replacements for mixtures of gasoline and ethanol. A simple analytical approach to the formulation of these ternary blends is described on the basis of the volumetric energy density of the pre-blended components, and a number of further physicochemical properties are characterised, including their stoichiometries, vapour pressures, distillation characteristics and propensities to phase separate. Data on the octane numbers of the blends are reported. The properties of quaternary iso-stoichiometric blends of water, gasoline, ethanol and methanol (the so-called hydrous ternary blends) are also examined.

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The trace polar species present in diesel were investigated by combining selective ionization with high resolution mass spectrometry. To eliminate matrix effects, the polar fraction was extracted using methanol and direct infusion with electrospray ionization and mass analysis were performed. The advantages and limitations of time-of-flight mass spectrometry and Fourier transform ion cyclotron resonance mass spectrometry for diesel analysis were discussed.Complementary information was obtained by considering both positive and negative ion mass spectra in terms of compounds that form part of the inherent fuel composition and compounds that represent fuel additives. Additionally, diluted fuels were separated by gas chromatography prior to atmospheric pressure chemical ionization and mass analysis. Results showed that a large portion of unsaturated polycyclic hydrocarbons were not detected during direct infusion experiments, indicating that these species were not extracted efficiently with methanol and/or ionized efficiently with electrospray.

Samples of a polypropylene homopolymer have been degraded and analysed with regard to chemical composition, molecular weight distribution and chemical composition distribution. FTIR shows the progress of degradation and a decrease in molecular weight can be observed from SEC. CRYSTAF shows that the chemical heterogeneity of the samples broadens with continuing degradation. SEC‐FTIR reveals that the degraded species are mainly found in the low molecular end of the molecular weight distribution. The spatial heterogeneity of the degradation process has been proven by the analysis of abrased layers.