AbstractFour unit operations of a soybean oil minirefinery — refining, bleaching, hydrogenating, deodorizing — have been tested and are now operational. Major emphasis in this paper is design and testing of the minirefinery but transducer development for computer control is the primary objective of continuing research. Weight, flow, temperature, infrared, refractive index and other transducers have been incorporated. Data output from the computer contains measurements, calculations, instructions and/or warnings that the process may not be operating as desired. Capability for direct digital control of parameters, as for a hydrogenation reactor heater and a neutralization column preheater, have been incorporated. At this stage of the minirefinery development, transducers can now be tested under conditions similar to large scale operati