Viscosity Index Distributions in Base Stocks Use of Thermal Diffusion

3 Viscosity Index Distributions in Base Stocks Use of Thermal Diffusion 

A 34 ft. long prototype of a commercial-scale unit was built by Standard Oil (Ohio) in the late 1950s to produce 120 VI base stock on a multiple gallon per day basis,35 but does not appear to have had commercial success. No further industrial-scale applications have been reported since then and all other published 

FIGURE 3.15 Schematic of the apparatus employed for thermal diffusion studies. Source H. A. Hamer III and M. M. Bellamy, Applications for Liquid Thermal Diffusion, American Laboratory January 4l—44 (1972). With permission. 

In another example of this technique, D. E. Cranton,36 at Imperial Oil, as part of a study on base stock oxidation stability, separated a midcontinent 150N solvent refined oil by thermal analysis and the ten fractions obtained were then further separated into saturates and aromatics by silica gel chromatography. Mass spectral analyses (Tables 3.11 and 3.12) show the results of the separation obtained in 

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