HR: 0830h
AN: A51F-0747    [PDF]
TI: Heterogeneous Interactions of Ethanol with Low-Temperature Aqueous Sulfuric Acid
AU: * Staton, S J
EM: statons@william.jewell.edu
AF: William Jewell College, Department of Biochemistry, Liberty, MO 64068 United States
AU: Michelsen, R R
EM: rmichelsen@mail.arc.nasa.gov
AF: NASA Ames Research Center, MS 245-5, Moffett Field, CA 94035 United States
AU: Iraci, L T
EM: liraci@mail.arc.nasa.gov
AF: NASA Ames Research Center, MS 245-5, Moffett Field, CA 94035 United States
AB: Tropospheric ethanol has both biogenic and anthropogenic sources. Evaporative emissions of ethanol will increase as its use in gasoline increases. Since ethanol has a sufficiently long lifetime to reach the upper troposphere and it is quite soluble in water, its interactions with tropospheric sulfate particles are of interest. Furthermore, ethanol undergoes two different reactions in acidic media and is therefore a useful molecule to test the ability of tropospheric sulfate to process organic matter. The reactivity ethanol exhibits in sulfuric acid is applicable to other primary alcohols, including biogenic compounds such as 2-methyl-3-buten-2-ol. The solubility of ethanol in low-temperature sulfuric acid + water solutions has been studied in a traditional Knudsen cell. Experimental conditions were representative of the upper troposphere; acid composition ranged from 40 to 80 wt. % sulfuric acid and temperature from 215 to 240 K. The solubility of ethanol increases with decreasing temperature and increasing acidity, with measured Henry's law coefficients ranging from 10$^{4}$ to 10$^{9}$ M atm$^{-1}$. Experimental evidence for the heterogeneous reaction of ethanol will be discussed as well.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0345 Pollution--urban and regional (0305)
DE: 0365 Troposphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting