Hexane

About: Hexane is a research topic. Over the lifetime, 3759 publications have been published within this topic receiving 57996 citations. The topic is also known as: CH3-[CH2]4-CH3 & hexyl hydride.

Adsorption isotherms of sesame oil in a concentrated miscella system

Abstract: The adsorption of peroxides, unsaturated carbonyls, free fatty acids and carotenoids from unrefined sesame oil on vegetable carbon (5%, w/w) in a miscella system was studied. Three different solvent conditions (hexane/ethanol, 100:0, 95:5 and 75:25, vol/vol), combined in a factorial design with five levels of solvent (0, 10, 20, 30 and 40%, w/w), were used to develop the miscella. Equilibrium adsorption was not achieved during the 100 min of adsorption, mainly because the oil components were involved in oxidation reactions during the adsorption process. However, for a given solvent concentration, adsorption of the oil components showed a significant linear regression on their respective initial concentration in the miscella (Ci). Peroxides and carbonyls showed, at all solvent levels investigated, an affinity for the carbon more independent of their Ci than free fatty acids and carotenoids. In general, at the same Ci, a higher adsorption was achieved as solvent concentration increased. The results indicated that free fatty acid adsorption may depend on competitive adsorption based on molecule hydrophobicity. However, in spite of the higher hydrophobicity of carotenoids, compared with free fatty acids, they might not be competing for the same adsorbing sites. Ethanol showed a prooxidant effect that increased peroxide production during adsorption but did not affect the reaction involved in carbonyl production.

Laboratory extraction of cottonseed with various petroleum hydrocarbons

Abstract: Solvent extraction of cottonseed with various hydrocarbons in the C5 to C7 range was studied to determine comparative yields and quality of oil produced with pure and commercial hydrocarbon solvents. The solvents used were Pure Grade (minimum 99 mol per cent purity) isopentane, normal pentane, cyclohexane, normal heptane, and benzene; Technical Grade (minimum 95 mol per cent purity) neohexane, diisopropyl, 2-methylpentane, 3-methylpentane, normal hexane, methylcyclopentane, and a 90 mol per cent cyclopentane; and Commercial Grade normal pentane, isohexanes, normal hexane, isoheptanes, and normal heptane. The effects of precooking the seeds and of the inclusion of hulls on yield and color of extracted oil were determined. Yields and colors of crude oils from cottonseed with both high and intermediate free fatty acid content were studied, and characteristics of the oils determined and compared. Refining losses, refined colors, and bleach colors of oils extracted with various hydrocarbons were compared. Color comparisons were made with a Gardner Color Comparator and a Fisher Electrophotometer. Other test methods used were modifications of official A.O.C.S. methods adapted to small samples. In general normal paraffins and isoparaffins were found to have some advantages over cyclic hydrocarbons.

Pressure and Temperature Dependence of Self-Diffusion in Liquid Linear Hydrocarbons

Abstract: The pressure and temperature dependence o f the self-diffusion coefficients D of n-butane, n-pentane, n-hexane, n-decane, trans-2-butene, cis-2-butene and 2-butyne were determined in the liquid state by NM R-techniques at pressure up to 200 MPa and temperatures up to 450 K. The results are taken as tests for the various dynamical models and compared to results obtained by M D calculations. The activation parameters for translational transport and the parameters for the RHS-m odel are derived and discussed.