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The extended hydrogen bond networks formed by alcohols are good indicators of their capacities to hold water. Results from molecular dynamics simulations on 24 linear alcohol isomers containing 6–12 carbon atoms show the effects of hydroxyl location on bulk hydrogenbonded structures. Calculated oxygen–oxygen radial distributions obtained from simulations were correlated to experimental liquid–liquid solvent extraction studies involving ternary water/ethanol/alcohol systems. It was found that hydroxyl group location determines the primary structure of the bulk alcohol’s hydrogen bond network and that an alcohol’s capacity for water correlates directly to the size of this network. 2006 Elsevier Ltd. All rights reserved.

Distribution coefficients and separation factors were determined for the partitioning of ethanol and water from aqueous mixtures into several vegetable oils and their fatty alcohol and fatty ester derivatives. Castor oil, ricinoleyl alcohol, and methyl ricinoleate all show higher ethanol distribution coefficients, and similar or reduced separation factors, relative to other oils and derivatives studied here or reported by others. Of particular interest, ricinoleyl alcohol has an ethanol distribution coefficient 50% higher than that of oleyl alcohol, a commonly studied solvent for ethanol extraction from fermentation broths.

The evaluation of the potential for separation of aqueous ethanol mixtures by liquid−liquid solvent extraction has been complicated by inconsistent results and differing experimental methodologies among researchers developing distribution coefficient data. A screening method for measuring equilibrium distribution coefficients for solvent extraction of ethanol from dilute aqueous solutions is presented to minimize potential sources of variation. These include entrainment, incomplete equilibration, impurities, and temperature changes during the preparation of samples for analysis. Multiple literature sources of data exist for each of 10 solvents. Results for these 10 solvents are compared among sources and to results generated from this method. The method also has general utility for the screening of solvents for extraction of other useful fermentation products.

Distribution coefficients have been measured for the partitioning of ethanol and water from aqueous mixtures into 57 different alcohol solvents. The study has focused on the effects of systematic variations in chemical structure of the alcohols. Factors found to be important include chain length and hydroxyl position for the x-alcohols (i.e., 1-heptanol through 1-dodecanol, 2-heptanol through 2-undecanol, etc.), branch structure (e.g., methyl, ethyl, n-propyl, i-propyl, etc.) for a branch located on the hydroxyl carbon, location of the branch relative to the hydroxyl carbon, and multiple branching.

Online analyzers enable manufacturers to operate modern polymerization processes as safely, reliably, and profitably as possible. The most critical application of this technology involves monitoring the reactor itself to determine the molecular weight and comonomer content of the polymer produced. Polymer process streams introduce unique challenges for online analyzers because the process chemistry, sample transport, and stream conditions are harsher, prone to fouling, and pose unique safety hazards. Spectroscopy lends itself very well to online analysis of polymers because the data it provides is information rich and can be deployed using fiber optics for remote sampling of gases, liquids, and solids. Additionally, it is relatively fast and reliable if well designed and installed properly. The combination of spectroscopy, fiber optics, and chemometrics gives manufacturers the ability to use modern spectrometers and statistical models to analyze and monitor diverse types of polymerization processes. Several examples are provided in this article, including application to polyethylene, polycarbonate, polyurethane, and polystyrene processes.