Steam pressure filtration

A modification to vapor pressure dewatering is the so-called Hi-Bar Steam Pressure Filtration (Bokela GmbH, Karlsruhe, Germany), where pure steam... 

Figure 29.9 Steam pressure filtration. (From Stahl, 1998.)...

Bott R. Hi-Bar filtration The continuous pressure and steam pressure filtration. Bo-kela Karlsruhe, Germany, 2000. 

The preservation of meat products by concentration is best illustrated by the preservation of beef extract. It is the evaporated filtrate obtained from new, clean beef, treated to high steam pressure. This extract according to Stutzer contains ... 

Indoleacetic acid In a 1-litre flask, fitted with a reflux condenser, place a solution of 35 2 g. of sodium cyanide in 70 ml. of water, then add 25 g. of gramine and 280 ml. of 95 per cent, ethanol. Reflux the mixture (steam bath) for 80 hours. Dilute the cooled reaction mixture with 35 ml. of water, shake with a little activated charcoal (e.g., Norit), filter and concentrate to about 350 ml. imder reduced pressure (water pump) in order to remove most of the alcohol. Cool to about 5°, filter off the solid and wash it with a little cold water keep the filtrate (A). Recrystallise the solid from alcohol-ether to give 5-0 g. of 3-indoleacetamide, m.p. 150-151°. 

After separation of the catalyst by filtration, raw succinic anhydride is purified by distillation under reduced pressure, ie, 4—13 kPa (30—98 mm Hg), and flaked. The material of constmction of the plant is stainless steel. Typical specific consumptions for the production of one metric ton of succinic anhydride are maleic anhydride at 1050 kg hydrogen, 300 m steam, 4500 kg cooling water, 100 m electricity, 350 kW nitrogen, 100 m and methane,... 

The solution of sodium methyl sulfide in absolute alcohol is transferred to a 3-I. three-necked flask, which is placed on a steam bath and fitted with a dropping funnel, a reflux condenser, and a mechanical stirrer. The solution is heated until the alcohol begins to boil. Heating is then discontinued and 302 g. (3.7s moles) of ethylene chlorohydrin (Note 5) is added dropwise with efficient stirring over a period of about two hours (Note 6). The reaction mixture is concentrated by distilling as much of the alcohol as possible on the steam bath. The mixture is then allowed to cool and the sodium chloride removed by filtration. The flask is rinsed, and the sodium chloride washed with three loo-cc. portions of 95 per cent alcohol. The combined filtrate and washings are concentrated on the steam bath under reduced pressure until no further distillate passes over. The residue is then transferred to a modified Claisen flask (Org. Syn. Coll. Vol. i, 125) and fractionally distilled under reduced pressure. The yield is 238-265 g. (74-82 per cent of the theoretical amount based on the sodium used) of a product boiling at 68-7o°/20 mm. 

D. Methionine.—A suspension of 21.5 g. (0.063 mole) of this tricarboxylic acid in 350 cc. of hot water is heated on the steam bath and 40 cc. of concentrated hydrochloric acid (sp. gr. 1.19) is added. Carbon dioxide is immediately evolved and the substance goes into solution. After heating for one and a half hours, 200 cc. more of concentrated hydrochloric acid is added and heating is continued for forty-five minutes longer. The solution, on cooling, deposits phthalic acid this is filtered off and washed with two 50-cc. portions of water (Note 3). The combined filtrate and washings are evaporated to dryness on the steam bath under reduced pressure, and the dry residue is dissolved in... 

The reaction mixture is filtered with suction and the cake is washed thoroughly with two 200-ml. portions of glacial acetic acid (Note 4). The combined filtrate and washings are evaporated under reduced pressure on the steam bath until a thick oil, which generally partially crystallizes, remains. To purify the crude product, 100 ml. of water is added, and the flask is warmed on a steam bath until the solid melts. The mixture of water and oil is stirred rapidly in an ice bath, and diethyl acetamidomalonate crystallizes as a fine white product. After cooling in an ice bath for an additional hour, the product is collected by filtration, washed once with cold water, and dried in air at 50°. A second crop is obtained by concentrating the mother liquor under reduced pressure. The yield of diethyl acetamidomalonate, m.p. 95-97° (Note 5), is 52-53 g. (77-78%) based on malonic ester. 

A suspended catalyst was removed from a process stream in a pressure filter. After filtration was complete, the remaining liquid was blown out of the filter with steam at a gauge pressure of 30 psi (2 bar). The pressure in the filter was blown off through a vent valve, and the fall in pressure was observ ed on a pressure gauge. The operator then opened the filter for cleaning. The filter door was held closed by eight radial bars, which fitted into U-bolts on the filter body. The bars were withdrawn from the U-bolts by turning a lai ge wheel, fixed to the door. The door could then be withdrawn. 

The mixture is decanted into an Erlenmeyer flask, the residual green salts are washed with two 15-ml portions of acetone, and the washings are added to the main acetone solution. Cautiously, sodium bicarbonate (approx. 13 g) is added to the solution with swirling until the pH of the reaction mixture is neutral. The suspension is filtered, and the residue is washed with 10-15 ml of acetone. The filtrate is transferred to a round-bottom flask and concentrated on a rotary evaporator under an aspirator while the flask temperature is maintained at about 50°. The flask is cooled and the residue transferred to a separatory funnel, (If solidification occurs, the residue may be dissolved in ether to effect the transfer.) To the funnel is added 100 ml of saturated sodium chloride solution, and the mixture is extracted with two 50-ml portions of ether. The ether extracts are combined, washed with several 5-ml portions of water, dried over anhydrous magnesium sulfate, and filtered into a round-bottom flask. The ether may be distilled away at atmospheric pressure (steam bath) or evaporated on a rotary evaporator. On cooling, the residue should crystallize. If it does not, it may be treated with 5 ml of 30-60° petroleum ether, and crystallization may be induced by cooling and scratching. The crystalline product is collected by filtration and recrystallized from aqueous methanol. 4-r-Butylcyclohexanone has mp 48-49° (yield 60-90 %). 

A solution of 10 g (0.023 mole) of cholesteryl acetate (mp 112-114°) in ether (50 ml) is mixed with a solution containing 8.4 g (0.046 mole) of monoperphthalic acid (Chapter 17, Section II) in 250 ml of ether. The solution is maintained at reflux for 6 hours, following which the solvent is removed by distillation (steam bath). The residue is dried under vacuum and digested with 250 ml of dry chloroform. Filtration of the mixture gives 6.7 g of phthalic acid (87% recovery). The solvent is evaporated from the filtrate under reduced pressure and the residue is crystallized from 30 ml of methanol, giving 6.0 g (58% yield) of -cholesteryl oxide acetate. Recrystallization affords the pure product, mp 111-112°. Concentration of the filtrate yields 1.55 g (15% yield) of a-cholesteryl oxide acetate which has a mp of 101-103° after crystallization from ethanol. 

Stirring. The succinimide is removed by suction filtration and washed twice with 10-mI portions of carbon tetrachloride. The combined filtrate and washings are fractionally distilled at atmospheric pressure to remove the carbon tetrachloride and excess olefin (steam bath). The residue is distilled under vacuum, giving about 60 % yield of 3-bromo-cyclohexene, bp 68715 mm or 4472 mm. 

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