Methanol liquid temperature range

Methanol looks particularly promising in this regard, as would all alcohols, many of which are found in the ISM or as processed molecules of comets. Hydrocarbon chemistry in a solvent such as acetylene would be supported over a large liquid temperature range, although the temperature is rather low and the chemistry would have to adapt. 

Estimation of adiabatic increase in the liquid temperature in circular micro-tubes with diameter ranging from 15 to 150 pm, under the experimental conditions reported by Judy et al. (2002), are presented in Table 3.7. The calculations were carried out for water, isopropanol and methanol flows, respectively, at initial temperature Tin = 298 K and v = 8.7 x 10" m /s, 2.5 x 10 m /s, 1.63 x 10 m /s, and Cp = 4,178 J/kgK, 2,606J/kgK, 2,531 J/kgK, respectively. The lower and higher values of AT/Tm correspond to limiting values of micro-channel length and Reynolds numbers. Table 3.7 shows adiabatic heating of liquid in micro-tubes can reach ten degrees the increase in mean fluid temperature (Tin -F Tout)/2 is about 9 °C, 121 °C, 38 °C for the water d = 20 pm), isopropanol d = 20 pm) and methanol d = 30 pm) flows, respectively. 

One of the most important characteristics of IL is its wide temperature range for the liquid phase with no vapor pressure, so next we tested the lipase-catalyzed reaction under reduced pressure. It is known that usual methyl esters are not suitable for lipase-catalyzed transesterification as acyl donors because reverse reaction with produced methanol takes place. However, we can avoid such difficulty when the reaction is carried out under reduced pressure even if methyl esters are used as the acyl donor, because the produced methanol is removed immediately from the reaction mixture and thus the reaction equilibrium goes through to produce the desired product. To realize this idea, proper choice of the acyl donor ester was very important. The desired reaction was accomplished using methyl phenylth-ioacetate as acyl donor. Various methyl esters can also be used as acyl donor for these reactions methyl nonanoate was also recommended and efficient optical resolution was accomplished. Using our system, we demonstrated the completely recyclable use of lipase. The transesterification took place smoothly under reduced pressure at 10 Torr at 40°C when 0.5 equivalent of methyl phenylthioacetate was used as acyl donor, and we were able to obtain this compound in optically pure form. Five repetitions of this process showed no drop in the reaction rate (Fig. 4). Recently Kato reported nice additional examples of lipase-catalyzed reaction based on the same idea that CAL-B-catalyzed esterification or amidation of carboxylic acid was accomplished under reduced pressure conditions. ... 

Liquid polyols are interesting among nonaqueous solvents because, like water and monoalcohols, they are hydrogen-bonded liquids with a high value of relative permittivity (Table 9.2.1), and therefore they are able to dissolve to some extent ionic inorganic compounds. Moreover, reactions can be carried out in such solvents under atmospheric pressure up to 250°C, i.e., at a temperature range higher than in water or monoalcohols such as methanol or ethanol. 

The critical temperature of pure CO2 is 31°C [7]. For the subcritical range of 31-50°C, the fluid entering the extraction cell will consist of two phases - a liquid methanol phase and a supercritical phase. It has been reported that the diffusivity of liquid is about 10-100 times smaller than that of the supercritical fluid [6] and this implies that the difficulty of mass transfer associated with the former is also magnified by the same factor. In an extraction process, mass transfer occurs during 1) the fluid s penetration of the matrix s pores and 2) the subsequent transport of the analyte (solute) from the matrix into the bulk fluid [6]. The presence of entrained liquid methanol droplets will thus greatly increases the amount of mass transfer resistance present in the system. Such resistance is reduced upon an increase in temperature and this accounts for the rise in extraction efficiency observed in the temperature range of 45-50°C. 

At the other end of the liquid scale, methanol boils at one temperature (65°C [149°F]) unlike gasoline which boils over a very wide temperature range. This characteristic of methanol, along with its low vapor pressure (32 kPa 38°C... 

The diffusion coefficients of n-paraffins with 12 to 22 carbon atoms in high density (HDPE) and low density polyethylene (LDPE) have been measured by a permeation method (Koszinowski, 1986). Methanol (MeOH) and ethanol (EtOH) were used as contacting liquid phases which minimized interaction between these polar solvents and the nonpolar polymers. No interaction was observed over the investigated temperature range of 6 to 40 °C for both solvents. 

For 50% methanol-water mixtures three series of buffers involving acetate, succinate, and phosphate have been established in the temperature range from 10 to 40°C by emf data obtained without liquid junction. With 50% methanol solutions an aqueous saturated calomel electrode is used as reference electrode, since liquid-junction potentials are adequately reproducible for operational pH values. 

The dynamics of the molecular rotation of 2-pyridone in toluene, carbon tetrachloride, methanol, and water have been investigated at 305 K by 13C and 2H NMR spectroscopy. Both chemical shifts and relaxation times show that it forms stable hydrogen-bonded complexes in methanol and in water, reorienting as a complete unit and taking with it two solvent molecules. These solvated species are stable within the liquid-state temperature range, and reorient according to the hydrodynamic law as indicated by the 14N line width measurements (85MRC460). 

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