Removal of copper from hydrogenated soybean oil

et al. 1974

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Four commercial hydrogenations were carried out on 20,000 lb batches of soybean oil with 0.25, 0.5, and 1% fresh copper-chromite catalyst and 1% used catalyst. Hydrogenations proceeded smoothly at catalyst levels of 0.5 and 1%, but the reaction was slow at a 0.25% concentration. Kinetic, selectivity ratio Ln (KL--S) and fatty acid compositional data were acquired during several of the hydrogenation runs. Nickel contamination, confirmed by analysis of used copper catalyst, lowered selectivity. Copper content of the oil rose during hydrogenation, but normal processing steps, particularly bleaching and winterization, removed it to below levels (0.01-0.02 ppm) detectable by direct atomic absorption spectroscopy. Both copper and chromium remaining in the oil after processing were concentrated by winterization in the stearine fraction. Organoleptic, oxidative, and room odor tests showed that oils of good stability can be produced on a commercial scale by copper hydrogenation and winterization. Information was gained regarding problems involved in the plant use of copper-chromite catalyst for hydrogenating soybean oil for edible purposes.

Section: Discussionmentioning

confidence: 99%

Hydrogenation of soybean oil with copper‐chromium catalyst: Preliminary plant‐scale observations

List

Evans

et al. 1974

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“…The filtered CuCr-HSBO and CuCr-Ni-HSBO were water washed continuously as described previously (21) to reduce copper in oil to 0.02 ppm or less and were dried under vacuum.…”

Section: Post-hydrogenation Processingmentioning

confidence: 99%

Flavor evaluation of copper‐nickel hydrogenated soybean oil and blends with unhydrogenated oil

Moulton

Warner

et al. 1975

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Soybean oils hydrogenated to zero linolenate in the pilot plant with a mixed copper-nickel catalyst and a straight copper chromite catalyst were evaluated and compared for flavor and odor. Hydrogenated oils were winterized and deodorized and stabilized with butylated hydroxytoluene, butylated hydroxyanisole, citric acid, and methyl silicone. Taste panel flavor scores of stored oils and room odor scores of oil at frying temperature were similar for oils hydrogenated either with straight copper chromite or with mixed copper chromite-nickel catalysts. Blends containing 1, 2, and 3% linolenate made from unhydrogenated soybean salad oil and soybean oil hydrogenated to 0% linolenate with mixed copper chromite-nickel catalyst were similarly evaluated. Panel responses indicated a blend of 29% unhydrogenated soybean salad oil and 71% hydrogenated soybean oil scored slightly lower than the hydrogenated soybean oil.

“…Copper-containing catalysts, such as copper chromite (1)(2)(3) and copper on silica gel (4), selectively and completely reduce linolenate in soybean oil with only a small decrease in linoleate.…”

Section: Introductionmentioning

confidence: 99%

Hydrogenation of soybean oil with copper catalysts containing small amounts of nickel catalysts

Moulton

Griffin

1973

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Reaction rates, linolenate/linoleate reaction selectivity, trans formation, and conjugated diene formation were determined for mixed commercial catalysts containing 0.5, I, 2, 10, and 20 parts nickel catalyst (25% nickel) per 1000 parts copper chromite catalyst (ppt) and at catalyst concentrations in the oil of 1.0, .0.5, and 0.25%. The rate of hydrogenation increased 'as. the amount of nickel increased. Addition of 0.5, 1, and 2 ppt nickel catalyst to copper chromite catalyst resulted in a small decrease in selectivity compared with straight copper chromite. When soybean oil was hydrogenated with these mixed catalysts sufficiently to reduce linolenate to 0, iodine values were 102-108 compared to 109-112 for straight copper chromite and to less than 80 for straight nickel.