Showing papers on "Acetone published in 1992"
TL;DR: In this article, photocatalyzed degradations of trace levels of various oxygenates and an aromatic in air were carried out using near-UV-illuminated titanium dioxide (anatase) powder.
498 citations
TL;DR: In this paper, a polymer nanoparticles were prepared as aqueous dispersions using an emulsion technique involving a salting-out process which avoids surfactants and chlorinated solvents.
205 citations
TL;DR: The interaction between volatile aromas and non-volatile compounds was studied by two techniques coupled with gas chromatography as mentioned in this paper, which showed that there exist interactions which depend on the nature of the volatile and nonvolatile compound and on the water content: for instance, the activity coefficient (measured by headspace analysis) of acetone and ethyl acetate in solution at infinite dilution increases in the presence of glucose.
121 citations
04 Oct 1992
TL;DR: In this paper, the decomposition performance of surface induced plasma chemical processing (SPCP) for chlorofluorocarbon (83 ppm CFC-113 in air), acetone, trichloroethylene, and isopropylalcohol was experimentally examined.
Abstract: The decomposition performance of the surface induced plasma chemical processing (SPCP) for chlorofluorocarbon (83 ppm CFC-113 in air), acetone, trichloroethylene, and isopropylalcohol was experimentally examined. In every case, very high decomposition performance, more than 90 or 99% removal rate, is realized when the residence time is about 1 second and the input electric power for a 16 cm/sup 3/ reactor is about 10 W. Acetone is the most stable compound and alcohol is most easily decomposed. The decomposed product-analysis by a gaschromato-massspectrometer has just started but very poor results are obtained. In fact, some portion of the isopropylalcohol may change to acetone which is worse than alcohol. The necessary energy to decompose one mol gas diluted in the air is calculated from the experiments. The necessary energy level for acetone and trichloroethylene is about one-tenth or one-fiftieth of that for chlorofluorocarbon.
97 citations
TL;DR: In an effort to improve the viability of acetone-butanol-ethanol fermentation by extractive fermentation, 63 organic solvents, including alkanes, alcohols, aldehydes, acids, and esters, were experimentally evaluated for biocompatibility with Clostridium acetobutylicum as discussed by the authors.
Abstract: In an effort to improve the viability of acetone-butanol-ethanol fermentation by extractive fermentation, 63 organic solvents, including alkanes, alcohols, aldehydes, acids, and esters, were experimentally evaluated for biocompatibility with Clostridium acetobutylicum by observing gas evolution from cultures in contact with candidate solvents. Thirty-one of these solvents were further tested to determine their partition coefficient for butanol in fermentation medium. The biocompatible solvent with the highest partition coefficient for butanol (4.8), was poly(propylene glycol) 1200, which was selected for fermentation experiments. This is the highest partition coefficient reported to date for a biocompatible solvent. Extractive fermentations using concentrated feeds were observed to produce up to 58.6 g·l−1 acetone and butanol in 202 h, the equivalent of three control fermentations in a single run. Product yields (based on total solvent products and glucose consumed) of 0.234 g·g−1 to 0.311 g·g−1 and within run solvent productivities of 0.174 g·l−1·h−1 to 0.290 g·l−1·h−1 were consistentwith conventional fermentations reported in the literature. The extended run-time of the fermentation resulted in an overall improvement in productivity by reducing the fraction of between-run down-time for fermentor cleaning and sterilization.
93 citations
TL;DR: Aqueous perfluorooctanoate (PFOA−) solution of water-miscible organic solvent (SOLV), such as dioxane and acetone, was separated into two immiscible phases reversibly by charge neutralization of PFOA ion with proton (H+) (pKa value of HPFOA was 1.01, atI = 0.1, 20 °C).
Abstract: Aqueous perfluorooctanoate (PFOA−) solution of water-miscible organic solvent (SOLV), such as dioxane and acetone, was separated into two immiscible phases reversibly by charge neutralization of PFOA− ion with proton (H+) (pKa value of HPFOA was 1.01, atI = 0.1, 20 °C). The transparent heavier phase, in which HPFOA was concentrated quantitatively, consisted of three components in the molar ratio of HPFOA∶SOLV∶H2O = 1∶4.0∶6.6 for acetone system, and 1∶0.47∶1.9 for dioxane system, respectively. This separation provides a new homogeneous liquid-liquid extraction method, which can be successfully applied to the ultra-high preconcentration of water-soluble porphyrin compounds: 104-fold concentration was achieved within 20 min.
88 citations
TL;DR: Secondary alcohols are readily converted to ketones under mild conditions by acetone in the presence of a catalytic amount of RuCl2(PPh3)3; in some cases the reaction is co-catalysed by acetophenone.
Abstract: Secondary alcohols are readily converted to ketones under mild conditions by acetone in the presence of a catalytic amount of RuCl2(PPh3)3; in some cases the reaction is co-catalysed by acetophenone.
59 citations
TL;DR: In this article, the authors investigated the formation of acetone from 2-propanol and Rh(111)-p(2 × 1)-O using temperature programmed reaction and X-ray photoelectron spectroscopy and isotopic labeling experiments under ultrahigh vacuum conditions.
48 citations
TL;DR: In this paper, a chemical heat pump, based on the reversible reaction couple of the i-propanol-acetone system, was investigated experimentally, and the optimal design specifications for the chemical heat-pump were determined.
Abstract: A chemical heat pump, based on the reversible reaction couple of the i-propanol-acetone system, was investigated experimentally. The endothermic dehydrogenation of i-propanol occurred at 80°C with a Raney nickel catalyst suspended in the liquid phase. The unreacted i-propanol was separated from gaseous products in a condenser. The exothermic hydrogenation reaction of the acetone was performed at 200°C and 1atm, in the presence of the Raney nickel catalyst. The positive value (ΔG) of the change of Gibbs free energy can make the dehydrogenation reaction of i-propanol rather difficult. This problem can, though, be overcome by the continuous removal of gaseous acetone and hydrogen products from the reaction medium. The dehydrogenation rate equation of i-propanol was obtained as V = 0.1 Cp/(1 + 7.0 CA). The gas phase hydrogenation reaction of acetone was performed in an exothermic tubular reactor. In order to estimate energy efficiency, a simulation of the separation stage was performed. Based on these experimental and simulation results, the optimal design specifications for the chemical heat pump were determined. The maximum hydrogenation of acetone was obtained when the mole ratio of acetone to hydrogen was 4.0. Energy efficiency was increased when the conversions of hydrogenation and dehydrogenation increased.
45 citations
TL;DR: In this paper, the stability of 10 selected polar organic compounds in canisters was investigated and the results are described in this paper, and two nonpolar compounds, methyl chloroform and toluene, shown to be stable in previous work were included in the stability study as controls.
Abstract: Because of considerable interest at US EPA for the collection of polar organic compounds in stainless steel canisters, particularly for the Toxic Air Monitoring Site (TAMS) study, the stability of 10 selected polar organics in canisters was investigated and the results are described in this paper. The polar organic compounds selected for this stability study were: methanol, acetone, isoprene, acrylonitrile, vinyl acetate, methyl ethyl ketone, t-butyl methyl ether, ethyl acetate, n-butanol, and ethyl acrylate. Two nonpolar compounds, methyl chloroform and toluene, shown to be stable in previous work were included in the stability study as controls. The compounds were loaded in unpolished and Summa-polished canisters at parts-per-billion (ppb) levels under dry and humid conditions. The canister samples were analyzed on Days 0, 1, 3, 4, 14, and 31 after loading. The experimental procedures and stability results are summarized briefly.
44 citations
TL;DR: The reaction of ferriosilanols Cp(CO)(L)Fe-SiR2H (R = Me, t-Bu, Ph, o-Tolyl; L = CO, Ph3P) 1a-e with dimethyldioxirane (as an acetone solution) leads directly to the corresponding ferriOSilanols in moderate to excellent yields.
Abstract: The reaction of ferriohydridosilanes Cp(CO)(L)Fe–SiR2H (R = Me, t-Bu, Ph, o-Tolyl; L = CO, Ph3P) 1a–e with dimethyldioxirane (as an acetone solution) leads directly to the corresponding ferriosilanols Cp(CO)(L)Fe–SiR2OH 2a–e in moderate to excellent yields.
TL;DR: Secondary alcohols are rapidly oxidized to ketones by a solution of trichloroisocyanuric acid in acetone as discussed by the authors, which is known as TOCA.
TL;DR: In this paper, photocatalyzed degradations of trace levels of various oxygenates and an aromatic in air were carried out using near-UV-illuminated titanium dioxide (anatase) powder.
Abstract: Photocatalyzed degradations of trace levels of various oxygenates and an aromatic in air were carried out using near-UV-illuminated titanium dioxide (anatase) powder. The initial rates of degradation for acetone, 1-butanol, formaldehyde, and m-xylene were well described by Langmuir-Hinshelwood rate forms. No reaction intermediates were detected for acetone oxidation at conversions of 5–20%. Butyraldehyde was the main product of 1-butanol oxidation for conversions of 20–30%. The influence of 5% water (simulating partial humidification) in the feedstream varied strongly: water vapor inhibited acetone oxidation, but had no influence on the 1-butanol conversion rate. m-Xylene conversion was enhanced by trace water addition, but inhibited at higher water levels. Some catalyst deactivation was detected between 1-butanol runs; the activity could be easily recovered by illuminating the catalyst in fresh air. Formaldehyde was also successfully oxidized. These results, taken together with earlier literature citations for photocatalyzed total oxidation of methane, ethane, trichloroethylene (but see (27)), toluene, and a very recent report for oxidation of odor compounds, indicate a favorable technical potential for photocatalyzed treatment of air in order to degrade and remove all major classes of oxidizable air contaminants.
TL;DR: In this paper, a cyclic formation of alkaline earth acetate followed by decomposition was used to convert acetic acid selectively into acetone in a fixed-bed flow system.
Abstract: Silica-supported alkaline earth oxides revealed excellent activity to convert acetic acid selectively into acetone in a vapor-phase fixed-bed flow system. Acetone was obtained through the cyclic formation of alkaline earth acetate followed by decomposition. Magnesium oxide should be supported on the silica surface without formation of magnesium silicate, which was inactive for the present reaction. Attempted syntheses of benzophenone and acetophenone are also described.
TL;DR: In this paper, 3-Bromopropiolic esters are efficiently prepared by reaction of corresponding propiolic isters with N-bromosuccinimide in acetone and silver nitrate as catalyst.
TL;DR: In this paper, the performance of industrial phenol plant, cumene oxidation and gas liquid loop reactors have been studied at laboratory scale, both the kinetic and the fluid dynamics models were developed and combined to give the industrial reactor model.
TL;DR: Citric acid (CA) has successfully been separated from fermentation broth by a novel and unique purification process, which is characterized by organic solvent extraction and precipitation with compressed carbon dioxide (CO 2 ) as a poor solvent as discussed by the authors.
Abstract: Citric acid (CA) has successfully been separated from fermentation broth by a novel and unique purification process, which is characterized by organic solvent extraction and precipitation with compressed carbon dioxide (CO 2 ) as a poor solvent. After the filtration of microorganisms, the condensed fermentation broth of CA was dissolved in acetone. In this extraction, a certain amount of impurities (mainly sugar) could be separated as precipitates. Compressed CO 2 was then dissolved in the acetone solution of crude CA to remove the residual impurities as precipitates using the anti-solvent effect of CO 2 . The deposited impurities were readily separated from the acetone solution of CA by a settler. Finally, food additive grade CA was easily obtained by simple decolorization and crystallization methods. Also, CA crystals could be obtained by the anti-solvent crystallization with CO 2 . crystallization with CO 2 .
TL;DR: The reaction of phenol and acetone to give bisphenol-A (4,4′-isopropylidenediphenol) has been investigated using zeolite as catalysts as mentioned in this paper.
Abstract: The reaction of phenol and acetone to give bisphenol-A (4,4′-isopropylidenediphenol) has been investigated using zeolite as catalysts. The zeolites are less active and selective than the cation-exchange resin, Amberlyst-15.
TL;DR: In this paper, a high-performance liquid chromatographic analysis was applied to detect the dehydroellagitannins in the plant extract, and the reaction of the acetone condensates with L-cysteine methyl ester was examined.
Abstract: The dehydroellagitannins having a dehydrohexahydroxydiphenoyl ester group in the molecule were found to undergo highly regio- and stereospecific condensation with acetone in the presence of ammonium ion under almost neutral conditions. This reaction was successfully applied to high-performance liquid chromatographic analysis to detect the dehydroellagitannins in the plant extract. Furthermore, the reactions of the acetone condensates with L-cysteine methyl ester were examined, and appear to be applicable to structural studies of dehydroellagitannins.
TL;DR: In this article, the conversion of n-butanol/acetone mixtures to C 1 -C 10 hydrocarbons has been studied using ZSM-5 type zeolites with different Si/Al ratios as catalysts.
Abstract: The conversion of n-butanol/acetone mixtures to C 1 -C 10 hydrocarbons has been studied. ZSM-5 type zeolites with different Si/Al ratios were used as catalysts. The best results were obtained with a HZSM-5 zeolite (Si/Al=36), using a 30 wt% sodium montmorillonite as binder. The effect of operating conditions (space time, temperature and pressure) and the influence of water content of the feed on the reaction conversion have been studied
TL;DR: It is concluded that for ambient air particulates (but not emission samples) acetone may extract some mutagenic compounds which are not extracted by DCM, and the amount of these additional extractable compounds seems to depend on the composition of the sample.
Abstract: The mutagenic activities in the Salmonella/microsome assay of dichloromethane (DCM) and acetone extracts of complex environmental mixtures were compared. The particulate samples used in the IPCS collaborative study were Soxhlet-extracted twice with DCM followed by a third extraction with acetone. Compared with the mutagenic activity of the first extract, the third (acetone) extract of the urban particulate matter showed a relatively high mutagenic activity. In contrast to this the third extract of the diesel particulate matter contributed very little additional mutagenic activity. Furthermore, 10 filter samples of air particulates from a suburban airport area were collected for comparison of the extraction efficiency of DCM and acetone. Each sample was divided into two samples of identical size followed by extraction with acetone and DCM, respectively. No clear difference in the mutagenic activity of these extracts was observed in strains TA98 and TA98NR. It is concluded that for ambient air particulates (but not emission samples) acetone may extract some mutagenic compounds which are not extracted by DCM. The amount of these additional extractable compounds seems to depend on the composition of the sample. As DCM extracts are better suited for further fractionation and chemical analysis DCM is considered to be the best choice for a general solvent system for extraction of complex environmental mixtures.
TL;DR: The metastable zone width for aqueous solutions of itaconic acid and kojic acid was determined by the polythermic method in this paper, where the solubility of both compounds was investigated.
Abstract: The solubility of itaconic acid in water and kojic acid in water, acetone, and N,N-dimethylformamide, respectively, was determined from 0.5 to 69 o C. The metastable zone width for the aqueous solutions of both compounds was determined by the polythermic method
TL;DR: In this article, the effect of reducing the substrate temperature during the radio frequency plasma deposition of organic films was examined using static secondary ion mass spectrometry (SIMS) and showed that a reduction in substrate temperature generally results in higher intensity of peaks characteristic of oxygenated ion structures.
Abstract: Static secondary ion mass spectrometry (SIMS) was used to examine the effect of reducing the substrate temperature during the radio frequency plasma deposition of organic films. Studies of two polymerizable plasma precursors (2-hydroxyethyl methacrylate and acrylic acid) and one nonpolymerizable precursor (acetone) deposited without substrate cooling and with liquid nitrogen cooling are presented. Acetone deposited with methanol/dry ice cooling was also investigated. Spectra of polymerizable precursors were analyzed by comparison to spectra for the corresponding conventionally-polymerized polymer films [i.e., poly(hydroxyethyl methacrylate) and poly(acrylic acid)]. Acetone spectra were interpreted by reference to SIMS analysis of plasma-deposited films prepared from isotopically-labelled acetone and to reference homopolymers. Comparison of the SIMS spectra of films deposited at different substrate temperatures indicates that a reduction in substrate temperature generally results in higher intensity of peaks characteristic of oxygenated ion structures. SIMS also suggests that the reduction of substrate temperature results in less polymer unsaturation and fewer structures which form by hydrogen redistribution during the deposition process. These results support the hypothesis that deposition at low substrate temperatures leads to an increase in the proportion of precursor incorporated into the film without substantial fragmentation. Corroborative results from high resolution x-ray photoelectron spectroscopy (XPS) and assays for precursor functional groups by chemical derivatization reactions in conjunction with XPS are also presented. © 1992 John Wiley & Sons, Inc.
TL;DR: Carotenoids were extracted from fresh orange peel with various solvents as mentioned in this paper, and two successive extractions with acetone after an initial washing with either acetone or methanol were adequate to remove 89% of the total carotenoid.
Abstract: Carotenoids were extracted from fresh orange peel with various solvents. Acetone was the most efficient of the solvents tested. Two successive extractions with acetone after an initial washing with either acetone or methanol were adequate to remove 89% of the total carotenoids. The extracts were concentrated, the carotenoids transferred to hexane and a crude pigment concentrate was obtained by hexane evaporation. Water washings prior to acetone extraction eliminated the solvent-solvent transfer to hexane. The extraction residue was used for pectin recovery. Carotenoid removal from the peel did not affect the yield and quality of the pectin.
Patent•
14 Jul 1992
TL;DR: In this article, a bisphenol A is produced by reacting phenol with acetone containing methanol as an impurity component in the presence of a catalyst, methanols concentration in acetone is made <= 10,000ppm.
Abstract: PURPOSE:To produce 2,2-bis(4-hydroxyphenyl)propane(bisphenol A) while preventing deterioration of a cation exchange resin catalyst and prolonging the life of the catalyst. CONSTITUTION:In producing bisphenol A by reacting phenol with acetone containing methanol as an impurity component in the presence of a catalyst, methanol concentration in acetone is made <=10,000ppm. A reaction mixture is treated by a bisphenol A separating column 3, a fraction comprising acetone, phenol, water and methanol is taken out form the top of the column and the fraction is treated by an acetone separating column 6. Acetone from which methanol is removed is obtained from the top of the column, mixed with fresh acetone, made into 10,000ppm methanol concentration by weight and used as raw material acetone 11 to produce bisphenol A.
TL;DR: The strongest correlation was between the concentration of acetone in urine and the degree of exposure, which suggests that urinary acetone concentration is the best biological index of occupational exposure to acetone.
Abstract: Concentrations of acetone in urine, alveolar air, and blood were measured by gas chromatography with flame ionisation detection for 110 subjects occupationally exposed to acetone (mean 372 ppm) in three factories. Significant relations were found between the time weighted average environmental concentration and the concentration in the biological samples. The strongest correlation was between the concentration of acetone in urine and the degree of exposure (r = 0.71, 95% CI 0.64-0.77). This suggests that urinary acetone concentration is the best biological index of occupational exposure to acetone.
TL;DR: Acetonitrile is an excellent dehydrating agent whose use does not necessitate modification of current techniques and whose low solubility limits the loss of membrane lipids and leads to a better preservation of tissue features.
Abstract: Tissue processing for transmission electron microscopy (TEM) is commonly accomplished using ethanol (EtOH) as a dehydrating solvent and propylene oxide (PO) as a transition fluid. Both solvents have some undesirable properties: EtOH solubilizes lipids; PO is highly flammable, volatile, toxic, and potentially carcinogenic. Their replacement by a compound devoid of these characteristics is therefore desirable. Acetonitrile (AN) appears to be such a solvent. It is freely miscible with water, alcohols, acetone, and epoxy resins; it does not interfere with epoxy polymerization; and the resulting cured resins have excellent cutting quality and beam stability. AN is also an excellent dehydrating agent whose use does not necessitate modification of current techniques. Most importantly, the low solubility of phospholipids (PL) in AN limits the loss of membrane lipids and, hence, leads to a better preservation of tissue features.