Propane Removal from Propane-Air Mixtures by Soil Beds

Dilute concentrations of hydrocarbons are difficult and expensive to remove from air by conventional scrubbing methods. Propane removal from propane-air mixtures by soil beds was measured in laboratory experiments and in an industrial application. In closed containers in the laboratory, the time to reduce the initial 1-3 percent propane concentrations by half was 5 to 20 hours for soils at pH 6-8, moderate moisture contents, and temperatures ≥15°C. The propane removal rate was slower when the soil was air dry at 2°C temperature, or was pH 5.3. A test soil bed continuously removed 92-98 percent of the propane from an input air stream containing 0.6-1 percent propane.