Experimental Study of the Influence of Ethanol Concentration and Temperature on Gum Formation during Prolonged Storage of Brazilian Gasoline-Ethanol Blends

Pradelle, Florian; Braga, Sergio Leal; Martins, Ana Rosa Fonseca de Aguiar; Turkovics, Franck; Souza, Renata N. C. De

doi:10.4271/2015-36-0169

Cited by 5 publications

(8 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nevertheless, such increased washed gum content was not observed in later literature. 3,45 An eventual contamination of ethanol with copper, observed by other authors during this period, could explain the results obtained by D'Ornellas. In 2005, Pereira et al 3 showed that the gum content decreased as the alcohol content increased.…”

Section: Introductionsupporting

confidence: 61%

Modeling of Unwashed and Washed Gum Content in Brazilian Gasoline–Ethanol Blends during Prolonged Storage: Application of a Doehlert Matrix

et al. 2016

View full text Add to dashboard Cite

Gasoline is a volatile mixture of hydrocarbons that is used in spark ignition engines. It is a complex mixture composed of inflammable olefinic, paraffinic, naphthenic, and aromatic hydrocarbons (C 4 −C 12 ). It presents low contents of oxygenates and traces of sulfur, nitrogen, and metals, which introduce instability to the mixture. In several countries, such as Brazil, ethanol is used purely as a renewable fuel or as an octane improver in blends with gasoline, especially in flex fuel engines. Nevertheless, some compounds in the fuel react slowly, at room temperature, with atmospheric oxygen, and with each other. The process is observed throughout the entire fuel production and use process and increases fuel density. These high-molar-mass insoluble oxidation products are commonly called gums and form deposits throughout the vehicle fuel system. Their accumulation has adverse effects on engine efficiency, performance, and durability, in the form of incomplete combustion, engine wear, and higher pollutant emissions. Consequently, it is necessary to prevent gum formation by improving gasoline quality and using additives. A prediction of gasoline blends behavior is also an important tool to assess critical conditions. This work studied the influence of aging period, temperature, and addition of anhydrous ethanol concentration on unwashed and washed gum content of Brazilian gasoline−ethanol blends. The effect of an additive was also evaluated, by comparing the results of regular and additivated gasolines. This study also defined predictive mathematic models for the studied properties through a Doehlert matrix with three factors, from which robustness was assessed.

show abstract

Section: Introductionsupporting

confidence: 61%

Modeling of Unwashed and Washed Gum Content in Brazilian Gasoline–Ethanol Blends during Prolonged Storage: Application of a Doehlert Matrix

et al. 2016

View full text Add to dashboard Cite

show abstract

“…The presence of an antioxidant additive in the blend strongly influences the gum formation. Pradelle et al 50 showed in their experimental study that the presence of such an additive reduced the measured washed gum content in ethanol− gasoline blends. They also observed in their predictive mathematical model that additivation reduced the relative influence of ethanol addition in comparison to thermodynamic parameters (temperature and aging period).…”

Section: Mechanisms and Kinetic Aspectsmentioning

confidence: 99%

Gum Formation in Gasoline and Its Blends: A Review

Pradelle¹,

Braga²,

Martins³

et al. 2015

Energy Fuels

Self Cite

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

“…These results reinforced the idea that ethanol solubilized the insoluble species. However, this increase of soluble gums was not observed in the most recent literature (Pereira and Pasa, 2005;Pradelle et al, 2015bPradelle et al, , 2016. One potential explanation can be found in the contamination of ethanol by copper described at the same period (Pereira and Pasa, 2005;Nery et al, 2003;Souza et al, 2005).…”

Section: Introductionmentioning

confidence: 61%

“…Nevertheless, data from two references could not be used for comparison since the results neither were inside the domain covered by the model (Pereira and Pasa, 2005;Pradelle et al, 2015b) nor obtained through natural oxidation processes at room temperature (Pereira and Pasa, 2005). Only the results previously published in Pradelle et al (2016) with E21 gasoline blended with hydrous ethanol (named E21) can be partially used for validation of the models for washed gum from the present study (named E0).…”

Section: Comparison With the Results From The Literaturementioning

confidence: 90%

“…This behavior is probably related to the different oxidation mechanism of ethanol (reduction-oxidation reactions) and olefins (radical-free reactions). Pradelle et al (2015b) modeled the impact of the addition of hydrous ethanol, temperature (25-45 • C), and aging period (0-161 days) on some physicochemical properties (washed gum concentration, induction period, water concentration, specific gravity and kinematic viscosity). They studied blends of gasoline with an initial concentration of anhydrous ethanol (21% (v/v)) with hydrous ethanol, up to 100% (v/v).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Certainties and challenges in modeling unwashed and washed gums formation in Brazilian gasoline–ethanol blends

Pradelle

Braga

Martins

et al. 2017

Chemical Engineering Research and Design

View full text Add to dashboard Cite

Experimental Study of the Influence of Ethanol Concentration and Temperature on Gum Formation during Prolonged Storage of Brazilian Gasoline-Ethanol Blends

Cited by 5 publications

References 11 publications

Modeling of Unwashed and Washed Gum Content in Brazilian Gasoline–Ethanol Blends during Prolonged Storage: Application of a Doehlert Matrix

Modeling of Unwashed and Washed Gum Content in Brazilian Gasoline–Ethanol Blends during Prolonged Storage: Application of a Doehlert Matrix

Gum Formation in Gasoline and Its Blends: A Review

Certainties and challenges in modeling unwashed and washed gums formation in Brazilian gasoline–ethanol blends

Contact Info

Product

Resources

About