Toluene residue separation

Devolatilization of Residual Toluene Residual toluene is continuously removed from a polymer melt stream of 454 kg/h at 230°C and 0.006 weight fraction of toluene, at a vacuum of 20 torr. The density of the polymer is 0.98 g/cm3, and the Florry-Huggins interaction parameter is yl2 = 0.43. (a) Calculate the equilibrium concentration, we- (b) If equilibrium is reached, that is, Wf = we, where uy is the final concentration, calculate the separation efficiency Fs = (wo — Wf)/wQ. (c) If the final concentration wy = 2we, calculate Fs- (d) Calculate for (c) the volumetric flow rate of the vacuum pump removing the volatiles. 

Column chromatography is used for several hydrocarbon type analyses that involve fractionation of viscous oils (ASTM D-2007, ASTM D-2549), including residual fuel oil. The former method (ASTM D-2007) advocates the use of adsorption on clay and clay-silica gel. followed by elution of the clay with pentane to separate saturates elution of clay with acetone-toluene to separate polar compounds and elution of the silica gel fraction with toluene to separate aromatic compounds. The latter method (ASTM D-2549) uses adsorption on a bauxite-silica gel column. Saturates are eluted with pentane aromatics are eluted with ether, chloroform, and ethanol. 

Y-Phenylbutyric acid. Prepare amalgamated zinc from 120 g. of zinc wool contained in a 1-litre rovmd-bottomed flask (Section 111,50, IS), decant the liquid as completely as possible, and add in the following order 75 ml. of water, 180 ml. of concentrated hydrochloric acid, 100 ml. of pure toluene (1) and 50 g. of p benzoylpropionic acid. Fit the flask with a reflux condenser connected to a gas absorption device (Fig. II, 8, l,c), and boil the reaction mixture vigorously for 30 hours add three or four 50 ml. portions of concentrated hydrochloric acid at approximately six hour intervals during the refluxing period in order to maintain the concentration of the acid. Allow to cool to room temperature and separate the two layers. Dilute the aqueous portion with about 200 ml. of water and extract with three 75 ml. portions of ether. Combine the toluene layer with the ether extracts, wash with water, and dry over anhydrous magnesium or calcium sulphate. Remove the solvents by distillation under diminished pressure on a water bath (compare Fig. II, 37, 1), transfer the residue to a Claisen flask, and distil imder reduced pressure (Fig. II, 19, 1). Collect the y-phenylbutyric acid at 178-181°/19 mm. this solidifies on coohng to a colourless sohd (40 g.) and melts at 47-48°. 

Figure 5 illustrates a typical distillation train in a styrene plant. Benzene and toluene by-products are recovered in the overhead of the benzene—toluene column. The bottoms from the benzene—toluene column are distilled in the ethylbenzene recycle column, where the separation of ethylbenzene and styrene is effected. The ethylbenzene, containing up to 3% styrene, is taken overhead and recycled to the dehydrogenation section. The bottoms, which contain styrene, by-products heavier than styrene, polymers, inhibitor, and up to 1000 ppm ethylbenzene, are pumped to the styrene finishing column. The overhead product from this column is purified styrene. The bottoms are further processed in a residue-finishing system to recover additional styrene from the residue, which consists of heavy by-products, polymers, and inhibitor. The residue is used as fuel. The residue-finishing system can be a flash evaporator or a small distillation column. This distillation sequence is used in the Fina-Badger process and the Dow process. 

Only trace amounts of side-chain chlorinated products are formed with suitably active catalysts. It is usually desirable to remove reactive chlorides prior to fractionation in order to niinimi2e the risk of equipment corrosion. The separation of o- and -chlorotoluenes by fractionation requires a high efficiency, isomer-separation column. The small amount of y -chlorotoluene formed in the chlorination cannot be separated by fractionation and remains in the -isomer fraction. The toluene feed should be essentially free of paraffinic impurities that may produce high boiling residues that foul heat-transfer surfaces. Trace water contamination has no effect on product composition. Steel can be used as constmction material for catalyst systems containing iron. However, glass-lined equipment is usually preferred and must be used with other catalyst systems. 

To a 3QQ-mL, round-bottomed flask fitted with a water separator, (Note 1) which contains 15 g of Linde 4A molecular sieve l/16-1nch pellets and Is filled with toluene, are added 7.3 g (0.04 mol) of cyclododecanone, 11.4 g (0.16 mol) of pyrrolidine, 100 mL of toluene, and 0.57 g (0.004 mol) of boron trifluoride etherate. The solution is heated under reflux for 20 hr. The water separator is replaced by a distillation head, and about 90 mL of the toluene is removed by distillation at atmospheric pressure. The residue containing l-(N-pyrrolidino)-l-cyclododecene (1) is used in the next step without further purification (Note 2). 

The reaction mixture is cooled in an ice bath and slowly poured into 1000 cc. of 10 per cent acetic acid cooled to 0° (ice< salt mixture). The toluene layer is separated, washed once with water, twice with cooled 7 per cent sodium carbonate solution, and again with water. The toluene is removed by distillation at ordinary pressure, and the residue is distilled under reduced... 

The reaction mixture is diluted with 250 ml of water, the mixture is transferred to a 2 liter flask using methanol as a wash liquid, and the organic solvents are distilled at 20-25 mm using a rotary vacuum evaporator. The product separates as a solid and distillation is continued until most of the residual toluene has been removed. The solid is collected on a 90 cm, medium porosity, fritted glass Buchner funnel and washed well with cold water. After the material has been sucked dry, it is covered with a little cold methanol, the mixture is stirred to break up lumps, and the slurry is kept for 5 min. The vacuum is reapplied, the solid is rinsed with a little methanol followed by ether, and the material is air-dried to give 9.1 g (85%), mp 207-213° after sintering at ca. 198°. Reported mp 212-213°. The crude material contains 1.0-1.5% of unreduced starting material as shown by the UV spectrum. Further purification may be effected by crystallization from methanol. 

Ethylenedioxy-2l-acetoxypregn-4-en-3-one A solution containing 3,3 20,20-bisethylenedioxypregn-5-en-21-ol acetate (120 mg) and /7-toluene-sulfonic acid hydrate (12 mg) in dry acetone (3 ml) is allowed to stand at 22° for 14 hr. Sodium bicarbonate solution and ether are added and the organic layer is separated, washed with water, dried and evaporated. Crystallization of the residue from hexane yields 81 mg (75%) of 20-monoketal, mp 140-141°. 

The toluene phase was separated and discarded. The aqueous phase, together with a precipitated water- and toluene-insoluble oil, was made alkaline and extracted repeatedly with chloroform. The chloroform solution was concentrated in vacuo. The residue was re-... 

To a solution of 35.3 parts of phenylacetonitrile and 47.6 parts of 2-bromopyridine in 175 parts of dry toluene is added 53.4 parts of sodamide slowly with stirring over a period of 45 minutes. The resultant mixture is stirred at 100 C for 2 hours before it is cooled and the excess sodamide is decomposed by the addition of water. The toluene layer is separated and washed with water to remove excess alkali. The toluene solution is extracted with 6N hydrochloric acid and the acid extract is made alkaline and then extracted with toluene. The toluene solution is dried over sodium sulfate and the solvent is evaporated. Recrystal-lization of the residue from alcohol-hexane gives a-phenvl-2-pyridineacetonitrile melting at about 87°-88°C. 

The toluene layer is separated and washed with water and extracted with 6N hydrochloric acid. The acid extract Is made alkaline and extracted with toluene. The toluene solution is washed with water and dried and the solvent is evaporated. Distillation of the residue gives 4-diisopropvlamino-2-phenvl-2-(2-pvridyl)-butvronitrile boiling at about 145 -160°C at 0.3 mm pressure. 

A solution or dispersion consisting of 20.1 g (0.1 mol) of 7-chloro-p-fluorobutyrophenone, 19.8 g (0.2 mol) of 4-methylpiperidine end 0.1 g of potassium iodide in 150 ml toluene is heated in a seeled gless tube for 15 hours at 100°C to 110°C. The potassium iodide and the 4-methylpiperidine hydrochloride formed in the reaction are separated by filtration and the solvent removed from the filtrate by evaporation In vacuum on a steam bath. The residue is distilled and the fraction obtained at 120°C to 125 0 and at a pressure lower than 0.1 mm Hg is collected. The basa Is dissolved in ether and the 4-fluoro-7-(4-methylpiperidino)-butyro-phenone precipitated as the hydrochloride. The reaction product is purified by recrystallization in ethanol/ether. 

To a slurry of sodamide in 200 cc of toluene representing 6.7 g of sodium was added at 30° to 40°C, 32.3 g (0.31 mol) of 2-aminopyridine. The mixture was heated to reflux temperature and was refluxed for VA hours. To the resulting mixture was added over a period of approximately one hour a solution of 32 g of freshly distilled N,N-dimethyl-i3-chloroethylamine in 40 to 50 cc of dry toluene. The reaction mixture was then haated for 2 hours at reflux temperature. Thereafter, 200 cc of water was added and the toluene layer was separated and washed with water. The toluene was stripped from the mixture by distillation and the residue was distilled under reduced pressure. The distillate was refractionated and the portion distilled at 93° to 103°C/1 mm was recovered. Yield of N-(2-pvridvl)-N, N -dlmethyl-ethvlenediamine, 60%. 

The toluene was then stripped off by distillation and the residue was distilled under reduced pressure. The main fraction was redistilled. Yield of N-(2-pyridyl)-N-(2-thenyl)-N, -N -dimethyl-ethylenediamine was 69% BP 130° to 140°C/0.4 mm. A portion of the product was dissolved in ether and an ether solution of hydrogen chloride was added. The monohydrochloride of N-(2-pyridyl)-N-(2-thenyl)-N, N -dimethyl-ethylenediamine which separated was washed with ether and dried. 

A stirred mixture of 5 parts of 2-chloro-10-[ r-(N Pipera2ino)propyl] phenothiazine, 1.92 parts of 2-bromoethanol, 2.11 parts of potassium carbonate and 35 parts of toluene is refluxed for 5 hours. The mixture is treated with water and benzene and the organic layer is separated, washed with water, dried over anhydrous potassium carbonate, filtered and evaporated. The residue is distilled at about 240°244°C and 0.15 mm pressure to yield 2-chloro-10-[-y-(N -/3-hydroxyethyl-N-pipera2ino)-propyl] phenothiazine according to U.S. Patent 2,838,507. 

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