Customer’s Problem The off-gases originate from a large paddle dryer that processes egg waste, along with other miscellaneous equipment such as material conveyors, two vessels, and two dumpsters. During the dehydration process, the egg waste releases odorous compounds—specifically ammonia (NH3) and hydrogen sulfide (H2S)—along with water vapor. Most of the water vapor is condensed before the remaining air streams combine and enter the scrubber system. Inlet Gas Conditions and Required Removal Efficiency Contaminants: NH3 and H2S Minimum Overall Removal Efficiency: 99% Desired Outlet Composition: H2S: <= 1 ppm NH3: <= 3 ppm Normal Gas Flow Rate: 5,000 ACFM (Air, H2O, H2S, and NH3) Normal Inlet Temperature: 84°F Inlet Pressure: –2.0 inches H2O Solution Provided To address the customer’s requirements, two packed tower scrubbers were supplied. The first stage uses sulfuric acid as a chemical reagent to remove NH3, while the second stage uses caustic and bleach to remove H2S. Th...
Air Pollution Control and Industrial Ventilation Technologies and Services