Coiled screen or Sulzer CY gauze structured packings, loaded with an activated carbon treated to make it partially hydrophobic, were employed to investigate the removal of SO2 from a stack gas. Measurements were made of SO2 removal and its conversion to H2SO4 and gas-side pressure drop as a function of gas and liquid loadings, temperature, and method of operation (continuous liquid flow vs intermittent liquid flow). Both packings exhibited remarkably high catalytic efficiency in terms of SO2 converted per gram of carbon, as well as high conversions of SO2 to H2SO4 and low-pressure drops. Although the Sulzer CY packing displayed the lowest pressure drop per meter of packing depth, the coiled screen provided higher removal of SO2 per volume of packing. The performances of each were close enough that a choice between them would require an economic analysis.