Acetone

About: Acetone is a research topic. Over the lifetime, 9458 publications have been published within this topic receiving 120867 citations. The topic is also known as: propanone & dimethylketone.

Continuous acetone-butanol-ethanol (ABE) fermentation using immobilized cells of Clostridium acetobutylicum in a packed bed reactor and integration with product removal by pervaporation.

Abstract: An integrated solvent (ABE) fermentation and product removal process was investigated. A stable solvent productivity of 3.5 g/L h was achieved by using cells of Clostridium acetobutylicum immobilized onto a packed bed of bonechar, coupled with continuous product removal by pervaporation. Using a concentrated feed solution containing lactose at 130g/L, a lactose value of 97.9% was observed. The integrated fermentation and product removal system, with recycling of the treated fermentor effluent containing only low amount of solvents (/but lactose and acids), leads to only low acid losses. Therefore, most of the acids are converted to solvents, and this results in a high solvent yield of 0.39 g solvents/g lactose utilized. The pervaporation system provided a high product removal rate even at low solvent concentrations. A solvent membrane flux of 7.1 g/m(2) h with a selectivity of 5 was achieved during these investigations. The system proved to be very reliable.

Cu catalyzed oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran and 2,5-furandicarboxylic acid under benign reaction conditions

Abstract: The renewable chemical building block 5-hydroxymethylfurfural (HMF) was oxidized to 2,5-diformylfuran by an oxidation system consisting of the radical 2,2,6,6-tetramethyl-piperidin-1-oxyl (TEMPO) and CuCl. The system was optimized by exploring several reaction conditions and by employing nitrogen containing promoters (NCPs) to obtain excellent yields. In acetonitrile a 95% DFF yield was obtained after 24 h with ambient pressure of dioxygen at room temperature in the presence of different NCPs, which – to our knowledge – is the best result reported thus far for this reaction. The use of NCPs made it further possible to apply various traditional solvents, e.g. acetone, methanol and methyl isobutyl ketone for the reaction. The latter can be used as extraction solvent for HMF synthesis in aqueous media and thus integrate the two processes. Additionally, HMF was oxidized to 2,5-furandicarboxylic acid by a modified oxidation protocol consisting of CuCl and t-BuOOH. In all the reactions, mild conditions, including room temperature were employed.

Strategies for the analysis of polar solvents in liquid matrixes.

Abstract: Various approaches to the analysis of polar compounds in different matrixes by solid-phase microextraction (SPME) were studied. The analysis of polar analytes in nonpolar matrixes was performed with custom-made SPME fibers coated with Nafion perfluorinated resin. The sensitivity of this fiber in this type of analysis was better by 1 order of magnitude on average as compared to those of any of the commercially available fibers. The fiber was the most sensitive for the most polar of the compounds studied, i.e., methanol. Determination of methanol, ethanol, and 2-propanol in unleaded gasoline was illustrated. Except for methanol, the fiber did not perform very well in the analysis of alcohols in water. The fiber was capable of extracting water from benzene. SPME analysis of polar compounds in water was studied using aqueous solutions of acetone, methyl ethyl ketone, methyl isobutyl ketone (MIBK), 2-propanol, 2-methyl-2-propanol, and tetrahydrofuran. Fibers coated with poly(dimethylsiloxane)/divinylbenzene yi...