E. H. Pryde

Variables affecting the yields of fatty esters from transesterified vegetable oils

Transesterification reaction variables that affect yield and purity of the product esters from cottonseed, peanut, soybean and sunflower oils include molar ratio of alcohol to vegetable oil, type of catalyst (alkaline vs acidic), temperature and degree of refinement of the vegetable oil. With alkaline catalysts (either sodium hydroxide or methoxide), temperatures of 60 C or higher, molar ratios of at least 6 to 1 and with fully refined oils, conversion to methyl, ethyl and butyl esters was essentially complete in 1 hr. At moderate temperatures (32 C), vegetable oils were 99% transesterified in ca. 4 hr with an alkaline catalyst. Transesterification by acid catalysis was much slower than by alkali catalysis. Although the crude oils could be transesterified, ester yields were reduced because of gums and extraneous material present in the crude oils.

Diesel fuel from thermal decomposition of soybean oil

Soybean oil was thermally decomposed and distilled in air or in nitrogen sparge with standard ASTM distillation apparatus. GC-MS analysis showed that approximately 75% of the products were made up of alkanes, alkenes, aromatics and carboxylic acids with carbon numbers ranging from 4 to more than 20. Fuel properties of the pyrolyzed materials were characterized and compared with those of the parent oil. The pyrolyzates had lower viscosities and higher cetane numbers than the parent vegetable oil. Thermally decomposed soybean oil shows promise as alternative fuel for the direct-injection diesel engine.

Supercritical CO2 extraction of lipid-bearing materials and characterization of the products

Supercritical fluid extraction has recently become a reality in the petroleum, coal and food industries and is rapidly increasing in importance as its advantages become known. Advantages of carbon dioxide as a supercritical fluid include its low toxicity, low cost, lack of flammability, lack of reactivity, wide range of solvent properties at different pressures and temperatures, and improved properties of separated components in certain cases. Disadvantages of such extractions include high capital costs for batch extraction and lack of engineering hardware technology for continuous operation. In the supercritical CO2 extraction of oil from soybeans, equilibrium solubility and high flow rates are readily achieved in a short-path batch reactor. The oil has a lighter color, less iron and ca. 1/10 of the phosphorus contained in hexane-extracted oil. The lower phosphorus content results in lower refining losses. During extraction, some fractionation is observed to take place, with some more polar and/or higher molecular weight compounds having a tendency to increase in the later fractions. In a long cylindrical batch extractor, the flakes perform much like the stationary phase of a chromatographic column. The same advantages that result from extraction of soybeans also apply to the extraction of oil from cottonseed and corn germ. Cottonseed oil obtained by supercritical CO2 extraction has a lower gossypol content and requires less alkali for refining. In the extraction of wheat germ and bran, the oil has a lighter color, a milder odor and less unsaponifiables than that obtained by hexane. Free fatty acid contents were comparable, but tocopherol was higher in the supercritical CO2 extract.

Quantitation in the analysis of transesterified soybean oil by capillary gas chromatography 1

A rapid quantitative capillary gas Chromatographic method has been developed for studying transesterification of soybean oil (SBO) to fatty esters. Standard solutions containing methyl linoleate, mono- , di- and trilinolein were analyzed with a 1.8 m X 0.32 mm SE- 30 fused silica column. The effect of carrier gas flow on reproducibility was determined. Prior to analysis, mono- (MG) and diglycerides (DG) were silylated with N,O- bis(trimethylsilyl) trifluoroacetamide.Tridecanoin was used as an internal standard. From plots of area and weight relationships, slopes and intercepts for all four compound classes were determined. Agreement between the measured and calculated compositions of the standard solutions was good; the overall standard deviation was 0.4. Slopes and intercepts also were determined for SBO and its methyl and butyl esters. Complete separation of ester, MG, DG and triglyceride was obtained in 12 min by temperature programming from 160 to 350 C. This method of analysis gave excellent results when used in a kinetic study of SBO transesterification.

Diesel engine evaluation of a nonionic sunflower oil-aqueous ethanol microemulsion

A nonionic sunflower oil-aqueous ethanol microemulsion was formulated, characterized and evaluated as a fuel in a direct injection, turbocharged, intercooled, 4-cylinder Allis-Chalmers diesel engine during a 200 hr EMA cycle laboratory screening endurance test. Differences in engine operation between a baseline Phillips 2D reference fuel and the experimental fuel were observed. The major problem experienced while operating with the microemulsion was an incomplete combustion process at low-load engine operation. Significant lubricating oil dilution was observed initially, followed by an abnormal increase in the viscosity of the lubricative oil. Heavier carbon residue on the piston lands, in the piston ring grooves and in the intake ports was noted. In addition, premature injection-nozzle deterioration (sticking of the needle) was experienced. At present, the sunflower oil-aqueous ethanol microemulsion studied cannot be recommended for long-term use in a direct-injection diesel engine, but further modifications in formulation may produce acceptable sunflower oil microemulsions as alternative diesel fuels.

• %Biochemical Modification of Fats by Microorganisms: A Preliminary Survey

Over 100 different strains of bacteria, actinomycetes, fungi and yeasts were incubated at 28 C for five days in the presence of soybean oil. Some soybean oil was consumed by many microorganisms, and some was also hydrolyzed to free fatty acids.Aspergillus oryzae, two different strains ofAmylomyces rouxii andRhizopus oligosporus hydrolyzed the oil completely (95%). The fatty acids fromAspergillus flavus fermentation contained less linolenic acid than the original soybean oil. Lipase was found intra- and extracellularly when microorganisms were grown in the presence of soybean oil.

Reactions of carbon monoxide with unsaturated fatty acids and derivatives: A review

The important reactions of carbon monoxide with unsaturated fatty derivatives that are reviewed in this paper include hydroformylation (the oxo reaction), Koch carboxylation and Reppe carbonylation. With oleic acid as a substrate, the products are C19 bifunctional compounds e.g., formyl- or carboxy-stearic acid. Double bond isomerization before carbon monoxide addition is characteristic of these catalytic reactions; additionally, rearrangement to introduce methyl branching occurs in the Koch carboxylation. Isomerization does not occur when a rhodium-triphenylphosphine catalyst replaces cobalt in the oxo reaction. Properties of the C19 dicarboxylic acids differ and depend upon method of preparation: Many areas of application have been reported for C19 compounds-lubricants, plasticizers, polyurethanes, epoxy resins, leather and other coatings, unsaturated polyester resins and transparent polyamide plastics.

Hydroformylation of unsaturated fatty acids

When hydroformylation of unsaturated fatty materials is done with rhodium-triphenyl phosphine (or phosphite) catalysts, a number of advantages become apparent compared to cobalt carbonyl-catalyzed reactions. With rhodium, the reaction can be carried out (a) at pressures as low as 200 psi, (b) at each double bond location in a polyunsaturated fatty acid, and (c) in high yield and conversion. Solubilized catalyst can be recovered from distillation residue and readsorbed on spent catalyst support by thermal treatment in a rotary kiln. The reconstituted catalyst is more active than the original catalyst and can be recycled indefinitely at a relatively low cost. Recently developed supports for “homogeneous” catalysis may make catalyst recovery even more effective. Acetalation, oxidation with air to polycarboxylic acids and catalytic hydrogenation to hydroxymethyl compounds can be done easily and in high yield on mono-, di- and triformyl derivatives alike. Other reactions investigated for monoformyl fatty esters include reductive amination to form aminomethyl derivatives and Tollen’s condensation with formaldehyde to form geminal,bis-hydroxymethyl compounds. although the Northern Center has carried out some basic investigations on the hydroformylation reaction and on the chemistry of the hydroformylated products, there is a great deal more that can be done with regard to synthesis of new compounds and development of new applications.

Catalytic hydroformylation and hydrocarboxylation of unsaturated fatty compounds

Abstract and SummaryThe two catalyst systems rhodium-triphenylphosphine and palladium chloride-triphenylphosphine were investigated for the respective hydroformylation and hydrocarboxylation of oleic acid or ester to produce C-19 bifunctional compounds. Compared to conventional cobalt carbonyl for making formylstearate, rhodium-triphenylphosphine permits lower pressures (1000–2000 psi vs. 3000–4000 psi), higher conversions (95% vs. 80%), and no loss of functionality (vs. 15% hydrogenation with cobalt). Although palladium chloride-triphenylphosphine for hydrocarboxylation introduces the carboxyl function directly into the fatty acid chain, CO pressures of 3000–4000 psi and corrosion-resistant equipment are necessary. When applied to polyunsaturated fatty acids, both rhodium and palladium catalyst systems have the outstanding advantage of introducing functionality at each double bond position to produce polyformyl- and polycarboxystearates. Selected formyl derivatives were converted in excellent yield to acetals, to acids and their esters, to hydroxymethyl compounds and their esters, and also to aminomethyl compounds that could be condensed to polyamides. Several of the esters and acetals were effective primary plasticizers for poly(vinyl chloride) that had outstanding low volatility characteristics. Other applications for these new and highly versatile derivatives included rigid urethane foams, urethane-modified coatings, ester lubricants, and a shrink-resist treatment for wool.

Nylon-9 from unsaturated fatty derivatives: Preparation and characterization

Methyl azelaaldehydate, soy nitriles, and oleonitrile were compared as starting materials for making nylon-9. Less difficulty was encountered in purifying intermediates from oleonitrile than from the other two. All 3 routes involved hydrolysis of methyl 9-aminononanoate to 9-aminononanoic acid. Self catalyzed hydrolysis of the amino ester in water produced low yields of monomer owing to oligomer formation, but hydrolysis in the presence of barium hydroxide was more successful. Polymerization of the amino acid proceeded smoothly with 9-acetamidononanoic acid used to control mol wt. Strength and moisture absorbing properties were determined for nylon-9, as well as for nylon-6/9, -9/11, and -9/12 copolymers. Nylon-9 has attractive properties, offering tensile yield and flexural strengths approaching those of nylon-6, while having low water absorption closely approaching that of nylon-11 and -12. The cost of producing 10,000,000 lb/year of nylon-9 from purchased oleonitrile was estimated to be