Fatty methyl ester hydrogenation to fatty alcohol part I: Correlation between catalyst properties and activity/selectivity

Fatty alcohols, derived from natural sources, are commercially produced by hydrogenation of fatty acids or methyl esters in slurry-phase or fixed-bed reactors. One slurry-phase hydrogenation of methyl ester process flows methyl esters and powdered copper chromite catalyst into tubular reactors under high hydrogen pressure and elevated temperature. In the present investigation, slurry-phase hydrogenations of C₁₂ methyl ester were carried out in semi-batch reactions at nonoptimal conditions (i.e., low hydrogen pressure and elevated temperature). These conditions were used to accentuate the host of side reactions that occur during the hydrogenation. Some 14 side reaction routes are outlined. As an extension of this study, copper chromite catalyst was produced under a number of varying calcination temperatures. Differences in catalytic activity and selectivity were determined by closely following side reaction products. Both activity and selectivity correlate well with the crystallinity of the copper chromite surface; they increase with decreasing crystallinity. The ability to follow the wide variety of side reactions may well provide an additional tool for the optimized design of hydrogenation catalysts.     

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.     

Manufacture of fatty alcohols based on natural fats and oils

The present worldwide capacity of fatty alcohols is ca. 1.0 million metric tons per year. About 60% of this capacity is based on petrochemical feedstocks, 40% on natural fats and oils. Three basic dominating commercial-scale processes are used to manufacture fatty alcohols: the Ziegler process and the Oxo synthesis starting from petrochemical feedstocks, and the high-pressure hydrogenation of natural fatty acids and esters. Basically, the high-pressure hydrogenation can be used with triglycerides, fatty acids or fatty acid esters as feedstock. The direct hydrogenation of fats and oils has not been developed to a commercial-scale process, mainly because it was not possible to prevent decomposition of the valuable byproduct glycerol. Conversion of fatty acids into fatty alcohols by catalytic hydrogenation without preesterification requires corrosion-resistant materials of construction and acid-resistant catalysts. Required reaction temperatures are higher, resulting in a higher hydrocarbon content. The majority of fatty alcohol plants based on natural fats and oils use methyl esters as feedstock. These can be made either by esterification of fatty acids or by-transesterification of triglycerides. For catalytic high-pressure hydrogenation of methyl esters to fatty alcohols, several process options have been developed. The bawic distinguishing feature is the catalyst application either in a fixed bed arrangement or suspended in the methyl ester feed.     

Recovery of short,medium, and long chain fatty acid methyl esters using wet halogenated hydrocarbons

Fatty acid methyl esters are prepared and analyzed by gas liquid chromatography using a simple procedure that does not involve evaporation steps or drying of the final extract. The esters of fatty acids down to caproate (C₆) are recovered quantitatively. The long chain fatty acid esters, including the polyunsaturated esters, are also recovered quantitatively and are at least as stable as esters isolated by conventional procedures. Preparation of the esters in methanolic reagents is followed by partition of the mixture between a small volume of ethylene chloride and a large volume of water. The lower halogenated hydrocarbon phase contains the methyl esters ready for analysis, and the aqueous phase contains the methanol, catalysts, and other water-soluble materials.     

Fatty acids,fatty alcohols,and wax esters fromLimnanthes douglassi (Meadowfoam) seed oil

Limanathes douglasii seed oil glycerides contain fatty acids which predominantly (97%) have 20 or more carbon atoms. Fatty acids were prepared by saponification; fatty alcohols, by sodium reduction of the glycerides; and liquid wax esters, byp-toluenesulfonic acid-catalyzed reaction of the fatty acids with the fatty alcohols. Solid waxes were prepared by hydrogenation of the glyceride oil and of the wax esters. Chemical and physical constants were determined forLimnanthes douglasii seed oil and its derivatives. The liquid wax esters had properties very similar to those of jojoba (Simmondsia chinensis) seed oil. The solid hydrogenated wax ester was identical in physical appearance and melting point to hydrogenated jojoba seed oil. A laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, USDA.     

Preparation of alcohols from cyclic fatty acids

Saturated C_18- and C₂₀-cyclic alcohols have been prepared by catalytic hydrogenation of methyl esters from cyclized linseed monomeric acids, purified saturated C₁₈-cyclic acids, ethylene adduct of conjugated soybean fatty acids, and ethylene adduct of conjugated octadecadienoic acids. The cyclic alcohols have also been prepared from free acids of crude cyclic linseed, cyclic linseed monomeric, and ethylene adduct of 9,11,t,t,-octadecadienoic. Conversion of esters and acids was 88–99% by hydroxyl determination; by gas-liquid chromatographic analysis, almost quantitative Hydrogenations were carried out with 10%, by weight, copper chromite catalyst, an initial hydrogen pressure of 2,100 psi, and a temperature of 280C for 3–5 hr. Preliminary evaluations indicate that saturated C_18- and C₂₀-cyclic alcohols have a potential use in cosmetic formulations. Presented AOCS meeting in Minneapolis, Minn., 1963. No. Utiliz. Res. & Dev. Div., ARS, USDA.     

Reactions of unsaturated fatty alcohols. I. Preparation and properties of some vinyl ethers

Summary A number of vinyl ethers of C₁₈ fatty alcohols have been prepared by reaction of the alcohol with acetylene at atmospheric pressure in the presence of a basic catalyst. Infrared spectroscopic data on long-chain fatty alcohols, their vinyl ethers, and related chemical derivatives have been obtained. Methods of analysis of long-chain vinyl ethers for vinyl group have been developed, namely, iodometric, hydroxylamine, and infrared methods. Preliminary experiments on the polymerization of long-chain vinyl ethers with ionic catalysts were carried out. Presented at fall meeting, American Oil Chemists’ Society, Philadelphia, Pa., Oct. 10–12, 1955.     

Synthesis of secondary ethers derived from meadowfoam oil

Secondary ethers can be obtained from meadow-foam-derived delta lactones or 5-hydroxy fatty acids by using Lewis or Brønsted acid catalysts in good yield (70–90%). The conversion of δ-lactone or 5-hydroxy fatty acid to 5-ethers is performed under atmospheric pressure between 67 and 125°C with 0.5–6.4 mole equivalents of acid catalyst in the presence of 2–40 equivalents of alcohol and a reaction time of 1–140 h. Acid catalysts include mineral acids, such as perchloric and sulfuric; Lewis acids, such as boron trifluoride; and heterogeneous catalysts, such as clays and ion-exchange resins. Primary alcohols, such as methanol, butanol, decanol, and oleyl alcohol, or branched-chain alcohols, such as 2-ethylhexanol, can be used to make secondary ether fatty esters. The 5-ether fatty esters and the process for their formation have not been previously known and appear to be limited to structures where stabilized cations can be formed. The novel ethers were fully characterized by nuclear magnetic resonance and gas chromatography-mass spectrometry.     

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.     

Trans- α, β-ungesättigte Fettsäuren und deren Reduktionsprodukte mit Lithium-Aluminium-Hydrid und Diisobutyl-Aluminium-Hydrid

Trans-α,β-Unsaturated Fatty Acids and Products formed by their Reduction with Lithium-Aluminium-Hydride and Di-isobutyl-Aluminium-Hydride A method for the preparation of pure methyl esters of α,β-unsaturated fatty acids is described. The reduction of these esters with LiAlH₄ led to poor yields of α,β-unsaturated alcohols. Saturated alkanols and aldehydes were mainly formed. Di-isobutyl aluminium hydride gave near quantitative yields of α,β-unsaturated alcohols. The reaction was studied with the help of gas chromatography using strongly polar stationary phases.     

Nachweis gesättigter cycloaliphatischer und aromatischer Fettsäuremethylester durch Dünnschicht- und Gas-Chromatographie

Detection of the Methyl Esters of Saturated Cycloaliphatic and Aromatic Fatty Acids with Thin-layer and Gas Chromatography Homologous series of methyl esters of saturated cycloaliphatic (CFA) and aromatic fatty acids (AFA), which were prepared by the alkali isomerisation of fish oil followed by hydrogenation and fractionation of the cyclised mixture as well as with the help of cyclising hydrogenation, were analysed by thin-layer and gas chromatography. Even 0.4% CFA and AFA, which do not form urea-adducts, can be detected in the fractions as a substance class in thin-layer chromatography. The equivalent carbon numbers (stearic acid = 18) of the principal isomers of CFA and AFA homologues (C₁₈ to C₂₂), which were obtained as a class in the thin-layer chromatographic separation, were determined by the gas chromatography.     

Identification of methyl-branched fatty acids from the triacylglycerols of subcutaneous adipose tissue of lambs

A concentrate of branched chain fatty acids (as methyl esters) was prepared from the triacylglycerols of subcutaneous adipose tissue lipids of lambs receiving a carbohydrate-rich (cereal) diet. This was accomplished by procedures which allowed the removal of unsaturated components by peroxidation and straight chain saturated components by urea-adduct formation. The concentrate was analyzed by high resolution gas chromatography in combination with mass spectrometry and was shown to consist of a complex mixture of saturated methyl-substituted fatty acids. Methyl substitution occurred on even-numbered carbon atoms (relative to the carboxyl group) and the chain lengths of the acids ranged from 10 to 18 carbon atoms. Acids with one methyl substituent in the fatty acyl chain were most abundant; di-, tri- and tetramethyl-substituted acids were also present. The biosynthesis of these methyl-substituted acids is discussed briefly.     

Gas-liquid chromatography of fatty derivatives. II. Analysis of fatty alcohol mixtures by gas-liquid chromatography

Conclusions Gas-liquid chromatography has been shown to be applicable to the analysis of fatty alcohols. Through the use of polyester columns these alcohols have been separated according to chain length and degree of unsaturation. A study has been made of the relationship between peak areas of the chromatograms and the actual weight percentages of the four C₁₈ alcohols found in the fatty alcohols derived from linseed oil. Fatty alcohols, prepared from soybean, linseed, and sperm oil have been prepared and analyzed by the proposed procedure. Craig and Murty (1) have recently reported that polyesters based on succinic acid are preferable for the liquid phase of the chromatographic column to those made from adipic in that they afford a better separation of methyl stearate from methyl oleate. Conversely adipic columns gave a more effective separation of the esters of linolenic and arachidic acids. The application of these polyesters to the analysis of fatty alcohol acetates is expected to improve their separation in a similar fashion, but further work is indicated in the search for a liquid phase that will permit both separations in the minimum time. ADM Technical Talk No. 166.     

Produkte der Dimerisierung ungesättigter Fettsäuren VIII: Über die Zusammensetzung der Fraktion der “Intermediates” bei der Fettsäuredimerisierung

Products of Dimerisation Unsaturated Fatty Acids VIII: The Fraction of “Intermediates” Obtained by Dimerisation of Unsaturated Fatty Acids The fraction of “intermediates” which is obtained by dimerisation of unsaturated fatty acid contains straight chain saturated fatty acids with 20-24 carbon atoms as well as methyl branched isomers thereof. The production of these compounds is probably caused by the presence of small amounts of monounsaturated fatty acids with 20-24 carbon atoms in the starting material. The fraction of “intermediates” contains in addition monocarboxylic acids with 36 carbon atoms. These are probably formed after dimerisation by an intramolecular cyclisation reaction under participation of one carboxylic group, followed by hydrogenation of the produced carbonyl group. Finally the formed alcoholic group is eliminated as a water molecule, and the produced double bond is hydrogenated.     

Über die Reduktion ungesättigter Fettsäuren und deren Ester zu ungesättigten Fettalkoholen durch selektive katalytische Hochdruckhydrierung III: Metallische und metallisch-oxidische Kupfer-Cadmium-Kontakte

Reduction of Unsaturated Fatty Acids and Their Esters to Unsaturated Fatty Alcohols by Selective Catalytic High Pressure Hydrogenation III: Metallic and Metal Oxide Copper-Chromium Catalysts Influence of catalyst composition and reaction conditions on the high pressure reduction of unsaturated fatty acids and their esters is described for metallic and mixed metal oxide copper-chromium catalysts. From these investigations and from a comparison with the efficacy of other metals in hydrogenation a hypothesis on the mechanism of the catalytic reaction in the reduction of carboxyl group and saturation of C? C double bonds is developed. The optimum reaction data of oleic acid and methyl oleate, which were used as test substances, are given.     

Influence of preparation method and boron addition on the metal function properties of Ru?Sn catalysts for selective carbonyl hydrogenation

BACKGROUND: Improvements in the selective hydrogenation of unsaturated fatty acid methyl esters in order to obtain unsaturated fatty alcohols have been attempted through the preparation and modification of supported group VIII metallic catalysts. Suitable catalysts appear to be those based on supported Ru modified by Sn. The influence of preparation and activation methods on the structural and electronic properties of the metallic phase and the effect of modifications to these properties on the catalytic performance of Ru? Sn/Al₂O₃ catalysts was studied regarding selective hydrogenation of carbonyl groups. RESULTS: Preparation methods have a marked influence on the electronic state of Ru and its interaction with Sn. Temperature‐programmed reduction (TPR), Fourier transform infrared spectroscopy of chemisorbed CO (FTIR‐CO) and X‐ray photoelectron spectroscopy (XPS) results clearly show that the incorporation of sodium borohydride in the preparation leads to a greater Ru? Sn interaction when compared with catalysts prepared by co‐impregnation without B. The activation of catalysts without B (either by direct reduction or calcinations‐reduction) does not produce a strong Ru? Sn interaction. B‐containing catalysts exhibit higher hydrogenolytic and lower dehydrogenating activities. Selectivity towards oleyl alcohol formation was 37% for this catalyst, while catalysts without B were not suitable for obtaining fatty alcohols. CONCLUSION: The degree of interaction between Ru and Sn strongly depends on catalyst preparation and activation method where strong interaction promotes selectivity with respect to oleyl alcohol formation. On the contrary, catalysts with a weak Ru? Sn interaction do not show significant selectivity for the unsaturated alcohol. Copyright © 2010 Society of Chemical Industry     

Gaschromatographische und dünnschichtchromatographische Untersuchung von Fettsäuren: Die Anwendung von gepackten Glaskapillarsäulen zur Trennung von cis- und trans-ungesättigten Fettsäuren

Gas Chromatographic and Thin-Layer Chromatographic Studies on Fatty Acids: The Application of Packed Glass Capillary Columns for Separation of cis- and trans-Unsaturated Fatty Acids from Saturated Fatty Acids Packed glass capillary columns were used for the quantitative determination of trans- and cis-unsaturated fatty acids in the presence of saturated fatty acids by gas chromatography. The fatty acids were analyzed as methyl esters after interesterification of the triglyceride samples. The conversion of glyceryl esters of fatty acids into methyl esters could be followed using short GC columns and by thin-layer chromatography.     

Selektive Härtung mehrfach ungesättigter Fettsäuren in der Flüssigphase

Selective Hydrogenation of Multi-Unsaturated Fatty Acids in the Liquid Phase Fatty acids and esters which contain only one double bond have interesting properties such as high oxidation stability or favourable pour points. For these reasons such products find a broad field of application for instance in the sections cosmetics, textile finishing agents or oilfield chemicals. However, natural fats and oils contain often multi-unsaturated fatty acids such as linoleic and linoleinic acid which are able - even in minor amounts - to change substantially the physical and chemical properties of the fatty material. Therefore, a hydrogenation procedure is needed which enables the selective conversion of multi-unsaturated into mono-unsaturated fatty acids without formation of completely saturated compounds. After a review of the general possibilities in selective hydrogenation a new method is described to hydrogenate with solvent-stabilized palladium colloid catalysts. A remarkable high selectivity was obtained applying very mild reaction conditions. By use of the liquid-liquid two phase technique an easy and complete catalyst recycle is possible.     

Plasma transport forms of ingested fatty alcohols in the rat

Previous studies have shown that ingested fatty alcohols are absorbed as fatty acids and fatty acid esters, particularly triglycerides. The present study was carried out to determine whether fatty alcohols are also transported as 0-alkyl glyceryl ethers, alk-1-enyl glyceryl ethers, and as wax esters. Oxidation of fatty alcohols to other lipids was assessed by using a mixture of [1-³H] hexadecanol and [1-¹⁴C] hexadecanol of predetermined ratio. The results indicate that the absorption of fatty alcohol, and of its transport forms, parallels the absorption of labeled fatty acids. Six to 25% of plasma radioactivity was present as 1-0-alkyl diacylglyceryl ethers with a smaller proportion of ether lipids in the phospholipid fraction. In addition, 4–13% of the ingested hexadecanol appeared in the plasma as a material having the chromatographic properties of wax ester. Fatty alcohols were not detected in the plasma as alk-1-enyl lipids.     

Darstellung und Eigenschaften von Fettsäurepolyglykolestersulfaten

Production and Properties of Fatty Acid Polyglycol Ester Sulfates Fatty alcohol oxethylates, produced by reaction of fatty alcohols from hydrogenated fatty acid methyl esters with ethylene oxide, are the basic material for an important class of anionic tensides, the fatty alcohol ether sulfates. The fatty acid polyglycol ester sulfates are a very interesting alternative to the fatty alcohol ether sulfates. The former are available by saving hydrogenation, in principle directly by fatty acid oxethylation or interesterification of fatty acids with polyglycols, followed by sulfatation. We report about the production of fatty acid ester sulfates by sulfatation of the fatty acid polyglycol monoesters by sulfurtrioxide or chlorosulfonic acid. By means of the results of physicochemical measurements and process trials it is discussed how far fatty acid polyglycol monoester sulfates are suited as alternative tenside raw material fatty alcohol ether sulfates.