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1.
Saudi Arabian heavy crude oil was separated into six fractions, including five distillate fractions (<93, 93–204, 204–260, 260–343 and 343–454 °C) and a >454 °C distillation residue. Each fraction was analysed by 1H and 13C n.m.r. spectroscopy, and combined gained information from these analyses provided reliable average structural parameters. These included estimation of aliphatic and aromatic content, average paraffinic chain length, and estimation of hydrogen, methyl and alkyl bearing aromatic carbons for each of the six fractions. The extent of branching in paraffinic chains and amount of aromatic bridgehead carbons were also calculated. 相似文献
2.
《Fuel Processing Technology》2006,87(11):1013-1019
In this paper comparative analysis of bio-oils and their subfraction from static, sweeping gas and steam pyrolysis of apricot pulp, a food industry waste, was investigated. Experimental studies were conducted in a well-swept fixed-bed reactor with a heating rate of 5 °C min− 1, to a final pyrolysis temperature of 550 °C. The oil yield which was 22.4% at the static atmosphere reached to the value of 23.2% in the sweeping gas atmosphere by using 100 cm3 min− 1 N2 flow rate. The yield of liquid product in steam pyrolysis was higher (27.2%) than the static and inert gas atmosphere.The elemental analyses of the pyrolysis oils were determined, and the chemical compositions of the oils were investigated using chromatographic and spectroscopic techniques. The liquid products were fractionated into pentane solubles and insolubles (asphaltenes). Pentane solubles were then solvent fractionated into pentane, toluene, and methanol subfractions by fractionated column chromatograpy. The aliphatic subfractions of the oils were then analysed by capillary column gas–liquid chromatography and GC/MS. For further structural analysis, the pyrolysis oils' aliphatic, aromatic and polar subfractions were conducted using FTIR and 1H NMR spectra. 相似文献
3.
M. F. King L. C. Boyd B. W. Sheldon 《Journal of the American Oil Chemists' Society》1992,69(3):237-242
Total lipid (TL), neutral lipid (NL), and phospholipid (PL) fractions were extracted from bluefish (Pomatomus saltatrix) white and dark muscle with skin. The effects of each fraction on the oxidative stability of a refined salmon oil model system
was measured by monitoring changes in the 2-thiobarbituric acid assay and decreases in the ratio of docosahexaenoic acid (DHA)
to palmitic acid (C22:6/C16:0) following incubation at 55°C or 180°C. Phospholipid fractions at 2.5% and 5.0% (wt/wt) of oil
improved the oxidative stability of oils incubated at both temperatures compared to controls, TL- and NL-supplemented oils
at similar concentrations. Phospholipid fractions exhibiting antioxidant properties contained an average of 34% DHA as compared
to only 15% in the NL and TL fractions. 相似文献
4.
M. L. Herrera J. A. Segura M. C. Añon 《Journal of the American Oil Chemists' Society》1991,68(11):793-798
Crystalline fractionation of hydrogenated sunflowerseed oil was performed and the chemical composition of the separated fractions
at different temperatures was determined. The results show that the triglycerides obtained after a short retention time (less
than 16.4 min) were enriched in the low-temperature fractions (lower than 22°C), the triglycerides of long retention time
(more than 21.5 min) were concentrated in the higher-temperature fractions (higher than 30°C), and the triglycerides of medium
retention time (between 16.4 and 21.5 min) were concentrated in the medium-temperature fractions (22°C to 30°C). The partition
ratio of triglycerides with retention times of 8.8, 12.5, 16.5, 21.5 and 29.1 minutes was increased as a function of the fractionation
temperature. 相似文献
5.
The carbonization of solubilized matter obtained from the hydrogenated and reductively alkylated quinoline-insolubles of pitches was studied to clarify the different carbonization properties shown by these materials. Dehydrogenation of hydrogenated QI started at 200 °C but continued until 400 °C, passing through a fused phase to give graphitizable carbon. In contrast, alkylated QI gave non-graphitizable carbon because it readily reverted to QI by dealkylation below 300 °C, before fusion. QI alkylated with butyl or benzyl groups was found to be nearly 80% soluble in benzene. 相似文献
6.
A rich (250¦t?1) Green River oil shale was retorted in a helium atmosphere. Isothermal, isobaric retort runs were conducted over a temperature range of 648–773 K (375–500 °C) and a pressure range of 78–765 kPa (11.3–111 psia). Oil was collected as a function of time. A deasphaltened, dry whole oil product (DDWO) was then separated into five fractions: polars (P), ‘weak’ polars (WP), saturates (S), aromatics (A), and olefins (O). One objective of this work was to determine the effect of pressure on the kinetic rate expressions for product oil and oil fraction formation. As the system pressure increased the kinetic rate constants, and, consequently, the product yield decreased. A second objective of the experimental programme was to determine kinetic rate constants for the five oil fractions. A first-order kinetic rate expression was utilized and kinetic parameters were determined for the product oil and oil fractions at each temperature and pressure studied. The kinetic rate constants flow an Arrhenius temperature dependence in the region 688–773 K (415–500 °C); at lower temperatures a change in the activation energy is observed. 相似文献
7.
Mangesh G. Kulkarni Sudhirprakash B. Sawant 《European Journal of Lipid Science and Technology》2003,105(5):214-218
Esters of castor oil and hydrogenated castor oil were prepared with C6, C12, C16, C18 fatty acids, using tetra‐n‐butyl titanate as a catalyst and n‐butyl benzene as a water entrainer. Physical properties such as melting point, refractive index, viscosity, and specific gravity of these esters were measured. Slip melting points of the esters were very low in both cases. These esters did not crystallize even at low temperature. The highest slip melting point obtained was 21 °C with stearoyl hydrogenated castor oil ester and lowest slip melting point obtained was —6 °C with hexanoyl castor oil ester. 相似文献
8.
Castor oil was hydrogenated to evaluate the effect of agitation during hydrogenation. The turbine and propeller impellers
were evaluated during hydrogenation of castor oil at various temperatures, pressures, and catalyst concentrations. The effect
of impeller position in the agitator at definite oil depth was also evaluated. Hydrogenation of castor oil at 130°C, 2.0 kg/cm2 hydrogen gas pressure with 0.5% Ni catalyst for 6 h while using two turbine impellers fitted in an agitator, one close to
the reactor bottom and another at a height just below the top oil layer, revolving at 350 rpm, resulted in a product of a
iodine value of 4.1, hydroxyl value of 156.4, and slip point of 84°C. 相似文献
9.
Preasphaltene, prepared in advance from hydrogenation of Akabira coal, was further hydrogenated at 385 °C with a hydrogen initial pressure of 9.8 MPa for various reaction times. According to the structural analysis and the variation of the inert oxygen content of the remaining preasphaltene and the benzenesoluble product, it is concluded that the conversion of preasphaltene to asphaltene plus oil is principally the reaction of the splitting of ether linkages which reduces the polymerization degree and the saturation of the aromatic rings with hydrogen which increases the solubility in benzene. 相似文献
10.
Peck Hong Yap J. M. de Man L. de Man 《Journal of the American Oil Chemists' Society》1989,66(5):693-697
Palm oil, palm stearin, hydrogenated palm oil (IV 27.5) and hydrogenated palm olein (IV 28) were crystallized at 5°C, temperature
cycled between 5 and 20°C, and kept isothermally at 5°C for 36 days. The polymorphic state of the fats was monitored by X-ray
diffraction analysis. Soft laser scanning of X-ray films was used to establish the increase inβ crystal content. Palm stearin was least stable in theβ′ form, followed by palm oil. The hydrogenated oils were very stable in theβ′ form. Differential scanning calorimeter (DSC) analysis was used to complement the X-ray data. 相似文献
11.
《Fuel》1987,66(11):1588-1595
Polar fractions of a coal-derived liquid obtained by mild hydrogenation of Japanese Taiheiyo coal were investigated. The acid fraction was mainly composed of dimethyl or trimethyl phenols with a minor content of indanols. Z = − 7 N (tetrahydroquinoline) and − 9 N (octahydro-phenanthridine/acridine) series were dominant in the base fraction. Neutral oil was separated into six fractions (DS01–06) by vacuum distillation and each fraction was further separated into saturate, aromatic and polar fractions by liquid chromatography. The polar sub-fractions of DS01 (b.p. 186–281 °C) and DS02 (b.p. 281–305 °C) were analysed by f.i.m.s. and g.c.-m.s. Phenols and tetralinols (or indanols) both with long alkyl chains were major components of these fractions. Those of DS03–DS06, which were too complex to analyse by g.c. only, were repeatedly hydrogenated to eliminate the functional groups and then dehydrogenated to simplify the subsequent analysis. The components in the hydrogenated/dehydrogenated products were identified by g.c. and g.c.-m.s. and compared with the type analysis data obtained from f.i.m.s. of each polar subfraction assuming that those aromatic nuclei having hydroxyl functional groups are partially hydrogenated, if at all. Thus a quantitative analysis of the neutral polar fractions was calculated, which shows them to be composed of only seven kinds of aromatic nuclei. 相似文献
12.
A. E. Bailey G. D. Oliver W. S. Singleton G. S. Fisher 《Journal of the American Oil Chemists' Society》1943,20(12):251-255
Summary 1. Samples of unhydrogenated and hydrogenated peanut oils, which had been refined, bleached, and deodorized, were separated
into two comparable series of fractions by molecular distillation. The various fractions were analyzed for tocopherols (and
related chromogens) by the method of Furter and Meyer, and stability tests by the Swift method were made on the larger distilled
fractions.
2. Molecular distillation at 140°, 160°, and 180° C. yielded antioxidant concentrates (presumably of tocopherols) from each
oil; distillation at 240° yielded fractions almost devoid of antioxygenic substances.
3. In the unhydrogenated and hydrogenated oils, approximately 40 percent and 20 percent, respectively, of the chromogenic
substances reacting in the Furter-Meyer tests were undistillable and remained in the residue comprising 10 percent of the
original oil.
4. Evidence was found of the presence of distillable antioxidants other than tocopherols, which either do not respond to the
Furter-Meyer test or else respond to it weakly, in proportion to their antioxygenic activity.
5. Hydrogenation of the oil had no appreciable effect on the activity of its distillable antioxidants.
6. The progressively increased addition of tocopherol-rich concentrates to fractions almost devoid of antioxidants resulted
in first decreasing and then increasing the initial rate of peroxide formation in the stability tests.
7. In the case of the unhydrogenated oil, there was an optimum level of antioxidant concentration above which the addition
of these substances had no stabilizing action. However, hydrogenated oil showed an increase in stability with the addition
of antioxidants up to the highest level to which the concentration of the latter was carried (approximately 0.15 percent,
calculated asa-tocopherol).
Presented before the American Oil Chemists’ Society Meeting, New Orleans, Louisiana, May 12 to 14, 1943. 相似文献
13.
When Illinois No. 6 whole coal or vitrain is extracted with pyridine-14C, the extracts and solid residues retain 12–20% and 9–16%, respectively (at temperatures of 23 and 130 °C) of the pyridine-14C. Repeated treatment of the extracts with benzene, followed by filtration and drying at 0.1 Pa for 48 h removes only 20–25% of the labelled amine, although 92–98% of the latter is exchangeable with unlabelled pyridine. The solid residues exhibit similar behaviour. Tetrahydroquinoline-14C (THQ-14C) was used to extract Illinois No. 6 vitrain at 270 °C; the soluble and insoluble fractions after exhaustive drying retained 18% and 15%, respectively, of the THQ-14C which could not be exchanged (from the soluble fraction) with a mixture of unlabelled THQ and quinoline. Ethylenediamine-14C (EDA-14C) was also used to extract Illinois No. 6 vitrain. The retention of EDA-14C was temperature-dependent (10% retained in 20 h at 120 °C, followed by 1 h at 150 °C). Following three exchanges with unlabelled EDA, all but 2.6% of the EDA-14C was removed. 相似文献
14.
In this study, the effect of ultrasound-assisted extraction (UAE) on oil yield and content of functional food ingredients of hulled and non-hulled sunflower is discussed and compared with conventional extraction methods. The optimum extraction parameters for UAE were as follows: n-hexane as extracting solvent, average particle size 250 ± 12 µm, extraction time 2 h, solid-to-solvent ratio 1:12, ultrasound frequency 24 kHz and temperature 50°C. Furthermore, the chromatograph showed that sunflower oil extracted by the UAE was rich in α-Linolenic acid (ω-3). In addition, a marginal reduction in peroxide values and tocopherols were determined. 相似文献
15.
Transition metals, including iron, occur naturally at significant concentrations in meat. Iron can be extracted from the food
into the oil and potentially decrease the stability of the oil during frying by accelerating thermoxidation. The objective
was to examine the thermoxidative stability of partially hydrogenated soybean oil after addition of heme iron. Heme iron (2.7
ppm) was added to the oil, and then oil samples were heated continuously at 160, 180, or 200°C for 72 h. Oil samples were
removed for analysis every 12 h. The acid values, color, food oil sensor readings, and TAG polymer content of the heated oil
samples were compared with oil samples containing no added iron that were held at the same temperatures. Generally, each oxidative
index increased with (i) an increase in temperature, (ii) an increase in heating time, and/or (iii) the addition of iron.
Generally, the extent of oxidation was greater for samples heated at 200°C than for oil samples heated at 160 or 180°C. The
oil samples heated at 200°C reached the target polymer content of 20% after 27 h of heating. If heme iron accumulates in the
oil, it will increase the rate of oxidation and thermal degradation and reduce the frying life of the oil. 相似文献
16.
Koji Ouchi Akihiko Mikami Hironori Itoh Masataka Makebe 《Fuel Processing Technology》1985,11(3):231-240
Yubari coal vitrite was extracted with quinoline at 420° C for 0–4 h and the products were separated into several fractions. Quinoline solubles (QS) and insolubles (QI) increased with time and the total recovered weight became nearly 200% of the original weight of the coal. A large part of this weight increase was due to the contribution of the formation of biquinoline and to quinoline addition to coal. Depolymerization to smaller molecules and polymerization to QI took place simultaneously via the addition of quinoline and the production of biquinoline. 相似文献
17.
A petroleum pitch and > 288 °C fraction of an ethylene pyrolysis tar are separated by sequential solvent extraction into fractions differing in average molecular weight. Average molecular parameters for each fraction are obtained using their H and 13C n.m.r. spectra. Average molecular structures which correlate with the observed data are drawn. The data presented here suggest that the average molecule of the fractions of both petroleum pitch and pyrolysis tar can be represented by an oligomeric structure in which small aromatic clusters are joined by aliphatic bridges and/or biaryl linkages. This contradicts the accepted assumption that the aromatic ring system in petroleum-derived products is fully condensed. Although the average molecular structure of the fractions of pitch and ethylene pyrolysis tar are basically similar, they differ in the number and types of ring-saturated carbons. 相似文献
18.
《Fuel Processing Technology》2006,87(1):25-32
Olive residues were pyrolysed in a fixed bed reactor under different pyrolysis conditions to determine the role of final temperature, sweeping gas flow rate and steam velocity on the product yields and liquid product composition with a heating rate of 7 °C/min. Final temperature range studied was between 400 and 700 °C and the highest liquid product yield was obtained at 500 °C. Liquid product yield increased significantly under nitrogen and steam atmospheres. Liquid products obtained under the most suitable conditions were characterised by elemental analyses, FT-IR and 1H-NMR. In addition, column chromatography was employed and the yields of the sub-fractions were calculated. Gas chromatography was achieved on n-pentane fractions. The results show that it is possible to obtain liquid products similar to petroleum from olive residue if the pyrolysis conditions are chosen accordingly. 相似文献
19.
《Fuel Processing Technology》2005,87(1):25-32
Olive residues were pyrolysed in a fixed bed reactor under different pyrolysis conditions to determine the role of final temperature, sweeping gas flow rate and steam velocity on the product yields and liquid product composition with a heating rate of 7 °C/min. Final temperature range studied was between 400 and 700 °C and the highest liquid product yield was obtained at 500 °C. Liquid product yield increased significantly under nitrogen and steam atmospheres. Liquid products obtained under the most suitable conditions were characterised by elemental analyses, FT-IR and 1H-NMR. In addition, column chromatography was employed and the yields of the sub-fractions were calculated. Gas chromatography was achieved on n-pentane fractions. The results show that it is possible to obtain liquid products similar to petroleum from olive residue if the pyrolysis conditions are chosen accordingly. 相似文献
20.
A shale oil sample from an above-ground 150 ton retort, designed to simulate the in-situ retort process, was vacuum distilled to obtain narrow distillate fractions. The optical rotation was measured for each distillate cut. The fraction with the highest optical rotation (470 °–485 °C) was subjected to elution chromatography using hexane, benzene and methanol, respectively. The resulting saturated fraction (hexane cut) was investigated by computerized gas chromatography-mass spectrometry. Three steranes, four pentacyclic triterpanes and five normal alkanes were identified, and the partial structures of two other compounds have been suggested. 相似文献