Diethylene glycol extraction

Solvent Extraction. Diethylene glycol extraction of benzene, toluene, and xylene from Platformates is one commercial method for the recovery of these materials. The process has been named the Udex process and has been described by Read (70). 

Diethylene glycol monoethyl ether [111-90-0] M 134.2, b 201.9", d 0.999, n 1.4273, n 1.4254. Ethylene glycol can be removed by extracting 250g in 750mL of benzene with 5mL portions of water, allowing for phase separation, until successive aqueous portions show the same volume increase. Dried, and freed from peroxides, as described for diethylene glycol mono-n-butyl ether. 

A solution of cholest-4-en-3-one (139), 1 g, in diethylene glycol dimethyl ether (20 ml) is treated for 1 hr with a large excess of diborane at room temperature under nitrogen and then left for a further 40 min. Acetic anhydride (10 ml) is added and the solution refluxed for 1 hr. The mixture is concentrated to a small volume, diluted with water and extracted with ether. The extracts are washed with 10% sodium hydroxide solution, then with water and dried over sodium sulfate. Removal of the solvent leaves a brown oil (1.06 g) which is purified by chromatography on alumina (activity I). Hexane elutes the title compound (141), 0.68 g mp 76-77°. Successive crystallization from acetone-methanol yields material mp 78-79°, [a]p 66°. 

The carbonyl compound to be reduced (0.1 mole) is placed in a 250-ml round-bottom flask with 13.5 g of potassium hydroxide, 10 ml of 85% hydrazine hydrate, and 1(X) ml of diethylene glycol. A reflux condenser is attached and the mixture is heated to reflux for I hour (mantle). After refluxing 1 hour, the condenser is removed and a thermometer is immersed in the reaction mixture while slow boiling is continued to remove water. When the pot temperature has reached 200°, the condenser is replaced and refluxing is continued for an additional 3 hours. The mixture is then cooled, acidified with concentrated hydrochloric acid, and extracted with benzene. The benzene solution is dried, and the benzene is evaporated to afford the crude product, which is purified by recrystallization or distillation. 

A mixture of 1B g of 1 -acetamido-3,5-dimethvladamantane, 3B g of sodium hydroxide, and 300 ml of diethylene glycol was refluxed for a period of 6 hours. The reaction product mixture was cooled and poured onto about IfiQQ ml of crushed Ice. The basic solution thus obtained was extracted five times with 250-ml portions of benzene and the aqueous layer was discarded. The combined benzene extracts were dried over sodium hydroxide and the dried benzene solution concentrated in vacuo to give a crude oil weighing 14 g and having np =... 

Soil sample is extracted with a mixture of methanol and 0.1 M ammonium chloride. Acetamiprid, IM-1-2 and IM-1-4 residues are extracted with dichloromethane under alkaline conditions. After adding diethylene glycol, dichloromethane in the extract is removed by rotary evaporation, and the residue is subjected to a cleanup procedure using Florisil PR column chromatography and then with a packed Extrelut 20 column. 

Recovery of acetamiprid, IM-1-2 and IM-1-4. Combine 20 g of the air-dried soil with 100 mL of a mixed solvent of methanol and 0.1 M ammonium chloride (4 1, v/v) in a 250-mL stainless-steel centrifuge tube, shake the mixture with a mechanical shaker for 30 min and centrifuge at 8000 r.p.m. for 2 min. Filter the supernatant through a Celite layer (1-cm thick) under reduced pressure into a 500-mL flask. Add a second 100 mL of mixed solvent to the residue and then extract and filter in the same manner. Combine the filtrates and add 150mL of distilled water with 1 g of sodium chloride. Transfer the aqueous methanol solution into a 1-L separatory funnel and shake the solution with 200 mL of dichloromethane for 5 min. Collect the dichloromethane in a flask and adjust the pH of aqueous methanol to 13 with sodium hydroxide. Extract the solution with two portions of 200 mL of dichloromethane for 5 min. Combine the dichloromethane extracts and pass through a filter paper with anhydrous sodium sulfate. Add 0.5 mL of diethylene glycol and then concentrate the dichloromethane extract to about 0.5 mL on a water-bath at ca 40 °C by rotary evaporation. 

Butex A process for separating the radioactive components of spent nuclear fuel by solvent extraction from nitric acid solution, using diethylene glycol dibutyl ether (also called Butex, or dibutyl carbitol) as the solvent. Developed by the Ministry of Supply (later the UK Atomic Energy Authority) in the late 1940s. Operated at Windscale from 1952 until 1964 when it was superseded by the Purex process. 

C. p-Bromodiphenylmethane. A 2-1. three-necked flask fitted with a distillation condenser, a thermometer, and an efficient mechanical stirrer is charged with 1.1 1. of diethylene glycol (Note 7) and a solution of 190 g. of potassium hydroxide in 100 ml. of water. The mixture is stirred, and water is distilled until the internal temperature reaches 180°. The resulting solution is allowed to cool to 100° or below, and 146 g. (0.40 mole) of l-/>-bromophenyl-l-phenyl-2,2,2-trichloroethane (Note 8) is added. The condenser is set for reflux, and the mixture is stirred and heated to boiling for 5 hours (Note 9). The hot solution is then poured onto 3 kg. of cracked ice, and the mixture is allowed to stand overnight. The oily layer is separated and dissolved in ether (any insoluble material is discarded), and the aqueous layer is extracted with 250 ml. of ether. The combined ethereal solution and extracts are dried over calcium chloride and filtered. The ether is removed under reduced pressure on a hot water bath. The product is distilled under reduced pressure b.p. 120-130° (3 mm.), 155-163° (13 mm.) (Note 10), n2id 1.6028, dH 1.342. The yield is 74-79 g. (75-80%) (Note 11). 

Solvent extraction of benzene works the same way. But instead of water, the various solvents used are sulfolane, liquid SO2, diethylene-glycol, and NMP (N-methyl pyrrolidone). The paint thinner/salt/water process described above might be called a batch solvent process, since it consists of sequential steps that can be repeated, batch after batch. Some low-volume commercial processes still operate that way. 

Like the solvent extraction process, extractive distillation relies on the intimate contact of the liquid solvent and the aromatics concentrate vapors to allow the aromatics to be preferentially dissolved in the solvent. The usual list of solvents includes DEG (Diethylene glycol), TEG (Triethylene glycol), NMP (N-methyl pyrrolidone), or methyl formamide. 

A 22-liter resin kettle was charged with 9.246 liters of toluene, diethylene glycol (2.50 mol), and dimethylterephthalate (2.50 mol) then heated to 80°C and treated with Novozyme 435. After heating and sparging the mixture for 24 hours at 80°C, toluene was distilled from the mixture at 70°C 50torr. The resulting solids were divided into three equal portions and extracted with 11 liters of refluxing chloroform for 3 hours. The hot chloroform extract was then filtered to remove the enzyme catalyst and the filtrate concentrated to about 3.5 liters. The solution was then cooled to ambient temperature, refiltered, and the product isolated as a white solid in 83% yield with 99% purity. 

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