Oligomerisation process

This invention relates to base oils for lubricating compositions. In particular, the present invention provides a process for the selective oligomerisation of C5 to C 20 alpha-olefins to produce polyalphaolefin oligomers with a molecular weight distribution that is suitable for use in lubricant base oils.

Oligomerisation process

This invention relates to base oils for lubricating compositions. In particular, the present invention provides a process for the selective oligomerisation of C5 to C20 alpha-olefins to produce polyalphaolefin oligomers with a molecular weight distribution that is suitable for use in lubricant base oils.

DFT studies of long-chain FAMEs: theoretical justification for determining chain length and unsaturation from experimental Raman spectra

Density functional calculations, using B3LPY/6-31G(d) methods, have been used to investigate the conformations and vibrational (Raman) spectra of a series of long-chain, saturated fatty acid methyl esters (FAMEs) with the formula CH2nO2 (n = 5-21) and two series of unsaturated FAMEs. The calculations showed that the lowest energy conformer within the saturated FAMEs is the simple (all-trans) structure and, in general, it was possible to reproduce experimental data using calculations on only the all-trans conformer. The only exception was C6H12O2, where a second low-lying conformer had to be included in order to correctly simulate the experimental Raman spectrum. The objective of the work was to provide theoretical justification for the methods that are commonly used to determine the properties of the fats and oils, such as chain length and degree of unsaturation, from experimental Raman data. Here it is shown that the calculations reproduce the trends and calibration curves that are found experimentally and also allow the reasons for the failure of what would appear to be rational measurements to be understood. This work shows that although the assumption that each FAME can simply be treated as a collection of functional groups can be justified in some cases, many of the vibrational modes are complex motions of large sections of the molecules and thus would not be expected to show simple linear trends with changes in structure, such as increasing chain length and/or unsaturation. Simple linear trends obtained from experimental data may thus arise from cancellation of opposing effects, rather than reflecting an underlying simplicity.

Conformations, vibrational frequencies and Raman intensities of short-chain fatty acid methyl esters using DFT with 6-31G(d) and Sadlej pVTZ basis sets

Density functional calculations, using B3LPY/6-31G(d) methods, have been used to investigate the conformations and vibrational (Raman) spectra of three short-chain fatty acid methyl esters (FAMEs) with the formula CnH2nO2 (n = 3-5). In all three FAMEs, the lowest energy conformer has a simple 'all-trans' structure but there are other conformers, with different torsions about the backbone, which lie reasonably close in energy to the global minimum. One result of this is that the solid samples we studied do not appear to consist entirely of the lowest energy conformer. Indeed, to account for the 'extra' bands that were observed in the Raman data but were not predicted for the all-trans conformer, it was necessary to add-in contributions from other conformers before a complete set of vibrational assignments could be made. Provided this was done, the agreement between experimental Raman frequencies and 6-31G(d) values (after scaling) was excellent, RSD = 12.6 cm(-1). However, the agreement between predicted and observed intensities was much less satisfactory. To confirm the validity of the approach followed by the 6-3 1 G(d) basis set, we used a larger basis set, Sadlej pVTZ, and found that these calculations gave accurate Raman intensities and simulated spectra (summed from two different conformers) that were in quantitative agreement with experiment. In addition, the unscaled Sadlej pVTZ, and the scaled 6-3 1 G(d) calculations gave the same vibrational mode assignments for all bands in the experimental data. This work provides the foundation for calculations on longer-chain FAMEs (which are closer to those found as triglycerides in edible fats and oils) because it shows that scaled 6-3 1 G(d) calculations give equally accurate frequency predictions, and the same vibrational mode assignments, as the much more CPU-expensive Sadlej pVTZ basis set calculations.

Comparison of flavor compounds of potato chips fried in palmolein and silicone fluid

The importance of the frying oil as a heat-transfer medium and as a source of flavor precursors for the formation of potato chip flavor was investigated. Potato slices were fried in palmolein or silicone fluid, and the volatile flavor compounds of the resulting chips were isolated onto Tenax and analyzed by gas chromatography-mass spectrometry. Although the heat-transfer coefficients of the oils did not differ significantly, their temperature profiles during frying were different, probably due to greater turbulence on placing potato slices in palmolein, leading to more efficient heat transfer. Levels of Strecker aldehydes and sulfides in chips fried in the two media were not significantly different, but levels of pyrazines were significantly higher in palmolein-fried chips. Amounts of 2,4-decadienal were also significantly higher in palmolein-fried chips, but there was no significant difference in hexanal levels between the samples.

Steam reforming of model compounds and fast pyrolysis bio-oil on supported noble metal catalysts

The production of hydrogen by steam reforming of bio-oils obtained from the fast pyrolysis of biomass requires the development of efficient catalysts able to cope with the complex chemical nature of the reactant. The present work focuses on the use of noble metal-based catalysts for the steam reforming of a few model compounds and that of an actual bio-oil. The steam reforming of the model compounds was investigated in the temperature range 650-950 degrees C over Pt, Pd and Rh supported on alumina and a ceria-zirconia sample. The model compounds used were acetic acid, phenol, acetone and ethanol. The nature of the support appeared to play a significant role in the activity of these catalysts. The use of ceria-zirconia, a redox mixed oxide, lead to higher H-2 yields as compared to the case of the alumina-supported catalysts. The supported Rh and Pt catalysts were the most active for the steam reforming of these compounds, while Pd-based catalysts poorly performed. The activity of the promising Pt and Rh catalysts was also investigated for the steam reforming of a bio-oil obtained from beech wood fast pyrolysis. Temperatures close to, or higher than, 800 degrees C were required to achieve significant conversions to COx and H-2 (e.g., H-2 yields around 70%). The ceria-zirconia materials showed a higher activity than the corresponding alumina samples. A Pt/ceria-zirconia sample used for over 9 h showed essentially constant activity, while extensive carbonaceous deposits were observed on the quartz reactor walls from early time on stream. In the present case, no benefit was observed by adding a small amount of O-2 to the steam/bio-oil feed (autothermal reforming, ATR), probably partly due to the already high concentration of oxygen in the bio-oil composition. (c) 2005 Elsevier B.V. All rights reserved.

Antibacterial activities of naturally occurring compounds against Mycobacterium avium subsp. paratuberculosis.

The antibacterial activities of 18 naturally occurring compounds (including essential oils and some of their isolated constituents, apple and green tea polyphenols, and other plant extracts) against three strains of Mycobacterium avium subsp. paratuberculosis (a bovine isolate [NCTC 8578], a raw-milk isolate [806R], and a human isolate [ATCC 43015]) were evaluated using a macrobroth susceptibility testing method. M. avium subsp. paratuberculosis was grown in 4 ml Middlebrook 7H9 broth containing 10% oleic acid-albumin-dextrose-catalase, 0.05% Tween 80 (or 0.2% glycerol), and 2 µg/ml mycobactin J supplemented with five concentrations of each test compound. The changes in the optical densities of the cultures at 600 nm as a measure of CFU were recorded at intervals over an incubation period of 42 days at 37°C. Six of the compounds were found to inhibit the growth of M. avium subsp. paratuberculosis. The most effective compound was trans-cinnamaldehyde, with a MIC of 25.9 µg/ml, followed by cinnamon oil (26.2 µg/ml), oregano oil (68.2 µg/ml), carvacrol (72.2 µg/ml), 2,5-dihydroxybenzaldehyde (74 µg/ml), and 2-hydroxy-5-methoxybenzaldehyde (90.4 µg/ml). With the exception of carvacrol, a phenolic compound, three of the four most active compounds are aldehydes, suggesting that the structure of the phenolic group or the aldehyde group may be important to the antibacterial activity. No difference in compound activity was observed between the three M. avium subsp. paratuberculosis strains studied. Possible mechanisms of the antimicrobial effects are discussed.

Granular fertilizer drying and agglomeration in storage

In the manufacture of granular NPK fertilizer the product is cooled before packaging and storage in moisture-proof bags. It has been shown that the temperature of the fertilizer prior to packing is significant in that at high temperatures, drying of the granules takes place in the bag which causes an increase in the humidity of the air surrounding the granules and thus an increase in moisture content at the granule - granule interface. This surface moisture was shown to increase the likelihood of agglomeration in the fertilizer by a capillary adhesion/unconfined yield stress model. An iterative model was set up to establish conditions that would prevent drying occurring, which takes into account fertilizer drying rate, fertilizer cooling rate cooling rate and the effect of coating oils on the drying mechanism.

Superoleophobicity under vacuum

By using superoleophobic alumina and low vapor pressure oils we have been able to study wetting behavior at high vacuum. Here, we show that a superoleophobic state can exist for some probe liquids, even under high vacuum. However, with other liquids the surfaces are only superoloephobic because air is trapped beneath the droplet and the contact angle decreases dramatically (150 degrees-120 degrees) if this air is removed. These observations open up the possibility of designing materials which fully exploit the potential of physically trapped air to achieve extreme oleophobicity and/or hydrophobicity. (C) 2011 American Institute of Physics. [doi:10.1063/1.3589352]

Oligomerisation of linear 1-olefins using a chlorogallate(III) ionic liquid

A Lewis acidic chlorogallate(III) ionic liquid, 1-ethyl-3-methylimidazolium hepta-chlorodigallate(III), [C(2)mim][Ga2Cl7], was successfully used to oligomerise 1-pentene. The influence of temperature, time, catalyst concentration, and stirring rate on conversion and product distribution was modelled using a design of experiment (DoE) approach (chemometrics). The process was optimised for lubricant base oils production; the C20-C50 fraction (where Cn indicates the number of carbons in the oligomer) was maximised, while the heavier oligomer fraction (>C50) was minimised.

Antibacterial activities of naturally occurring compounds against antibiotic-resistant Bacillus cereus vegetative cells and spores, Escherichia coli, and Staphylococcus aureus

After demonstrating the lack of effectiveness of standard antibiotics against the acquired antibiotic resistance of Bacillus cereus (NCTC 10989), Escherichia coli (NCTC 1186), and Staphylococcus aureus (ATCC 12715), we showed that the following natural substances were antibacterial against these resistant pathogens: cinnamon oil, oregano oil, thyme oil, carvacrol, (S)-perillaldehyde, 3,4-dihydroxybenzoic acid (beta-resorcylic acid), and 3,4-dihydroxyphenethylamine (dopamine). Exposure of the three pathogens to a dilution series of the test compounds showed that oregano oil was the most active substance. The oils and pure compounds exhibited exceptional activity against B. cereus vegetative cells, with oregano oil being active at nanogram, per milliliter levels. In contrast, activities against B. cereus spores were very low. Activities of the test compounds were in the following approximate order: oregano oil > thyme oil approximate to carvacrol > cinnamon oil > perillaldehyde > dopamine > beta-resorcylic acid. The order of susceptibilities of the pathogens to inactivation was as follows: B. cereus (vegetative) much greater than S. aureus approximate to E. coli much greater than B. cereus (spores). Some of the test substances may be effective against antibiotic-resistant bacteria in foods and feeds.

Phase Equilibria of Binary and Ternary Systems Containing ILs, Dodecane, and Cyclohexanecarboxylic Acid

This paper reports both the binary and ternary phase behavior of ionic liquids for extracting cyclohexanecarboxylic acid (CCA) from dodecane. This system is a model for the extraction of acids representative of naphthenic acids found in crude oils. In order to develop an effective ternary liquid-liquid extraction system the preliminary selection of ionic liquids was based on CCA miscibility and the dodecane immiscibility with selected ILs. A wide range of ILs based on different cations, anions, cation alkyl-chain length, as well as the effect of temperature on the overall fluid phase behavior is reported. Factors such as variation of cation group, anion effect, alkyl-chain length, and temperature all impact the extraction to various degrees. The largest effects were found to be the lipophilicity of the IL cation and the co-ordination ability of the anion. While CCA capacity increased with lipophilicity of the cation, as did the dodecane. Highly coordinating anions such as trifluoroacetate and triflate demonstrated that highly efficient extraction could be obtained producing favorable tie-lines in the ternary phase diagram. Overall, this study demonstrates that ILs can selectively extract acids from hydrocarbon streams and offers possible treatment solutions for problems associated with the processing of high acid crude oils.

Metabolomic Profiling of In Vivo Plasma Responses to DioxinAssociated Dietary Contaminant Exposure in Rats: Implications for Identification of Sources of Animal and Human Exposure

Dioxin contamination of the food chain typically occurs when cocktails of combustion residues or polychlorinated biphenyl (PCB) containing oils become incorporated into animal feed. These highly toxic compounds are bioaccumulative with small amounts posing a major health risk. The ability to identify animal exposure to these compounds prior to their entry into the food chain may be an invaluable tool to safeguard public health. Dioxin-like compounds act by a common mode of action and this suggests that markers or patterns of response may facilitate identification of exposed animals. However, secondary co-contaminating compounds present in typical dioxin sources may affect responses to compounds. This study has investigated for the first time the potential of a metabolomics platform to distinguish between animals exposed to different sources of dioxin contamination through their diet. Sprague-Dawley rats were given feed containing dioxin-like toxins from hospital incinerator soot, a common PCB oil standard and pure 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (normalized at 0.1 µg/kg TEQ) and acquired plasma was subsequently biochemically profiled using ultra high performance liquid chromatography (UPLC) quadropole time-of-flight-mass spectrometry (QTof-MS). An OPLS-DA model was generated from acquired metabolite fingerprints and validated which allowed classification of plasma from individual animals into the four dietary exposure study groups with a level of accuracy of 97-100%. A set of 24 ions of importance to the prediction model, and which had levels significantly altered between feeding groups, were positively identified as deriving from eight identifiable metabolites including lysophosphatidylcholine (16:0) and tyrosine. This study demonstrates the enormous potential of metabolomic-based profiling to provide a powerful and reliable tool for the detection of dioxin exposure in food-producing animals.