Tuesday, May 1, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Ethanol and butanol are alternative clean energy sources that are being considered as gasoline additives due to rising crude oil prices and a global effort to reduce green house gas emissions. When combined with gasoline, ethanol increases octane levels and promotes better fuel burning, which reduces harmful emissions. Compared to ethanol, butanol has several desirable characteristics, such as high energy density, low vapor pressure, and low water solubility, making it an attractive second generation fuel additive. However, these alternative fuels can be contaminated with chloride and sulfate, which can contribute to plugging and corrosion of automobile engines. The current maximum permissible concentrations of sulfate and chloride in ethanol is 4 mg/L and 40 mg/L, respectively as defined by the American Society for Testing and Materials (ASTM) specification D 4806. Permissible limits have not been defined for butanol, but the current ethanol specifications are a good benchmark for the quality of butanol. This paper describes two simple ion chromatography methods for the determination of total and potential sulfate and total chloride in ethanol and butanol. Method one directly injects ethanol samples on a Thermo Scientific Dionex IonPac AS4A-SC with suppressed conductivity detection and a run time of 10 min. Method two directly injects the butanol sample on an IonPac AS22 column with suppressed conductivity detection and a run time of 15 min. Linearity, limits of detection and quantification, and precision for both methods will be discussed.