Showing papers on "Isopropyl alcohol published in 2016"

Acetone Hydrodeoxygenation over Bifunctional Metallic–Acidic Molybdenum Carbide Catalysts

Abstract: Metallic–acidic bifunctionality of molybdenum carbidic catalytic formulations can be tuned by oxygen cofeed and reductive pretreatments to control carbonyl hydrodeoxygenation (HDO). Acetone is deoxygenated over activated Mo2C via sequential hydrogenation of acetone to equilibrium and subsequent dehydration of isopropyl alcohol (IPA). Dehydration to propylene occurs over Bronsted acid sites with an intrinsic activation energy of 103 ± 1 kJ mol–1 and a rate-determining step of β-hydrogen scission, as inferred from a kinetic isotope effect (KIE) of 1.85. HDO rate-determining dehydration rates were kinetically independent of H2 and oxygenate pressure from 10 to 82 kPa and from 0.05 to 4 kPa, respectively. Both the kinetics and the deoxygenation reaction pathway were shown to be similar for the aldehyde group of propanal. Oxygen treatment of activated carbides via 13.5 kPa O2 cofeed was shown to decrease the catalyst surface area from 68 to 9 m2 g–1 and to suppress metallic hydrogenation of acetone to IPA. IPA...

Direct growth of defect-rich MoO3−x ultrathin nanobelts for efficiently catalyzed conversion of isopropyl alcohol to propylene under visible light

Abstract: We report a robust and highly active photocatalyst for the C3H6 evolution reaction that is constructed by surfactant-free growth of oxygen vacancy-rich MoO3−x ultrathin nanobelts. Under visible-light irradiation, the new catalyst can selectively (95% selectivity) dehydrate isopropyl alcohol into C3H6 with yields above 98%.

Zr-Based MOF-808 as Meerwein–Ponndorf–Verley Reduction Catalyst for Challenging Carbonyl Compounds

Abstract: In the fine chemical industry, transfer hydrogenation of carbonyl compounds is an important route to selectively form the corresponding allyl alcohol. The Meerwein–Ponndorf–Verley reduction (MPV) is catalyzed by a Lewis acid catalyst and easily oxidizable alcohols serve as hydrogen donor. We successfully used the Zr-based metal-organic framework (MOF) MOF-808-P as MPV-catalyst with isopropyl alcohol as solvent and hydride donor. After only 2 h, 99% yield of cinnamyl alcohol was obtained. The highly active MOF-808-P is also a good catalyst for the selective reduction of more challenging substrates such as R-carvone and β-ionone. Two strategies were successfully used to shift the equilibrium towards the desired allylic alcohol products: (1) evaporation of formed acetone and (2) the use of the more strongly reducing 1-indanol. Carveol yield was increased to >70%. These results highlight the great potential of this recently discovered Zr-MOF as a chemically and thermally stable catalyst.

119Sn MAS NMR Study of the Interaction of Probe Molecules with Sn-BEA: The Origin of Penta- and Hexacoordinated Tin Formation

Abstract: 119Sn CPMG MAS NMR was applied to study the adsorption of acetonitrile, methanol, isopropyl alcohol, isobutyl alcohol, and water over Sn-BEA enriched with 119Sn isotope. Two signals observed at ca. −422 and −443 ppm over dehydrated samples were attributed to tetracoordinated framework tin sites with strong and weak Lewis acidity, respectively. The adsorption of acetonitrile and methanol resulted in the observation of pentacoordinated tin species, due to the formation of 1:1 adsorption complexes over both Sn sites. Water adsorption led first to formation of pentacoordinated tin species, which were further converted into hexacoordinated species at longer reaction times. The latter transformation was found to be kinetically limited and was attributed to chemical interaction of tin sites with water, such as hydrolysis of Si–O–Sn bonds. The adsorption of isopropyl alcohol and isobutyl alcohol was accompanied by the formation of pentacoordinated Sn species in the case of weak sites and hexacoordinated Sn over s...

Supercritical water oxidation (SCWO) for the removal of N-containing heterocyclic hydrocarbon wastes. Part I: Process enhancement by addition of isopropyl alcohol

Abstract: The present work investigates the destruction of nitrogen-containing heterocyclic hydrocarbons frequently encountered in hazardous wastes by supercritical water oxidation (SCWO), with focus on the process enhancement using isopropyl alcohol (IPA) as co-fuel. 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) was selected for SCWO in a continuous plug flow reactor, under a range of temperatures (400–525 °C), oxidant ratios nSR (0.8–2.0) and IPA/DBU ratios (0.5–3.5). Experimental results were presented in terms of total organic carbon (TOC) removal %, and nitrogenous products yield %. Based on GC–MS analysis, a free radical reaction mechanism for SCWO of DBU was proposed. Results showed that temperature was the predominant factor to influence the rate of DBU oxidation, while oxidant ratio (nSR) significantly affected the N speciation in the exit stream. IPA addition had a significant impact on shifting recalcitrant aqueous ammonia NH 4 + in the liquid stream to gaseous nitrogen. It also increased TOC removal % (DBU + IPA) due to the increased free radicals produced by IPA oxidation.

Influence of Coadsorbed Water and Alcohol Molecules on Isopropyl Alcohol Dehydration on γ-Alumina: Multiscale Modeling of Experimental Kinetic Profiles

Abstract: Successfully modeling the behavior of catalytic systems at different scales is a matter of importance not only for a fundamental understanding but also for a more rational design of catalysts and a more precise definition of the kinetic laws used as inputs in chemical engineering. We have developed here a multiscale modeling of the dehydration of isopropyl alcohol to propene and diisopropyl ether on γ-alumina catalysts, which clearly evidences and explains the central character of cooperative effects between coadsorbates in the kinetic network. The evolution of partial pressures with contact time was simulated using an original DFT-based microkinetic model based on a “macro site” centered on the main active site located on the (100) planes of alumina and comprising several neighboring adsorption sites. The formation of isopropyl alcohol–isopropyl alcohol or water–isopropyl alcohol dimers on the surface was required to correctly simulate the production of the minor product, diisopropyl ether, and the evolu...

Solubility and Dissolution Thermodynamics for 1,3,5-Trichlorobenzene in Organic Solvents

Abstract: The solubility of 1,3,5-trichlorobenzene in n-propanol, isopropyl alcohol, n-butanol, isobutyl alcohol, cyclohexane, toluene, ethyl acetate, and acetone were obtained experimentally in temperatures ranging from (273.15/280.65 to 308.15) K under a pressure of 0.1 MPa with a chromatographic method. The solubility data of 1,3,5-trichlorobenzene in those selected organic solvents increased with increasing temperature. The order of the solubility data values is as follows: toluene > cyclohexane > ethyl acetate > (n-butanol, acetone) > isobutyl alcohol > n-propanol > isopropyl alcohol. The obtained solubility data of 1,3,5-trichlorobenzene in the studied solvents were correlated by using modified Apelblat equation, λh equation, Wilson model, and NRTL model. The four models all provide acceptable results for the system of 1,3,5-trichlorobenzene in the selected solvents. Furthermore, the thermodynamic properties of solution, including molar dissolution enthalpy (ΔsolH0) and the excess enthalpy for 1,3,5-trichloro...

Nano-NiFe2O4 as an efficient catalyst for regio- and chemoselective transfer hydrogenation of olefins/alkynes and dehydrogenation of alcohols under Pd-/Ru-free conditions

Abstract: Here, we have demonstrated the magnetic nano-NiFe2O4 catalyzed transfer hydrogenation of olefins/alkynes using isopropyl alcohol as a source of hydrogen under ligand/base/Pd-/Ru-metal-free conditions, and dehydrogenation of alcohols under oxidant-free conditions.

Iridium-Catalyzed Transfer Hydrogenation of 1,10-Phenanthrolines using Formic Acid as the Hydrogen Source

Abstract: The iridium-catalyzed highly regioselective transfer hydrogenation of a variety of 2-substituted and 2,9-disubstituted 1,10-phenanthrolines under mild conditions with formic acid as the hydrogen source is described. In the presence of a catalytic amount of the iridium complex [Cp*IrCl2]2, the transfer hydrogenation proceeded smoothly in 1,4-dioxane under ligand-free conditions, exclusively leading to a range of 1,2,3,4-tetrahydro-1,10-phenanthroline products in high yields. The catalyst generated in situ from [Cp*IrCl2]2 and (R,R)-(CF3)2C6H3SO2-dpen [N-(2-amino-1,2-diphenylethyl)-3,5-bis(trifluoromethyl)benzenesulfonamide] could efficiently catalyze the asymmetric transfer hydrogenation of these 1,10-phenanthrolines in isopropyl alcohol (i-PrOH) to afford chiral 1,2,3,4-tetrahydro-1,10-phenanthrolines in high yields with up to >99% ee. The key to the success of the reduction is the choice of solvent and hydrogen source.

Selective Oxidation of Methanol to Formaldehyde Over Active Molybdenum Oxide Supported on Hydroxyapatite Catalysts

Abstract: Hydroxyapatite (HAP) was synthesized by sol–gel method. Different ratios of molybdenum oxide (1–15 % w/w) supported on HAP were prepared by the impregnation method and calcined at 400 °C in a static air atmosphere. The catalysts were characterized by thermogravimetry, differential thermal analysis, X-ray diffraction, FTIR spectroscopy and nitrogen sorption measurements. The surface acidity of the catalysts was investigated by the dehydration of isopropyl alcohol and the adsorption of pyridine (PY) and 2,6-dimethyl pyridine (DMPY). The gas–phase oxidation of methanol to formaldehyde was carried out in a conventional fixed-bed flow type reactor using N2 as a carrier gas. The obtained results clearly revealed that HAP–MoO3 systems were active and selective towards the formation of formaldehyde. The maximum yield of formaldehyde (97 %) was achieved on the catalyst containing 5 wt% MoO3/HAP. The generation of Mo6+as Lewis together with Bronsted acid sites play the main role in the formation of formaldehyde. Catalytic oxidation of methanol over MoO3/HAP calcined at 400 °C for 4 h.

Oxidative Alkoxycarbonylation of Alkynes by Means of Aryl α‐Diimine Palladium(II) Complexes as Catalysts

Abstract: The straightforward in situ synthesized bis(2,6-diisopropyl)acenaphthenequinonediimine palladium triflate catalyst was generally employed for both the mono-alkoxycarbonylation of terminal alkynes, and the bis-alkoxycarbonylation of 1,2-disubstituted alkynes by using mild reaction conditions [carbon monoxide pressure (PCO)=4 bar, temperature=20 °C]. Utilizing low catalyst loading (down to 0.5 mol%), a variety of propiolic esters were synthesized with good to excellent isolated yields. Most importantly the system was very efficient not only with methanol but also with a range of different alcohols, starting from the less hindered benzyl alcohol to the most hindered ones, such as isopropyl alcohol and tert-butyl alcohol. In addition, aromatic and aliphatic 1,2-disubstituted alkynes were converted into maleic acid derivatives, together with an acid-catalyzed isomerization reaction, showing modest to good selectivity and excellent combined yields. In particular 3-hexyne showed a satisfactory degree of selectivity for the maleic diesters of methanol and benzyl alcohol, obtaining the corresponding products with good isolated yields.

Modelling and Simulation of a Reactive Distillation Process for Fuel Additive Production

Abstract: This research work has been carried out to model and simulate a reactive distillation process producing fuel additives. The fuel additives considered were isopropyl alcohol and diisopropyl ether. To simulate the process, Aspen HYSYS was employed to develop the model of the process using Distillation Column Sub- Flowsheet having 21 stages apart from the condenser and the reboiler. The column was divided into five (condenser, rectifying, reaction, stripping and reboiler) sections. The feeds into the column were passed at the same room temperature but different pressures. After simulating the developed model of the process, the fluid package of which was Non-Random Two-Liquid (NRTL), using Sparse Continuation Solver, the results obtained revealed that the novel technology (that is, reactive distillation) was able to suppress the secondary reaction of the process because the ratios of the mole fraction, the mass fraction and the volume fraction of isopropyl alcohol to diisopropyl ether obtained from the condenser section of the column as the top product of the process were approximately 185, 108 and 101, respectively. This has, therefore, demonstrated the ability of reactive distillation process in suppressing a secondary reaction because very large quantity of the primary product, which was isopropyl alcohol, of the process was given compared to the secondary one (diisopropyl ether).

Mechanistic Investigation of Molybdate-Catalysed Transfer Hydrodeoxygenation

Abstract: The molybdate-catalysed transfer hydrodeoxygenation (HDO) of benzyl alcohol to toluene driven by oxidation of the solvent isopropyl alcohol to acetone has been investigated by using a combination of experimental and computational methods. A Hammett study that compared the relative rates for the transfer HDO of five para-substituted benzylic alcohols was carried out. Density-functional theory (DFT) calculations suggest a transition state with significant loss of aromaticity contributes to the lack of linearity observed in the Hammett study. The transfer HDO could also be carried out in neat PhCH2OH at 175 °C. Under these conditions, PhCH2OH underwent disproportionation to yield benzaldehyde, toluene, and significant amounts of bibenzyl. Isotopic-labelling experiments (using PhCH2OD and PhCD2OH) showed that incorporation of deuterium into the resultant toluene originated from the α position of benzyl alcohol, which is in line with the mechanism suggested by the DFT study.

Formation and Phase Behavior of Winsor Type III Jatropha curcas -Based Microemulsion Systems

Abstract: The formation and phase behavior of Jatropha curcas-based microemulsion systems, which could potentially be used in enhanced oil recovery applications, has been investigated. Winsor type III microemulsions were obtained by adding n-octane to Winsor type I microemulsion systems prepared using various concentrations of alkyl polyglucoside (APG). To optimize the formulation of type III microemulsion systems, five different types of co-surfactants, i.e. normal butyl alcohol (NBA), isobutyl alcohol, isopropyl alcohol, fatty acid alcohol C8 (FAC8) and fatty acid alcohol C8/C10 (FAC8/C10) were used. The microemulsion phase behavior was determined along with particle size distributions by dynamic light scattering measurements. Results show that the optimum Winston type III system can be achieved by mixing 3 wt% of NBA, 1 wt% APG and 3 wt% NaCl. At the optimum formulation, the IFT reached a minimum value (0.016 mN/m) and formed very small emulsion droplets with a narrow particle size distribution.

Mild and Direct Multiple Deuterium‐Labeling of Saturated Fatty Acids

Abstract: We have established a mild and direct platinum on carbon (Pt/C)-catalyzed multi-deuterium labeling of various saturated fatty acids including bioactive compounds with high deuterium efficiencies in a mixed solvent of isopropyl alcohol and deuterium oxide (i-PrOH)/D2O under neutral conditions at 120 °C without the external addition of deuterium or hydrogen gas.

Vapor–Liquid Equilibria for Ternary Mixtures of Isopropyl Alcohol, Isopropyl Acetate, and DMSO at 101.3 kPa

Abstract: The vapor–liquid equilibrium (VLE) data for the binary system isopropyl alcohol + dimethyl sulfoxide (DMSO), isopropyl acetate + DMSO, and ternary system isopropyl alcohol + isopropyl acetate + DMSO were measured with a VLE modified Othmer still at 101.3 kPa. The experimental data were proved to be thermodynamically consistent when the point-to-point consistency test of Van Ness test was applied. The binary experimental data were correlated with the nonrandom two-liquid (NRTL), Wilson, and universal quasichemical (UNIQUAC) activity coefficient models. Then, the ternary VLE data were predicted with the obtained binary interaction parameters. The results indicate that the values of equilibrium temperature and vapor mole fraction calculated by the NRTL, Wilson, and UNIQUAC models are in good agreement with the experimental data. When the mole ratio of the binary azeotrope to DMSO was 1:1.5, the binary azeotrope of isopropyl alcohol and isopropyl acetate was eliminated. Therefore, DMSO is a potential extracti...

Selective synthesis of acetone from isopropyl alcohol over active and stable CuO–NiO nanocomposites at relatively low-temperature

Abstract: CuO–NiO nanocomposite catalysts were synthesized by an oxalate precipitation route. The basicity of the catalysts was measured using adsorption–desorption of acetic acid. The catalytic conversion of isopropanol to acetone was carried out in a conventional fixed bed flow type reactor at 200 °C using N2 as a carrier gas. The results indicated that, the addition of NiO to CuO greatly enhanced the electrical conductivity via the creation of new charge carriers (Cu+–Ni3+). In addition, the results revealed that the catalyst containing 30 wt.% NiO calcined at 400 °C possesses the highest catalytic activity with 98% conversion and 100% selectivity to acetone. The remarkable catalytic performance of the synthesized catalysts is attributed to the decrease of the energy gap, the increase in the concentration of charge carries (Cu+–Ni3+), and to the creation of more weak and intermediate basic sites.

The Activation Effects of Low Level Isopropyl Alcohol Exposure on Arterial Blood Pressures Are Associated with Decreased 5-Hydroxyindole Acetic Acid in Urine.

Abstract: Purposes The objectives of this paper are to study the impact of low level isopropyl alcohol exposure on blood pressure and to explore its potential mechanism. Methods This cross-sectional study was based on a prospective occupational cohort in south China, which focusing on occupational risk factors related cardiovascular health problems. A total of 283 participants (200 low isopropyl alcohol exposed workers and 83 controls) was finally enrolled in this study. Linear regression models were used to analyze the relationship between arterial blood pressures and low level isopropyl alcohol exposure. We used mediation method to explore possible mediated roles of neurogenic factors. Results Systolic blood pressure (SBP, 123±10 vs. 118±11), diastolic blood pressure (DBP, 79±7 vs. 74±7) and mean blood pressure (MBP, 93±8 vs. 89±9) were different between the exposed group and the control group (p < 0.01). After adjusting for covariates, the difference was still significant. Besides, isopropyl alcohol and smoking had an interactive effect on DBP and MBP (p < 0.05). Furthermore, we observed a mediated effect of 5-hydroxyindole acetic acid (5-HIAA) on isopropyl alcohol exposure induced arterial blood pressure increase, which accounted for about 25%. Conclusions Our results suggest that low level isopropyl alcohol exposure is a potential risk factor for the increased arterial blood pressure and 5-HIAA partly mediates the association between low level isopropyl alcohol exposure and arterial blood pressures.

Mixed vapour identification using partition column-QCMs and Artificial Neural Network

Abstract: This Paper presents the identification of mixed vapour using electronic nose system composed of Quartz Crystal Microbalance (QCM) sensor array and a partition column of gas chromatography. The polymer coated QCMs produced a specific frequency shift. The data set was processed by an Artificial Neural Network using Backpropagation algorithm as a pattern recognition. The result showed that this equipment was able to identify five types of vapours namely benzene, acetone, isopropyl alcohol, non-polar and polar mixture (i.e. benzene and acetone), and also polar and polar mixture (i.e. isopropyl alcohol and acetone) with the identification rate of 96%.

Antimicrobial activity of Butyl acetate, Ethyl acetate and Isopropyl alcohol on undesirable microorganisms in cosmetic products

Abstract: Objective The microbiological contamination risk of a cosmetic product has to be assessed by the manufacturer, according to the composition, to determine whether microbiological testing is required. Certain ingredients in cosmetic formulations help to create an environment hostile towards microbial growth. In this study, the influence on microbial survival of some solvents used in nail varnishes was evaluated. The purpose of this study was two-fold. The first was to define the thresholds to be considered for the exemption of products from microbiological testing. The second was to assess the cross-contamination risk linked to the use on successive consumers of solvent-based products in beauty salons. Methods Strains of Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans and Trichophyton rubrum were exposed to various concentrations of ethyl acetate, butyl acetate and isopropyl alcohol in culture medium to estimate their MIC (minimum inhibitory concentration). These strains are relevant to cosmetic products as they are associated with skin and nail infections. Mixtures of the three solvents, which are characteristic of nail varnish compositions, were also tested for their cidal activity. Results Ethyl and butyl acetates had a stronger impact than isopropyl alcohol: the MIC of ethyl and butyl acetate is ≤5% for all of the tested strains, whereas that of isopropyl alcohol is ≤10%. Various combinations of the three solvents tested showed a significant effect on both fungal and bacterial strains (greater than 3 log reduction in 15 min for the bacterial test strains and in 30 min for T. rubrum). Conclusion Products containing more than 5% ethyl or butyl acetate or more than 10% isopropyl alcohol are hostile towards microbial growth. These products can therefore be considered as microbiologically low risk during both production and use, and so do not require microbiological testing (challenge test and end-product testing). Moreover, the nine tested mixtures of these three solvents – which are characteristic of nail varnish compositions – all have a high cidal activity on the tested strains within a short time. The risk of cross-contamination can therefore be considered as controlled when the nail varnishes are applied on successive clients in beauty salons.

Solubility of 1,3,5-Benzenetricarboxylic Acid in Different Solvents

Abstract: The solubility of 1,3,5-benzenetricarboxylic acid in pure water, isopropyl alcohol, isobutyl alcohol, methanol, ethanol, and ethylene glycol were measured at the temperature range from 298 to 360 K. The order of solubility of 1,3,5-benzenetricarboxylic acid was ethanol > methanol > ethylene glycol > isobutanol > isopropyl alcohol > water. In addition, the Apelblat equation was used to correlate the solubility with temperature in different solvents.

Solid–Liquid and Solid–Liquid–Liquid Equilibria in the KI+H2O+i-C3H7OH Ternary System within 10–120°C

Abstract: The solubility of components, phase equilibria, and critical phenomena in the ternary potassium iodide (KI) +water (H2O) +isopropyl alcohol (i-C3H7OH) system were studied in the range of 10–120°C by the visual polythermal method. Potassium iodide was found to have a salting-out effect at temperatures above 97.0°C, and homogeneous water–isopropanol solutions were delaminated. The formation temperature of the critical tie line of the monotectic state (97.0°C) and the compositions of the solutions corresponding to the critical liquid–liquid solubility points at 104.2, 110.1, 115.6, and 120.1°C were determined. The distribution coefficients of isopropyl alcohol between the organic and aqueous phases in the monotectic state at 100.0, 110.0, and 120.0°C were calculated. The salting-out effect of potassium iodide relative to isopropyl alcohol from aqueous solution is small (the distribution coefficient Kd of isopropanol is 1.8 at 100.0°C) and slightly increases with temperature (Kd is 3.4 at 120.0°C).

Solid–Liquid Phase Equilibrium of trans-Cinnamic Acid in Several Alcohols: Measurements and Thermodynamic Modeling

Abstract: The solubilities of trans-cinnamic acid (t-CA) in methanol, ethanol, propanol, n-butanol, isopropyl alcohol, and isobutyl alcohol were measured by a synthetic method at temperatures ranging from (283.15 to 333.15) K. The modified Apelblat equation, the λh equation, and activity coefficient models (nonrandom two-liquid, NRTL; universal quasichemical, UNIQUAC) were used to correlate these data. It was found that all of the models show good agreement with the experimental data, and the modified Apelblat equation and NRTL model give better correlation results. Furthermore, on the basis of the NRTL model and experimental data, the thermodynamic excess functions (GE, SE, HE) of t-CA + alcohols (methanol, ethanol, propanol, n-butanol, isopropyl alcohol, and isobutyl alcohol) system were determined.