SO2 Removal Using Mg(OH)2, AV Cell, Canada - Case Study

Solution
During 2013 a root & branch assessment of the chemistry & process of SO2 absorption using the SO2-HSO3 -SO3 system with an Mg2+ cation in a recirculated slurry fluid bed scrubber was undertaken by FTL/Osprey. This was followed by half year proving trials using our proprietary eccentric Turboid® packings in a tower upgrade to boost SO2 removal performance, minimise constant plugging issues and de-bottleneck the column.

Results
By maintaining SO2 performance with nearly half of the previous pressure drop and maintaining plugging & clogging free operation the old retrofitted Flakt tower is no longer prone to frequent & unexpected shutdowns which previously averaged every 2-3 months. The key to success in such a large tower & complex process is tight pH control to minimise MgSO3.xH2O precipitation, maximise Mg(HSO3)2 product and simultaneously ensure sufficient SO2 absorption to comply with ever tightening emissions limits. The mathematical model developed to allow such tight control was critically augmented by use of Turboid® elements with optimally low bed heights to reduce ?P, improve flow distribution, eliminate clogging & greatly reduce abrasion.