Purity aspects of higher alpha olefins

The various processes which are used commercially to manufacture detergent range alpha olefins are compared in terms of the quality of the products obtained. Thermal cracking ofn-paraffins gives the least pure olefins. Processes based on ethylene oligomerization are superior and, of these, the Shell SHOP (Shell Higher Olefins Process) process gives alpha olefins which are somewhat better in quality than those obtained from processes based on aluminum alkyl chemistry. The practical consequences of the presence of internal and vinylidene olefins, dienes and paraffins in alpha olefins are considered for the manufacture of alpha olefin sulfonates, linear alkyl-benzene, epoxides, alkyl bromides, rnercaptans and copolymers with ethylene (linear low density polyethylene). Low levels of impurities are desirable in most cases to minimize formation of unwanted byproducts, or to reduce the cost of bleeding of inert components, or to ensure that the quality of the final product meets the requirements of the marketplace. Presented at the AOCS Meeting in Toronto, May 1982.     

生物化学品制线性α-烯烃催化技术研究进展

乙烯齐聚法因工艺简单、技术成熟等优点成为线性α-烯烃的主流方法,但该方法受限于乙烯原料,且已被世界石油巨头所垄断。本文介绍了从生物化学品出发制备线性α-烯烃的物质来源和可行的技术路线,简述了可用于生产线性α-烯烃的物质来源,包括高级脂肪酸酯、高级脂肪酸和高级脂肪醇等,分析了可行的催化转化技术路线,如内烯烃及不饱和脂肪酸交叉歧化、脂肪族羧酸催化脱羧、生物内酯和不饱和酸转化、不饱和脂肪酸两步法、甲基辛基醚分解、脂肪醇脱水、混合线性辛烯和/或线性辛醇制1-辛烯工艺等国内外新技术,指出利用生物化学品生产α-烯烃已经成为生物质转化中一个积极的方向,开发高效的催化剂及其工艺是该技术的研究重点。     

Alpha olefin sulfonates from a commercial SO3-Air reactor

Alpha olefin sulfonate (AOS) can be made by SO₃-air sulfonation of straight chain alpha olefins followed by saponification of the neutralized product. The sulfonation step forms unsaturated sulfonic acids, sultones and sultone sulfonic acids. Hydrolysis of the various sultones yields a mixture of unsaturated and hydroxy sulfonates. Sulfonation of commercial mixtures of straight chain alpha olefins in a large-scale SO₃ falling film unit has given AOS of 1.5–3.0% oil based on active content and tristimulus color of about 40% saturation (2% solution) which is readily bleachable with 1–3% NaOCl to about 10–15% saturation. Performance of AOS made from C₁₅−C₁₈ alpha olefin is comparable to that of the high-foaming C₁₁−C₁₄ LAS in both detergency and dishwashing foam. It is superior to similar products made from internal straight chain olefins. The product shows a low order of toxicity and biodegrad-ability slightly better than that of LAS. A C₁₅−C₁₆ AOS blend is especially attractive in liquid detergent formulations. Presented at the AOCS Meeting, Los Angeles, April 1966.     

Kinetic study of the decomposition of 2‐butanol on carbon‐based acid catalyst

The catalytic conversion of 2‐butanol on a carbon‐based acid catalyst prepared by chemical activation of olive stone with phosphoric acid was investigated. The carbon catalyst showed a considerable amount of surface phosphorus, presumably in form of phosphate groups, as revealed by XPS, despite a washing step carried out after the activation process. Conversion of 2‐butanol yields mainly dehydration products, mostly cis‐2‐butene and trans‐2‐butene with lower amounts of 1‐butene, and a very small amount of mek as dehydrogenation product. Kinetic interpretation of the experimental data was performed using two elimination mechanisms for the dehydration reaction; an E1‐mechanism (two‐step mechanism) and an E2‐mechanism (one‐step mechanism). The rate expressions derived from both models fit properly the experimental results, suggesting that probably the two mechanisms occur simultaneously. This is supported by the similar rate constant obtained for the formation of the carbocation and the olefins in the E1 and E2 mechanisms, respectively. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

The Condensation of Carbonyl Compounds with Electron‐Rich Arenes: Mercury,Thallium, Gold or a Proton?

Gold(III) chloride, mercury(II) perchlorate, thallium(III) perchlorate and p‐toluenesulfonic acid were found to efficiently catalyze the condensation of two furans with aldehydes or acetone. The olefinic unit of α,β‐unsaturated carbonyl compounds reacts faster than the carbonyl group, other olefins do not react selectively. The first (addition) step is rate‐limiting, the second (substitution) step is much faster.     

Oxidative decarboxylation of unsaturated fatty acids

Long‐chain internal olefins were prepared by silver(II)‐catalyzed oxidative decarboxylation of unsaturated fatty acids by sodium peroxydisulfate. Similar to saturated carboxylic acids, 1‐alkenes were the major decarboxylation product in the additional presence of copper(II), whereas in the absence of copper(II) alkanes were predominantly formed. In both cases, the internal unsaturation of the fatty acids remained largely intact, although the moderate yields indicated that side reactions occurred to a significant extent. The simple procedure makes this multistep one‐pot reaction useful for the synthesis of a variety of internally unsaturated hydrocarbons. The purified products, almost all of which are prepared for the first time, may serve as reference compounds for studies on the heterogeneously catalyzed decarboxylation of triglycerides and fatty acids in the absence of hydrogen. Practical applications: The products of the chemistry described in this contribution, i.e., unsaturated long‐chain hydrocarbons, provide bio‐based building blocks for further chemical modification toward products which may be applied as (bio)fuels, lubricants, solvents, and polymeric materials.     

Selectivity of lipases: isolation of fatty acids from castor,coriander, and meadowfoam oils

The lipase‐catalyzed hydrolysis of castor, coriander, and meadowfoam oils was studied in a two‐phase water/oil system. The lipases from Candida rugosa and Pseudomonas cepacia released all fatty acids from the triglycerides randomly, with the exception of castor oil. In the latter case, the P. cepacia lipase discriminated against ricinoleic acid. The lipase from Geotrichum candidum discriminated against unsaturated acids having the double bond located at the Δ‐6 (petroselinic acid in coriander oil) and Δ‐5 (meadowfoam oil) position or with a hydroxy substituent (ricinoleic acid). The expression of the selectivities of the G. candidum lipase was most pronounced in lipase‐catalyzed esterification reactions, which was exploited as part of a two‐step process to prepare highly concentrated fractions of the acids. In the first step the oils were hydrolyzed to their respective free fatty acids, in the second step a selective lipase was used to catalyze esterification of the acids with 1‐butanol. This resulted in an enrichment of the targeted acids to approximately 95—98% in the unesterified acid fractions compared to the 70—90% content in the starting acid fractions.     

On the UV Curability and Mechanical Properties of Novel Binder Systems Derived from Poly(ethylene terephthalate) (PET) Waste for Solventless Magnetic Tape Manufacturing, 2. Methacrylated Oligoesters

Recycling of poly(ethylene terephthalate) PET waste by chemical methods is a well‐known process that generates value‐added products. Depolymerization products of PET recycling were commonly applied as starting materials for the synthesis of polyurethanes, saturated and unsaturated polyester resins. In this current work we are reporting on a novel application of the depolymerized products obtained by glycolysis of PET by converting the hydroxyl functional groups to methacrylate groups. The obtained methacrylated oligoesters were tested for UV curability by UV irradiation, in the presence of 2‐benzyl‐2‐dimethylamino‐1‐(4‐morpholinophenyl)‐1‐butanone (BDMB) as a photo initiator. This gave cured films of high mechanical properties when these methacrylated oligoesters were either cured alone or as mixtures with other commercially available diacrylate/dimethacrylate monomers. The measured tensile properties were in the range of 7.21–43 MPa for maximum tensile strength and 0.90–3.0 GPa for Young's modulus.     

Cross‐metathesis of methyl 10‐undecenoate with diethyl maleate: Formation of an α,ω‐diester via a metathesis reaction network

The cross‐metathesis of methyl 10‐undecenoate 1 derived from castor oil as a renewable raw material with diethyl maleate 2 was investigated. These reactions were carried out with several phosphine and N‐heterocyclic carbene ruthenium catalysts. The reaction conditions were optimised for high conversions in combination with high cross‐metathesis selectivity. This single‐step and atom‐economic synthetic method illustrates an efficient and selective preparation procedure of linear α,ω‐dicarboxylic acid esters starting from renewable resources and comparatively inexpensive base chemicals. Further by‐products are hardly obtained due to their consumption in secondary metathesis reactions. Hence, a sustainable alternative for polyamide and polyester monomers is presented.     

Palladium‐Catalyzed Synthesis of Selectively Substituted Phenanthridine Derivatives

Selectively substituted phenanthridine derivatives are obtained by a facile reaction of o‐alkylated aryl iodides, o‐bromoarenesulfonylanilines and activated olefins in the presence of palladium and norbornene as catalysts. The reaction takes place under mild conditions to give the products in satisfactory yields using readily available starting materials.     

Novel Method for the Synthesis of Cholesteryl Glucosides starting from Disaccharides

Steryl glucosides (SG) and acylated steryl glucosides (ASG) are natural components of plant cell membranes and present in different concentrations in various plant foods. Currently, their positive effects on human health are under investigation. The present work presents a new and efficient synthesis method for cholesteryl glucosides starting from disaccharides. A five‐step synthesis protocol is done to obtain the desired product in 35% overall yield. In the first step, the hydroxy groups of the starting material sucrose are protected using benzyl ethers. After the subsequent acidic hydrolysis the obtained pyranosyl moiety of the disaccharide is transformed to its trichloroacetimidate derivative. Next, the formation of the glycosidic bond to cholesterol is performed and catalytic transfer hydrogenation in order to remove the protecting groups leads to the desired product. In this context, APCI‐MS‐TOF has turned out to be an excellent analytical tool for the high sensitive analysis of SG as well as intermediates. Practical Applications: Due to the comparatively high amounts of SG and ASG in seeds and oils, not only the food industry but also in biodiesel production, these natural compounds are of increasing interest. However, analysis of the compounds is difficult, commercially available pure standard materials are costly and their synthesis often requires time‐consuming work‐up procedures. The described preparation method allows the synthesis of cholesteryl glucosides which can be used as reference or standard material for the quantitative analysis of phytosteryl glucosides in plant derived samples. The general synthesis method could be also applied to other SG and ASG derivatives. Cholesteryl glucosides are synthesized using a new and efficient five‐step synthesis protocol starting from disaccharides. The preparation method provides products with good overall yield and high purity and, therefore, the synthesized glucosides can be used as reference or standard material for the quantitative analysis of phytosteryl glucosides in plant derived samples. APCI‐MS‐TOF is extensively used as analytical tool for the sensitive analysis of cholesteryl glucosides as well as intermediates.     

Synthesis of γ‐Fluoro‐α, β‐unsaturated Carboxylic Esters from Saturated α‐Fluoro Aldehydes

γ‐Fluoro‐α, β‐unsaturated carboxylic esters 7a, 7b and 7d and 4‐fluoro‐4‐phenylbut‐3‐enoic ester ( 8 ) are obtained by two alternative pathways from 2‐fluoro aldehydes 5a—d , either by Horner—Wadsworth—Emmons reaction or by Wittig reaction. The aldehydes 5a—d are prepared by Swern oxidation of the corresponding fluorohydrins 4a—d . These are available from α‐olefins by bromofluorination, bromineby‐acetate replacement and subsequent hydrolysis.     

Cracking paraffinic hydrocarbons to make alpha olefins—a review

Various methods for the production of linear alpha olefins are described. The main emphasis has been given to the literature information available on the cracking of paraffinic hydrocarbons or wax for making alpha olefins, a new chemical product for use in the detergent industry.     

One‐step production of alkoxylated ethyl acetate with narrow adduct distribution

Oligo‐ethylene/propylene glycol ethyl ether acetate (oligo‐EGEEA and oligo‐PGEEA) used to be synthesized in a two‐step process with acetic acid as starting material. This paper describes a one‐step production process catalyzed by the Al? Mg composite oxide, achieved by alkoxylation of ethyl acetate directly. Aiming at a narrow adduct distribution to get high product selectivity of mono‐derivatives, the alkoxylation parameters, such as the Al/Mg molar ratio of the catalyst, molar ratio of reactants, temperature, initial reaction pressure, and reactant feed rate were investigated. The highest content of mono‐ and di‐derivatives in the products was: w (oligo‐EGEEA) = 73.8%, w (oligo‐PGEEA) = 87.9%, respectively. The product selectivity of mono‐EGEEA was decreased by only 5% after reusing the catalyst for ten runs. A 1.26‐fold increase in the yield of mono‐PGEEA was achieved by treating the catalyst surface with alcoholic potash. Copyright © 2006 Society of Chemical Industry     

Organocatalytic Asymmetric Sulfa‐Michael Addition to α,β‐Unsaturated Ketones

The highly enantioselective organocatalytic sulfa‐Michael addition to α,β‐unsaturated ketones has been accomplished using benzyl and tert‐butyl mercaptans as the sulfur‐centered nucleophiles. Optically active products are obtained in high yields and good to excellent stereocontrol (up to 96 % ee) from a large variety of enones. Central to these studies has been the use of the catalytic primary amine salt A , derived from 9‐amino‐(9‐deoxy)‐epi‐hydroquinine and D ‐N‐Boc‐phenylglycine, in which both the cation and the anion are chiral, that exhibits high reactivity and selectivity for iminium ion catalysis with enones.     

Downer Catalytic Pyrolysis (DCP): A Novel Process for Light Olefins Production

Based on the analysis of different existing cracking processes, the DCP (downer catalytic pyrolysis) process is proposed for the production of light olefins from heavy feeds. A hot downer reactor with the height of 4.5 m and the inner diameter of 13 mm was designed and built to examine the details. The experimental results show that high olefins yields can be obtained from the DCP process: at the temperature of 659 °C and residence time of 0.75 seconds, the total yields of ethylene, propylene and butylene are up to 51.54 wt.‐%, while the methane and coke are suppressed. At the same time, the stability of liquid products is desirable because of the high content of aromatics but low concentration of olefins.     

Effect of Feedstocks on High‐Severity Fluid Catalytic Cracking

A novel fluid catalytic cracking (FCC) process, that utilizes a downer reactor, has been developed to enhance the yield of light olefins under high‐severity reaction conditions. The effect of heavier feedstock on this high‐severity fluid catalytic cracking (HS‐FCC) process has been investigated using a small‐scale HS‐FCC pilot plant (0.1 b/d). Hydrotreated and virgin vacuum gas oils (VGO), hydrotreated and virgin atmospheric residues (AR) were used as test‐feeds in a previous study. The yield of desired products, such as gasoline and light olefins, produced from virgin VGO cracking was 79 wt.‐%, which is much higher than that obtained from a conventional FCC process. In the case of hydrotreated VGO, the yield of desired products decreased to 76%, however. On the other hand, AR feeds exhibited a performance similar to VGO with a slight increase in coke formation. In this study microactivity test (MAT) results are reported in which the activity and selectivity of the Y‐zeolite based catalyst is evaluated. Kinetic modeling was also done based on a four‐lump reaction model.     

Hydrogenation of low‐molar‐mass,OH‐telechelic polybutadienes. I. Methods based on diimide

Low‐molar‐mass, OH‐telechelic polybutadienes were hydrogenated (1) by diimide alone and (2) by using a novel method, consisting of the following two steps: up to some 95% degree of conversion by gaseous hydrogen with conventional Ziegler–Natta catalysts, and, only then, up to almost full saturation by diimide. The two‐step method, which has been found to be equally efficient, enables one to decrease substantially the necessary feed of p‐toluenesulfonylhydrazide, by the thermal decomposition of which diimide is generated. The crude saturated products, which could not be purified by a conventional (re)precipitation technique due to their low molar mass, contained a relatively large amount of a side‐product, bis(p‐tolyl)disulfide (TDS). It was found that free TDS can be converted quantitatively by reduction cleavage into p‐tolyl mercaptan (TM) without changing the structure of the polymeric product, and TM can then be removed from the mixture by alkaline extraction. Alternatively, the crude product can be freed from TDS by chromatography. With the two‐step hydrogenation method, only a small amount of the fragments and/or precursors of TDS add to the 5% residual CC double bonds of the partially hydrogenated polybutadiene chains. After any of the two purification procedures, the fully saturated products usually contained less than 1 wt % of such undesirable substituents only, which is comparable with the reported single‐step diimide hydrogenation of the initial, fully unsaturated polybutadiene in the presence of a proton scavenger (tri‐n‐propylamine). © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3203–3213, 1999     

Processing the wastes from the production of methyl chloride in the synthesis of olefins from natural gas

The gas phase (200–400°C) catalytic hydrodechlorination (HDC) of the main waste components (CH₂Cl₂, CH₃Cl, CCl₄) obtained in the production of methyl chloride from methane was studied with the aim of utilizing them in the development of promising technology for the synthesis of light olefins from methane via the pyrolysis of methyl chloride. Laboratory investigations were conducted on industrial hydrogenation and hydrotreating catalysts. Three catalytic systems and the conditions ensuring the stable operational characteristics of the HDC process were chosen. Methane, methyl chloride, light olefins, and HCl are the main products of this process. The use of Ni-Mo/Al₂O₃ catalyst leads to an increase in the CH₃Cl and olefin concentrations in the products. All the products of the HDC process can be used in the production of olefins to create a wasteless and chlorine-balanced technology for the synthesis of olefins from natural gas (methane). Owing to their considerable waste volumes, the technology for the synthesis of olefins cannot be realized without the HDC stage.     

Analysis of surfactant mixtures. I

Summary Some data on the use of 93% phosphoric acid as a reagent for recovering the hydrophobic portion of surfactants are presented, and their application to the analysis of surfactant mixtures is discussed. Aromatic sulfonates, straight-chain alkyl sulfates, fatty acid amides, and fatty acid esters decomposed to give good yields of the starting hydrophobic materials. Dioctylsulfosuccinate gave a mixture of octyl alcohols and olefins while the ethylene oxide condensates of lauryl alcohol, tridecyl alcohol, and tertiary dodecyl mercaptan gave olefins derived from the starting hydrophobic materials. Diisobutylene phenol-ethylene oxide condensate decomposed to olefins, conjugated olefins, and alcohols formed by rupture of the aromatic ring. The products are characteristic of the hydrophobic oils, and in most cases products from mixtures of surfactants can be separated by known analytical methods.Alpha-sulfo fatty acids or alkane sulfonates do not give recoverable oils by this treatment.