Carbon Number Of Alcohol Research Articles

Microemulsion and interfacial properties of anionic/nonionic surfactant mixtures based on sulfonate surfactants: The influence of alcohol

The influence of alcohols on the microemulsion and interfacial properties of sulfonate and nonionic surfactant mixtures (LAS-IPA/AEO9 mixture) were explored. Surface properties and interaction parameters were investigated to determine the optimum molar ratio of the LAS-IPA to AEO9, and the subsequent experimental studies in this paper were based on the system of mixtures (nLAS-IPA: nAEO9 (4:6)). The microemulsion phase behaviors of LAS-IPA / AEO9 / alcohol / n-decane / water were investigated by constructing a pseudo-ternary phase diagram. Results suggest that the microemulsion systems with n-butanol and n-pentanol as cosurfactants behave have optimal solubilization capacity when the corresponding alcohol to mixed surfactant (Km value) mass ratios are 1:1 and 1:1 ∼ 1:2, respectively. The solubilization capacity of the two systems reached their maximum in the temperature range of 35 °C–40 °C. The hydrodynamic diameters of microemulsion were determined by employing dynamic light scattering (DLS), and the average hydrodynamic diameters of microemulsion increased with the carbon number of alcohol, which ranges from 12 nm to 21 nm. Moreover, the equilibrium oil–water interfacial tension, the dynamic adsorption mechanism, and the dilational viscoelasticity of the oil–water interfacial film were studied using spinning-drop method and drop shape analysis, respectively. The results shows that equilibrium oil–water interfacial tension decreased with increased carbon number of the regular alcohol in the system. However, the decrease of interfacial tension with decreased Km is not significant when the carbon numbers of regular alcohol are 5 and 6. At the initial stage, diffusion-controlled adsorption processes were followed with n-propanol and n-butanol as cosurfactants when the Km values were 1:2, but systems of the other two cosurfactants yielded mixed kinetics-diffusion control. The dilatational modulus of oil–water interfacial film increased with the carbon number increase in regular alcohol or the decreased Km value. The contact angles of n-butanol based microemulsion system at the hydrophilic interface and the lipophilic interface reached 20° and 18°, which had excellent bi-phasic wettability property. At the same time, the oil film removal efficiency of the n-butanol based microemulsion was the highest, which was close to 100 % at 24 h.

Chitosan/MCM-41-SO3H composites as catalyst of the etherification of limonene

Etherification of limonene with methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-butanol to ethers were performed using a mesostructured silica with sulfonic groups, like MCM-41-SO3H, immobilized in chitosan (CHT), as composite catalyst (MCM-41-SO3H/CHT). The main product of limonene etherification in the present of MCM-41-SO3H/CHT composites was the α-terpinyl ether, which can be used in pharmaceutical and fine industry.Composite materials with different amounts of catalyst were prepared. These materials were used in methoxylation of limonene. It was observed that the catalytic activity of composite materials increased with the loading of MCM-41-SO3H dispersed in chitosan. The composite catalyst with highest activity was [MCM-41-SO3H]3/CHT.Composite material, [MCM-41-SO3H]3/CHT, can be recovered and reused in reaction of limonene with methanol.As [MCM-41-SO3H]3/CHT composite showed the highest catalytic activity in methoxylation of limonene, this material was applied in etherification of limonene with ethanol, 1-propanol, 2-propanol, 1-butanol and 2-butanol. An increased of activity with a decrease of the carbon number of alcohols was observed. A possible explanation is the presence of some internal limitations in channelling of composite catalyst.Selectivity of [MCM-41-SO3H]3/CHT to ethers was studied. When the carbon number of alcohol chain increase, a decrease of selectivity of composites is verified.

Ca‐based bifunctional acid‐basic model‐catalysts for n‐butanol production from ethanol condensation

AbstractEthanol to n‐butanol conversion is a process that can increase the carbon number of alcohols by coupling. There is increasing interest in the mechanisms for n‐butanol production in a simple step through the effective use of bifunctional acid–base catalysts. In this context, commercial hydroxyapatite (HAP) and two synthetized model supported catalysts, Ca/Al2O3 and Ca‐P/Al2O3, were used in bioethanol condensation. Characterization and acid–base sites were considered, and Fourier‐transform infrared (FTIR) spectroscopy and diffuse reflectance infrared Fourier‐transform spectroscopy–mass spectrometry (DRIFT‐MS) reactivity tests were performed in situ, as a first approximation to design a sustainable catalytic process rationally, and with the aim of understanding the process at the catalytic surface. The results indicated that the reactions occur at a large range of temperatures (200–450 °C). Hydroxyapatite and Ca/Al2O3 have similar basic sites (low and medium) and Ca‐P/Al2O3 presented the strongest Brönsted and Lewis combined acid sites. Three major reactions were identified: non‐oxidative dehydrogenation, aldol condensation, and intermolecular reduction, associated with the basic‐acid sites Ca‐O‐Ca/Ca‐O‐P/Ca‐O‐Al. Side reactions also occur involving different acid sites related to Lewis alumina centers favoring ethylene or diethyl‐ether production. © 2020 Society of Industrial Chemistry and John Wiley & Sons Ltd

Syngas to higher alcohols synthesis over 3D printed KMoCo/ZSM5 monolith

The catalytic conversion of syngas into high carbon number alcohols (ethanol, propanol, butanol) has opened an avenue for the development of sustainable aviation fuels. The commercial production of higher alcohols from syngas remain challenging because of several constraints including poor selectivity, harsh operating conditions, and unavailability of suitable technology. The present study is based on metal impregnated zeolite-based catalysts for catalytic conversion of syngas into higher alcohols. Following the superior catalytic performance of powdered ZSM5 (Si/Al 100), a structured monolith was engineered via 3D printing (Hyrel 3D – Engine SR). The catalyst precursors (K–Mo–Co) were in situ grown (by hydrothermal treatment) onto channels of zeolite monolith. A comparison between monolithic and powdered structures revealed a similar catalytic performance at lower space velocities (< 3000 h−1). With an increasing space velocity at 6000 h−1 and above, the structured catalyst retained its catalytic performance, whereas, carbon monoxide conversion dropped significantly (~20%) over powdered catalyst. Moreover, the by-products formation (methane and carbon monoxide) were reduced over structured monolith. The development of zeolite-based monolith has provided an opportunity to overcome diffusional limitations for better utilization of intrinsic kinetics of Mo-Co based catalysts for higher alcohols synthesis.

The catalytic activity of KMoCo carbon spheres for higher alcohols synthesis from syngas

Catalytic conversion of syngas to higher carbon number alcohols remains challenging till date owing to poor alcohols selectivity and limited understanding of catalytic active sites. In this study, we report bimetallic molybdenum-cobalt carbon spheres produced via in-situ hydrothermal reduction mediated by monosaccharides (glucose). The addition of potassium promoter (K/Mo = 0.14) during hydrothermal synthesis increased the concentration of high-valence molybdenum (MoO2) and selectivity towards higher alcohols (28 %). The field emission-SEM and HR-TEM images revealed a spherical morphology, embedding nanocrystalline MoCo oxides. The resulting carbon spheres enabled C2+ alcohols synthesis under mild operating conditions (270 ⁰C, 30 bar, and 3000 h−1).

Distribution characteristics of lipids in hadal sediment in the Yap Trench

In this study, cored sediment samples collected by the Jiaolong Submersible at 6 779 m depth from the hadal zone of the Yap Trench in May 2016 were sliced in 1-cm interval from top to bottom, and lipids in each sediment layer were quantitatively and qualitatively analyzed. The vertical distribution profiles of the lipids in the sediment sample, their main existing forms, and their possible sources were investigated. The results show that the concentration of lipid in the surface sediment was the highest with the carbon number from 12 to 27, dominated by medium and short-chain lipids. The total concentration of fatty acids in surface sediment was much higher than those in the offshore and deep-sea areas, being up to 325.77 μg/g due to the funnel effect caused by the “V” terrain of the trench. Fatty acid 18.0 was the most abundant lipids in the sediment sample. Abnormal high concentrations of fatty acid 18.ω7 and alkanes indicated the existence of hydrothermal fluids in the study area. In addition, saturated fatty acids and monounsaturated fatty acids existed mainly in free form, and polyunsaturated fatty acids existed mainly in bound form. Most of the alkanes were in bound form, and their major source was autochthounous input. The carbon number of alcohols in the sediment sample ranged from 12 to 20, mainly existed in bound form. The source of fatty acids was mainly autochthonous input, and the neutral lipids had both marine and terrestrial origin. This is the first study of lipids in hadal sediment of the Yap Trench. The results will promote deeper understanding of organic carbon cycle in marine environment.

Tailoring product characteristics in the carbonisation of brewers’ spent grain through solvent selection

Agricultural, food and other biomass wastes represent an untapped resource of hydrocarbonaceous material with potential for valorisation into fuels and chemical products. A key challenge in this area is directing the characteristics of the products for different applications. Here, the use of different solvents – water and simple alcohols – is shown to directly impact on the products arising from the carbonisation of brewers’ spent grain (BSG). Unprocessed BSG was carbonised using water, methanol, ethanol and 2-propanol under pressure. The synthesised biochar was analysed using infrared spectroscopy, thermogravimetic analysis, elemental analysis and bomb calorimetry. Biochar synthesised in alcohol solvents exhibited significantly different properties to that produced via conventional hydrothermal carbonisation (HTC) in water. HTC yielded a biochar with reduced heteroatom content and more favourable properties for application as a solid fuel. The alcohol solvents yielded greater quantities of water soluble oil (WSO), with the yield increasing with alcohol chain length. These trends are correlated with physical properties such as dielectric constant and increased solubility of organics in higher carbon number alcohols. These results show that the choice of solvent can direct the properties of synthesised chars for specific applications or can maximise the yield of bio-oil for fuel.

Experimental data and thermodynamic modelling of gallic acid solubility in a variety of pure solvents

ABSTRACTThe solubility of gallic acid (GA) in butan-1-ol, butan-2-ol, hexan-1-ol, 1,4-dioxane, ethyl acetate, methyl acetate and cyclohexanone from 293.15 to 318.15 K has been experimentally measured using a thermostatted reactor and UV/vis spectrophotometer analysis. The results demonstrate that the solubility of GA generally increased with the temperature and at a given temperature decreased with the increase of the carbon number of alcohols. The van’t Hoff model, modified Apelblat equation, h equation and the Two Local composition models of Wilson and NRTL model were used to predict the reported solubilities, resulting in a mean relative deviation of 3.47%, 3.54%, 2.90%, 3.12% and 3.18%, respectively. The obtained data showed that the h equation model is the most suitable for description of the solid–liquid equilibrium containing GA. Furthermore, the standard molar Gibbs energy and standard molar enthalpy of dissolution of GA were estimated.

Biosynthesis of acetate esters by dominate strains, isolated from Chinese traditional fermented fish (Suan yu)

Biosynthesis of acetate esters by Lactobacillus plantarum 120, Staphylococcus xylosus 135 and Saccharomyces cerevisiae 31, isolated from Chinese traditional fermented fish (Suan yu) were studied. A buffer system containing acyl donors (acetic acid/glyceryl triacetate/acetyl-CoA) and aliphatic alcohols (C2-C6) was established, inoculated with intracellular and extracellular extracts of the three strains. The results showed that the biosynthesis pathway of L. plantarum 120 was esterification and alcoholysis, while the biosynthesis pathway of S. xylosus 135 and S. cerevisiae 31 was hydrolysis and esterification, rather than alcoholysis. The ester-synthesizing activity of L. plantarum 120 via alcoholysis was higher than that via esterification at high pH value, while an opposite result for each strain was observed at low pH value. Moreover, the ester-synthesis activity of L. plantarum 120 was higher than that of S. xylosus 135 and S. cerevisiae 31. In addition, microbial ester-synthesis activity increased with the increase of aliphatic alcohol carbon number.

Carbon Nanotube-Supported Copper-Cobalt Catalyst for the Production of Higher Carbon Number Alcohols through Carbon Monoxide Hydrogenation

A series of carbon nanotube (CNTs)-supported copper-cobalt catalysts were prepared and investigated in a slurry reactor for their ability to selectively convert syngas into higher carbon number alcohols. The 7.5Cu7.5Co/CNTs catalyst achieved superior selectivity towards the formation of ethanol (30.1%) and C2+ alcohols (57.7%), while the 10Co5Cu/CNTs catalyst exhibited the largest alcohol space-time yield (372.9 mg gcat -1 h-1). However, the pure Cu (15Cu/CNTs) catalyst displayed negligible activity. Cobalt reduction was enhanced in the presence of copper. In addition to the Cu0-Co0 center, Co0-Co2+ also presented dual active sites for higher alcohols synthesis, the Co2+ site could terminate carbon chain growth to produce alcohols. The ratio of Cu/Co considerably influences the metal particle properties-synergistically effecting the active species.

Solubility Measurement and Correlation of Two Erlotinib Hydrochloride Polymorphs in Alcohols and Ketones from 273.15 to 323.15 K

The solubility of two erlotinib hydrochloride polymorphs (form A and form B) in methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, and methyl isobutyl ketone from 273.15 to 323.15 K were determined by means of high-performance liquid chromatography (HPLC). The modified Apelblat equation and the Buchowski–Ksiazczak λh equation were used to correlate the experimental solubility data. The results showed that the solubility of both forms generally increased with the temperature and at a given temperature decreased with the increase of the carbon number of alcohols; furthermore, methyl isobutyl ketone showed the largest solubility in the studied ketones. Meanwhile form A had a higher solubility than form B which demonstrated that form A was the metastable form. Furthermore, both models mentioned above gave satisfactory correlation results, in which the modified Apelblat equation worked better than the Buchowski–Ksiazczak λh equation.

Controllable synthesis of SiO 2 nanoparticles: effects of ammonia and tetraethyl orthosilicate concentration

SiO2 nanoparticles can be used as drug carriers in drug delivery systems, wherein the size of the nanoparticles plays a vital role in their distribution in vivo. SiO2 nanoparticles were synthesised using the Stober method and characterised by dynamic light scattering and scanning electron microscopy. The effects of the ammonia concentration, tetraethyl orthosilicate (TEOS) concentration, water loading and alcohol type on the size and dispersion of the SiO2 nanoparticles were investigated. The results showed that the concentration of ammonia was the most important factor in dictating the size of the SiO2 nanoparticles. The size of the particles increased with increasing ammonia and TEOS concentrations. Increasing the water loading caused a reduction in the particle size but an increase in the dispersion. Both the particle size and dispersion increased with increasing alcohol carbon number. Linear relationships were observed between the SiO2 particle size and the concentrations of ammonia and TEOS, which could be used to control the size of SiO2 nanoparticles during synthesis.

Tailoring the key fuel properties using different alcohols (C2–C6) and their evaluation in gasoline engine

The use of ethanol as a fuel for internal combustion engines has been given much attention mostly because of its possible environmental and long-term economical advantages over fossil fuel. Higher carbon number alcohols, such as propanol, butanol, pentanol and hexanol also have the potential to use as alternatives as they have higher energy content, octane number and can displace more petroleum gasoline than that of ethanol. Therefore, this study focuses on improvement of different physicochemical properties using multiple alcohols at different ratios compared to that of the ethanol–gasoline blend (E10/E15). To optimize the properties of multiple alcohol–gasoline blends, properties of each fuel were measured. An optimization tool of Microsoft Excel “Solver” was used to find out the optimum blend. Three optimum blends with maximum heating value (MaxH), maximum research octane number (MaxR) and maximum petroleum displacement (MaxD) are selected for testing in a four cylinder gasoline engine. Tests were conducted under the wide open throttle condition with varying speeds and compared results with that of E15 (Ethanol 15% with gasoline 85%) as well as gasoline. Optimized blends have shown higher brake torque than gasoline. In the terms of BSFC (Brake specific fuel consumption), optimized blends performed better than that of E15. In-cylinder pressure started to rise earlier for all alcohol–gasoline blends than gasoline. The peak in-cylinder pressure and peak heat release rate obtained higher for alcohol gasoline blend than that of gasoline. On the other hand, the use of optimized blends reduces BSCO (Brake specific carbon monoxide) and BSHC (Brake specific hydrocarbon) emission with compared to the use of gasoline and E15. BSNOx (brake specific nitrogen oxides)emission of all alcohol–gasoline blends was higher than that of gasoline. However, MaxR, MaxD, MaxH reduces BSNOx significantly than that of E15. Thus, optimized multi alcohol–gasoline blends were found to be a better option in terms of fuel properties, engine performance, combustion and emission for an unmodified gasoline engine.

Synthesis of a new cyclosporine-based stationary phase and separation behaviors toward aromatic positional isomers by high-performance liquid chromatography.

A new cyclosporine-bonded stationary phase has been synthesized through the Staudinger reaction between azido cyclosporine A (CsA) and aminopropyl silica gel and applied in separations of six disubstituted aromatic analytes by high-performance liquid chromatography. For dimethyl phthalate, nitroaniline and chloronitrobenzene, their positional isomers were well-separated on this CsA stationary phase, in which the separation factor for m-/o-dimethyl phthalates was the biggest. For nitrotoluene, dichlorobenzene and benzenediol, the m-/o-isomers were co-eluted. Then, effects of chromatographic conditions (such as types and content of alcoholic modifiers) on separation of nitroaniline positional isomers have been investigated. Retention behaviors of nitroaniline isomers on the column exhibited the strengthening trend along with increasing carbon number of alcohols, from ethanol to 1-propanol, and to 1-butanol. A similar phenomenon was observed by lowering the content of alcohol.

Assessing the ability of force-fields to predict liquid–liquid equilibria of ternary systems of light alcohols + water + dodecane by Monte Carlo simulation

Dodecane may be used as an extractive solvent to remove light alcohols from water in downstream processing in the Fischer–Tropsch process. In order to understand the ternary liquid–liquid phase behaviour for the systems and determine the effectiveness of alcohol removal with dodecane, both experimental liquid–liquid equilibria measurements and molecular simulations were undertaken as part of a previous study. Monte Carlo simulations for the systems proved to be difficult and therefore an assessment was undertaken to determine the effectiveness of the simple point charge (SPC) and TIP4P water models, in conjunction with the transferable potentials for phase equilibrium (TraPPE) model for the organics, in describing the liquid–liquid equilibria of such systems at atmospheric pressure. The light alcohols in question were methanol, ethanol, and propan-2-ol, and the temperatures for comparison with experimental data were at 313.14 and 333.15K. It was found that the simulations agreed favourably with the experimental data for the system containing methanol over the entire composition range, and only within certain compositional bounds for the systems containing ethanol and propan-2-ol. The deviation of the molecular simulations from the experimental data increased with increasing alcohol carbon number.

Origin of hydrophilicity of cellulose hydrogel from aqueous LiOH/urea solvent coagulated with alkyl alcohols

Surface and structural properties of cellulose hydrogel prepared from LiOH/urea solvent with alcoholic coagulation were examined. As coagulants, alcohols from methanol to butanol were employed. Alcohol with high water miscibility (MeOH, EtOH, 1-PrOH, 2-PrOH, and t-BuOH) gave a nano-porous structure consisting of a fibrous network of cellulose, while alcohol with low water miscibility (1-BuOH, 2-BuOH, i-BuOH) showed aggregation of a fibrous structure because of large shrinkage during the coagulation process. Congo red adsorption measurement showed that an increase in the carbon number of alcohol brought about a less hydrophobic surface. This is likely to occur because the alkali/urea/cellulose complex was formed during the coagulation process in the case of ethanol, propanol, and butanol, leading to a higher crystalline content of cellulose II, the surface of which is thought to be highly hydrophilic.

Purification and characterization of a novel 1,3- propanediol oxidoreductase from Klebsiella oxytoca

A novel 1,3-propanediol oxidoreductase (YqhD-1) found in Klebsiella oxytoca M5al was purified to homogeneity with a his-tag on a Ni-NTA column. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of the purified protein showed a molecular weight of 42 kDa. When YqhD-1 was tested as a dehydrogenase, the optimal pH was 11 and the optimal temperature was 37°C. Both Zn 2+ and Fe 2+ promoted YqhD-1 activity, whereas Mn 2+ , Ni 2+ , SO 4 2- and EDTA markedly inhibited YqhD-1 activity. Broad substrate specificity was observed for YqhD-1 with activity for several alcohols, including 1,3-propanediol, 1,2-propanediol, propanol, glycerol, 1-butanol, 1,3-butanediol and isopentanol. However, the enzyme preferred high carbon number alcohols such as 1-butanol and isopentanol. When tested as an aldehyde reductase, YqhD-1 could convert acetaldehyde and propaldehyde to their respective alcohols. When 1,3-PD and propaldehyde served as substrates, the apparent Km values of the enzyme for NADP and NADPH were 0.14 and 0.64 mM, respectively. Key words: Klebsiella oxytoca, 1,3-propanediol oxidoreductase, purification, YqhD.

Free volume and polymeric structure analyses of aromatic polyamide membranes: A molecular simulation and experimental study

Molecular simulation techniques were adopted to investigate the membrane free volume morphologies and alcohol sorption behaviors of aromatic polyamide (PA) membranes for pervaporation applications. A molecular dynamics (MD) technique was adopted to analyze the fractional free volume (FFV), the fractional accessible volume (FAV), and the size and shape distributions of the free volume. Experimental FFV results from Bondi's group contribution method and positron annihilation lifetime spectroscopy were also adopted to compare with the simulation data. The radial distribution function was also used to analyze the polymer chain stiffness and mobility. A Monte Carlo (MC) method was used to analyze the membrane absorption behavior. The FFV, FAV, and free volume morphology analyses revealed that bulky groups in the PA membranes contributed to the formation of a larger and more continuous free volume. The sorption analysis indicates that high carbon number alcohols have a higher affinity with the membranes, which might lead to a higher attractive force, reducing the permeability. The MD and MC results demonstrate good agreement with the experimental data, validating the feasibility of molecular simulation techniques in PV membranes at the molecular scale.

Microcalorimetric Studies on the Critical Micelle Concentration and Thermodynamic Functions of the Poly(oxyethylene) Lauryl Ether and Poly(oxyethylene glycol) Octylphenyl Ether in N,N-Dimethylformamide + Long-Chain Alcohol Systems at 298.15 K

The power−time curves of the micelle formation process are determined for the nonionic surfactants (Brij-35 and TX-100) in dimethylformamide (DMF) + long-chain alcohol systems by titration microcalorimetry. From the power−time curves, the critical micelle concentration (cmc) and the ΔHθm are obtained with ΔGθm and ΔSθm calculated. For this system, the relationships among the alcohol carbon number, the alcohol concentration with cmc, and the thermodynamic functions are discussed.

Selective Sorption and Desorption of Organic Solvent for δ-Syndiotactic Polystyrene

The desorption and sorption kinetics of organic solvents in the cavity of δ- and empty δ-forms of syndiotactic polystyrene (sPS) were investigated as a function of molar volume and shape of the solvent molecules. The desorption process was performed for films cast from chloroform, benzene, chlorobenzene, toluene, and p-xylene in supercritical CO2 at 40 °C and 10 MPa. The nanoporous structure of δ-sPS after extraction of solvent molecules was dependent on the solvent used. Large size solvent molecules were slowly excluded from δ-sPS. The relation between the cavity volume of δ-sPS and the dimensions of the solvent molecule suggests that desorption is slow for solvent molecules that are tightly packed in the cavities. The sorption kinetics of alcohols was investigated as a function of chain length using the nanoporous structure of empty δ-sPS. When empty δ-sPS was soaked in a linear alcohols with carbon numbers from 1 to 10, the alcohols with carbon number less than 6 could be incorporated in the cavity of empty δ-sPS. The diffusion coefficient of alcohols into the cavity was estimated using the Fickian equation. The diffusion became slower for longer chain length alcohols. In order to compare the sorption of different molecular shaped alcohols, structural isomers of 4 and 5 carbon number alcohols were investigated. These isomers were classified into two categories; alcohols with hydroxyl side groups and those with methyl side groups. Alcohols with hydroxyl side groups could be incorporated into empty δ-sPS; however, the methyl side group prevented the insertion of alcohol molecules into the cavity of empty δ-sPS.