Ammonia vapor

Ammonium Phosphates. In the manufacture of ammonium phosphates, an atmosphere of ammonia may need to be maintained because the partial pressure of ammonia rises rapidly as either the temperature or the NH2/P20 mole ratio of the reaction mass increases. Phosphoric acid reacts quickly with ammonia vapor and is used in multistage reactor systems as a scmbber fluid to prevent NH emissions and recover ammonia values. For example, H PO scmbbing of coke-oven off-gases produces ammonium phosphates of relatively good purity. 

Chevron s WWT (wastewater treatment) process treats refinery sour water for reuse, producing ammonia and hydrogen sulfide [7783-06-04] as by-products (100). Degassed sour water is fed to the first of two strippers. Here hydrogen sulfide is stripped overhead while water and ammonia flow out the column bottoms. The bottoms from the first stripper is fed to the second stripper which produces ammonia as the overhead product. The gaseous ammonia is next treated for hydrogen sulfide and water removal, compressed, and further purified. Ammonia recovery options include anhydrous Hquid ammonia, aqueous Hquid ammonia, and ammonia vapor for incineration. There are more than 20 reported units in operation, the aimual production of ammonia from this process is about 200,000 t. 

Because the solution is capable of absorbing one mole of carbon monoxide per mole of cuprous ion, it is desirable to maximize the copper content of the solution. The ammonia not only complexes with the cuprous ion to permit absorption but also increases the copper solubiUty and thereby permits an even greater carbon monoxide absorption capacity. The ammonia concentration is set by a balance between ammonia vapor pressure and solution acidity. Weak organic acids, eg, formic, acetic, and carbonic acid, are used because they are relatively noncorrosive and inexpensive. A typical formic acid... 

Adequate ventilation is necessary for aH process lines to ensure worker safety. Electroless copper baths must have good ventilation to remove toxic formaldehyde vapors and caustic mist generated by the hydrogen evolution reactions and air sparging. Electroless nickels need adequate ventilation to remove nickel and ammonia vapors. Some states and municipalities requite the removal of ammonia from wastewaters. A discussion of printed circuit board environmental issues and some sludge reduction techniques is avaHable (25). 

Copper-based alloys Ammonia (vapors and solutions) Amines Sulfur dioxide Nitrates, nitrites... 

Ammonia vapor is mixed with air and converted into nitrogen oxide at an elevated temperature in the presence of a catalyst, which generally contains noble metals such as platinum and rhodium. The optimal gauge temperature is maintained by controlled ammonia and combustion air preheating. The reaction is highly exothermic ... 

Air stripping Solution containing ammonia high pH Ammonia vapor in air... 

The atmospheric dispersion model for dense ammonia vapor evolves a slice of the plume, from the source to receptor (Kaizer, 1989 ... 

Estrogens Apply bands of sample solution, expose to ammonia vapor and dinitrogen tetroxide (from copper and cone, nitric acid), blow off excess and develop the nitroestrogens so formed. Detection by diazotization and coupling. [58]... 

Note If the chromatogram developed by method B was exposed to ammonia vapors for 10 min before being immersed in liquid paraffin— -hexane (1 -I- 2) the fluorescence of the chromatogram zones became deep red. Glucose and fructose also appeared red. 

Fig. 2 Fluorescence plots of the sugars after separation on a Si-50 000 layer without ammonia-vapor treatment. Start (1), raffinose (2), lactose (3), sucrose (4), glucose (5), fructose (6).

In some cases, e.g. the detection of antioxidants [6], the plate is heated to 105 °C for 5 min after being sprayed and the still hot plate placed immediately in an ammonia-vapor chamber. The blue color of the tryptamine derivatives is also stabilized by spraying afterwards with a 5% methanolic ammonia solution [12]. 

Detection and result The chromatogram was freed from mobile phase (NH3 ) in a stream of cold air for 45 min. It was then immersed in the dipping solution for 1 s and heated to 100°C for ca. 20 min. The chromatograms could be further treated with ammonia vapor if a colored background was found to be troublesome. The pale red zones then became bright red spots and the background frequently... 

It is often possible to increase the detection sensitivity in visible light by exposing the dipped or sprayed chromatogram to ammonia vapors it can also be sprayed with caustic soda or potash solution. When this is done the fluorescence intensity is reduced on silica gel layers and increased on RP ones. 

Nitroindole (ARf 40—45), 5-chloroindole (jiRf 60 — 65) and indole QiRf 70—75) yielded orange-yellow chromatogram zones on a pale yellow background. If the chromatogram was exposed to ammonia vapor for 15 s the color was intensified. The detection limits were 10 ng substance per chromatogram zone. 

Asunoniak-dampf, m. ammonia vapor, -ent-wicklung,/. evolution of ammonia, -flasche,... 

There were placed 120 g of Lthree-necked flask equipped with a stirrer thermometer and methanol/dry ice cooling and 1.5 liters of liquid ammonia were allowed to enter at -40°C. Then there were added under continuous cooling 50 g (2.17 mols) of sodium metal in portions of 1 to 2 g during the course of one hour. The end of the reaction was recognized by the continuation of the blue color. After the end of the reaction the excess sodium was destroyed by the addition of ammonium chloride and the ammonia vaporized at normal pressure. The residue was taken up in 500 ml of water and concentrated in a vacuum to 200 ml in order to remove residual ammonia, and again treated with 300 ml of water. The entire operations were carried out under a nitrogen atmosphere. 

Diesel began work on an economical engine as early as 1880. The following year he took out his first patents—for machines to make clear ice. Throughout the remainder of the decade he worked on an ammonia vapor engine and (less rigorously) on a solar-powered engine. In 1889 he moved to Berlin to work as Linde s representative there. In... 

Read aqua-ammonia vapor pressure curves at wt percent NH3 and corrected temperature (base temperature plus rise) (= 90 + 17.8 = 107.8°F, e.g., or 41.1°C). Read 29.5 mm Hg as vapor pressure of ammonia, Figure 9-76. 

Ammonia vapors from a stripping operation are to be condensed. Select the condenser pressure, which sets the top of stripper pressure, and design a condenser. Water at 90°F is to be used. 

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