Showing papers on "Methyl isobutyl ketone published in 2006"

Liquid-liquid equilibria for the ternary system methyl isobutyl ketone + water + hydroquinone

Abstract: Experimental liquid−liquid equilibria data of dilute hydroquinone concentration were determined for the ternary system methyl isobutyl ketone + water + hydroquinone at (25, 40, and 50) °C under atmospheric pressure. The experimental data were satisfactorily correlated with the UNIQUAC equation and the NRTL equation. The relative root-mean-square deviations and absolute mean deviations between the calculated and the experimental value are less than 1.2 %.

Preparation and characterization of organic–inorganic hybrid composites based on multiepoxy silsesquioxane and cyanate resin

Abstract: A multiepoxy cubic silsesquioxane was prepared by the hydrolysis and polycondensation of trifunctional monomer (γ-glycidoxypropyl)trimethoxysilane in a solvent mixture of methyl isobutyl ketone and anhydrous ethanol with a tetraethyl ammonium hydroxide aqueous solution acting as the catalyst, and it was successfully introduced into a cyanate resin and formed highly crosslinked organic–inorganic hybrid composites on a molecular level via a mutual cure reaction. The properties of the multiepoxy cubic silsesquioxane/bisphenol A dicyanate ester resin composites were investigated, and the results showed that introducing the cubic silsesquioxane unit into the cyanate resin successfully modified the local structure of the molecule, made the chain more rigid, restricted the chain mobility, and eventually improved the thermal stability and flame retardancy of the resin. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3652–3658, 2006

Dehydrogenation and condensation in catalytic conversion of iso-propanol over CuO/MgO system doped with Li2O and ZrO2

Abstract: The effects of Li 2 O and ZrO 2 -doping on the surface and catalytic properties of CuO/MgO system have been investigated. The dopant concentration was changed between 0.6 and 3.6 mol% Li 2 O and that of ZrO 2 between 2.4–7.7 mol%. Pure and variously doped solids were calcined at 673 and 773 K. The techniques employed for characterization of different solids were XRD, nitrogen adsorption at 77 K and catalytic conversion of iso -propanol at different reaction temperatures ranged between 423 and 573 K. The results revealed that the addition increasing amounts of dopant (Li 2 O and ZrO 2 ) to CuO/MgO solid led to an increase in the degree of dispersion of CuO phase and a decrease in the specific surface areas of the investigated solids. Li 2 O and ZrO 2 -doping increases the catalytic conversion of iso -propanol, which proceeds mainly via dehydrogenation to give acetone and aldol condensation of the produced acetone to give methyl isobutyl ketone (MIBK). Doping with 1.2 mol% Li 2 O for the solids calcined at 673 K increases both of total conversion and selectivity to MIBK at reaction temperature 473 K with 24% and 25%, respectively. Doping with 7.7 mol% ZrO 2 for the investigated solids calcined at 673 K increases both of total conversion and selectivity to MIBK at reaction temperature 473 K with 32% and 99%, respectively.

Synthesis of methyl isobutyl ketone from acetone over metal-doped ion exchange resin catalyst

Abstract: The kinetics of one-step synthesis of methyl isobutyl ketone from acetone was studied in the presence of the bifunctional commercial ion exchange resin, Amberlyst CH28 over a wide range of temperature, total pressure and catalyst loading in a batch reactor. An activity-based kinetic model is proposed to predict the observed results, with the non-idealities of the liquid phase being described using the UNIQUAC method. Formation of mesityl oxide was found to govern the overall rate of reaction. Low reaction rates were observed at higher conversion, possibly due to a pseudo-equilibrium caused by reversible deactivation of the catalyst as a result of formation of water in the reaction system. Simultaneous removal of water during the course of the reaction may result in an enhanced conversion.

Performance and Microbial Diversity of a Trickle‐Bed Air Biofilter under Interchanging Contaminants

Abstract: A trickle-bed air biofilter (TBAB) was evaluated under conditions of interchanging the feed volatile organic compounds (VOCs) in the sequence methyl ethyl ketone (MEK), toluene, methyl isobutyl ketone (MIBK), styrene, and then back to MEK. The obtained performance results revealed that the biofilter provided high removal efficiency within the critical loading of each VOC, which was previously defined in the non-interchanging VOC fed biofilter. The biofilter easily acclimated to the oxygenated compounds (MEK and MIBK), but re-acclimation was delayed for the aromatic compounds (toluene and styrene). Ratios of the molar mass of CO2 produced per molar mass of VOC removed were investigated. It has been found that the ratios for the aromatic compounds closely resembled the theoretical complete chemical oxidation based ratios while larger differences were encountered with the oxygenated compounds. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA genes was used to assess the impact of interchanging VOCs on the bacterial community structure in the biofilter. The results from denaturing gradient gel electrophoresis (DGGE) showed that the structure of the microbial community in the biofilter was different after each interchange of VOCs.

Optimisation of the derivatization in cellulose-type chiral selectors for enantioseparation by centrifugal partition chromatography.

Abstract: Cellulose was chemically modified with hydrophobic dodecanoyl groups followed by 3,5-dimethylphenylcarbamoyl substituents forming mixed ester/carbamate derivatives in order to improve the solubility in lipophilic solvents compared to the corresponding homosubstituted cellulose tris(3,5-dimethylphenylcarbamate). Two mixed derivatives of different degree of substitution were prepared, tested as chiral selectors (CSs) in counter-current chromatography (CCC) and compared to the homo-substituted derivative. Alternatively, cellulose tris(3,5-dichlorophenylcarbamate), was synthesised and tested with the same purpose. The racemic drugs pindolol and warfarin were used as test compounds. Biphasic organic/aqueous solvent systems, composed of methyl isobutyl ketone, t-butyl methyl ether or ethyl acetate and aqueous ammonium acetate or sodium phosphate buffer, were used. Centrifugal partition chromatography, a variety of CCC, in the classical elution mode and the pH-zone-refining displacement mode was applied. The enantioseparation of pindolol and warfarin was achieved in the latter conditions. The presence of dodecanoyl chains on the CS increased solubility in the organic solvents used. The selectivity of the mixed dodecanoyl/3,5-dimethylphenylcarbamoyl cellulose derivative with low degree of dodecanoyl groups (degree of substitution 0.3/degree of substitution 2.6, respectively) was similar to that of the homo-substituted derivative. Furthermore, the loading capacity for pindolol was increased by a factor of three compared to cellulose tris(3,5-dimethylphenylcarbamate). Nevertheless, the increasing degree of substitution with dodecanoyl groups on the CS, although improved solubility in the stationary phase, contributed negatively to the enantioselectivity, where warfarin was more affected than pindolol.

A hydrotalcite-based catalyst system for the single-stage liquid-phase synthesis of MIBK

Abstract: A comparative study was performed between Pd supported on activated hydrotalcites bi-functional catalysts and physical mixtures of activated hydrotalcites with Pd supported on carbon nanofibers for the single-stage liquid-phase synthesis of methyl isobutyl ketone from acetone and H2 Since it was found earlier that the dehydration reaction of diacetone alcohol over activated hydrotalcites is the rate-determining step in this process, Mg–Al hydrotalcites were investigated in the condensation of acetone to diacetone alcohol and its dehydration to mesityl oxide to enhance the activity A correlation between the number of active base sites, as determined by volumetric CO2 adsorption measurements at low pressures, and the activity in the dehydration reaction could be derived A dependency on the Pd-loading (0–1 wt%) of Pd supported on activated hydrotalcites catalysts was found in the single-stage synthesis of methyl isobutyl ketone, whereas no such an effect was found when using physical mixtures of activated hydrotalcites with Pd on carbon nanofibers Results from TEM, CO2 chemisorption and N2 physisorption as well as catalytic experiments in the hydrogenation of mesityl oxide and of cyclohexene indicate that this dependency is largely accounted for by entrapment of Pd particles in the agglomerates of the irregular stacks of hydrotalcite platelets, making these sites inaccessible for the reactants

Solvent sublation and spectrometric determination of Iron(II) and total iron using 3-(2-pyridyl)-5,6-bis(4-phenylsulfonic acid)-1,2,4-triazine and tetrabutylammonium bromide

Abstract: Solvent sublation has been studied for the separation and determination of trace iron(II) in various kinds of water samples. A strongly magenta-colored anionic [Fe(FZ)3](4-) complex was formed at pH 5.0 upon adding 3-(2-pyridyl)-5,6-bis(4-phenylsulfonic acid)-1,2,4-triazine (ferrozine, FZ) to the sample solution. Tetrabutylammonium bromide (TBAB) was added in the solution to form the (TBA)4[Fe(FZ)3)] ion pair, and an oleic acid (HOL) surfactant was added. Then, the (TBA)4[Fe(FZ)3] ion pairs were floated by vigorous shaking in the flotation cell and extracted into methyl isobutyl ketone (MIBK) on the surface of the aqueous solution. The iron collected in the MIBK layer was measured directly by spectrophotometry and/or flame atomic-absorption spectrophotometry. Different experimental variables that may affect the sublation efficiency were thoroughly investigated. The molar absorptivity of the (TBA)4[Fe(FZ)3] ion pair was 2.8 x 10(4) l mol(-1) cm(-1) in the aqueous layer. Beer's law held up to 1.0 mg L(-1) Fe(II) in the aqueous as well as in the organic layers. The adopted solvent sublation method was successfully applied for the determination of Fe(II) in natural water samples with a preconcentration factor of 200. The application was extended to determine iron in pharmaceutical samples.

Interactions of Hydrophobic and Hydrophilic Solvent Component Degradation in an Air-Phase Biotrickling Filter Reactor

Abstract: Interactions amongst the degradation rates of toluene, xylenes, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and n-butyl acetate (n-BA) were investigated. Experiments were performed in a biotrickling filter reactor packed with polypropylene Pall rings in a counter-current air-water mode of operation. Under pseudo-steady-state conditions, the removal efficiency (RE) of the individual components in the middle of and at the effluent above the reactor bed was evaluated. By using a mixed microbial culture as the biocatalyst, the results revealed that an increased loading of toluene and xylene had a competitive effect on the RE of MIBK. After reaching a saturation point of the overall catabolic capacity of the biocatalyst, variations of RE were observed for the different components. This was most pronounced under conditions of overloading with the water-soluble components mixture. Despite such variations, the system was able to efficiently degrade this complex pollutant mixture for a period of 1 yr.

Measurements of Quaternary Liquid-Liquid Equilibrium for Water + Acetic Acid + Propionic Acid + Solvent (Butyronitrile, Benzyl Acetate, or Methyl Isobutyl Ketone) at 298.15 K

Abstract: Liquid−liquid equilibrium data of water + acetic acid + propionic acid + solvent (butyronitrile, benzyl acetate, and methyl isobutyl ketone (MIBK)) quaternary systems were measured. Complete phase diagrams were obtained by determining solubility curves and tie-line data at 298.15 K. The experimental data were compared with predicted values obtained from the UNIFAC method. Selectivity values for solvent separation efficiency were derived from the tie-line data. A comparison of the extracting capabilities of the solvents was made with respect to distribution coefficients, separation factors, and solvent-free selectivity bases. The reliability of the data was ascertained from Othmer−Tobias plots. We conclude that the performance of the solvents increases in the order of butyronitrile, MIBK, and benzyl acetate.

Performance of Trickle-Bed Air Biofilter: A Comparative Study of a Hydrophilic and a Hydrophobic Voc

Abstract: Two lab-scale trickle-bed air biofilters were operated for investigating the difference in performance between a hydrophilic and a hydrophobic volatile organic compound (VOC) Methyl isobutyl ketone (MIBK) and styrene were selected as a model hydrophilic and hydrophobic VOCs, respectively Effects of loading rates, biofilter re-acclimation, removal profile along biofilter depth, nitrogen consumption, and CO2 production were compared under three operating conditions, namely, backwashing and two non-use periods (starvation and stagnant)

Gas-Phase Conversion of Acetone to Methyl Isobutyl Ketone over Bifunctional Metal/Carbon Catalysts. 2. Examination of the Hydrogenation Potential of Different Metals

Abstract: The single-stage self-condensation and subsequent hydrogenation of acetone to methyl isobutyl ketone (MIBK) in the gas phase was carried out using catalysts consisting of hydrogenating metals supported on active carbon (Me/C). The reaction was conducted in a continuously operated, ideally backmixed Berty reactor at 1 MPa and 623 K. Platinum, palladium, nickel, and copper were applied as metal components, and their hydrogenation activity decreased in the order Pt > Pd > Ni > Cu. The impact of the hydrogenation reactions in the reaction network can also be enhanced by increasing the molar ratio of hydrogen to acetone in the feed, and by raising the metal content of the Me/C catalysts. A low hydrogenation activity negatively affects the acetone conversion and promotes the production of mesityl oxide. Hydrogenation conditions being too severe may favor the unwanted hydrogenation of acetone to 2-propanol and of MIBK to methyl isobutyl carbinol, but this effect is less detrimental to the MIBK selectivity than an unsufficient hydrogenation activity. The best performance showed a Pt/C catalyst with 0.5% m/m Pt and a Ni/C catalyst with a higher Ni loading (2.71% m/m); the optimum H 2 /acetone feed ratio was 0.5, which is the stoichiometric value for the idealized formation of MIBK from acetone. Despite the higher metal content required, the Ni/C catalyst allows for a considerable reduction of the costs for catalyst production.

Method and apparatus for producing purified methyl isobutyl ketone

Abstract: This invention relates to a method of producing purified methyl isobutyl ketone (MIBK) comprising subjecting a feed stream containing MIBK and impurities to a first distillation procedure from which acetone is recovered. The bottom product of the first distillation procedure is fed to a liquid-liquid separator and an organic phase from the said liquid-liquid separator is fed to the top region of a second distillation column to produce an overhead product. The said overhead product is condensed and fed to the said liquid-liquid separator. A bottom product containing MIBK is withdrawn from the second distillation column. This bottom product is fed to a third distillation column, high boiling impurities are withdrawn as a bottom product, and purified MIBK is also withdrawn. The invention also relates to an apparatus used in such a method.

Gas-Phase Conversion of Acetone to MIBK over Bifunctional Metal/Carbon Catalysts. I. Investigation of the Acid−Base Sites

Abstract: Platinum supported on active carbon (Pt/C) is introduced as a novel kind of catalyst for the single-stage self-condensation and subsequent hydrogenation of acetone to methyl isobutyl ketone (MIBK) in the gas phase. The reaction was conducted in a continuously operated, backmixed Berty reactor at 1 MPa and 623 K. The nature of the acid−base sites catalyzing the aldol condensation was investigated by artificial alteration of the active carbon surface chemistry through oxidative pretreatments. Unexpectedly, the oxygen functional groups on the carbon surface were found to be of minor importance for the catalytic performance. Rather, there are strong indications that certain mineral components such as alkaline earth oxides and hydroxides embedded and finely dispersed within the carbon structure might be responsible for the activity in the aldol condensation. The main advantage of the Pt/C catalysts under investigation refers to their excellent stability in prolonged catalytic runs.

Copper catalyst for vapor catalytic dehydrogenation of methyl isobutyl alcohol and its preparation process and application method

Abstract: The copper catalyst for vapor catalytic dehydrogenation of methyl isobutyl alcohol is prepared with the materials including Cu(NO3)2.3H2O 5-10 weight portions, Zn(NO3)2.6H2O 1-10 weight portions, Al(NO3)3.9H2O 1-5 weight portions and alkaline carbonate precipitant 5-20 weight portions, and through co-precipitation and roasting formation. The copper catalyst is used in dehydrogenating methyl isobutyl alcohol to prepare methyl isobutyl ketone in tubular fixed bed reactor. The copper catalyst has relatively high dehydrogenating stability and relatively long service life; results in relatively low reaction temperature of dehydrogenating methyl isobutyl alcohol to synthesize methyl isobutyl ketone, single pass conversion of 60-82 %, selectivity of 96-99 %, multiple pass conversion over 99 % and multiple pass reaction selectivity over 98 %; and may be used in industrial production.

Ultrasonic velocities and isentropic compressibilities of N-methyl-2-pyrrolidone with ketones and branched alcohols at 303.15 K

Abstract: The ultrasonic sound velocities and densities are measured for the binary mixtures of N-methyl-2-pyrrolidone (NMP) with ketones and branched alcohols at 303.15 K. The ketones include methyl ethyl ketone, methyl propyl ketone, diethyl ketone, methyl isobutyl ketone and cyclohexanone. The branched alcohols include 2-propanol, 2-methyl-1-propanol, 3-methyl-1-butanol, 2-butanol and 2-methyl-2-propanol. The ultrasonic sound velocity data were used to compute isentropic compressibilities (k s). The deviations in the value of k s from ideal value were computed. Except cyclohexanone all the binary mixtures formed by NMP with ketones at 303.15 K exhibit negative deviation from ideal behaviour over the entire range of composition. Cyclohexanone with NMP exhibit positive deviation over the entire range of composition. An inversion in the sign of Δk s from positive to negative was observed for 2-propanol system and negative deviation was observed in four binary mixtures formed by NMP with other branched alcohols at 3...

Zinc Isotope Separation by Phenol Formaldehyde Type 15-Crown-5 Resin in Organic Solvents

Abstract: Zinc adsorption and isotope separation by newly synthesized benzo-15-crown-5 resin was evaluated using various solvents. This resin was synthesized in the pores of silica beads for chromatography use. Larger adsorption of zinc was obtained in the case of acetic acid derivatives than in protic solvent such as water and alcohol by the batch treatment. The displacement chromatography was conducted to study zinc isotope separation. The isotope separation coefficient e=0.32×10 -3 , 0.69×10 -3 and HETP=0.2268, 0.3968 cm were determined for isotopic pair of 68 Zn/ 64 Zn at 25°C by five meters migration experiment using methyl isobutyl ketone and acetic acid, respectively. The improvement of enrichment ratio is very small between 1 and 5 m migration. Hydrogen chloride and/or water obviously reduce zinc adsorption to this resin.

High efficient corrosive-proof paint

Abstract: The invention discloses high active anticorrosive paint. Its material includes bisphenol A diglycidyl ether, epoxy resin with 371 equivalent weight, bisphenol A, N-methylethanolamine, and methyl isobutyl ketone, multi- isocyan phenolic ester, talc, and coat tar. It can effectively solve the current metal corrosion problem, and can play the action of protection against corrosion for hardware.

Selective Extraction of Mercury(II) by 1-Naphthylthiourea-Methyl Isobutyl Ketone System

Abstract: Selective extraction of Mercury(II) using 1‐naphthylthiourea–methyl isobutyl ketone (ANTU‐MIBK) system from hydrochloric acid solutions (0.1–10 M) has been studied. Influence of foreign ions, acid and ligand concentrations has been investigated. Addition of ANTU in MIBK enhanced, extraction capacity of MIBK to several times. Low effect of foreign ions and high separation factors for a number of metal ions determined at 0.5 M hydrochloric acid concentration evaluated the proposed method efficient and selective. The experimental data obtained from application of the method for extraction of mercury from a synthetic aqueous solution reveal that more than 99% mercury can be separated from cadmium, zinc and selenium in a single step with five minutes equilibration.

Improvement of separation process of synthesizing MIBK by the isopropanol one-step method

Abstract: The separation process of synthesizing MIBK (methyl isobutyl ketone) by an isopropanol one-step method, in which the multi-component mixture contains AC (acetone), IPA (isopropanol), water, MIBK, MIBC (methyl isobutyl carbinol), DIBK (di-isobutyl ketone), etc., was studied. As a high-purity of MIBK over 99.5 wt% is required in industry, the development of an effective separation method is urgent. In this work, first, by means of VLE (vapor-liquid equilibrium) experiments and PROII simulation, the possible azeotropes formed in the investigated system were tested. Then, the separation process was simulated with the result that the calculated and designed values were in good agreement, which indicated that the calculated results were reliable. On this basis, the original separation process was improved. In the original separation process, the yield of MIBK for a concentration of MIBK over 99.5 wt% was small, only 32.5%. In the improved separation process (step two), two columns (one extractive distillation column and the other solvent recovery column) were added and some simplification was made so as to recycle MIBK. In this case the yield of MIBK was 91.7%. Moreover, about 27.6% water stream per kilogram MIBK product is saved.