Load dampening system for vapor phase bioreactors

Vapor phase bioreactors are receiving increasing attention as a cost-effect ive treatment method for air contaminated with volatile organic compounds ( VOCs). in this study, a novel absorption and humidification system was eval uated for its ability to dampen transient VOC loads, and to reduce their de trimental effects on a downstream bioreactor. A model based on the mass tra nsfer characteristics of two target compounds (acetone and toluene) was dev eloped and takes into account a closed water recirculation loop that minimi zes fugitive emissions and simultaneously humidifies the inlet gas stream. When water is used as the scrubbing liquid, model and experimental results indicate that the system effectively dampens hydrophilic compounds and segr egates them from the hydrophobic compounds in the waste gas stream. The res ponse of a vapor phase bioreactor to the pretreated stream has also been as sessed, and results indicate that the load dampening system works effective ly for hydrophilic, but not hydrophobic, VOCs. However, when an organic cos olvent is used in conjunction with water, hydrophobic VOCs can also be damp ened efficiently.