Enthalpy of Fuel-Gas Odorants on Surrogate Soil Surfaces by Gas Chromatography
K E. Miller, Thomas J. Bruno
Heats of adsorption and heats of interaction for natural gas odorants on clay and organo-clay, respectively, were determined using wall coated open tubular (WCOT) column gas chromatography. Clay stationary phases were created using synthetic clay. Subsequent coatings with octadecane created an organo-clay stationary phase. Experimental results show that, as a class, the sulfide odorants have larger enthalpies on clay and organo-clay surfaces than the thiol ordorants. Therefore, we conclude that thiols are less likely to be sequestered on soil surfaces. Further, we demonstrate that Lewis acid-base chemistry on clay surfaces explains the significant difference in enthalpy magnitudes between the sulfide and thiol classes.