Synthesis of oleyl oleate as a jojoba oil analog

Synthesis of a wax ester analog of jojoba oil was accomplished from oleic acid and oleyl alcohol with a zeolite as catalyst. A full 2³ factorial design at two levels has been used in the synthesis. The variables selected were temperature, reduced pressure and initial catalyst concentration. The most important variable within the range studied was temperature. Reduced pressure had a negative influence, and initial catalyst concentration showed a positive influence on the process. A response equation has been determined for the yield of ester. The properties of the synthesized product are similar to those of natural jojoba oil.     

Functionalization at the double-bond region of jojoba oil. 9. solid-state nuclear magnetic resonance characterization of substituted jojoba wax chemically bonded to a polystyrene matrix

Solid extractants for metal ions have been prepared by chemical bonding of jojoba wax to a polystyrene backbone, followed by phosphonation or sulfur-chlorination of the jojoba moiety. In this study, the intermediates and final solid products of the reactions were characterized by solid-state ¹³C and ³¹P nuclear magnetic resonance spectroscopy. The spectra showed the expected chemical shifts of the atoms involved in the chemical reactions, as well as other parts of the reacting molecules. Thus, the carbonyl carbon of the jojoba chain appears at 175 ppm, the methyl carbons at 15 ppm, the polystyrene backbone at 40–42 ppm (aliphatic carbons) and 128, 137, 143–147 (aromatic carbons). Carbons adjacent to N, S, and P appear at 45–55, 60, and 48 ppm, respectively.     

Composition and oxidative stability of soybean oil in mixtures with jojoba oil

Improvement of the oxidative stability of soybean oil (SBO) by blending with jojoba oil (JO) was investigated. SBO in the presence of 5, 10, 15 and 20 wt‐% of JO was subjected to accelerated storage at 60 °C. Peroxide values (PV), anisidine values (AV), UV absorption characteristics (K₂₃₂ and K₂₇₀ values), and headspace volatiles were determined to monitor the oxidative stability of oil samples. JO was effective in reducing the formation of hydroperoxides and volatile compounds in SBO. The effect was remarkable in SBO/JO blends containing 15 and 20% JO, which showed significant reductions in PV, AV and volatile content with respect to pure SBO. The increased oxidative stability of SBO/JO blends could not be attributed to JO tocopherols, since the addition of JO to SBO significantly reduced the tocopherol content of SBO. Besides the tocopherol content and unsaturation degree of SBO and JO, the effect of the JO ester structure on the oxidative stability of the blends is discussed. The enhanced chemical and flavor stabilities of SBO/JO blends with respect to pure SBO may make a significant contribution to improve the shelf life of SBO by reducing the deterioration reactions related to lipid peroxidation.     

Solubilization of lycopene in jojoba oil microemulsion

The unique properties of jojoba oil make it an essential raw material in the manufacture of cosmetics. New, totally dilutable U-type microemulsions of water, jojoba oil, alcohols, and the nonionic surfactant polyoxyethylene-10EO-oleyl alcohol (Brij 96V) have been formulated recently. Here, these microemulsions are shown to be capable of solubilizing lycopene, a nutraceutical insoluble in water and/or oil, much more effectively than the solvent (or a solvent and surfactant blend) can dissolve them. In water-in-oil (W/O) and oil-in-water (O/W) microemulsions with 10 and 90 wt% water, respectively, the normalized maximal solubilization efficiency α is ca. 20-fold larger than its solubility. The solubilization capacity of the system is mainly surfactant-concentration dependent. The lycopene resides at the interfaces of the W/O and O/W microemulsions and engenders significant structural changes in the organization of the microemulsion droplets. In the absence of lycopene, the droplets are spherical; when lycopene is added, compaction of the droplets and formation of threadlike droplets are observed. On further addition of lycopene, the bridging effect wanes and the droplets revert to a spherical shape. The enhanced solubilization demonstrated for lycopene opens up new options for formulators interested in making liquid and transparent products for cosmetic or pharmaceutical uses.     

Functionalization at the double bond region of jojoba oil. 6. Production of aminesvia azides

The apolar and hydrophobic jojoba molecule was made more hydrophilic by the incorporation of primary amino groupsvia the introduction and subsequent reduction of azido groups. The azides were obtained by the substitution of bromine or a mesylate group introduced into the jojoba oil molecule; by opening of the epoxide ring in epoxy jojoba; or by the addition of bromoazide to the double bonds of jojoba.     

Functionalization at the double-bond region of jojoba oil. 8. Chemical binding of jojoba liquid wax to a polymer matrixvia an amine “spacer”

Jojoba wax was chemically bonded to a polymer matrixvia stable C-N covalent bonds. The polymer matrix was prepared by amination of several types of styrene-divinyl benzene or styrene-vinylbenzylchloride-divinylbenzene copolymers with diamines or polyethylene imines (polyamines). The jojoba wax was attached to the aminated polystyrene matrix by reacting an allyl-brominated derivative of jojoba with the matrix to form a C-N bond between the matrix and the jojoba wax. The amount of bound jojoba wax added to the polymer was in the range of 20–70% (w/w), depending on the type of polymer matrix and reaction conditions. The double-bond regions in the jojoba wax bonded to the matrix were preserved, and they were subsequently functionalized by phosphonation and sulfur-chlorination reactions.     

Functionalization at the double-bond region of jojoba oil. 7. Chemical binding of jojoba liquid wax to polystyrene resins

Jojoba wax was chemically bonded to a polystyrene matrixvia a stable C-C covalent bond. This was achieved by binding allyl-brominated jojoba derivatives to lithiated crosslinked polystyrene-2% divinylbenzene or XAD-4 polymeric beads via a nucleophilic substitution reaction. The double-bond regions in the jojoba wax were preserved. A side reaction that accompanied the nucleophilic substitution was HBr elimination, which produced diene and triene systems in the bound jojoba. Phosphonation and sulfur chlorination at the double bonds of the jojoba wax, bonded to the polystyrene matrix, were also performed.     

Optimization of transesterification of castor oil with ethanol using a central composite rotatable design (CCRD)

In the present study, the synthesis of fatty acid esters from castor oil using an alkaline catalyst was optimized. The variables reaction time, catalyst amount and oil:ethanol molar ratio were studied using a central composite rotatable design. The effects and significance of the models on the response variable and on ethyl biodiesel yield derived from pure castor oil were evaluated using a response surface curve and analysis of variance. All the variables significantly affected the reaction yield, the amount of catalyst being the most effective. The highest yield was obtained using an oil:ethanol molar ratio of 1:11, 1.75% KOH and a reaction time of 90 min.     

Optimization of silver cementation yield in fixed bed reactor using factorial design and central composite design

This work deals with cementation of silver onto iron grid in fixed bed reactor. The influence of several parameters is studied namely: initial concentration of silver [Ag⁺]₀, flow rate, solution pH, and mass of iron. Moreover, their influence on the yield of the reaction of cementation is investigated statistically by the experimental design in view of industrial application. The estimation and the comparison of the parameter's effects are realised by using two‐level factorial design. The analysis of these effects permits to state that the most influential factor is the mass of iron with an effect of (+5.642), the second in the order is the initial concentration of silver ions (Ag⁺) with an effect of (+4.005), the third is the flow rate of the electrolytic solution with an effect of (+3.824). A central composite design methodology is employed to determine the optimum conditions for a silver cementation yield onto iron grid. For this end, the experimental results were approximated by a second‐order model as well as the surface contour plots and surface responses are drowned. The optimal conditions found for initial silver concentration, such as a flow rate, pH of the solution and mass of iron, are respectively: 21.25 mg/L, 4.43 L/min, 3.6 and 50 g. Under these conditions, the obtained silver cementation yield is 96.851%.     

Hydroxymethylation of jojoba oil by lewis acid-catalyzed ene reaction with formaldehyde

Formaldehyde undergoes ethylaluminum dichloride-catalyzed ene reaction with jojoba oil to afford a mixture of 1∶1 and 1∶2 adducts. The hydroxymethyl products were identified by comparison with model adducts prepared from methyl oleate and oleyl acetate.     

An efficient synthesis of muscalure from jojoba oil or oleyl alcohol

A four-step synthesis of (Z)-9-tricosene (muscalure), a component of the pheromone of the housefly, from jojoba oil (or three-step from oleyl alcohol) by 3-carbon (or 5-carbon) unit elongation was developed in overall high yield. The sequence of reactions and the purity of the products could be easily followed, with relatively good accuracy, by NMR technique.     

杂多酸催化剂走向分子设计

从分子设计的角度讨论了杂多酸的结构与催化性能、制备方法以及在有机合成、石油化工中的应用进展。     

Development of a multi-component drug from turmeric using central composite design

A methodology to develop multi-component drugs based on traditional Chinese medicines has been developed using central composite design. Several active components from the traditional Chinese medicine turmeric were chosen for use in a multi-component antitumor drug. Response surface methodology based on a central composite design was applied to determine the quantitative composition-activity relationships in order to optimize the amount of each component in the drug. An MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to measure the pharmacological activity as the response value. The experimental antitumor activity of the optimum combination was 92.85% in the MTT assay and superior to the activities of each single component. These results demonstrate that response surface methodology based on a central composite design is suitable for the design of multi-component drugs.     

Optimisation of reaction conditions for the synthesis of single‐walled carbon nanotubes using response surface methodology

The effects of three preparation variables, i.e. reaction temperature, reaction time and reaction gas (methane/nitrogen) flow rate, on the ratio of the intensity of the Raman D band to the intensity of the G band (I_D/I_G), carbon mass and the presence of radial breathing mode (RBM) peaks were investigated by using a central composite design to develop two linear models. The most influential factor in each experimental design‐response was identified using the analysis of variance. The predicted I_D/I_G ratio, carbon mass and presence of RBM peaks determined during the process optimisation were found to agree satisfactorily with the experimental values. The optimum conditions for synthesising single‐walled carbon nanotubes were determined to be a reaction temperature of 900°C, a reaction time of 59 min and a reaction gas flow rate of 54 mL/min. © 2011 Canadian Society for Chemical Engineering     

Quantitative effects of synthesis conditions on oil absorptive properties of oil gels based on EPDM/4‐tert‐Butylstyrene

The oil absorption properties of porous polymeric gels are dependent on their synthesis conditions. In this work, we have investigated whether it is feasible to find a quantitative relationship between the synthesis conditions of porous poly(EDPM/4‐tert‐Butylstyrene) gels and their behavior in the kerosene absorption through a factorial design of experiments. For this purpose, a series of such oil gels have been synthesized in toluene with various divinylbenzene (DVB) and EPDM contents. The kerosene absorbency and kerosene‐absorption kinetics of oil gels were determined. Finally, empirical models correlating the synthesis conditions with the kerosene absorbency (Q_eq) and kerosene‐absorption kinetic constant (K) were calculated; it was observed that lower the DVB concentration and higher the EPDM fraction in the monomeric mixtures, the higher the kerosene absorbency. With regard to the kerosene‐absorption kinetics, the largest K value was achieved with the lowest DVB concentration and the highest EPDM fraction. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Modeling of biodiesel production: Performance comparison of Box-Behnken,face central composite and full factorial design

The performances of the response surface methodology (RSM) in connection with the Box-Behnken, face central composite or full factorial design (BBD, FCCD or FFD, respectively) were compared for the use in modeling of the NaOH-catalyzed sunflower oil ethanolysis. The influence of temperature, catalyst loading, and ethanol-to-oil molar ratio (EOMR) on fatty acid ethyl esters (FAEE) content was evaluated. All three multivariate strategies were efficient in the statistical modeling and optimization of the influential process variables but BBD and FCCD realization involved less number of experiments, generating smaller costs, requiring less work and consuming shorter time than the corresponding FFD. All three designs resulted in the same optimal catalyst loading (1.25% of oil) and EOMR (12:1). The reduced two-factorinteraction (2FI) models based on the BBD and FCCD defined a range of optimal reaction temperature (25℃-75℃) and 25℃, respectively while the same model based on the 3³ FFD appointed 75℃. The predicted FAEE content of about 97%-98.0% was close to the experimentally obtained FAEE content of about 97.0%-97.6% under the optimal reaction conditions. Therefore, the simpler BBD or FCCD might successfully be applied for statistical modeling of biodiesel production processes instead of the more extensive, more laborious and more expensive FFD.     

Optimization of CO2–CH4 separation performance of integrally skinned asymmetric membranes prepared from poly(2,6‐dimethyl‐1,4‐phenylene oxide) by factorial design

Integrally skinned asymmetric flat sheet membranes were prepared from poly(2,6‐dimethyl 1,4‐phenylene oxide)(PPO) for CO₂–CH₄ separation. Various experiments were carried out to identify PPO membranes, which have good mechanical strength and gas separation abilities. Membrane strength and selectivity depend on the interplay of the rate of precipitation and the rate of crystallization of the PPO. The effects of major variables involved in the membrane formation and performance, including the concentration of the polymer, solvent, and additive, the casting thickness, the evaporation time before gelation, and the temperature of the polymer solution, were investigated. Factorial design experiments were carried out to identify the factor effects. The membrane performance was modelled and optimized to approach preset values for high CO₂ permeance and a high CO₂ : CH₄ permeance ratio. Membranes were prepared based on the optimum conditions identified by the model. Essentially, defect‐free membranes were prepared at these conditions, which resulted in a pure gas permeance of 9.2 × 10⁻⁹ mol/m² s Pa for CO₂ and a permeance ratio of 19.2 for CO₂ : CH₄. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1601–1610, 1999     

Lipase-catalyzed alcoholysis of crambe oil and camelina oil for the preparation of long-chain esters

Crambe oil and camelina oil were transesterified with oleyl alcohol, the alcohols derived from crambe and camelina oils, n-octanol or isopropanol using Novozym 435 (immobilized lipase B from Candida antarctica), Lipozyme IM (immobilized lipase from Rhizomucor miehei), and papaya (Carica papaya) latex lipase as biocatalysts. The highest conversions to alkyl esters were obtained with Novozym 435 (up to 95%) in most cases, whereas Lipozyme IM and papaya latex lipase gave lower (40 to 50%) conversions. The conversions with long-chain alcohols (oleyl alcohol, crambe alcohols, and camelina alcohols) were higher (40 to 95%) than with medium-chain n-octanol (30 to 85%). Isopropyl esters of crambe oil and camelina oil were obtained with rather low conversions using Novozym 435 (<40%) and Lipozyme IM (about 10%) as biocatalysts, whereas with papaya latex lipase no isopropyl esters were formed. The conversions of crambe oil and camelina oil to oleyl and n-octyl esters using Novozym 435 as biocatalyst were hardly affected by the ratio of the substrates, but with Lipozyme IM the conversions to alkyl esters distinctly increased with an excess of alcohol substrate Presented as part of the doctoral thesis of Georg Steinke to the University of Münster, Münster, Germany     

Re-refining of used lubricant oil by solvent extraction using central composite design method

The primary aim of this study was to recover base oil from used oil using solvent extraction followed by the adsorption method. Many effective variables were examined within the solvent extraction method, including using different solvents, solvent/used oil, temperature and speed of blending. Central composite design (CCD) was applied as the statistical method. Response surface methodology was then used to find the optimum conditions in the process of extraction: ratio of solvent/used oil 2.4 and 3.12 vol/vol, temperature=54 and 18 °C, and speed of mixing=569 and 739 rpm for 1-butanol and methyl ethyl ketone (MEK), respectively. Various flocculation agents were used with the solvent, such as Sodium hydroxide (NaOH), Potassium hydroxide (KOH) and Monoethylamine (MEA); they provided an increase in the separation efficiency. The best result was obtained when using 2 grams of MEA/kg solvent; this amount of MEA increases sludge removal from 12.6% to 14.7%. In the process of clay adsorption, the variables that were tested included the ratio of clay/extract oil, temperature and time of contact. The best conditions in the process of adsorption by activated bentonite were a ratio of clay/extract oil=15 wt/vol%, temperature=120 °C, and time of contact=150 minutes. The recovered base oil was analyzed by Fourier transform infrared spectroscopy (FTIR) and compared to Iraqi specifications of base oils. The recovered base oil specifications were analyzed, including, viscosity @100 °C 8.32, 9.22 cSt, pour point ?17.35, ?22.23 °C, flash point 210.12, 223.04 °C, total acid number (TAN) 0.25, nill, total base number (TBN) nill, nill, ash 0.031, 0.0019 wt% and color 3.0, 2.5 for two types of base oil recovered using MEK, 1-butanol with activated bentonite, respectively.     

Separation of <6 mm oil shale using a compound dry separator

A large amount of fine granular materials (<6 mm) are produced during the mining of oil shale. The combustion characteristics of oil shale improve with decreasing size of these materials, for which reason fine-grain oil shale has a high utility value. However, fine oil shale also contains a significant amount of inorganic mineral impurities which can be reduced by physical separation to improve the oil quality. Based on an analysis of the physical properties of oil shale, this paper proposes a compound dry separation process for the cleaning of <6 mm oil shale grains. The effects of the vibration intensity, air velocity, and back angle of the employed separator on the separation results and oil content of the cleaned oil shale were systematically analyzed. Under the optimal vibrational conditions defined by a vibration intensity of 25.76 (amplitude = 4.0 mm, frequency = 40 Hz), air velocity of 0.66 m/s, and back angle of 45°, the yield comprised 35.8% concentrate and 64.2% tailings, with corresponding oil contents of 10.02% and 0.85%, respectively. The probable error of the highest intensity of segregation achieved was 0.155. The proposed compound dry separation of oil shale particles of up to 6 mm was found to be more efficient compared with conventional methods, and the separated fine grade material can be comprehensively utilized by further pyrolysis treatment.