WRI has investigated Venturi scrubber performance in desulfurizing off-gas generated by WRI's 10-ton oil shale retort. A theory of weak electrolyte transport is derived, and two computer models are developed which describe desulfurization. Data on hydrogen sulfide removal and transmissometry are presented. The hydrogen sulfide removal data are analyzed using the above models. Desulfurization was selective, regardless of the solvent used. Removal efficiencies of 60 to 70% were routinely observed, even though solvent concentrations were low compared with industrial applications. This suggests the use of a low-cost desulfurization process using a Venturi absorber. Based on the above, it is concluded that a Venturi scrubber may be the best device for the treatment of in situ oil shale retort gas. The transmissometry data show good correlation with Venturi operating parameters, demonstrating the usefulness of transmissometry applications.