Hydrogenation, fats nonselective

The usual practice for the process operator is to determine the refractive index of a sample of the oil during hydrogenation, since this can be done in a few minutes, on site. It correlates well with the iodine value of the oil and also the solid fat index. If a hydrogen gas meter is available, this will have been set at a precalculated amount of gas at which to stop the reaction for determination of the refractive index. Calculation of the amount of gas required is based on the stoichiometry of hydrogenation (Mattil 1964). When the desired refractive index is reached, the batch is cooled for filtration and the solid fat index is determined in the laboratory. This is by far the most important analysis method in hydrogenation control. Typical solid fat indices for selectively and nonselectively hydrogenated canola oil are given in Table IV (Teasdale, 1975). 

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