Adapting Biofilter Processes to Treat Spray Painting Exhausts: Concentration and Leveling of Vapor Delivery Rates, and Enhancement of Destruction by Exhaust Recirculation.

摘要

The goal of this Phase II SBIR effort was to demonstrate the compatibility of a concentrator regenerator coupled with a biofilter air pollution control process for the treatment of intermittent paint booth emissions. A field-pilot system was temporarily installed at Tyndall Air Force Base. The concentrator regenerator was shown to work effectively in the laboratory. In the field, however, a combination of marginal loading from the paint booths and solvent sinks (indicated by a system mass balance) in the pilot unit initially produced too low a delivery rate from the concentrator/ regenerator to adequately feed the biofilter on a continuous basis. When supplementary and, later, regenerated vapors became available to the biofilter, it achieved greater than 80% removal of the solvent-laden air. In instances where a constant, synthetic feed stream was supplied to the biofilter over a short time span (within days), the biofilter removed greater than 87% of all the organics within the first 0.5 feet of bed height Air recycling at recycle ratios of 44%, 61%, 73%, and 78% provided increased removal efficiencies of 88%, 94%, 95%, and 98%, respectively. Capital costs for the concentrator regenerator and biofilter were estimated to be $804,500 and $70,700, respectively. Yearly operating costs for the concentrator regenerator and biofilter were estimated to be $68,700 and $5,580, respectively. Robustness, reliability, and minimal intervention are design targets for improvement, but technical feasibility of the design concept was successfully demonstrated.