Methanol, use

Interest of this reaction is that uses OTC chemicals or non suspicious, as NaN02 (it s used in food industry as a conserver), and it s really easy. Methanol used is drugstore methanol, PdCk is from photografy supplier in the net or elsewhere... 

Until the 1920s the major source of methanol was as a byproduct m the production of charcoal from wood—hence the name wood alcohol Now most of the more than 10 billion lb of methanol used annually m the United States is synthetic prepared by reduc tion of carbon monoxide with hydrogen... 

Brown and Lin reported a quantitative method for methanol based on its effect on the visible spectrum of methylene blue. In the absence of methanol, the visible spectrum for methylene blue shows two prominent absorption bands centered at approximately 610 nm and 660 nm, corresponding to the monomer and dimer, respectively. In the presence of methanol, the intensity of the dimer s absorption band decreases, and that of the monomer increases. For concentrations of methanol between 0 and 30% v/v, the ratio of the absorbance at 663 nm, Asss, to that at 610 nm, Asio, is a linear function of the amount of methanol. Using the following standardization data, determine the %v/v methanol in a sample for which Agio is 0.75 and Ag63 is 1.07. 

From Table 12.3 we find that the polarity index is 10.2 for water and 5.1 for methanol. Using equation 12.30, the polarity index for a 60 40 water-methanol mixture is... 

Methanol use would also reduce pubHc exposure to toxic hydrocarbons associated with gasoline and diesel fuel, including ben2ene, 1,3-butadiene, diesel particulates, and polynuclear aromatic hydrocarbons. Although pubHc formaldehyde exposures might increase from methanol use in garages and tunnels, methanol use is expected to reduce overall pubHc exposure to toxic air contaminants. 

Formaldehyde solutions exist as a mixture of oligomers, H0(CH20) H. Their distribution has been deterrnined for 6—50 wt % HCHO solutions with low methanol using nmr and gas chromatographic techniques (28,29). Averages of the equiUbtium constants for equation 4 ate K2 = 7.1, = 4.7,... 

Methylphenol. This phenol, commonly known as o-cresol, is produced synthetically by the gas phase alkylation of phenol with methanol using modified alumina catalysis or it may be recovered from naturally occurring petroleum streams and coal tars. Most is produced synthetically. Reaction of phenol with methanol using modified zeoHte catalysts is a concerted dehydration of the methanol and alkylation of the aromatic ring. 2-Methylphenol [95-48-7] is available in 55-gal dmms (208-L) and in bulk quantities in tank wagons and railcars. 

Solvent Recovery. A mixture of methanol and methyl acetate is obtained after saponification. The methyl acetate can be sold as a solvent or converted back into acetic acid and methanol using a cationic-exchange resin such as a cross-linked styrene—sulfonic acid gel (273—276). The methyl acetate and methanol mixture is separated by extractive distillation using water or ethylene glycol (277—281). Water is preferred if the methyl acetate is to be hydroly2ed to acetic acid. The resulting acetic acid solution is concentrated by extraction or a2eotropic distillation. 

Ash is a measure of residual sodium acetate. A simple method consists of dissolving the PVA in water, diluting to a known concentration of about 0.5 wt %, and measuring the electrical conductivity of the solution at 30°C. The amount of sodium acetate is estabUshed by comparing the result to a cahbration curve. A more lengthy method involves the extraction of the PVA with methanol using a Soxhlet extractor. The methanol is evaporated and water is added. The solution is titrated using hydrochloric acid in order to determine the amount of sodium acetate. 

Recovery of dilute acetic acid is achieved by esterification with methanol using a sulfonated resin (Dowex 50w) in a packed distillation column (54). Pure methyl acetate is obtained. This reaction is second order in acetic acid, 2ero order in methanol, and partially diffusion controlled. 

Fig. Electropherogram of a) catechin standards, b) green tea sample prepared in 50 % methanol using liquid extraction...

Run a single-point energy calculation on methanol using the HF/6-31++G(d,p) model chemistry, including the GFPrint and GFinput keywords in the route section which request that the basis set information be included in the output file (in tabular and input format, respectively). Examine the basis set output and identify its main components. 

This is 0.22 electron-volt greater than the value of J for nitric acid in water. The relative positions of the proton levels in methanol, using this value, is shown in Fig. 65. 

The Karl Fischer procedure was applied to the determination of water present in hydrated salts or adsorbed on the surface of solids. The procedure, where applicable, was more rapid and direct than the commonly used drying process. A sample of the finely powdered solid, containing 5-10 millimoles (90-180 mg) of water, was dissolved or suspended in 25 mL of dry methanol in a 250-mL glass-stoppered graduated flask. The mixture was titrated with standard Karl Fischer reagent to the usual electrometric end point. A blank titration was also carried out on a 25 mL sample of the methanol used to determine what correction (if any) needed to be applied to the titre obtained with the salt. 

Once methanol-using organisms had been isolated they were screened in small-volume shake-flask cultures to determine their ability to grow in methanol-minimal-medium (such as Medium B described in the previous section) to produce high yields at high growth rates. Optimum growth temperatures and pHs were also determined. 

Methanol is available in Technical, C.P. (99.85% purity) and electronic (used to cleanse and dry components) grades. US Spec 0-M-232E (July 30, 1968) with Amd 1 (Sept 11, 1970), covers the requirements and tests for methanol used by all Federal agencies (see below)... 

Mix 1 part of prepared Dowex 1-X8 with 2 parts of prepared Dowex 50W-X8, by weight, in a 1-L beaker. Add methanol until the resin mixture is covered. Mix well and stand overnight. Filter off the methanol using a filter funnel and filter paper. Evaporate off the remaining methanol in a rotary film evaporator under vacuum at 40°C, rotating slowly, until visibly dry. 

Synthesis of dimethyl carbonate by transesterification of ethylene carbonate and methanol using quaternary ammonium salt catalysts... 

Kuwabata S, Nishida K, Tsuda R, Inoue H, Yoneyama H (1994) Photochemical reduction of carbon dioxide to methanol using ZnS microcrystaUite as a photocatalyst in the presence of methanol dehydrogenase. J Electrochem Soc 141 1498-1503... 

Maceration of crnshed or gronnd material in methanol containing small amounts of HCl (<1%) is commonly used at refrigerated temperatures for times ranging from a few hours to overnight. The extracted material is usually too dilute for further analyses and the extraction procednre is usually followed by evaporation of the methanol using vacnnm and mild temperatures (30 to 40°C). Alternatively, the plant materials and solvents can be mixed well with a laboratory blender for a few minutes or a chemical-resistant stir bar for a longer time. Concentration of anthocyanin extracts can be done by rotary evaporation under vacuum conditions for volatile solvents or lyophilization for water. 

Figure 4.2 Microsoft Excel spreadsheet output of green metrics analysis for the synthesis of diphenyl-methanol using the Crignard methodology.

The recovery is low on extracting n from soil by refluxing with water containing methanol. Metabolite n in soil can be extracted by sonication with alkaline methanol. Using this alkaline extraction procedure, another metabolite, 2-chlorobenzylsulfonic acid, is also extracted simultaneously. ... 

Figure 33.2. Esterification of dodecanoic acid with methanol, using an alcohokacid ratio of 3 1 and sulfated zirconia (SZ) as catalyst.

We next investigated the dealkylation of S-b-tBM with TMSI. Unlike the reaction with S-b-MM, it required only 4 hr at room temperature to completely cleave the t-butyl ester. Work-up under acidic conditions gave S-b-MA which was virtually identical by NMR, IR, GPC, and titration with that just described above. Likewise, neutralization with KOH resulted in quantitative conversion to S-b-MA.K. Although the initially formed product of the reaction of alkyl esters with TMSI is presumably the trimethylsilyl ester (1 7 ), we were not able to isolate or characterize this copolymer. It is known that trimethysilyl methacrylate and its polymers spontaneously hydrolyze even in moist air (19). Any traces of water in the methanol used to precipitate the reaction mixture would thus preclude isolation of the intermediate trimethylsislyl ester. 

Investigate the use of a gasketed plate heat exchanger for the duty set out in Example 12.1 cooling methanol using brackish water as the coolant. Titanium plates are to be specified, to resist corrosion by the saline water. 

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