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High-resolution proton nuclear magnetic resonance ( 1 H n.m.r.) spectroscopy allows the rapid and exact quantitative determination of the composition and quality of gasolines. For this study about 140 gasolines from Austrian filling stations were analysed. The amounts of methanol, methyl tert-butyl ether (MTBE), benzene and aromatics were determined quantitatively using an internal standard...
The thermal-oxidative stability of unleaded motor gasolines of diverse composition and origin were measured using pressure differential scanning calorimetry (p.d.s.c.) in the temperature programmed mode. The samples were exposed to a heating profile of 1°C min -1 under 2000 kPa oxygen pressure from 80°C to 200°C. From the resulting d.s.c. exotherms, the oxidative induction temperature...
Oxygenates of the type C 1 to C 4 alcohols and MTBE have been used for improving the octane number of gasoline and helping in reduction of emissions. These oxygenates are used as substitutes for the poisonous tetraethyl lead. The ASTM D-4815 method utilizes a GC method for determining methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol (2-methyl-1-propanol),...
A 1 H NMR-based method has been developed for determining the composition (aromatics, naphthenes and paraffins) of straight run gasoline fractions. The equations required for the calculations have been derived based on the assignment of the overlapped 1 H NMR spectra of the samples with particular emphasis on signals from naphthenes and iso-paraffins. The 1 H NMR results have...
A simple method to successfully predict vapour-pressures of gasoline-alcohol mixtures is demonstrated. Vapour-pressures of mixtures of gasoline with methanol, ethanol, isopropanol, and t-butanol were measured at 37.8 o C (100 o F) as a function of mixture composition. Infinite dilution activity coefficients were found from this data and used to find constants in the Wilson equation,...
A systematic method for the determination of sulfur compounds in light petroleum fractions and gasoline is tested, on the basis of a developed analytic method for the sulfide sulfur-silver nitrate complex method. The distribution of various sulfur compounds in simulated light petroleum fraction as well as in FCC and RFCC gasoline has been quantitatively determined.
A new theoretical model has been developed which explains the association between the molecular structure and the knock resistance of individual gasoline compounds convincingly. The constitutions of more than 300 individual gasoline components were correlated with their knock rating (Blending Research Octane Number, BRON) simultaneously. 13 C NMR spectra of all compounds were binned in...
A simple, accurate and rapid method has been developed for the estimation of benzene and total aromatics (0.5-50% w/w) including heavier aromatics (C 8 , C 9 , and C 10 ) in commercial gasoline using packed column GC and NMR techniques. The benzene content can be estimated as low as 0.1% w/w. The response of a flame ionisation detector (FID) to each major aromatic group...
A fast and simple 1 H NMR spectroscopic method was developed for the concentration measurement of aromatic, olefinic and aliphatic fractions in gasoline samples. Simultaneously, individual components such as benzene, methyl tert-butyl ether and several dienes could be determined. The method relies on only a few, well-established assumptions about the molecular compositions and is therefore...
A new simple no-linear calculation method of isomerisation gasoline Research Octane Number (RON) is presented. The calculation method effectively utilizes the compositional data from high-resolution capillary GC analysis, and the measured pure and blending RON values of various HCs, which are widely published. The method, which is a simple non-linear method, utilizes calculable weighting factors,...
Analytical procedures for the isolation of the sulfide and thiophene classes of compounds from fluid catalytic cracking (FCC) and residue fluid catalytic cracking (RFCC) gasoline are described. The methods are based on an effective composite extractant, sulfuric acid and water (SA–H 2 O), which has high efficiencies for extraction and recovery of sulfides from light petroleum fraction as well...
A good approach of the critical molecular dimensions of 35 linear and branched C5–C8 paraffins by DFT quantum chemical calculations at B3LYP/6-31G** level of theory in gas phase is described. In this context, we found that either the determined molecular width or width-height average values can be used as critical measures in the analysis for selection of molecular sieves materials, depending on their...
Silica gel chemically modified with 2-aminotiazole groups (SiAT), was used for preconcentration of cupper, zinc, nickel and iron from gasoline, normally used as a engine fuel. Surface characteristics and surface area of the silica gel were obtained before and after chemical modification using FT-IR, Kjeldhal and surface area analysis (B.E.T.). The retention and recovery of the analyte elements were...
A simple electric impedance sensor embedded in ethanol and regular gasoline blends for determining mass ratios was built and tested in the present work. It was carried out a quantitative evaluation of mixtures for several fuel mass ratios in the temperature range of −10 to 40°C. A non-linear dimensionless electrical conductivity–fuel mass ratio correlation was obtained for a 0–100% ethanol mass content...
Unfortunately, addition of organic solvents (heavy aliphatic, light aliphatic and aromatic hydrocarbons) in Brazilian gasoline is very frequent, and this illegal practice does not guarantee gasoline quality. Organic solvent adulterations of gasoline samples have been investigated. For characterization and comparison of these samples, physico-chemical parameters together with gas chromatographic analyses...
Desulphurization of FCC gasoline and diesel fuels has been investigated by chemical oxidation of sulphur containing compounds with hydrogen peroxide in the presence of an acid catalyst such as formic acid and acetic acid, followed by extraction of the oxidized compounds using acetonitrile. Oxidative desulphurization (ODS) of diesel fuel was found to be very promising approach for the reduction of...
Gasoline is a volatile, inflammable liquid composed of a mixture of paraffinic, naphthenic, olefinic, and aromatic hydrocarbons (C 4 –C 12 ). During storage, these components react with atmosphere oxygen and with each other, promoting changes in their physical–chemical characteristics due to the formation of gums. These materials have polymeric character and normally cause unwanted...
An empirical model for the estimation of evaporative hydrocarbon emissions from canister-equipped vehicles has been developed from experimental data obtained from repeated tests on a single carbon canister. The model is able to predict canister adsorption and desorption behaviour under different loading and purging conditions and it calculates canister weight and breakthrough emissions for various...
The selective removal of sulfur species in atmospheric residue (AR) is strongly wanted since the species of the hydrodesulfurized AR (HDS-AR) define the sulfur content of the product gasoline in the subsequent fluid catalytic cracking (FCC). Hence, the correlations between sulfur species in HDS-AR and FCC gasoline were explored in the present study. HDS-AR was fractionated into vacuum gas oil (VGO)...
After the energy crisis in the 1970s, considerable attention was focused on the development of alternate energy resources. At present, there is a renewed interest in biofuels due to increasing concerns about energy security and environmental pollution. One such biobased fuel that is being widely commercialized is biodiesel. With the increasing production of biodiesel a glut of glycerol has been created,...
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