On startup, the air quality control system (AQCS) at Deerhaven Generating Station was not able to meet its guarantees for SO capture and reagent usage. Also, the material handling systems were not operating properly, forcing the units to shutdown. To identify and solve these problems, Alden built three scaled physical flow models to simulate the complex gas-solids interactions in each component of the Turbosorp system. The design solutions that were found during model testing were implemented in the field with great success. As a result, the Deerhaven AQCS was able to meet all the performance guarantees within its contract, and has since been host to a dry scrubbers users group as an example of how these systems should operate.