Suitability of automobile gasolines for prolonged storage

Shatalov, K. V.; Seregin, E. P.

doi:10.1007/s10553-009-0157-z

Cited by 7 publications

(7 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For instance, Shalatov et al 78 proposed a method of determination of chemical stability of 50 ± 1 mL of automobile gasolines based on the accelerated oxidation (3 h) under a high pressure of oxygen (800 ± 10 kPa) and high temperature (120 ± 1 °C), followed by 180 min of cooling. The chemical stability of the automobile gasolines was calculated from the proportion of absorbed oxygen (PAO), defined as…”

Section: Mechanisms and Kinetic Aspectsmentioning

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: Mechanisms and Kinetic Aspectsmentioning

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

“…Among them, the cyclic and branched olefins are the main gum producers. ,,,− The variation in the rate of gum content is dependent on the oxygen content absorbed by gasoline. The greater this proportion is, the higher the oxidation rate is and the faster the gum concentration attains the maximally permissible value. − Traces of transition metals strongly accelerate gasoline oxidation, by catalyzing the decomposition of hydroperoxides into radicalar species. Metals that suffer the transference of one electron, such as copper, iron, cobalt, and manganese ions, are the most effective. − ,,, …”

Section: Introductionmentioning

confidence: 99%

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

“…Further storage of the fuel for up to 4 months resulted in a further increase in gum content. The existent gum content in the samples relative to the starting content increased to the level of 11.0–30.3 mg/100 mL, exceeding the permissible limit according to EN 228 for all of the tested gasolines. The unwashed gum content quadrupled compared with the initial samples, and the content of potential gum increased 5–7 times.…”

Section: Resultsmentioning

confidence: 73%

“…The effect of the chemical composition of fuel and/or the presence of trace metals and sulfur, nitrogen, and oxygen compounds on gum formation during storage of the fuel has been studied by many authors. − Pradelle, , , Shatalov, and Majoch attempted to describe and predict the effects of fuel aging. They also presented studies on the prevention of these negative effects with the use of suitable additives. − Nagpal concluded that the cyclic and dicyclic structures were the major causes of gum formation. Reynolds connected the cause of the low-temperature hydrocarbon oxidation process with the presence of copper in ethanol.…”

Section: Introductionmentioning

confidence: 99%

Changes in the Quality of E15–E25 Gasoline during Short-Term Storage up to Four Months

et al. 2016

View full text Add to dashboard Cite

Nowadays, the main reason for the blending of biofuels stems from the necessity to reduce greenhouse gas emissions. Depending on market requirements, all gasoline fuels should be blended with 5–25 vol % ethanol. Low-blend ethanol gasolines are characterized by alcohol contents ranging from 5 to 10 vol % in Europe and up to 15 vol % in the United States. The achievement of new emission reduction targets and implementation of the requirement to replace fossil energy with renewable energy set out in RED Directive 2009/28/EC will demand blending of 20–25 vol % ethanol gasoline in Europe. Such blends should be stable while being kept in storage or car tanks for a certain time. This article presents the results of research on the evaluation of changes in the physicochemical properties and parameters characterizing the chemical stability of E15–E25 gasoline during short-term storage. Studies have shown that after 4 months of storage, E15, E20, and E25 gasoline did not meet the required minimum in vapor pressure and E70 the distillation parameter and density in relation to the requirements of the EN 228 standard. In the studied gasolines, the water content increased rapidly during storage for up to 4 months. It was found that the determination of the induction period does not differentiate E15 from E25 in terms of stability. A clear differentiation was observed in the determination of unwashed gum content as well as existent gum and potential gum. The results obtained in this research show that low-blend ethanol gasoline even during short-term storage (i.e., less than 4 months) requires special handling.

show abstract

Suitability of automobile gasolines for prolonged storage

Cited by 7 publications

References 2 publications

Gum Formation in Gasoline and Its Blends: A Review

Gum Formation in Gasoline and Its Blends: A Review

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

Changes in the Quality of E15–E25 Gasoline during Short-Term Storage up to Four Months

Contact Info

Product

Resources

About