Abstract: Systems and processes for removing sulfur compounds from a hydrocarbon stream. Sulfur compounds are extracted from a hydrocarbon feed stream with a caustic stream to provide a treated hydrocarbon stream and a rich caustic stream. The sulfur compounds in the rich caustic stream are oxidized in the presence of a catalyst to provide a lean caustic stream. The lean caustic stream is returned to extract sulfur from the hydrocarbon stream. Data such as a concentration of sulfurs species and degree of caustic saturation with the sulfur species in the rich caustic stream may be provided by a sensor, compared against other real-time or historical data and used to provide a recommended adjustment to process conditions associated with an extraction unit, or an oxidation unit, or both.