Alcohols separation

Methyl p-toluenesulphonate. This, and other alkyl esters, may be prepared in a somewhat similar manner to the n-butyl ester with good results. Use 500 g. (632 ml.) of methyl alcohol contained in a 1 litre three-necked or bolt-head flask. Add 500 g. of powdered pure p-toluene-sulphonyl chloride with mechanical stirring. Add from a separatory funnel 420 g. of 25 per cent, sodium hydroxide solution drop by drop maintain the temperature of the mixture at 23-27°. When all the alkali has been introduced, test the mixture with litmus if it is not alkaline, add more alkali until the mixture is neutral. Allow to stand for several hours the lower layer is the eater and the upper one consists of alcohol. Separate the ester, wash it with water, then with 4 per cent, sodium carbonate solution and finally with water. Dry over a little anhydrous magnesium sulphate, and distil under reduced pressure. Collect the methyl p-toluenesulphonate at 161°/10 mm. this solidifies on cooling and melts at 28°. The yield is 440 g. 

Eosin (Tetrabromofluorescein). Place 16 5 g. of powdered fluorescein and 80 ml. of rectified (or methylated) spirit in a 250 ml. flask. Support a small dropping funnel, containing 36 g. (12 ml.) of bromine, above the flask make sure that the stopcock of the funnel is well lubricated before charging the latter with bromine. Add the bromine diopwise during about 20 minutes. When half the bromine has been introduced, and the fluorescein has been converted into dibromofluor-escein, all the solid material disappears temporarily since the dibromo derivative is soluble in alcohol with further addition of bromine the tetrabromofluorescein (sparingly soluble in alcohol) separates out. Allow the reaction mixture to stand for 2 hours, filter ofiF the eosin at the pump, wash it with alcohol, and dry at 100°. The yield of eosin (orange-coloured powder) is 25 g. 

Gadamer and Amenomiya have prepared a well-defined sesquiterpene vhich they term atractylene, by dehydrating atractylol, a crystalline sesquiterpene alcohol separated from the oil of Atractylis ovata. It is an oil with an odour of cedar wood, and is prohahly bicyclic. It polymerises on keeping and has the following characters —... 

Recently, high-quality SOD membranes for water separation have been developed by Khajavi etal. [21, 52]. These zeolite membranes should allow an absolute separation of water from almost any mixture since only very small molecules such as water, hydrogen, helium, and ammonia can theoretically enter through the six-membered window apertures. Water/alcohol separation factors 10 000 have been reported with reasonable water fluxes up to 2.25 kg nr h at 473 K in pervaporation experiments. 

Impurities can be either soluble or insoluble. For example, the material that gives cheap wine its unique bouquet is soluble in the alcohol. If you distill cheap wine, you get clear grain alcohol separated from the impurities, which are left behind in the distilling flask. 

The presence of the stereogenic centre at C(l) introduces an additional factor in the asymmetric epoxidation now, besides the enantiofacial selectivity, the diastereoselectivity must also be considered, and it is helpful to examine epoxidation of each enantiomer of the allylic alcohol separately. As shown in Fig. 10.2, epoxidation of an enantiomer proceeds normally (fast) and produces an erythro epoxy alcohol. Epoxidation of the other enantiomer proceeds at a reduced rate (slow) because the steric effects between the C(l) substituent and the catalyst. The rates of epoxidation are sufficiently significative to achieve the kinetic resolution and either the epoxy alcohol or the recovered allylic alcohol can be obtained with high enantiomeric purity [9]. 

Another type of mixed-matrix membranes for alcohol/water pervaporation applications was developed utilizing hydrophiUc poly(vinyl alcohol) (PVA) and ZSM-5. The ZSM-5/PVA mixed-matrix membranes demonstrated increased selectivity and flux, compared to pure PVA, for the water/isopropyl alcohol separation [97]. This type of mixed-matrix membranes, however, may have membrane swelling issue due to the hydrophilic nature of the PVA polymer. Mixed-matrix membranes comprising modifled poly(vinyl chloride) and NaA zeolite have shown both enhanced flux and selectivity for the ethanol/water separation at high NaA loadings [98]. 

The best method for recovering the alcohol is to collect the 60-70% alcohol and rectify it and to collect the 80% alcohol separately and use it for the dehydration of the next batch of nitrocellulose. 1251. of 95% alcohol is consumed per 100 kg of dehydrated nitrocellulose of this 30-35 1. remain in the nitrocellulose and about 90 1. are recovered by rectification. 

The perfluoroalkylethyl alcohol (Zonyl Ba ) has proven to be a very versatile synthetic intermediate. The ethyl group spacer in the alcohol separates the electronegative perfluoroalkyl group from the alcohol moiety, which leads to... 

Figure 25-23 Pulsed electrochemical detection of alcohols separated on Dionex AS-1 anion-exchange column with 0.05 M HCIOA. Peaks 1, glycerol 2, elhylene glycol 3, propylene glycol ...

Di-o-tolyl tellurium dichloride, (CH3.C6H4)2TeCl2,is prepared in a similar manner to the corresponding phenyl compound. It is best recrystallised from absolute alcohol, separating as small monoclinic tablets. M.pt. 183° C., readily soluble in benzene, toluene or xylene, but sparingly soluble in ligroin, methyl or ethyl alcohol. 

E Le Fur, PX Etievant, JM Meunier. Interest of pulsed electrochemical detection for the analysis of flavor-active alcohols separated by liquid chromatography. J Agric Food Chem 42 320-326, 1994. 

The presence of a stereogenic center at Cj of an allylic alcohol introduces an additional factor into the asymmetric epoxidation process in that now both enantiofacial selectivity and dias-tereoselectivity must be considered. It is helpful in these cases to examine epoxidation of each enantiomer of the allylic alcohol separately. Epoxidation of one enantiomer proceeds normally and produces an erythro epoxy alcohol in accord with the rules shown in Figure 6A.1. 

B. Boil 2 g of the ester with 30 ml of 10 per cent sodium or potassium hydroxide solution under reflux for at least 1 hour. If the alcohol formed is water (or alkali) soluble, the completion of the hydrolysis will be indicated by the disappearance of the ester layer. Distil off the liquid through the same condenser and collect the first 3-5 ml of distillate. If a distinct layer separates on standing (or upon saturation of half the distillate with potassium carbonate), remove this layer with a capillary dropper, dry it with a little anhydrous potassium carbonate or anhydrous calcium sulphate and determine the b.p. by the Siwoloboff method (Section 2.34). Whether an insoluble alcohol separates out or not, prepare a crystalline derivative (e.g. the 3,5-dinitrobenzoate, Section 9.6.4, p. 1241) and determine its m.p. 

W.Y. Chiang, C.C. Huang, Separation of liquid mixtures by using polymer membranes. Part IV. Water—alcohol separation by pervaporation through modified acrylonitrile poly(vinyl alcohol) copolymer, J. Appl. Polym. Sci. 48 (1993) 199-203. 

Alternative Fuel Includes methanol, denatured ethanol and other alcohols, separately or in mixtures of 85% by volume or more with gasoline or other fuels, CNG, LNG, LPG, hydrogen, coal derived liquid fuels, fuels other than alcohols derived from biological materials, electricity, neat biodiesel, or any other fuel determined to be substantially not petroleum and yielding substantial energy security benefits and substantial environmental benefits. It is defined pursuant to the EPACT (Energy Policy Act of 1992), alternative fuels. 

NaN[Si(CH3)3]2, reacts with (2R,3R)-3 to form an 18 1 mixture of 5 and the epi-meric alcohol, separated by flash chromatography to provide 5 in about 40% yield. 

The O Connell correlation (149, Fig. 7.5a). This correlation is based on test data from 31 plant columns, including hydrocarbon, chlorinated hydrocarbon, and alcohol separation columns. It evolved from an earlier correlation by Drickamer and Bradford (150), which empirically correlated efficiency test data for 54 refinery columns, The earlier correlation was modified by O Connell to include nonhydrocarbon and high-relative-volatility systems. 

This is an example of the second step in the acid-mediated solvolysis of a tertiary alcohol. Note that the protonated alcohol separates as water and leaves the positive charge on the carbon atom. For clarity, the bond was lengthened to allow space for the arrow. Note that the electrons in the bond move toward the positive charge residing on the oxygen. Arrow pushing is illustrated below ... 

Alcohols Separated from Products of Nitrided Iron Catalysts Fe304-Al20a-Kj0 catalyst at 21.4 atmospheres Weight-% of total condensed product exclusive of water ... 

Alcohols separated from oil phase, from aqueous layer, plus those liberated by saponification of the aqueous layer. 

The isomeric o-aimnophenylmercurie acetate is difficult to separate from the larger amount of the p- compound which would separate with it if the filtrate from the initial crop of the p- acetate were allowed to stand. Dimroth found, however, that there was a considerable difference m the solubilities of the chlorides, so the filtrate is treated with an excess of sodium chloride solution, precipitating p-aminophenylmercuric chloride in the amorphous state, while the o-ammo chloride separates in crystalline form. The mixture is sucked off, dried, and the 0- derivative extracted with not too much warm alcohol, separating as leaflets after the solution is chilled and allowed to stand The amorphous residue of p- chloride may be boiled with alcohol or benzene, and separates from the cold solution as leaflets melting at 1880, with decomposition. 

Add the word alcohol, separating the words with a space. 

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