Mechanism of Gum Formation in Cracked Gasoline - Formation of Peroxide, Aldehyde, and Acid in Storage

Dryer, C. G.; Lowry, C. D.; Morrell, J. C.; Egloff, Gustav

doi:10.1021/ie50296a020

Cited by 8 publications

(6 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Even if the number of publications on this subject is reduced, gum formation is a pre-occupation since the late 1920, with the problem of stability in cracked gasoline. − The present work intends to review all information available in the literature on the formation of gum in gasoline blends. First, stability concepts, gum formation, and a general structure of gum are defined.…”

Section: Introductionmentioning

confidence: 99%

Gum Formation in Gasoline and Its Blends: A Review

Pradelle¹,

Braga²,

Martins³

et al. 2015

Energy Fuels

View full text Add to dashboard Cite

Gasoline is a volatile mixture of hydrocarbons that is used in spark-ignition (SI) engines. It is a complex mixture composed of olefinic, paraffinic, naphthenic, and aromatic hydrocarbons (C 4 −C 12 ), among other substances in a smaller concentration. In several countries, such as Brazil, ethanol is used pure as a renewable fuel for SI engines, especially in flex fuel engines, and/or an additive to improve the octane number of gasoline. During storage, some classes of hydrocarbons in gasoline blends, particularly olefins and diolefins, are able to slowly react, at ambient temperatures, with the oxygen in the air. The formed oxidation products are responsible for the formation of an insoluble solid, commonly called deposits or gums, which sticks to the metal surfaces along the vehicle-fuel system, from the tank to the combustion chamber. Accumulation of these products can cause engine wear and can have adverse effects on engine efficiency, performance, emission, and durability. Consequently, it is necessary to predict gasoline blend behavior and prevent gum formation, improving gasoline quality and using additives. Even if the number of publications dedicated to gum formation in gasoline blends is reduced, results available in the literature for other fuels can be applied to the gasoline issue. This review intends to define more precise fuel stability concepts and what is considered a gum. It also aims to present the oxidation mechanism involved in gum formation, determine the main parameters influencing gum deposition in gasoline blends, and describe the experimental tools available to measure gum content.

show abstract

Section: Introductionmentioning

confidence: 99%

Gum Formation in Gasoline and Its Blends: A Review

Pradelle¹,

Braga²,

Martins³

et al. 2015

Energy Fuels

View full text Add to dashboard Cite

show abstract

“…Palladium nanoparticles are widely employed in catalysts for hydro-treatment of petrochemicals, , synthesis of fine chemicals and purification of automobile exhaust gas, as well as in potential applications for magnetic storage materials and hydrogen storage materials. − Supported Pd nanocatalysts are among the most frequently used hydrogenation catalysts due to their wide range of processing conditions and superior selectivity. − While the geometric and electronic structure of pure palladium nanoparticles has been extensively investigated to uncover their effects on catalytic activity, − relatively little is known to date about the effect of hydrogen absorption on the structure of Pd catalysts in the nm size range.…”

Section: Introductionmentioning

confidence: 99%

Determination of Nanoparticle Size by Measuring the Metal–Metal Bond Length: The Case of Palladium Hydride

Wang

Jiang

et al. 2014

J. Phys. Chem. C

View full text Add to dashboard Cite

Formation and properties of Pd nanoparticles have been investigated in situ in the temperature range between 186 and 483 K by X-ray absorption fine structure (XAFS) spectroscopy and by ex situ electron microscopy. Results of the experiments conducted under hydrogen and helium atmospheres were compared, in order to illuminate and explain the changes in bond length of Pd particles as a result of hydride formation. By contrasting the data obtained at these two atmospheres we were able to isolate the effects of both the finite particle size and hydrogen absorption on Pd−Pd bond length, obtain hydrogen intake values, and, as a result, estimate the particle size. The calculated average particle size agreed with the electron microscopy data. These results open up new opportunities for in situ size investigations by XAFS of catalytic Pd particles in reaction conditions, when catalyst fragmentation, shape change, and/or coarsening may occur.

show abstract

“…In all cases studied, gasolines in which the original induction periods had been increased 200 minutes by use of an inhibitor, proved stable in storage for more than a year, and some in which the increase was 150 minutes were stable for this period. 4. In many gasolines an induction period of 300 minutes assures storage stability under laboratory conditions for longer than one year.…”

Section: Gum Formation During Induction Periodmentioning

confidence: 99%