Trickle‐bed scrubbing of flue gas SO2 using non‐aqueous solvents

Experiments were carried out on the performance of several ketone solvents for the scrubbing of dilute SO₂ from a gas stream and its conversion to sulfuric acid in a trickle‐bed reactor packed with activated carbon. Using a bench‐scale trickle bed packed with a structured packing based on Sulzer static mixers coated with Centaur^TM activated carbon and a Teflon binder, measurements of SO₂ removal, conversion to acid and catalyst productivity showed that all were considerably greater than levels achieved with water flushing. The combination of Teflon‐coated Centaur activated carbon with a non‐aqueous solvent as the flushing agent provided from 10 to 100 times higher catalyst productivity than those obtained with water alone and other activated carbons. Also, the productivities obtained by this combination were up to 40 times higher than the productivity of typical vanadium pentoxide catalyst operating at 350°C to 400°C.