Corrosion Behavior of Al in Ethanol–Gasoline Blends

Abstract

The corrosion behavior of pure aluminum (Al) in 20 v/v% ethanol–gasoline blends has been studied using electrochemical techniques. Ethanol was obtained from different fruits including sugar cane, oranges, apples, or mangos, whereas other techniques included lineal polarization resistance, electrochemical noise, and electrochemical impedance spectroscopy for 90 days. Results have shown that corrosion rates for Al in all the blends were higher than that obtained in gasoline. In addition, the highest corrosion rate was obtained in the blend containing ethanol obtained from sugar cane. The corrosion process was under charge transfer control in all blends; however, for some exposure times, it was under the adsorption/desorption control of an intermediate compound. Al was susceptible to a localized, plotting type of corrosion in all blends, but they were bigger in size and in number in the blend containing ethanol obtained from sugar cane.

Methods for Testing the Steel Corrosion Inhibition in Alcohol–Gasoline Blends Using Diethylenetriamine

“…The bioethanol produced from the other crops was found to have lower corrosion effects. 23 Joseph et al 24 performed polarization measurements to evaluate the corrosion effects of E40 fuels with different contents of sodium chloride. They tested lowcarbon steel with a scanning rate of 10 mV/s.…”

“…In contrast, carbon, stainless steel, and tin reached the corrosion rates of 4.95 × 10 −5 , 1.07 × 10 −5 , and 1.20 × 10 −5 mm/year, respectively. 22 Brito-Franco et al 23 used EIS in a three-electrode arrangement for corrosion tests of aluminum in an E20 fuel. The bioethanol used was produced from four different crops: sugarcane, oranges, apples, and mangoes.…”

“…The E20 fuel containing sugarcane bioethanol was found to be the most corrosive one as the aluminum in this fuel had the lowest polarization resistances at about 10 7 Ω·cm 2 , whereas the polarization resistances measured in the bioethanols obtained from mangoes, apples, and oranges were about 2 orders of magnitude higher. The bioethanol produced from the other crops was found to have lower corrosion effects . Joseph et al performed polarization measurements to evaluate the corrosion effects of E40 fuels with different contents of sodium chloride.…”