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[en] Full text:The nature, power of electron acceptor centers of new, V-P-O and V-P-O (Co) and V-P-O (Mo) catalysts with acetone adsorption have been studied. The existence of the different centers on the surface has been determined
[en] In recent years, among the problems of anthropogenic pollution of nature, the problem of exposure to organic substances of different classes has attracted great attention. Therefore, it is important to study the laws of the photochemical formation of oxygen-containing organic molecules, taking into account the anomalous phenomena occurring in the atmosphere. During the photooxidation of methane in the atmosphere, the most common hydrocarbon formaldehyde is formed. The average life span of formaldehyde in the atmosphere is approximately three hours. A study was made of the kinetic laws of formation of oxygen-containing (formaldehyde, formic acid and acetone) hydrocarbons during the photochemical conversion of air-methane mixtures.
[en] Highlights: • Process design of a separation section in an ethanol-to-butanol process performed. • Separation costs are estimated to be 7.9–10.6 MJ/kg n-butanol. • Energy consumption affected by splitter column influent composition. • Energy consumption affected by catalyst ability to use aqueous ethanol. - Abstract: A complete separation scheme has been designed for the effluent of a high-pressure ethanol-to-butanol catalytic reactor, producing 250,000 tonnes of n-butanol per year. The effluent contains water, hydrogen and a diverse range of C2-C4 oxygenates: unconverted ethanol, n-butanol, acetaldehyde, ethyl acetate, and acetal. Fundamental phase equilibrium relationships suggested use of conventional, extractive, and heterogeneous azeotropic distillation units to perform the separations. All reactor effluent species exit the separation process at mole purities of at least 99%. Separation costs are estimated to range from 9.0 to 10.6 MJ/kg n-butanol, which is comparable with the separation costs of n-butanol obtained from established acetone-butanol-ethanol (ABE) separation process.
[en] The 8 coumarin derivatives have been synthesized from 8 starting materials(2-hydroxy-benzophenone, 2,2'-dihydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-5-methylbenzophenone, 5-chloro-2-hydroxy-4-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-4'-dimethoxybenzophenone) with phenylacetic acid and Ac2O/TEA in acetone at reflux temperature. The ratio of o-hydroxybenzophenone, phenylacetic acid, Ac2O and TEA is 1:1:8:8 in acetone. Our results showed higher products yields of coumarin derivatives than Shama and Ray's method in previous papers. A new intermediate form was proposed to our mechanism of coumarin synthetic method
[en] Pimeleodendron griffithianum, locally known as Perah ikan is available in Thailand, Peninsular Malaysia and Sumatra. The plant can be found in wet forest, secondary forest, pole forest, semi-swamps, and along logging roads or on hill slopes. In Malaysia, the stem of P. griffithianum being used as commercial timber. So far, no chemical constituents have been reported from P. griffithianum. In this study, a phytochemical study was conducted on the stem bark of P. griffithianum. The stem bark was obtained from Sungai Siput, Perak. The cleaned, chopped and dried stem-bark was extracted using acetone for several times. The separation of the components was carried out using vacuum liquid chromatography (VLC) followed by recrystallization method. The structure of the pure compound was elucidated by spectroscopic methods including nuclear magnetic resonance (NMR), ultraviolate - visible (UV-Vis) and comparison with literature. One compound (1) was isolated and identified as acetyl aleuritolic acid. This compound was reported for the first time from this plant. (author)
[en] Full text: Partial oxidation of isopropyl alcohol into acetone at the zeolite of A-type modified by ions copper and palladium at the temperature interval 150-230 degree C, of volume velocity 2400 H-1 under different ratio alcohol-oxygen-helium at atmoshpheric pressure has been studied. It has been established that the conversion of isopropyl alcohol on zeolites CuPdNaA and CuPdCaA is noticable however selective by acetone alcohol, modofoed zeolites, acetone
[en] Muon spin rotation studies can in principle determine the formation mechanism of muonic free radicals. Evidence for mechanisms involving intermediate radical anion and muonic cation states is presented
[en] Reaction of 2-aminopyridine with allyl bromide, methallyl chloride, 2-bromoallyl bromide, and propargyl bromide in acetone furnished 2-amino-1-allyl-, methallyl-, (2-bromoallyl)-, and propargylpyridinium halides. 2-Amino-1-allyl(methallyl)pyridinium halides reacted with bromine and iodine to form 2-halomethyl-2,3-dihydro-1H-imidazo[1,2-a]pyridinium systems. 2-Amino-1-(2-bromoallyl)pyridinium bromide underwent heterocyclization under the action of bromine, and did not react with iodine. 2-Amino-1-propargylpyridinium bromide reacted with bromine and iodine to form 2-halomemylene-2,3-dihydro-1H-imidazo[1,2-a]pyridinium systems.