Concentration and Recovery of Atmospheric Odor Pollutants Using Activated Carbon

Activated carbon filters were used to concentrate atmospheric mixtures of acrolein, methyl sulfide, and n-propyl mercaptan. Removal efficiency and carbon capacity for each of the odor compounds were investigated using two different carbons, Cliff char {4-10 mesh) and Barnebey-Cheney (C-4). A closed system was devised to establish a known atmospheric odor concentration for each filter run. Solvent extraction techniques were employed to desorb and recover the odor compounds from the carbon filters. All quantitative analyses were conducted with gas liquid chromatography utilizing the hydrogen flame ionization detector. The removal studies conducted indicate that the efficiency of removal of a carbon filter is essentially 100 percent up to the point of filter breakthrough. This breakthrough point is governed by the filter’s capacity for a particular compound. This study indicated that the filter capacity is dependent both on the type of carbon employed and the particular odor compound adsorbed. Solvent recovery of the odor compounds from the carbons varied from 0 to 4.5 percent for the mercaptan up to 96 to 98 percent for acrolein. Percent recovery was found to vary for a given odor compound with different carbons and for a given carbon with different odor pollutants.