Removal of Acetone

PRATT, H. R. C. and Glover, S. T. Trans. Inst. Chem. Eng. 24 (1946) 54. Liquid-liquid extraction Removal of acetone and acetaldehyde from vinyl acetate with water in a packed column. 

The reversible reduction of aldehydes or ketones to the corresponding alcohols using aluminum alkoxides such as aluminum isopropoxide (Al[OCH(CH3)2]3), the reducing alcohol usually being isopropyl alcohol (Le., RCOR + CH3CH(0H)CH3 RCH(OH)R + CH3C0CH3). The reaction is facilitated by the removal of acetone by distillation". This reaction has served as a model for metal-ion-dependent hydride transfer reactions catalyzed by certain enzymes. The reverse reaction is known as the Oppenauer oxidation . ... 

Mouse bioassay. The digestive glands of shellfish were extracted thrice with acetone at room temperature. After removal of acetone by evaporation, the aqueous suspension was extracted thrice with diethyl ether, the combined ether solution was backwashed twice with small portions of water and evaporated. The residue was suspended in 1% Tween 60 solution and serially diluted suspensions were injected intraperitoneally into mice weighing 17-20 g each. The mice were observed for 24 hr and the minimum amount of toxin required to kill a mouse at 24 hr was defined as one mouse unit (1). 

The hydrogenated resin of acetophenone and formaldehyde (400 g, Mn 1000 Da) was condensed with isophorone diisocyanate (90 g) in the presence of 0.2% (on resin) 2,6-bis(f-butyl)-4-methylphenol and 0.1% of dibutyltin dilaurate (on resin) in 40% dilution with acetone. The mixture was refluxed until an NCO number of less than 0.1% was reached. The product was then isolated and had a melting range of from 171 to 176°C after the removal of acetone. 

The authors have used ratios of ace-tone/chloroform varying from 1 1, 1 2, 1 2.4, to even 1 5. A greater proportion of chloroform reduces the amount of acetone in the aqueous phase and may eliminate the need for removal of acetone by rotary evaporation. This evaporative step, however, takes little time with no apparent anthocyanin degradation. Therefore, the authors favor using 1 1 or 1 2 ratios to avoid excessive use of the chloroform solvent. 

Apple C, EC, procyanidin B2 Extraction with aqueous acetone, centrifugation normal phase neutralization, SPE with C18 reversed phase removal of acetone Silica C-18 MeOH-DCM-formic acid MeOH-H20-formic acid HPLC/DAD (280 nm) 112... 

A solution of 8.2 g. (0.040 mole) of purified aluminum isopropoxide and 2.75 g. (0.011 mole) of 4-keto-l,2,3,4-tetrahydrochrysene in 25 cc. of dry toluene is refluxed for four hours, in an oil bath. After the solution has cooled slightly, 25 cc. of dry isopropyl alcohol is added to facilitate removal of acetone, the water is removed from the reflux condenser, and a water condenser set for downward distillation is attached to the top by means of a short bent tube (a Hahn partial condenser with a 1-cm. layer of isobutyl alcohol in the inner condensing tube may be used). The mixture is heated at such a rate that slow distillation occurs (2 to 5 drops per minute, the volume of solution should be maintained by further addition of solvent as needed). When the test for acetone is completely negative, f the toluene solution is cooled and the aluminum salt is decomposed with cold 10% sulfuric acid (from 5 cc. of concentrated sulfuric acid and 80 cc. of water). The product is separated with the toluene, and the solution is washed with dilute aqueous ammonia and water, and then evaporated at room temperature under a stream of air (solutions of secondary alcohols which are susceptible to dehydration should be evaporated at room temperature a stream of air should not be used with carbinols boiling below 200°). There is obtained 2.10 g. (76%) of colorless 4-hydroxy-l, 2,3,4-tetrahydrochrysene melting at 156-158°. Two recrystallizations from a mixture of benzene and petroleum ether bring the melting point to 160-162°. 

Tetralone has been reduced to (7 )-1-tetralol with 166 at the 200-L scale (Scheme 12.65). The hydrogen source was /-PrOH. Initially, the maximum concentration to achieve high conversion was 0.05m in a closed system, but the ee decreased near the latter conversions. The key discovery in process optimization was removal of acetone by-product during the reaction. The catalyst is not stable at higher than 40°C however, the reaction can be performed under a slight vacuum (10-50 mbar) to remove acetone. Fresh IPA is added to the reaction to maintain constant volume. Under these conditions coupled with efficient agitation, substrate concentrations of 0.5m are achieved with complete conversions (TOF = 500-2500 Ir1) and reproducible enantioselectivity.212... 

Izak P, Ruth W, Pei Z, Dyson PJ, Kragl U (2008) Selective removal of acetone and butan-l-ol from water with supported ionic liquid-polydimethylsUoxane membrane by pervaporation. Chem Eng J 139 318-321... 

The ground host (2.00 mmol) was evacuated in a 250-mL flask that was connected at a vacuum line to a second 250-mL flask containing 2 mmol (for 4 3 mmol for 5 and 6 6 mmol) acetone. After 1 h at room temperature excess gas was condensed into flask 2 and the inclusion product evacuated for 1 h at 5 xlO 4 Torr. The table gives the molar ratio, the C=0 IR frequency of the included acetone, the desorption temperature (from TGA experiments), and the comparison with the molar ratio that was obtained from crystallization of the complex in liquid acetone. Below the imbibition ratios the acetone gas was completely taken up within detection limits. Exhaust gases required column flow systems for removal of acetone as an inclusion compound. 

Acetone is to be absorbed from its mixture with air into a nonvolatile oil. The entering gas contains 30 mole-% acetone and 70% dry air. Removal of acetone from the air is to be 97%. Calculate the following ... 

The adsorption of VOC vapor with activated carbon is a mass transfer from fluid to solid and an exothermic reaction with an increase in the local temperatme. Fig. 13 shows the temperature evolution, obtained by an infrared camera, inside the column during the removal of acetone in air. The polluted air flows from the top to the bottom of the adsorber. 

Removal of Acetone and Methanol from Air Using Pulsed Corona Discharge... 

The removal of acetone by hydrolysis would then yield n-tagaturonic acid (LXXVa), which may also be named 5-keto-L-galactonic acid or... 

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