Energy requirements to capture and liquefy isobutane in an electrothermal swing adsorption system

A bench-scale system was developed to capture, recover, and condense low concentration organic gases using activated carbon fiber cloth and electrothermal desorption with post-desorption liquefaction using compression and cooling. This gas recovery system (GRS) will improve the economics of industrial processes that emit low concentration organic gases that could be reused if they were captured and recovered rather than thermally oxidized. The energy required to capture and condense organic gases is of interest so that comparisons to traditional abatement techniques (e.g., thermal oxidation) can be made. Isobutane was used as the model adsorbate to determine the energy requirements of the GRS. The energy required to recover liquid isobutane was determined for several heating and compression times ranging from 3-9 mm. A minimum in the amount of energy required to recover liquid isobutane occurred at moderate heating/compression times (5-7 mm). This minimum resulted from the balance between adequately desorbing the adsorbed gas and diminishing returns on the amount of isobutane desorbed at longer heating times. This is an abstract of a paper presented at the 106th AWMA Annual Conference and Exhibition (Chicago, IL 6/25-28/2013).