Showing papers on "Hexane published in 1987"
TL;DR: In this paper, the total vapor pressure of three CO2-C6 hydrocarbon systems, including CO2 n-hexane, CO2 benzene and CO2 cyclohexane systems, was measured at 273.15, 283.15 and 303.15 K by a bubble point method.
67 citations
TL;DR: In this paper, a pilot plant scale extraction from seeds of Amaranthus cruentus was performed using hexane on a pilot scale from seeds after the seeds were subjected to an efficient abrasive milling, which revealed a considerable variation in the content of the principal fatty acids, palmitic, oleic and linoleic.
Abstract: Oil was extracted with hexane on a pilot plant scale from seeds ofAmaranthus cruentus after the seeds were subjected to an efficient abrasive milling. Optimum conditions were then determined for refining and bleaching this oil. The yellow oil obtained is similar in appearance and composition to corn oil, but comparison with previously published analyses reveals a considerable variation in the content of the principal fatty acids, palmitic, oleic and linoleic, although the squalene content (5–8%) was in the expected range.
66 citations
TL;DR: In this article, an extraction of oil from rice bran with supercritical carbon dioxide (SC-C02) at pressures of 150 to 350 kg/cm2 G at 40°C was demonstrated.
Abstract: Extraction of oil from rice bran with supercritical carbon dioxide (SC-C02) at pressures of 150 to 350 kg/cm2 G at 40°C was demonstrated. The constituents of the selective fractions obtained at different pressures differed. Fractions obtained at higher pressures contained less free fatty acid and waxes or unsaponifiables. The phosphorus and iron contents were very low in the SC-C02 extracted oil, while the color of the oil was significantly lighter than that of hexane-extracted oil. The yield of low acid value oil was comparable to that for hexane extraction. One problem of the SC-C02 oil is its poor oxidation stability. This method of extraction may be effective in simplifying the processing of edible rice bran oil. Grinding the raw material was found to be effective in decreasing the C02 required and shortening the extraction period.
59 citations
TL;DR: In this paper, the Tait equation was used to predict densities at temperatures up to 0.66 times the critical temperature and pressures up to 150 MPa over a wide range of temperature and pressure.
Abstract: Accurate density data for n-alkanes over a wide range of temperature and pressure have been used to test existing correlation and prediction methods. It is found that the most successful representation at temperatures up to 0.66 times the critical temperature and pressures up to 150 MPa is given by the Tait equation in the form (ρ−ρ0)/ρ=C log [(B + P)/(B + P0)], where subscript 0 refers to 0.101 MPa, with C equal to 0.2000, and [B+(Cn−6)], where Cn is the number of carbon atoms in the alkane chain, is a smooth function of reduced temperature. A simple extension of this method to mixtures gives an excellent prediction of densities at pressures up to 150 MPa over the same reduced temperature range.
56 citations
TL;DR: In this article, the lutein adsorption of crude soybean oil miscella on dispersed silicic acid resulted in three different Freundlich type isotherms, depending on the amount of adsorbent used.
Abstract: Adsorption of lutein from crude soybean oil miscella on dispersed silicic acid resulted in three different Freundlich type isotherms, depending on the amount of adsorbent used. Normally, changing the amount of adsorbent gives a new point on the same isotherm. Further investigation of the lutein adsorption revealed that addition of 1% isopropanol to the hexane solvent and deactivation of the silica acid with water decreased lutein adsorption. Purification of the lutein resulted in increased adsorption, indicating that triglyceride was competing for adsorption sites. The triglyceride competition was confirmed by calculating an adsorption isotherm for triglyceride from crude soybean oil miscella. Use of silicic acid as a column rather than dispersed yielded multiple isotherms for lutein adsorption based on the amount of adsorbent used. Also, lutein adsorption on columns was concentrated at the entrance to the column. Experiments showed that lutein adsorption was not due to partitioning between bound triglyceride and hexane solvent.
42 citations
TL;DR: The first bicyclo[2.2.0] was synthesized by the co-condensation of 1,1,2,2-tetrachlorodi-isopropyldisilane and 1,2dichlorotetraisopropylhexasilane with lithium in tetrahydrofuran.
Abstract: The first bicyclo[2.2.0]hexasilane, decaisopropylhexasilabicyclo[2.2.0]hexane was synthesized by the co-condensation of 1,1,2,2-tetrachlorodi-isopropyldisilane and 1,2-dichlorotetraisopropyldisilane with lithium in tetrahydrofuran.
32 citations
TL;DR: In this article, the authors proposed that the high aromatization selectivity of Pt supported in zeolite L is caused by the ability of the channels to collimate the flux of hexane molecules, leading to end-on adsorption at the Pt surface.
Abstract: It is proposed that the high aromatization selectivity of Pt supported in zeolite L is caused by the ability of the channels to collimate the flux of hexane molecules, leading to end-on adsorption at the Pt surface.
22 citations
TL;DR: In this paper, supercritical carbon dioxide (SCCO2) extraction of oil from peanuts is used as an alternative to hexane extraction or the mechanical oil press.
19 citations
TL;DR: Aqueous stock solutions of Ekofisk crude oil were prepared in darkness and under illumination, and fractions of both types of stock solutions were further treated by controlled evaporation, illumination, extraction with hexane and dichloromethane and phytoplankton cultivation as discussed by the authors.
17 citations
TL;DR: In this paper, five adsorbents were studied for their ability to remove terpenes from cold-pressed Valencia orange oil by frontal-analysis displacement adsorption chromatography; columns were dry-packed to eliminate the use of hexane.
Abstract: Five adsorbents were studied for their ability to remove terpenes from cold-pressed Valencia orange oil by frontal-analysis displacement adsorption chromatography. Only the potable solvent 95% aqueous ethanol was used in the process; columns were dry-packed to eliminate the use of hexane. The most successful studies were carried out using silica gel and Florisil. Adsorptive capacities of 4.4 and 2.0g oil/g adsorbent were achieved for silica gel and Florisil, respectively. Compositions of the oil fractions were determined by gas chromatography and peaks identified by mass spectrometry. Silica gel provided products with the lowest terpene level and the highest oxygenated compound content. The terpene content of the product considered best was reduced to one fifth and one seventh of the original level for Florisil and silica gel, respectively, and had higher oxygenated compound levels than either 10-fold or 25-fold orange oil concentrates.
16 citations
15 Mar 1987
TL;DR: In this article, van der Waals spectra for van derWaals complexes of 2,5-diphenylfuran (PPF) and 2.5-Diphenyloxazole (PPO) with normal alkanes ranging from pentane to dodecane were measured under supersonic jet conditions.
Abstract: Fluorescence excitation spectra are reported for van der Waals complexes of 2,5-diphenylfuran (PPF), 2,5-diphenyloxazole (PPO) and 2,5-diphenyloxa-1,3,4-diazole (PPD), with a number of normal alkanes ranging from pentane to dodecane, measured under supersonic jet conditions. It is shown that referencing the spectral red shifts for alkane complexes against the corresponding pyrene S0 → S2 data provides a useful means of detecting structural variations. The PPF complexes with alkanes from heptane to dodecane show an odd—even effect, where n-alkane guests of different symmetries give rise alternately to single and doubled resonances. Thus, even-alkane complexes have two indistinguishable isomers of C1 symmetry, which contribute to a single spectrum. On the other hand, odd-alkane complexes also have a Cs isomer, which has a slightly different electronic origin resonance, so that a double spectrum results, with spacing on the order of 10 cm−1. These conclusions are consistent with the general predictions of atom—atom pair-potential calculations. We also show that further splitting may be induced in the spectra by complexation of the asymmetrical molecule 2,5-diphenyloxazole (PPO). Complexes with the shorter alkanes pentane and hexane show increased complexity in the spectrum, which is attributed to greater flexibility in the complexation geometry.
TL;DR: In this paper, the p(T) projections of the (solid + liquid + gas) (slg) freezing-temperature depression curves were measured on hydrogen+, methane+, ethane+, ethene+, propane+, butane+, hexane+, octane+, decane+, and carbon dioxide + pyridine.
TL;DR: In this article, the sorption of several aromatic substances by water-free cellulose from dilute n-hexane solutions has been determined by UV spectroscopy, indicating that it is interactions between the cellulose and these groups rather than between the a-electrons of the ring that constitutes the main driving force for sorption.
Abstract: The sorption of several aromatic substances by waterfree cellulose from dilute n-hexane solutions has been determined by UV spectroscopy. Strong sorption is observed for substances with strongly acidic (benzoic acid, phenol) or basic (pyridine) groups. Weaker bases and weak amphoterics show a much lower extent of sorption. Substances where the carboxyl or hydroxyl group is separated from the benzene ring by one or more carbon atoms also show strong sorption, indicating that it is interactions between the cellulose and these groups rather than between cellulose and the a-electrons of the ring that constitutes the main driving force for sorption. The sorption isotherms can be described as the sum of a Langmuir-type isotherm and a Henry isotherm. This fact together with the kinetic behavior of the sorption provides support for the hypothesis that the sorption occurs both as surface adsorption and as bulk sorption into the noncrystalline regions of the cellulose.
TL;DR: In this paper, a gas chromatographic method is presented to determine traces of di-and tri-n-butyltin compounds in fish by use of an innovative clean-up cartridge.
Abstract: A gas chromatographic method is presented to determine traces of di- and tri-n-butyltin compounds in fish by use of an innovative clean-up cartridge. The cartridge used was packed with a moderately sulfonated low capacity cation exchange resin. The organotin compounds in fish tissue were extracted with hydrochloric acid-ethanol solution as their chlorides, transferred to an ethylacetate/hexane phase by liquid-liquid extraction, and the organic layer was concentrated with a rotary evaporator. The organotin chlorides were trapped on the resin by passing through the cartridge. The sampled cartridge was washed successively with ethanol, water and sodium chloride solution. The trapped organotin compounds were converted to their hydrides by passing a sodium borohydride ethanol solution through the cartridge, and these hydrides were eluted with 1/1 hexane/ethanol. The eluted organotin hydrides were extracted with hexane by shaking the eluate with water and hexane. The hexane layer was subjected to gas chromatographic separation, and identified by mass spectroscopy. The di- and tri-n-butyltin compounds in a fish sample could be determined as their chlorides with 2.7-4.8% relative standard deviations in the range 0.1-2.0μg/g. The detection limits of di- and tri-n-butyltin compounds as their chlorides were 3ng/g and 8ng/g for 10g of the sample.
TL;DR: In this paper, the properties of pseudo-ternary systems involving brine, sodium dodecylsulfate (SDS), pentanol and dodecane or hexane have been investigated.
Abstract: The properties of pseudo-ternary systems involving brine, sodium dodecylsulfate (SDS), pentanol and dodecane or hexane have been investigated. When the hydrocarbon is dodecane, the microemulsion system includes in addition to the main monophasic area a small lens inserted in an oil-rich zone. With hexane, the microemulsion domain splits into two parts, one of which consists of a narrow scythe-blade shaped area which spreads from the water top up to compositions very rich in hydrocarbon. The properties of these uncommon microemulsions were compared with those of microemulsions belonging to the main monophasic area in order to gain additional understanding of their structure. Results of experiments including electrical conductivity and viscosity measurements, electrochemical and fluorescent probe studies lead to the following conclusions: Microemulsions of the small lens of the brine/SDS/pentanol/dodecane system exhibit properties which are reminiscent of structures with at once water and oil countinuous phases. Microemulsions of the lenticular area of the brine/SDS/pentanol/ hexane system seem to undergo the same structural transitions as microemulsions of systems which present a single monophasic area: water-continuous, bicontinuous and oilcontinuous structures.
TL;DR: In this article, a dehydrogenation catalyst for alkanes was obtained by exposing Zr(OH)4 to 0.05M-(NH4)2CrO4, followed by calcination in air at 600-800 °C and reduction at 550 °C.
Abstract: A dehydrogenation catalyst for alkanes was obtained by exposing Zr(OH)4 to 0.05M-(NH4)2CrO4, followed by calcination in air at 600–800 °C and reduction at 550 °C; this catalyst converted hexane into benzene with a selectivity of up to 84%.
TL;DR: It is confirmed that GC-MS will not be eligible for the 2016 Rio Olympics because of concerns over the integrity of its anti-doping procedures.
Abstract: ヘキサクロロベンゼン (HCB) はキセノンランプ照射下, とくに212.8nmから292.1nmの波長域において容易に光分解を受け, 252.6nmで最大の分解率を示した. 33.3分照射下において, 1ppm溶液, 10ppm溶液とも252.6nmでほとんど分解した. 100ppm溶液においては37.6%の親化合物が残存していた. 光分解反応は還元的脱塩素反応であり, 光分解生成物として, ペンタクロロベンゼン, テトラクロロベンゼン, トリクロロベンゼン, ジクロロベンゼンおよびモノクロロベンゼンがGC-MSにより同定された. 異なった波長での照射下では, 異なった種類のクロロベンゼンが生成し, その量も波長により異なった. キセノンランプ照射後の回収率, とくに286.1nm以上での結果は, 分解は遅いが, 環境中でのHCBの光分解の可能性を示唆した.
TL;DR: In this article, the excess volumes of 1-chlorohexane with a each of five hexane isomers have been measured at 298.15 K using a vibrating-tube densimeter.
Abstract: The excess volumes of 1-chlorohexane with a each of five hexane isomers have been measured at 298.15 K using a vibrating-tube densimeter. The results have been correlated using several generalized van der Waals models, including random and non-random distribution of the molecules, as well as lattice-with-holes models. None of the models is clearly superior to the other, and all of them give very poor predictions of non-fit excess properties for systems of an alkane with a hexane isomer.
TL;DR: In this paper, the authors present a discussion de donnees cinetiques calculees a partir de resultats experimentaux, a partire de resultat experimentaux.
Abstract: Presentation et discussion de donnees cinetiques calculees a partir de resultats experimentaux
TL;DR: In this article, the pyrolysis of two C6 alkanes, n-hexane and 3-methylpentane, was investigated in a conventional static apparatus at 420°C and 133 mbar, at low extents of reaction.
Journal Article•
TL;DR: In this article, the qualitative and quantitative analyses of phospholipids in chloroform-methanol extracted crude and hexane extracted deodorized soybean oils were carried out by High-Performance Liquid Chromatography (HPLC).
Abstract: The qualitative and quantitative analyses of phospholipids in chloroform-methanol extracted crude and hexane extracted deodorized soybean oils were carried out by High-Performance Liquid Chromatography (HPLC). The phosphorus contents in hexane extracted crude, degummed, refiend, bleached and deodorized soybean oil were 510, 120, 5, 1.4 and 1 ppm, respectively. The chloroform-methanol extracted crude soybean oil had 800 ppm phosphorus. The phospholipids found in crude oil were phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine and phosphatidic acid. Only phosphatidylchonine and phosphatidylethanolamine were detected in the deodorized soybean oil. The HPLC method described in this report can separate and detect individual phospholipids in soybean oil at 0.1 ppm level in 30 min.
TL;DR: In this paper, it was shown that quaternary ammonium ions are not essential for the crystallisation of the silicalite-1 framework. But they are necessary for the formation of the structure.
Abstract: (Hexane-1,6-diamine)–silicalite-1 is crystallised at 100 °C from the reaction mixture 10M2O/60SiO2/10H2N[CH2]6NH2/3000H2O (M = K or Rb); quaternary ammonium ions are not essential for the crystallisation of the silicalite-1 framework.
TL;DR: The effect of n-hexane and its metabolite, 2,5-hexanediol, on the haemopoietic system has been investigated in the rat and spleen and bone marrow were the target sites for the metabolites, whereas n- hexane as such does not affect these organs.
Abstract: The effect of n-hexane and its metabolite, 2,5-hexanediol, on the haemopoietic system has been investigated in the rat. 59Fe uptake was decreased in the bone marrow of n-hexane-treated animals. Spleen and bone marrow were the target sites for the metabolite 2,5-hexanediol, whereas n-hexane as such does not affect these organs.
TL;DR: In this paper, a micro-scale quantitative method for low-molecular-weight monocarboxylic (C 1 −C 4 ) and dicarboxyl (C 2 -C 5 ) acids in permanganate oxidation products of humic substances (kerogen) was established.
TL;DR: In this article, Levin and Ohlson proposed a model for the first time, which is based on the work of the International Journal of Distributed Sensor Networks (JDSN).
Abstract: Chairman: 1983—85 M. Naudet (France); 1985—87 O. Levin (Sweden); Vice-Chairman: A. Hautfenne (Belgium); Secretary: W. D. Pocklington (UK); Titular Members: J. L. BeareRogers (Canada; 1985—87); E. Kurucz (Hungary; 1985—87); 0. Levin (Sweden; 1983—85); J. Pokorn (Czechoslovakia; 1983—85); H. Wessels (FRG); Associate Members: J. L. BeareRogers (Canada; 1983—85); A. Dieffenbacher (Switzerland); E. Fedeli (Italy); J. Gracian-Tous (Spain; 1983—85); T. Hashimoto (Japan; 1985—87); G. Hølmer (Denmark; 1985—87); B. Jacobsberg (Belgium); A. Karleskind (France; 1985—87); F. H. Koelman (Netherlands); E. Kurucz (Hungary; 1983—85); R. G. Manning (USA); A. T. Møller (Denmark; 1983—85); R. Ohlson (Sweden; 1985—87); M. Teupel (FRG); A. Visapaa (Finland); G. Zwerenz (Austria); National Representatives: A. M. Gad (Arab Republic of Egypt); N. G. Bazan (Argentina; 1983—85); R. R. Brenner (Argentina; 1985—87); A. R. Johnson (Australia); R. C. A. Lago (Brazil; 1983—85); D. G. Chobanov (Bulgaria); A. P. Tulloch (Canada); J. Pokorn (Czechoslovakia; 1985—87); G. HØlmer (Denmark; 1983—85); J. V. Holm (Denmark; 1985—87); G. Ostermann (FRG); R. Linko (Finland); J. P. Wolff (France); V. M. Kapoulas (Greece; 1983— 85); D. Boskou (Greece; 1985—87); M. Jeránek (Hungary; 1985—87); N. V. Bringi (India; 1983— 85); A. G. Matthew (India; 1985—87); M. McCarthy (Ireland; 1983—85); A. M. Sharkey (Ireland; 1985—87); A. Dolev (Israel); E. Tiscornia (Italy); T. Hashimoto (Japan; 1983—85); 5. Watanabe (Japan; 1985—87); A. S. H. Ong (Malaysia); P. W. Hendrikse (Netherlands); F. B. Shorland (New Zealand; 1983—85); L. Eyres (New Zealand; 1985—87); W. Zwierzykowski (Poland); G. D. Carr (Republic of South Africa); R. Stoica (Romania); M. Gassiot Matas (Spain); R. Ohlson (Sweden; 1983—85); H. BrUschweiler (Switzerland); R. Penn (Turkey; 1983—85); T. Tuglular (Turkey; 1985—87); V. L. Roubaijlo (USSR); A. E. Waltking (USA).
01 Oct 1987
TL;DR: In this article, a 3-year period of work was performed with the goal of characterizing the oil-solubilizing properties of alkylaryl compounds with two or more sulfonate groups in the molecule.
Abstract: This report covers work performed over a 3-year period with the goal of characterizing the oil-solubilizing properties of alkylaryl compounds with two or more sulfonate groups in the molecule. One material studied was a petroleum fraction, containing a large portion of diphenylalkanes, that had been oversulfonated. The other was an alkyldiphenyl ether sulfonate. Several monosulfonates were studied for comparison: a petroleum sulfonate (TRS 10-410), technical grades of sodium pentadecylbenzenesulfonate and sodium dodecylbenzenesulfonates; and two isometrically pure materials, sodium n-octylbenzenesulfonate and a branched-chain sodium tetradecylbenzenesulfonate (''Texas No. 2''). The experimental technique was measurement of phase volumes of surfactant-oil systems in alkane and salinity scans. All oils were pure or mixed alkanes from hexane to dodecane. Each surfactant system was characterized by its values of the parameters in the Salager correlation (1), along with the solubilization parameter and width of the 3-phase region. The results are reported in terms of how these parameters varied with polysulfonation, equivalent weight, mixing of surfactants, and calcium in the brine. A limited study was made of alcohol and sulfonate partitioning and their effect on interpretation of the data. It was found that many of the properties of polysulfonates are a consequence of their low equivalent weight.more » However, disulfonates are more water soluble, and act more like alcohols, than do monosulfonates of similar equivalent weight. They have less solubilizing power at the same hydrophilic-lyophilic balance, and they decrease the effect of calcium on the behavior. 24 refs., 50 figs., 21 tabs.« less