Gasoline Quality Research Articles

Survey of air pollution in Cotonou, Benin—air monitoring and biomarkers

Exposure to genotoxic compounds present in ambient air has been studied in Cotonou, Benin, a city where two-stroke motorbikes are the major form of transportation and gasoline quality is poor. Personal monitoring and biomarkers were used to assess the exposure. Non-smoking taxi-moto drivers (city) and village residents were the study subjects. Benzene exposure was significantly higher in the city, as compared to the village (76.0 ± 26.8 μg/m 3 versus 3.4 ± 3.0, p = 0.0004). Urinary excretion of benzene and S-phenylmercapturic acid (S-PMA) were also highest in subjects living in the city, whereas 1-hydroxypyrene was not different. The level of total polycyclic aromatic hydrocarbons (PAHs), associated with particles, ranged from 76.21 to 103.23 in Cotonou versus 1.55 ng/m 3 for the village. Determination of DNA damage in lymphocytes showed that subjects from the city had elevated number of lesions compared to subjects in the village in terms of bulky DNA adducts, 8-hydroxy-2′-deoxyguanosine and 5-methylcytosine, whereas DNA fragmentations analysed by alkaline gel electrophoresis was not different between the subjects. In conclusion, this study shows that air pollution is pronounced in Cotonou, Bénin and is associated with elevated levels of DNA damage in residents of the city compared to people living in a non-polluted rural village.

Brazilian gasoline quality: study of adulteration by statistical analysis and gas chromatography

The addition of organic solvents (heavy aliphatic, light aliphatic and aromatic hydrocarbons) in Brazilian gasoline is unfortunately very frequent, and this illicit 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 were selected as the factor for hierarchic multivariate analysis (Cluster Analysis). However, these parameters are not efficient to detected all kinds of adulteration. Gas Chromatographic (GC) analysis can be used as a procedure to improve the detection of adulterated gasoline. More detailed information of their compositions was revealed. The use of physico-chemical properties of gasoline samples for hierarchic multivariate analysis and gas chromatographic fingerprints is a practicable method to adulteration detection.

Adulteration detection of Brazilian gasoline samples by statistical analysis

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 data were proposed as the factors for multivariate analysis. Hierarchical clusters analysis was used to improve the detection of the type of solvent and their relative proportion used for this practice. More detailed information of their compositions was revealed. It was found that using physico-chemical properties of gasoline samples together with statistical analysis are a useful method to adulteration detection.

Trends of exhaust emissions from gasoline motor vehicles in the metropolitan area of Mexico city

Light duty gasoline vehicles account for most of CO, hydrocarbons and NOx emissions to the urban environment in the metropolitan area of Mexico City. In order to ameliorate air pollution, several control measures have been imposed in the last decade, such as: up-grade of gasoline's quality, stringent environmental standards, and catalytic converters. On the other hand and from the beginning of 2001, Tier I emission standards became mandatory for all new model year sold in the country. Car manufacturers in Mexico do not guarantee the performance of their exhaust emissions systems for a given mileage. In this work, we present results on brand new vehicles that indicate that NOx emission factors, though they are within the Tier I standard, deteriorate rapidly with the travelled distance (mileage).

Automotive Gasoline Quality Analysis by Gas Chromatography: Study of Adulteration

The addition of organic solvents (light aliphatic, heavy aliphatic and aromatic hydrocarbons) in Brazilian gasoline is unfortunately very frequent, and this illicit practice impares gasoline quality. Gas chromatography (GC) and gas chromatography coupled to mass spectrometry (GC-MS) analyses can be used as a procedure to improve the detection of adulterated gasoline. The results showed that adulterated samples and also the type of organic solvent used in adulteration can be detected by comparison of chromatographic profiles (standard samples versus adulterated samples). However, a single GC analysis can detect an adulterated gasoline, and so decrease the number of adulterated samples approved as presenting good quality.

The development of catalytic cracking catalysts: acidic property related catalytic performance

To meet the requirements for improving fluid catalytic cracking (FCC) yield structure and gasoline quality, a variety of novel FCC catalysts have been developed. The development is closely related to the different approaches to the modification and fine-tuning of the catalyst acidic properties.

Improvement of standard analytical methods for gasoline quality control

Improvement of standard analytical methods for gasoline quality control

Effect of the operating conditions on the conversion of syngas into liquid hydrocarbons over a Cr2O3-ZnO/ZSM5 bifunctional catalyst

The effect of the operating conditions (pressure, temperature, space time, CO/H2 ratio in the feed and time on stream) on the conversion of syngas into liquid hydrocarbons over a Cr2O3–ZnO/ZSM5 bifunctional catalyst has been studied by means of experimentation in an integral fixed bed reactor. On the basis of the results, the global stoichiometry of the process is established and the relative importance of the operating variables in order to reach a good compromise between catalyst activity and gasoline quality is analysed. © 1998 SCI

Prediction of Gasoline Properties with near Infrared Spectroscopy

The test measurements used for the analysis of gasoline quality are mostly complicated standard procedures which are time consuming and which require special equipment, large volume of samples and specialists. The standard test methods could be partly replaced with non-destructive near infrared (NIR) spectroscopic measurements which are fast and less expensive. The aim of this paper is to present a feasible procedure for the prediction of quality parameters of gasoline from its NIR spectrum in a large and very diverse sample set. 350 commercially available gasoline samples were collected from July 1996. The samples covered summer and winter grades of normal, super and superplus unleaded gasolines with minimum RON requirements of 91, 95 and 98, respectively. These fuels covered a wide range of samples from very different sources including Hungarian and foreign refineries and pumps. An InfraPrime Lab Analyser (Bran+Luebbe) with high quality optical fibres in combination with multivariate calibration (PLSR) was used to determine 12 different chemical and physical properties of gasolines including reseach octane number (RON), motor octane number (MON), benzene, methyl-tertier-buthyl-ether (MTBE), sulphur content, distillation characteristics, Reid vapour pressure (RVP) and density at 15°C. The developed NIR methods predicted four important gasoline properties (RON, MON, benzene and MTBE content) with reproducibilities equivalent to the standard test procedures. The standard errors of prediction were 0.34 for RON, 0.30 for MON, 0.13%(vv−1) for benzene and 0.21%(vv−1) for MTBE content. The correlation coefficients were better than 0.970 in these calibrations. Calibrations developed for other gasoline properties showed poor correlation coefficients and allowed each parameter to be predicted only with higher standard error than the reference values. The NIR methods described are suitable for routine selection measurements in large series of gasoline samples.

INDIAN GASOLINE QUALITY AND REQUIREMENT OF DEPOSIT CONTROL ADDITIVES FOR ENGINE INTAKE SYSTEM CLEANLINESS

To meet the growing demand of gasoline, heavier ends of crude are being converted into distillate products through secondary refining processes such as fluid catalytic cracking (FCC), thermal cracking, etc. Present day gasoline in India consists of a mixture of unstable streams such as coker, FCC and visbreaker naphtha besides straight run (SR) naphtha and reformate, affecting the overall quality and stability of the fuel. Out of thirteen refineries in India, nine are equipped with FCC units. In these refineries, gasoline is composed of 50 to 90% of FCC stock. This paper presents data on Indian gasoline quality. Effectiveness of a number of commercially available multifunctional additives on carburettor and intake valve cleanliness was studied on gasolines from different refineries. In addition, the effect of these additives on engine performance and emissions is reported.

96/03662 Contents of benzene and oxygenates function of motor gasoline quality

96/03662 Contents of benzene and oxygenates function of motor gasoline quality

Kinetic model based on a molecular description for catalytic cracking of vacuum gas oil

A kinetic model based on a molecular approach is proposed to represent the cracking reactions of industrial feedstocks on a commercial equilibrium catalyst. Special attention is given to the definition of lumps to represent correctly the effect of the feedstock composition on the gasoline composition through the most important reactions occurring between lumps. The latter are defined not only by their boiling range but also by their chemical composition. The kinetic model is built from experiments with a small fixed bed reactor (the microactivity test). The analysis of cracked products is done by chromatography simulated distillation and a detailed gas chromatographic analysis of gases and gasoline. The study is done at 803 K with various reaction conditions (catalyst hold-up, initial catalyst coke content) to observe primary and successive products. Three typical commercial feedstocks (aromatic, naphthenic or paraffinic) are used to distinguish the effects of feedstock components. The selected reactions are grouped as: (i) cracking reactions by β scission of paraffin, alkyl-aromatic or naphthenic chains, (ii) condensation reactions of olefins possibly with aromatic hydrocarbons, (iii) cyclization of olefins, (iv) hydrogen transfer reactions. The attention is focused on the deactivation function of the catalyst. This function is experimentally determined by testing previously coked catalysts. It takes into account chemical deactivation by coke fouling and diffusional limitation due to pore plugging by coke. The results show that this function depends on the feedstock composition. The reactor is modelled as isothermal, plug flow and unsteady because of the deactivation by coke. The kinetic expressions suppose generally an order one versus each reactant. The kinetic constants are determined by non-linear adjustment with experimental data. The obtained set of kinetic constants describes satisfactorily the experimental results. The kinetic model shows the importance of the condensation and hydrogen transfer reactions for coke formation and gasoline quality. It can be used for modelling a commercial FCC riser.

Source reduction through on-line optimization

Chemical process optimization is studied using an equation based flowsheeting strategy and MINOS 5.1 to solve large nonlinear programming problems. Case studies are based on Sunoco's Sarnia hydrocracker fractionation plant. The case studies highlight some difficulties that must be addressed for a successful practical optimization implementation. The profit function includes utility consumption, chemicals pricing, gasoline quality and the heating value of streams destined for fuel. The complete plant model, embedded as constraints within a nonlinear programming problem, contains 2891 variables with 10 degrees of freedom. Each degree of freedom corresponds to a setpoint for the control system in the plant. There were significant differences between the solutions found by optimizing single units as compared to solving the complete plant model. A case with a fouled heat exchanger showed that most of the setpoints must be changed to optimally compensate for the equipment performance deterioration.

Nonlinear optimization of a hydrocracker fractionation plant

Chemical process optimization is studied using an equation based flowsheeting strategy and MINOS 5.1 to solve large nonlinear programming problems. Case studies are based on Sunoco's Sarnia hydrocracker fractionation plant. The case studies highlight some difficulties that must be addressed for a successful practical optimization implementation. The profit function includes utility consumption, chemicals pricing, gasoline quality and the heating value of streams destined for fuel. The complete plant model, embedded as constraints within a nonlinear programming problem, contains 2891 variables with 10 degrees of freedom. Each degree of freedom corresponds to a setpoint for the control system in the plant. There were significant differences between the solutions found by optimizing single units as compared to solving the complete plant model. A case with a fouled heat exchanger showed that most of the setpoints must be changed to optimally compensate for the equipment performance deterioration.

Formaldehyde and acetaldehyde air contamination. A two years study before the introduction of new gasoline in Italy

Probably, the future change of gasoline quality will induce a new formaldehyde (FA) and acetaldehyde (AA) atmospheric scenario. For this reason an evaluation of FA and AA air pollution has been carried out during 24 consecutive months in the Piedmont region (Italy). Results underline the direct relationship between the intensity of this pollution and geography (industrial activities and demographic density). Furthermore, FA and AA are found in higher quantity during summer but, only in this season, during workdays. Day and night results, as well as the relationship with some meteochemical parameters, show a complex aldehydes chemism characterized by many factors involved.

Calculational method for determination of carburetor icing rate

This paper investigates the dependence of the carburetor icing rate on the density, distillation curve, and vapor pressure of gasoline. More than 100 gasoline samples, covering a range of volatility, were investigated. No clear-cut relationship can be observed between the carburetor icing rate and any specific property index of the gasoline. At the same time, there are certain variables that cannot be observed directly but can be interpreted readily through which the influence of gasoline quality on the carburetor icing rate can be explained. The conversion to these variables was accomplished with regard for the values of the variance and correlation of the carburetor icing rate. Equations are presented that may be used to predict the carburetor icing rate when using gasolines differing in quality. The equations can also determine the need for incorporating antiicing additives in the gasoline.

Mobil Methanol-to-Gasoline Process

This paper explains that 2 major concerns in the development of the methanol-to-gasoline (MTG) process are heat removal from the reactor and the formation of durene (1-,2-,4-,5-tetramethylbenzene). Conversion of methanol to gasoline is highly exothermic (about 1510-1740 kJ/kg of methanol converted) and the adiabatic temperature rise would be almost 600C. Within Mobil, 2 types of reactor configurations were adopted for development: an adiabatic fixed-bed and a fluid-bed reactor. The fixed-bed reactor is ready for immediate commercialization and is more suitable for smaller scale operation. The fluid-bed reactor is under development and possesses the following potential advantages over the fixed-bed reactor: reaction heat removal is simplified by using the superior heat transfer characteristics of a fluid bed; when coupled with alkylation, the fluid bed gives a higher gasoline yield than the fixed bed; and constant catalyst activity, gasoline selectivity, and gasoline quality can be maintained with the fluid-bed operation. Fixed-bed is cyclic.

Diffusion of Catalytic Techniques Through a Population of Medium Size Petroleum Refining Firms

THIS paper reports a study of the diffusion of two catalytic refining techniques, reforming and cracking, among forty-three medium-size petroleum refining firms. The paper has four parts: a brief description of the relevant technology; a development of some hypotheses; a report of research design and findings; a brief. interpretation of these findings. Petroleum is a mixture of compounds with different boiling points and molecular structures. Refining consists in separating the compounds and converting the less valuable compounds to higher valued compounds by changing their boiling points and/or structure. The most important product of petroleum refining is gasoline.1 '[T]he principal mark of gasoline quality has been resistance to knocking, which is expressed as number ' [Hengstebeck, 1959, P. 3]. In I950 the two main ways of converting petroleum compounds were cracking and reforming. Cracking does three things: breaks up large molecules into smaller ones; changes structures of molecules, most importantly increasing octanes of compounds in the gasoline boiling point range; recombines fragments into unwanted low value heavy compounds. Reforming compounds already in the gasoline boiling point range primarily changes their structure to increase octane without changing their weight. Although there is wide variation among petroleums, and the proportions devoted to various uses depends on market conditions, it is possible to make a rough * The theory that underlies the paper was developed jointly with Kenneth D. Mackenzie. Any error in applying the theory is mine. Nancy Bernhardt pointed out a logical error in an early draft and made extensive editorial improvements. Helpful comments were made by Frank Carmone, Irwin Feller, and W. Robert Needham. Many refining company executives generously gave time to fill out a questionnaire. 1 In I947, the nearest census date before the period studied, gasoline accounted for about 45 per cent of the value of petroleum refinery output [Cassady, 1954, p. io]. For plants with cracking facilities the proportion of value accounted for by gasoline tended to be higher-from approximately 60 per cent to over 75 per cent. This is based on statements of operating results for two hypothetical refineries with cracking equipment that appeared in trade journals. The 60 per cent figure assumes that market conditions favored 'limited gasoline and maximum kerosene and fuel oil production' [Read, 1946, p. 248]. The 75 per cent figure assumes that conditions favored the production of gasoline [Anon, 1949, p. 557].

Automotive gasoline quality change during storage in buried tanks

1. There is essentially no quality change in A-66 unleaded automotive gasoline (GOST 2084-56) when stored in buried tanks with a 0.3-m cover in the southern climatic zone for 16 months or in the central climatic zone for 24 months.

Basic requirements for automotive gasoline quality

Basic requirements for automotive gasoline quality