Column ammonia

The reactor effluent, containing 1—2% hydrazine, ammonia, sodium chloride, and water, is preheated and sent to the ammonia recovery system, which consists of two columns. In the first column, ammonia goes overhead under pressure and recycles to the anhydrous ammonia storage tank. In the second column, some water and final traces of ammonia are removed overhead. The bottoms from this column, consisting of water, sodium chloride, and hydrazine, are sent to an evaporating crystallizer where sodium chloride (and the slight excess of sodium hydroxide) is removed from the system as a soHd. Vapors from the crystallizer flow to the hydrate column where water is removed overhead. The bottom stream from this column is close to the hydrazine—water azeotrope composition. Standard materials of constmction may be used for handling chlorine, caustic, and sodium hypochlorite. For all surfaces in contact with hydrazine, however, the preferred material of constmction is 304 L stainless steel. 

Ammonia absorption/ desorption from ammonia water 240 Pilot-plant study in a polypropylene hollow-fiber column ammonia is absorbed in diluted sulfuric acid... 

All samples were analyzed in an AllTech 1/8"I.D, 20 foot column, packed with VZ-7 resin, using helium as the carrier gas. This column proved more effective for the measurement of the C4 components than the Poropak- N column. Ammonia was not detected by this column and as a result some of the assumptions employed to treat the solvent phase are described in a later paragraph. The G.C. was run with the injector chamber set at 115 C, the column oven temperature at 60 C and the filament current set at 150 ma. Column analyses were performed by an Autolab Integrator. A Leeds and Northrup strip chart recorder was used to plot the output of the integrator and to... 

Commercial production of ethanolamines (EOA) is by reaction of ethylene oxide with aqueous ammonia. The ethylene oxide reacts exothermically with 20% to 30% aqueous ammonia at 60 to 150°C and 30 to 150 bar in a tubular reactor to form the three possible ethanolamines (mono-ethanolamine - MEA, di-ethanolamine - DEA and tri-ethanolamine - TEA) with high selectivity. The product stream is then cooled before entering the first distillation column where any excess ammonia is removed overhead and recycled. In the second column, ammonia and water are removed and the EOA s are separated in a series of vacuum distillation columns. 

P.A. D Agostino and L.R. Provost, Detection of sarin and soman in a complex airborne matrix by capillary column ammonia chemical ionization gas chromatography-mass spectrometry and gas... 

Metal-focusing process after the sample injection is i shown in Fig. 3. After all ions in the sample are extracted in the stationary phase, mobile phase is introduced in the column. Ammonia in the stationary phase begins to be j neutralized with hydrochloric acid in the mobile phase. The neutralization area, where reaction between the acid and the base has just finished, is shown as pH border in Fig. 3. The pH border proceeds from left to right (the same direction as the mobile phase) however, its flow rate is, ... 

The catalysts were tested in a conventional laboratory apparatus with a tubular fixed-bed (length 10" diameter 1/4"), working at atmospheric pressure and at 360-480°C. The analysis of propane, propene, acrylonitrile, acetonitrile and uncondensable gases were made by gas-chromatographic techniques (with Poropack QS and Carbosieve packed columns) ammonia and hydrogen cyanide was detected by absorptions and titrations. The composition of the feed was propane 25%, oxygen 20%, ammonia 10% and the remainder heUum. The catalyst (2 ml) was loaded as grains (30-40 mesh) and the contact time was around 2 s. A thermocouple, placed in the middle of the catalyst bed, was used to verify that the axial temperature profile was within 3°C. 

Alkalinity and buffer capacity Dissociation of ammonium ions to ammonia results in the production of hydrogen ions. Unless the water column or soils are well buffered, the medium can be acidified and the rate of ammonia volatilization can decrease. Thus, a water column with high alkalinity and calcium carbonate content can buffer the system and maintain high-pH conditions. Alkalinity is affected by the balance between photosynthesis and respiration by algae and submersed macrophytes in the water column. Ammonia volatilization losses are directly proportional to the alkalinity of the system. 

Gas stripping packed or tray column ammonia, column only with internals. FOB cost = 550000 at design flow rate of sour water = 12 L/s with n = 0.53 for the range 3-55 L/s. L+M = 3.0. Factors tower only, X 1.00 tower plus reboiler, condensers, accumulators, shutdown tankage, piping, X 4.2. Retrofit, X 1.6. 

Hydrogen chloride released dissolves in water during condensation in the crude oil distillation column overhead or in the condenser, which cause corrosion of materials at these locations. The action of hydrochloric acid is favored and accelerated by the presence of hydrogen sulfide which results in the decomposition of sulfur-containing hydrocarbons this forces the refiner to inject a basic material like ammonia at the point where water condenses in the atmospheric distillation column. 

To a vigorously stirred suspension of 2 mol of lithium amide in 2 1 of liquid atimonia (see II, Exp. 11) was added in 15 min 1 mol of propargyl alcohol (commercial product, distilled in a partial vacuum before use). Subsequently, 1 mol of butyl bromide was added dropwise in 75 min. After an additional 1.5 h, stirring was stopped and the ammonia was allovied to evaporate. To the solid residue were added 500 ml of ice-water. After the solid mass had dissolved, six extractions with diethyl ether were performed. The (unwashed) combined extracts were dried over magnesium sulfate and then concentrated in a water-pump vacuum. Distillation of the residue through a 40-cm Vigreux column afforded 2-heptyn-l-ol, b.p. 

To a solution of 22 g of K0-tert.-Ci,H9 (see Exp. 4, note 2) in 400 ml of anhydrous liquid ammonia were added 22 g of the bis-ether (note 1). After stirring for 4 h, 20 g of powdered ammonium chloride were introduced in small portions. The ammonia was removed by placing the flask in a water-bath at 40°C, then 200 ml of water were added and five extractions with small portions of redistilled pentane were carried out. The combined extracts were washed with water, dried over magnesium sulfate and then concentrated in a water-pump vacuum. The residue was carefully distilled through a 40-cm Vigreux column, giving the allenic bis-ether,... 

Acetaldehyde can be isolated and identified by the characteristic melting points of the crystalline compounds formed with hydrazines, semicarbazides, etc these derivatives of aldehydes can be separated by paper and column chromatography (104,113). Acetaldehyde has been separated quantitatively from other carbonyl compounds on an ion-exchange resin in the bisulfite form the aldehyde is then eluted from the column with a solution of sodium chloride (114). In larger quantities, acetaldehyde may be isolated by passing the vapor into ether, then saturating with dry ammonia acetaldehyde—ammonia crystallizes from the solution. Reactions with bisulfite, hydrazines, oximes, semicarb azides, and 5,5-dimethyl-1,3-cyclohexanedione [126-81 -8] (dimedone) have also been used to isolate acetaldehyde from various solutions. 

ALkanolainines aie manufactuied fiom the coiiesponding oxide and ammonia. Anhydtous 01 aqueous ammonia may be used, although anhydtous ammonia is typically used to favor mono alkan olamine production and requires high temperature and pressure (20). Mono-, di-, and trialkanolamines are produced in the reactor and sent to downstream columns for separation (Fig. 2). 

Extensive work has been done on corrosion inhibitors (140), activated carbon use (141—144), multiple absorption zones and packed columns (145,146), and selective absorption and desorption of gas components (147,148). Alkan olamines can also be used for acid gas removal in ammonia plants (149). 

The ammonolysis of phenol (61—65) is a commercial process in Japan. Aristech Chemical Corporation (formerly USS Chemical Division of USX Corporation) currently operates a plant at Ha verb ill, Ohio to convert phenol to aniline. The plant s design is based on Halcon s process (66). In this process, phenol is vapori2ed, mixed with fresh and recycled ammonia, and fed to a reactor that contains a proprietary Lewis acid catalyst. The gas leaving the reactor is fed to a distillation column to recover ammonia overhead for recycle. Aniline, water, phenol, and a small quantity of by-product dipbenylamines are recovered from the bottom of the column and sent to the drying column, where water is removed. 

The reaction may be carried out in a corrosion-resistant apparatus fitted with an appropriate fractionating column. Here, the ammonia is separated from the aniline and removed from the reaction. The pressure is controlled to maintain the temperature near 300 °C. When conversion reaches 50—60%, the... 

Fig. 5. Fermentative production of amino acids (140). A, pure culture B, inoculation C, boiler D, air compressor E, air filter F, seed tank G, ammonia water for pH control H, fermenter I, sterilizer , culture media K, preparation tank L, centrifugal separator M, ion-exchange column N, crystallizing...

A fiactionating column is lequked foi the removal of ammonia and recycle of ethylenediamine. The molten product (mp 133°C) is then mn into ice water to give a solution that is methylolated with 37% aqueous formaldehyde. 

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