The report gives results of a 7-month series of nearly 200 tests of the Dustraxtor limestone wet scrubbing system in 1971, both in Key West, Florida, and at TVA's Shawnee Plant in Kentucky. At Key West, No. 6 fuel oil containing 1-2.2% sulfur was burned; at Shawnee, 2-4% sulfur pulverized coal was burned. The tests included systematic variation of stoichiometry, reactant particle size, slurry concentration, pressure drop, and gas flow rate. Reactants tested included coral marl, Fredonia Valley limestone, dolomite, lime, aragonite, and precipitated calcium carbonate. Tests also included evaluation of spent reactant material, boiler injection of dry aragonite, addition of an inhibitor and catalyst, and effects on particulate and NOx removal. After installing an annular fresh water spray ring to reduce scale formation, the Dustraxtor worked satisfactorily. SO2 removal efficiencies varied up to 90-plus %, depending on the reactant used. Absorption efficiency increased significantly with increased pressure drop, decreased gas flow rate, increased stoichiometric ratio, and increased liquid-to-gas ratio.

"September 1974." "EPA-650/ 2-74-077." "Contract no. CPA 70-61, ROAP no. 21AQO-001, Program element no. 1AB013." "EPA project officer: Norman Kaplan."