Showing papers on "Acetone published in 1982"

Effect of pH and butyrate concentration on the production of acetone and butanol by Clostridium acetobutylicum grown in continuous culture

Abstract: When Clostridium acetobutylicum was grown in continuous culture under glucose limitation at neutral pH and varying dilution rates the only fermentation products formed were acetate, butyrate, carbon dioxide and molecular hydrogen. The Y glucose max and (Y ATP max ) gluc exp values were 48.3 and 23.8 dry weight/mol, respectively. Acetone and butanol were produced when the pH was decreased below 5.0 (optimum at pH 4.3). The addition of butyric acid (20 to 80 mM) to the medium with a pH of 4.3 resulted in a shift of the fermentation from acid, to solvent formation.

Continuous production of acetone and butanol by Clostridium acetobutylicum in a two-stage phosphate limited chemostat

Abstract: When Clostridium acetobutylicum was grown in continuous culture under phosphate limitation (0.74 mM) at a pH of 4.3, glucose was fermented to butanol, acetone and ethanol as the major products. At a dilution rate of D=0.025 h−1 and a glucose concentration of 300 mM, the maximal butanol and acetone concentrations were 130 mM and 74 mM, respectively. 20% of the glucose remained in the medium. On the basis of these results a two-stage continuous process was developed in which 87.5% of the glucose was converted into butanol, acetone and ethanol. The cells and minor amounts of acetate and butyrate accounted for the remaining 12.5% of the substrate. The first stage was run at D=0.125 h−1 and 37° C and the second stage at D=0.04 h−1 and 33° C. High yields of butanol and acetone were also obtained in batch culture under phosphate limitation.

Acetone Metabolism During Diabetic Ketoacidosis

Abstract: The presence and the importance of acetone and its metabolism in diabetic ketoacidosis has largely been ignored. Therefore, we studied acetone metabolism in nine diabetic patients in moderate to severe ketoacidosis. The concentration of acetone in plasma, urine, and breath, and the rates of acetone production and elimination in breath and urine were determined and the rates of vivo metabolism were calculated. Plasma acetone concentrations (1.55-8.91 mM) were directly related and were generally greater than acetoacetate concentrations (1.16-6.08 mM). The rates of acetone production ranged from 68 to 581 mumol/min/1.73 m2, indicating the heterogeneous nature of the patients studied. The average acetone production rate was 265 mumol/min/1.73 m2 and accounted for about 52% of the estimated acetoacetate production rate. Urinary excretion of acetone remained constant and accounted for about 7% of the acetone production rate in all patients. There was a positive linear relationship between the percentage of the acetone production rate accounted for by excretion in breath and the plasma acetone concentration. At low plasma acetone concentrations, approximately 20%, and at high plasma acetone concentrations, approximately 80% of the production rate was accounted for by breath acetone. In contrast, there was a negative linear relationship between the percentage of acetone production rate undergoing in vivo metabolism and plasma acetone concentration. At low plasma acetone concentrations, approximately 75%, and at high concentrations, approximately 20% of acetone production rate was accounted for by in vivo metabolism. Radioactivity from 2-[14C]-acetone was variably present in plasma acetone, glucose, lipids and proteins. No radioactivity was found in plasma acetoacetate, beta-hydroxy butyrate or free fatty acids or other anionic compounds. Exchange rates of acetone into other metabolites could not be estimated because of non-steady-state precursor product relationships in these patients.

High efficiency organosolv saccharification process

Abstract: Comminuted cellulosic materials which may or may not contain lignin are partially or totally hydrolyzed or saccharified by an improved organosolv process using an aqueous acetone solvent mixture containing a small amount of an acidic compound and containing at least about 70 percent by volume of acetone and up to virtually anhydrous acetone. The process is performed at elevated reaction temperatures, preferably at 145° C. to 230° C., for a limited period of time and then with cooling such that the resultant dissolved sugars from the hydrolysis are not degraded into non-sugars. In particular the reaction is conducted such that the cellulosic material is dissolved and such that at least ninety percent or more of available sugars in the cellulosic material are recovered. Unexpectedly it has been found that acetone at high concentration forms stable complexes with the sugars which prevents their degradation and also facilitates separation of the sugars. Lignin and sugars derived are commercially useful chemical compounds.

Molecular inclusion in functionalized macrocycles. Part 5. The crystal and molecular structure of 25,26,27,28,29-pentahydroxycalix[5]arene–acetone (1 : 2) clathrate

Abstract: A phenol–formaldehyde cyclic pentamer, 25,26,27,28,29-pentahydroxycalix[5]arene (1), has been isolated after dealkylation of a fraction of cyclic products from the base-catalysed reaction of p-(1,1,3,3-tetramethylbutyl) phenol and formaldehyde. This compound, which is the first cyclic product with an odd number of phenolic units isolated in such reactions, is able to form an inclusion complex (1 : 2) with acetone. The symmetry of the macrocyclic molecule is Cs and the acetone molecules interact with the OH crown and with the cavity with O ⋯ O and CH3–phenyl contacts respectively.

The structure ofcis-dichloro-bis-(triphenylphosphine)platinum(II); a product in the reaction ofcis-[PtCl2(CO)(PPh3)] with tin (II) chloride

Abstract: The reaction ofcis-[PtCl2(CO)(PPh3)] with two equivalents of SnCl2. 2H2O in acetone solution allows isolation ofcis-[PtCl2(PPh3)2] as the acetone solvate, the crystal structure of which has been determined. Crystals ofcis-[PtCl2(PPh3)2]·C3H6O are monoclinic, space groupP21/c (No. 14) with four formula units in a cell of dimensionsa=10.288(3),b=24.372(5),c= 15.367(3) A, /gb=98.07(2)°. The structure was solved by the heavy-atom method and refined by full-matrix least-squares calculations to a finalRof 0.033 for 3761 reflections withI>(I). The crystal structure contains discrete well-resolvedcis-PtCl2(PPh3)2 molecules with acetone of solvation filling cavities in the crystal structure. The Pt coordination is slightly distorted square-planar with Pt-Cl 2.333(2) and 2.356(2), Pt-P 2.251(2) and 2.265(2) A, P-Pt-P 97.8(1), and Cl-Pt-Cl 87.1(1)°.

Preparation of hydrogen peroxide

Abstract: Hydrogen peroxide is produced in a reaction between carbon monoxide, oxygen, and water in the presence of a solvent using a Group 8 noble metal as a catalyst. Especially preferred as the working solution is palladium chloride in acetone.

Process for the separation of sterols or mixtures of sterols

Abstract: The invention relates to a process for the isolation of sterols or sterol mixtures from unsaponifiable fractions of extractants of vegetable origin, especially from the neutral substance of crude soap from the sulphate cellulose process. According to the process, the neutral substance and a small amount of a suitable solvent which, depending on the desired composition of the product, preferably is methanol or a mixture of methyl ethyl ketone, are mixed, when required, while heating, the cooled mixture is filtered and the sterol precipitate obtained is washed with a suitable wash solvent, preferably acetone or a mixture of acetone and methanol. The sterol mixture prepared according to the invention and obtained when starting out from the unsaponifiables of crude soap obtained from raw wood comprising birch and using methanol as solvent contains about 5% campesterol, 65 to 80% β-sitosterol and 15 to 25% α-sitosterol. When using a mixture of methyl ethyl ketone and water as solvent, a product is obtained having a low α-sitosterol content (<5%), a campesterol content of 6 to 8% and a β-sitosterol content of 85 to 90%.

Ozonization of Organic Compounds. VI. Relative Reactivity of Protic Solvents toward Carbonyl Oxide

Abstract: Tetramethylethylene was ozonized at 0 °C in several binary protic solvents and the relative reactivities of the solvents toward acetone carbonyl oxide were measured. The reactivity was found to decrease in the order methanol, ethanol, propyl alcohol, isopropyl alcohol, water, t-butyl alcohol, and acetic acid.

Infrared Study of the Oxidation of 2–Propanol on TiO2

Abstract: Oxidation of 2-propanol on TiO2 was studied by infrared spectroscopy as well as analysis of reaction products. Propene and acetone are formed from isopropoxide species on TiO2. Only adsorbed acetone is oxidized to carbon dioxide via carboxylate species. Propene undergoes no oxidation.

Separation of acetone from methanol by extractive distillation

Abstract: Acetone cannot be completely removed from acetone-methanol mixtures by distillation because of the presence of the minimum boiling azeotrope. Acetone can be readily separated from methanol by using extractive distillation in which the extractive agent is a higher boiling oxygenated, nitrogenous and/or sulfur-containing organic compound or a mixture of two or more of these. Typical examples of effective agents are: Glycerine, 1,5-Pentanediol, Dimethylsulfoxide, n-Hexanol, Dioctyl phthalate and N,N-Dimethylacetamide.

Crystallization of amino acid

Abstract: PURPOSE: To separate the amino acids such as tryptophan, phenylalanine, etc. in high purity, by adding a lower alcohol or ketone to the crystallization stock solution of the amino acids, and neutralizing and crystallizing the amino acid from the alkaline side at a crystallization temperature about the transition point of the amino acid. CONSTITUTION: Tryptophan or phenylalanine is separated by the neutralizing crystallization of the anino acid from the alkaline side. The process is carried out by adding a lower alcohol (e.g. ethanol) or a ketone (e.g. acetone) to an alkaline solution of said amino acid, and neutralizing and crystallizing with H 2 SO 4 , etc. at a crystallization temperature of above the transition point of said amino acid (about 60°C for tryptophan and about 37°C for phenylalanine in an aqueous system). The addition of the lower alcohol, etc. is effective to give large and thick crystals which can be separated from the liquid easily, and can be purified easily by the removal of pigment and other impurities. The effect cannot be attained by the crystallization from the acidic side. COPYRIGHT: (C)1984,JPO&Japio

Increased acetone exhalation induced by metabolites of halogenated C1 and C2 compounds.

Abstract: Rats were exposed, in a closed desiccator jar chamber, to concentrations of various halogenated C1 and C2 compounds at which the metabolizing capacities were saturated (Vmax conditions). Within the exposure period of 50 h concentrations of the xenobiotic and of exhaled acetone were monitored in the gas phase of the system. The quantitative extent of acetone exhalation was dependent on the individual compound examined. Acetone exhalation was stimulated in presence of vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene fluoride, cis-and trans-1,2-di-chloroethylene, trichloroethylene, perchloroethylene, methylene chloride, chloroform, carbon tetrachloride and 1,1,2-trichloroethane. No stimulation of acetone exhalation occured with 1,1,1-trichloroethane and with the reference hydrocarbon n-hexane. Also, acetone exhalation was evoked by infusions of either fluoroacetate or chloroacetate, two anticipated or proven metabolites of some haloethylenes; the infusion rates of which were based on calculations of the metabolic rates of vinylidene fluoride and of vinyl chloride, respectively.

Method of preparing benzothiazepine derivatives

Abstract: A benzothiazepine derivative of the formula: ##STR1## wherein R is hydrogen or acetyl, is prepared by condensing a compound of the formula: ##STR2## wherein R is the same as defined above, with 2-(diamethylamino)ethyl halide (i) in the presence of potassium hydroxide in acetone; or (ii) in the presence of potassium carbonate in acetone, lower alkyl acetate, a mixture of acetone and water or a mixture of lower alkyl acetate and water.

Vapour-Liquid Equilibria and Excess Gibbs Free Energy in Binary Systems of Acetone with Aliphatic and Aromatic Hydrocarbons at 313 15 K

Abstract: Results of the total vapour pressure measurements performed at 313-15 K by a static method are reported for binary mixtures of acetone with five aliphatic hydrocarbons (hexane, heptane, octane, nonane, decane) and five aromatic hydrocarbons (benzene, toluwe, ethylbenzene, o-xylene, p-xylene). From the pressure isotherms the following quantities have been calculated by Barker's method: constants of the Redlich-Kister ^-approximation polynomials, activity coefficients, vapour compositions and some auxiliary functions concerning the least squares approximation and vapour phase nonideaKty.

Determination of desorption efficiencies in the 3M 3500 Organic Vapor Monitor

Abstract: A simple method for the determination of desorption efficiencies of organic compounds collected on the 3M 3500 Organic Vapor Monitor has been developed. The technique involves the introduction of the organic compound, in the liquid state, onto a piece of filter paper placed between the elutriation cap and the diffusion plate of the organic vapor monitor. This is accomplished by direct injection of the organic compound through the center elutriation port of the monitor cap. The port is closed and the organic compound is given sufficient time to vaporize and consequently be adsorbed by the charcoal sorbent. The filter paper is removed and analyzed as a separate sample to assure complete transfer of the organic compound. All samples are desorbed by a suitable solvent and analyzed by gas chromatography. Desorption efficiencies for methyl chloroform, benzene, heptane, acetone, dioxane, isobutanol and ethyl acetate are determined. A comparison with results by the phase equilibrium method is made.

ROLE OF ACID CENTERS OF Sn/Mo OXIDE CATALYST IN PROPYLENE CONVERSION TO ACETONE

Abstract: Infrared spectroscopic studies of the nature of catalyst centers indicate the presence of Bronsted and Lewis acid centers on the surface. Propylene conversion to acetone proceeds via proton transfer from the surface to propylene with the formation of a (CH3)2−C(H)−O−Me type compound, and its subsequent dehydration.

Process for separating acetone from carbonylation mixtures

Abstract: The disclosure relates to a process for separating acetone from reaction mixtures originating from the reaction of methyl acetate and/or dimethylether with carbon monoxide and optionally hydrogen in the presence of a catalyst system consisting of carbonyl complexes of noble metals of group VIII of the Periodic System of the elements, acetic acid, an organophosphorus or organonitrogen compound, methyl iodide and optionally carbonyl-yielding compounds of common metals. To this end, the disclosure provides for the reaction mixture containing acetic anhydride, acetic acid, ethylidene diacetate, methyl iodide, acetone and methyl acetate which is distilled off from the catalyst solution, or just its low boiler fraction consisting of methyl acetate, methyl iodide and acetone to be subjected wholly or partially to an extractive distillation with acetic acid and for pure methyl iodide to be distilled off; for an acetone/methyl acetate mixture to be distilled off from the acetic acid extract; for this mixture to be separated in known fashion and for the acetic acid extractant to be recycled into the extraction stage, if desired after separation of the final reaction products comprised of acetic anhydride; ethylidene diacetate and acetic acid.

Catalytic Oxidation of Propene

Abstract: The oxidation of propene on simple and mixed oxide catalysts to form various oxygen-containing products — acrylaldehyde, acrylic acid, acetone, and acetic acid — is surveyed, and the role of individual components of the active catalysts discussed. A list of 110 references is included.