Kerogen structure by stepwise oxidation: Use of sodium dichromate in glacial acetic acid

Green River shale kerogen was degraded by a careful five-step oxidation with sodium dichromate in glacial acetic acid. Products isolated from each oxidation step were examined by capillary gas chromatography and combined gas chromatography-mass spectrometry. The analyses revealed the presence of several homologous series. Saturated normal monocarboxylic acids (C₆C₃₅) and saturated normal α,ω-dicarboxylic acids (C₄C₃₃) were the major constituent series, while isoprenoid acids (C₁₄C₂₁, except C₁₈), iso and anteiso acids (C₆C₁₆), branched dicarboxylic acids (C₂₀C₂₉), triterpenoidal acids (C₂₇C₃₃), cyclic, and oxo-acids were the minor constituent series. Moreover, a few aromatic acids, branched ketones, heterocyclic compounds, as well as a series of (C₂₅C₃₀) n-alkanes were identified. The results were discussed in terms of the qualitative and quantitative variations of the products with duration of oxidation. The data corroborate the conclusion of a predominantly open chain crosslinked aliphatic structure for Green River kerogen, and indicate that aromatic structures are mainly in the form of isolated phenyl and tolyl groups. The results further confirm the presence of etioporphyrin as a significant constituent in the kerogen studied.     

Comparison of the chemical structure of coal hydrogenation products,athabasca tar sand bitumen and Green River shale oil

Coal hydrogenation products, Athabasca tar sand bitumen, and Green River shale oil produced by retorting were analyzed by the Brown—Ladner method and the Takeya et al. method on the basis of elemental analysis and ¹H-NMR data, by ¹³C-NMR spectroscopy and by FT-IR spectroscopy. Structural characteristics were compared.The results show that the chemical structure of oils from Green River shale oil and Athabasca tar sand bitumen, and the oils produced in the initial stage of hydrogenation of Taiheiyo coal and Clear Creek, Utah, coal is characterized as monomers consisting of units of one aromatic ring substituted highly with C_3–6 aliphatic chains and heteroatom-containing functional groups. The chemical structure of asphaltenes from Green River shale oil and Athabasca tar sand bitumen is characterized by oligomers consisting of units of 1–2 aromatic rings substituted highly with C_3–5 aliphatic chains and heteroatom-containing functional groups. The chemical structure of asphaltenes from coal hydrogenation is characterized by dimers and/or trimers of unit structures of 2 to 5 condensed aromatic rings, substituted moderately with C_2–5 aliphatic chains and heteroatom-containing functional groups.The close agreement between fa(¹H-NMR) and fa(¹³C-NMR) for Green River shale oil derivatives and Athabasca tar sand derivatives indicates that the assumption of 2 for the atomic H/C ratio of aliphatic structures is reasonable. For coal hydrogenation products, a value of 1.6–1.7 for the H/C ratio of aliphatic structures would be more reasonable.     

Screening vegetable oil alcohol esters as fuel lubricity enhancers

Methyl and ethyl monoalkyl esters of various vegetable oils were produced for determining the effects of type of alcohol and fatty acid profile of the vegetable oil on the lubricity of the ester. Four methyl esters and six ethyl esters were analyzed for wear properties using the American Society for Testing and Materials method D 6079, Evaluating Lubricity of Diesel Fuels by the High-Frequency Reciprocating Rig. Ethyl esters showed noticeable improvement compared to methyl esters in the wear properties of each ester tested. No correlation was found between lubricity improvement and fatty acid profile of the ester, except that esters of castor oil had improved lubricity over other oils with similar carbon chain-length (C₁₈) fatty acids.     

A simple method for estimation of cetane index of vegetable oil methyl esters

This article illustrates a simple method for estimation of cetane indexes of vegetable oil methyl esters from their saponification and iodine numbers. The range of the calculated values covers all the cetane numbers of vegetable oil methyl esters determined experimentally. when it was applied to individual fatty acid methyl esters from C₈ to C₂₄, a straight line parallel to that of Klopfenstein was obtained.     

Chemical structure of long-chain esters from “sansa” olive oil

The major objective of this study was to determine the chemical structure of long-chain esters present in lower-grade olive oil. The classes of esters composing the hexanediethyl ether (99∶1) extract of the wax fraction from a pomace olive oil were: (i) esters of oleic acid with C₁−C₆ alcohols, (ii) esters of oleic acid with long-chain aliphatic alcohols in the range C₂₂−C₂₈ and (iii) benzyl alcohol esters of the very long-chain saturated fatty acids C₂₆ and C₂₈. The analysis and the structure assignments were carried out by gas chromatography coupled with mass spectrometry and by comparison with synthetic authentic model compounds. This work provided precise data on the chemical nature of the wax esters present in olive oil and should represent a means to detect adulteration of higher-grade olive oil with less expensive pomace olive oil and seed oils.     

Three new oilseeds rich incis-11-eicosenoic acid

Marshallia cacspitosa Nutt. seed oil (family Compositae) contains 44%cis-11-eicosenoic acid, and is the first oil from the Compositae found to contain a high proportion of C₂₀-monoenoic acid. Seed oils ofAlyssum maritimum (L.) Lam. and ofSelenia grandis Martin (family Cruciferae) contain 42 and 58% of the same acid, respectively. The C₂₀ acids from all three oils were obtained in nearly pure form by fractional distillation of the mixed methyl esters by means of a spinning band column. Permanganate-periodate oxidation of the purified methyl esters yielded predominantly nonanoic and undecanedioic acids. Presented at the AOCS meeting, Toronto, Canada, 1962. A laboratory of the Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

Distribution of short chain n-fatty acids in retort water from green river oil shale

n-Fatty acids in the range of C₂ to C₁₀ were found in retort water from a simulated in situ retorting process of Green River oil shale. The distribution of these fatty acids shows no preference between molecules of odd and even numbers of carbon atoms. A comparison with retort water from an aboveground retorting proces suggests that differences in the distribution of these acids depend largely on the technique and operating conditions employed in the retorting process.     

The fatty acids of menhaden oil

Summary The methyl esters of a specimen of menhaden oil have been fractionated in an efficient still. The C₁₂, C₁₄, C₁₆, and C₁₈ main fractions have been studied, mainly by low temperature crystallization procedures. The oil has been shown to contain traces of lauric and dodecenoic acids. The C₁₄ acids are made up of 2.2% tetradecenoic acid and 97.8% of myristic; based on the whole ester composition of Table I, these values amount to 0.1 and 6.8%, respectively. The C₁₆ acids are palmitic, 50.9%; hexadecenoic, 46.6%; and hexadecatrienoic (including a small amount of tetrenoic acid) 2.5%, or based on the whole esters, 15.5, 14.1 and 0.8%, respectively. A very rough calculation of the composition of the C₁₈ fraction gives the following reults, values based on the whole esters being included in parenthesis: stearic, 11.5 (3.1); octadecenoic, 58.6 (15.7); octadecadienoic, 13.4 (3.6); octadecatrienoic, 7.2 (1.9); and octadecatetrenoic, 9.3% (2.5%). In the course of this investigation the following acids and their methyl esters were isolated from the oil by crystallization procedures; myristic, tetradecenoic (80%), palmitic, hexadecenoic, stearic, and oleic. Evidence was presented that the octadecenoic acids of this oil were a mixture of oleic acid with isomeric acids of this series, a finding which is in agreement with a recent report from this laboratory (11), describing the multiple nature of the octadecenoic acids of a number of animal fats. Presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate School.     

Synthesis and Surface Active Properties of Sulfonated Acrylate Esters Based on Al‐Cedre Oil

Sulfonated acrylate esters have been synthesized by using renewable raw materials such as fatty alcohols of Al‐Ceder oil. Mixed fatty acids were isolated from Al‐Ceder oil by hydrolysis; both saturated and unsaturated fatty acids were isolated from the mixed fatty acids. The methyl esters of mixed fatty acid, saturated and unsaturated acids of Al‐Cedre oil were subjected to reduction with (LiAlH4) to give the corresponding fatty alcohols. The products of the reduction process were saponified and the hydroxyl values were estimated to further confirm the reduction occurrence. The acrylate esters were synthesized by esterification of acrylic acid with fatty alcohols of C_16:0, C_18:0, C_18:1, and C_18:2 mixed saturated, mixed unsaturated and mixed fatty acids of Al‐Cedre oil, respectively. This esterification was followed by addition of NaHSO₃ to form bisulfite adducts. The structures of the prepared surfactants were characterized by IR and ¹HNMR spectroscopy. A series of useful surface parameters, stability towards acids and base hydrolysis and calcium stability have been determined.     

Determination of physicochemical properties of some fatty acid methyl esters by gas liquid chromatography

Physicochemical data such as vapor pressures (p⁰), heats of vaporization (ΔH_v), activity coefficents at infinite dilution (γ^∞) and excess partial molar entropy (ΔS _e ⁰ ) are considered important for conducting unit processes and designing reactor equipment. Scanty information regarding such data is available in the literature for the higher fatty acid methyl esters. The objective of this research was to determine the physicochemical properties of higher fatty acid methyl esters (C₁₁–C₂₃) by a gas-liquid chromatographic technique with SE-30 and diethylene glycol adipate as stationary phases. Correlations between carbon numbers and various thermodynamic properties have indicated definite trends, which could be useful in predicting the properties of unknown fatty acid methyl esters. The data generated may be useful to chemical engineers in the construction of storage tanks, solvent extractors and distillation columns. IICT communication no. 2993.     

Analysis of the dark-colored impurities in sulfonated fatty acid methyl ester

A fractionally distilled C₁₄−C₁₆ fatty acid methyl ester, derived from palm oil, was sulfonated with gaseous SO₃ in a falling film reactor to form an α-sulfo fatty acid methyl ester (α-SF; unbleached and unneutralized form). The included dark-colored impurities were then separated from α-SF as a diethyl ether-insoluble matter. After purification by thin-layer chromatography, the colored species were analyzed by ion-exchange chromatography, gel-permeation chromatography, and nuclear magnetic resonance spectrometry. These data suggested that the colored species were polysulfonated compounds with conjugated double bonds. Minor components in the raw fatty acid methyl ester, found by gas chromatography/mass spectrometry, were spiked into the purified methyl palmitate and then sulfonated. The unsaturated methyl ester and hydroxy ester showed the worst color results. The methyl oleate and methyl 12-hydroxystearate were then sulfonated and analyzed. Deep black products were obtained, which showed the same properties as the colored species in α-SF. It was concluded that low levels of unsaturated fatty acid methyl esters and hydroxy esters in the fatty acid methyl ester are the main causes of the coloring.     

The Optimization of the Production of Methyl Esters from Corn Oil Using Barium Hydroxide as a Heterogeneous Catalyst

In recent years, vegetable oils, as renewable raw materials, became a promising feedstock for chemicals and biodiesel production. The main products derived from oils are esters of fatty acids, especially methyl esters, obtained by their transesterification with methanol, in presence of acid or alkaline catalysts. The use of such catalysts implies the need for washing operations, which leads to environmental pollution. In the present paper, the response surface methodology based on a central composite design, has been developed to optimize the process of transesterification of corn oil. Ba(OH)₂ in presence of diethyl ether was used as catalyst. A quadratic polynomial equation was obtained. It correlates the reaction parameters [methanol/oil molar ratio (x _r), reaction time (x _t) and catalyst concentration (x _c)] with methyl esters yield. Analysis of variance analysis showed that only methanol/oil molar ratio and catalyst concentration have had the most significant influences on the conversion. The maximum methyl esters yield was obtained using the following optimum parameters: methanol/corn oil ratio of 11.32, reaction time of 118 min and catalyst concentration of 3.6 wt%.     

Glycerol esters from the reaction of glycerol with dicarboxylic acid esters

Mono- and di-esterified glycerols were synthesized by the base catalyzed reaction of glycerol with aliphatic dicarboxylic acid esters (C₂−C₉): 2,3-dihydroxy-propyl oxalate (2), 1,3 dioxalyloxy propan-2-ol (3), 1,3-dimethoxyoxalyloxy propan-2-ol (5), 2,3-dihydroxy-propyl malonate (6), 2,3-dihydroxy-propyl methyl malonate (7), 2,3-dihydroxy-propyl methyl succinate (8), 1,3-dimethoxysuccinyloxy propan-2-ol (9), 2,3-dihydroxy-propyl methyl glutarate (10), 1,3-dimethoxyglutaryloxy propan-2-ol (11), 2,3-dihydroxy-propyl methyl azelate (14), and 1,3-dimethoxyazelyloxy propan-2-ol (15). Their structures were elucidated by spectrometric methods. Compounds 8, 10, 2,3-dihydroxy-propl methyl adipate (12) and 14 were found to possess surface active properties and the ability to reduce the interfacial tension between paraffin and water.     

Cis-5-polyenoic acids inLarix leptolepis seed oil

cis-5,cis-9-Octadecadienoic acid (2.7%) andcis-5,cis-9,cis-12-octadecatrienoic acid (24.9%) are present in the seed oil ofLarix leptolepis. The double bond positions were identified by ozonolysis and by gas chromatography-mass spectrometry of methoxy derivatives. Small quantities of branched chain acids of various chain lengths were indicated by gas chromatography. The presence of C₁₇ and C₁₉ branched methyl esters was confirmed by gas chromatography-mass spectrometry.     

Trace metal composition of Green River retorted shale oil

Crude shale oils from an aboveground and two in-situ retorting processes were characterized for 26 trace element constituents. The shale oils were pyrolysed from Green River Formation oil shale by pilot plant or semiworks-sized facilities. Trace elements were resolved into those predominantly associated with suspended shale fines or emulsified water, and those more intimately associated with the shale oil matrix. The abundance of the metals As, Co, Fe, Hg, Mo, Ni, Sb, Se, V and Zn were quantified in whole and fractionated shale oil samples; the possible chemical nature of several metals is discussed. Based on the shale oils examined, the following observations were noted: the shale oils contained moderately high levels of Fe (33–63 ppm) and As (9.3–29 ppm), and lower quantities of Co, Mo, Ni, Se and Zn (≈1–10 ppm); most trace metals were associated with asphaltene or resin components; relative to reported mean values for petroleum, the As, Co, Fe, Mo and Se were more prevalent in Green River shale oil; in-situ retorting processes appeared to introduce Mo into the product shale oil.     

The rearrangement of fatty cyclopropenoids in the presence of boron trifluoride

The destruction of the cyclopropenoid ring system of methyl 9,10 methyleneoctadec-9-enoate (methyl sterculate) with boron trifluoride etherate has been shown to give a complex mixture of products, including methyl esters of C₁₉ allenes (12%), a C₁₈ alkyne (11%) and a variety of C₁₉ and C₂₀ conjugated dienes containing either a methyl or methylene branch. The methylene group lost from the methyl sterculate reactant in the formation of methyl octadec-9-ynoate is incorporated into a second molecule of reactant to yield a mixture of methyl 9-methylene-trans-nonadec-10-enoate and the 11-methylene-trans-9-isomer.     

Alkali-isomerized linoleic acid

Summary Alkali-isomerized linoleic acid and its methyl ester have been found to have boiling points higher than the corresponding normal C₁₈ acids and esters. By careful fractional distillation of methyl esters of alkali-isomerized C₁₈ cottonseed acids, methyl linoleate of 95% or more purity is obtained consisting of 75% conjugated methyl linoleate and some 20% of methyl ester of an altered linoleic acid. Paper No. 69, Journal Series, Research Department, General Mills, Inc. (Presented at the 19th Annual Fall Meeting of the American Oil Chemists’ Society, Nov. 7–9, 1945, in Chicago, Ill.)     

Production of hydrocarbons by pyrolysis of methyl esters from rapeseed oil

The pyrolysis of a mixture of methyl esters from rapeseed oil has been studied in a tubular reactor between 550 and 850°C and in dilution with nitrogen. A specific device for the condensation of cracking effluents was used for the fractionated recovery of liquid and gaseous effluents, which were analyzed on-line by an infrared analyzer and by gas chromatography. The cracking products in the liquid effluent were identified by gas chromatography/mass spectrometry coupling. The effects of temperature on the cracking reaction were studied for a constant residence time of 320 ms and a constant dilution rate of 13 moles of nitrogen/mole of feedstock. The principal products observed were linear 1-olefins,n-paraffins, and unsaturated methyl esters. The gas fraction also contained CO, CO₂, and H₂. The middle-chain olefins (C₁₀–C₁₄ cut) and short-chain unsaturated esters, produced with a high added value, had an optimum yield at a cracking temperature of 700°C.     

Fatty acids,fatty alcohols,wax esters,and methyl esters fromCrambe abyssinica andLunaria annua seed oils

Crambe abyssinica andLunaria annua, members of the Cruciferae family, have seed oil glycerides containing ca. 55–65% of C₂₂ and C₂₄ unsaturated fatty acids. Fatty acids were prepared by saponification; fatty alcohols, by sodium reduction of glycerides; liquid wax esters, byp-toluenesulfonic acid-catalyzed reaction of fatty acids with fatty alcohols; and methyl esters, by reaction of fatty acids with diazomethane. Solid hydrogenated glyceride oils and wax esters were compared with several commercial waxes. Chemical and physical constants were determined for the seed oils and their derivatives. Position of unsaturation in theCrambe fatty acids was determined by gas chromatographic analysis of the permanganate-periodate degradation products. The major dicarboxylic acid was brassylic (C₁₃), proving the docosenoic acid to be erucic. Presented in part at the AOCS meeting in New Orleans, La., 1962. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

Acid dissolution of mineral matrix in Green River oil shale

The mineral matrix in Green River oil shale was partially removed by treatment with dilute HCl. The major ionic species in the solution from acid treatment (AT) were identified as Na⁺, Al³⁺, Fe²⁺, Mg²⁺, and Ca²⁺. The ion yields expected from reaction stochiometry, gravimetric analyses and comparison of calculated CO₂ yields with measured levels were consistent with the fact that Na⁺ and Al³⁺ originated primarily from analcite: Fe²⁺ and Mg²⁺ from dolomitic ankerite and Ca²⁺ from both dolomitic ankerite and calcite. Temperature and shale particle size were important parameters in the efficacy of AT. An increase in temperature and a decrease in particle size increased the rate of mineral dissolution. Fe²⁺ showed an anomalous trend in that the rate initially declined with increasing temperature after which it showed the usual increase with temperature. The kinetics of ion build-up in the solution from AT were analysed in detail for the case of Al³⁺. The Arrhenius expression was found to be valid only for finer particle sizes (e.g., ?35, +45 US mesh shale). A simple model is finally presented to account for the combined effect of temperature and shale particle size on mineral dissolution rates.