Ammonia soda process

The soda-ammonia process occurs in two main stages. First, brine is saturated with ammonia gas and this ammoniacal brine is then treated with carbon dioxide. The equilibrium... 

When heated, sodium hydrogencarbonate readily decomposes evolving carbon dioxide, a reaction which leads to its use as baking powder when the carhon dioxide evolved aerates the dough. In the soda-ammonia process the carbon dioxide evolved is used to supplement the main carbon dioxide supply obtained by heating calcium carbonate ... 

Ammoniak-rest, m. ammonia residue (amidogen, NH2). -rohr, n. ammonia tube or pipe, -salpeter, m. ammonia saltpeter (ammonium nitrate), -salz, n. ammonium salt, -selfe,/. ammonia soap, -soda, /. ammonia soda, Solvay soda, -stickstoff, m. ammonia nitrogen. -verbindung, /, ammonia compound ammonium compound, -verfahren, n. ammonia process, -wasche, /. ammonia scrubbing ammonia recovery plant, -wascher,... 

Ammonia, another well known cleaner, is also used to manufacture fertilizers, nitric acid, sodium carbonate (washing soda), explosives, nylon, and baking soda. Ammonia is produced by combining nitrogen gas (obtained from the air) and hydrogen gas (obtained from natural gas) in a process called the Haber-Bosch process ... 

Calcium chloride is obtained as a by-product in the manufacture of sodium carbonate (soda ash) by ammonia-soda (Solvay) process. The process involves the reaction of sodium chloride with calcium carbonate and ammonia. Calcium chloride is currently produced in bulk amounts by evaporation of natural underground brines. In the laboratory, calcium chloride can be prepared by treating bmestone with hydrochloric acid followed by evaporation of solution to obtain crystals. The crystals are dehydrated to obtain anhydrous salt. Calcium oxide or hydroxide may be used instead of carbonate. 

He conducted experiments that led to the ammonia process for producing sodium carbonate. On 15 April 1861, the eve of his twenty-third birthday, Ernest Solvay took out his first patent on the industrial manufacture of carbonate of soda by means of sea salt, ammonia and carbonic acid. ... 

Te-Pang, Hou, Manufacture of Soda with Special Reference to the Ammonia Process—A Practical Treatise. New York, 1933, pp. 15-17. 

Much ingenuity has been exercised by chemists in attempts to effect this change through a series of reactions. In the older Le Blanc soda process sulphuric acid is used in the first step and coal (carbon) in another, and neither of these auxiliary substances is recovered. The soda process which is employed exclusively today is known as the Solvay or ammonia process and uses ammonia as an auxiliary substance. The ammonia is almost 100 per cent recoverable, however, and can be used over and over indefinitely. The successive steps in the process are as follows ... 

FIG. 9-1. Diagram of a chemical plant for making sodium carbonate by the ammonia-soda (Solvay) process. 

Sodium bicarbonate is manufactured either by passing carbon dioxide into a cold saturated solution of sodium carbonate, or by the ammonia-soda (Solvay) process, in which first ammonia and then carbon dioxide is passed into a sodium chloride solution to precipitate sodium bicarbonate while the more-soluble ammonium chloride remains in solution. 

This method is similar to the Soda-Ash process. The difference consisted of g a solution of sodium sulphite (16 -17% Na SOj) added with ammonia gas bubbling it to 2% free NHj. The solution should have pH 5. The pH value to 8.5 after mixing the solution with TNT (15 min). The solution contains onium nitrate, sulphate and sulphite. Free sodium sulphite causes the form-n of a red colour in the slurry of TNT with the aqueous solution. TNT made this method is slightly darker owing to the action of ammonia on 0- and itrotoluene producing traces of 2.4- and 4.6 dinitro-3-toluidine. Traces of... 

TABLE 7.2 Quality of Typical Sodium Carbonate from the Ammonia-Soda (Solvay) Process"... 

FIGURE 7.2 Flowsheet for the ammonia-soda (Solvay) process to provide sodium carbonate. Units numbered I and 2 are ammonia stills, the first being used to recover free ammonia and the second to recover that produced by the addition of slaked lime (Eq. 7.16). 

Calcium Chloride. Irtergravin -Orales. CaCI. mo] wt 110,99. Ca 36.11%, Cl 63.89%. Forms mono-, di -, tetra -and hexahydrates. Obtained as a byproduct of the ammonia-soda (Solvay) process and as a joint product from natural salt brines Faith, Keyes Clark s Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Intersci-ence, New York, 4th ed., 1975) pp 186-190. Acute toxicity I. B. Syed, F. Hosain, Toxicol. Appl. Pharmacol. 22, 150 (1972). 

T.-P. Hou, The manufacture of soda, with special reference to the ammonia process , Hafner Publishing Co., 1969. 

Additional units could be added to the ammonia process. Reactants should be mixed before entering a reactor, not just combined. Simply combining flour, eggs, water, and baking soda is not enough. The reactants must be mixed to bake a cake. The simplest mixer combines two or more streams into one stream ... 

In addition to the ammonia processes already discussed, a number of other procedures for the manufactuie of hexamethylenetetramine are also described in the patent literature.- In a method employing ammonium Salts. formal deh -de solution is added gradual to a solution of ammonium chloride which is supersaturated with sodium bicarbonate or to the ammonium bicarbonate-salt solutions obtained in the Soh ay soda process. It is stated that the saline hexamethylenetetramine produced by this method can be used dii-ectly for resin manufacture or purified by extraction with alcohol.. Another procedure of this describes addition of formaldehyde to an aqueous solution of ammonium sulfate and the oxide, hydroxide or carbonate of an alkaline-earth metal. 

Carbon dioxide is used in the manufacture of sodium carbonate by the ammonia-soda process, urea, salicyclic acid (for aspirin), fire extinguishers and aerated water. Lesser amounts are used to transfer heat generated by an atomic reactor to water and so produce steam and electric power, whilst solid carbon dioxide is used as a refrigerant, a mixture of solid carbon dioxide and alcohol providing a good low-temperature bath (195 K) in which reactions can be carried out in the laboratory. 

Caustic Soda. Diaphragm cell caustic is commercially purified by the DH process or the ammonia extraction method offered by PPG and OxyTech (see Fig. 38), essentially involving Hquid—Hquid extraction to reduce the salt and sodium chlorate content (86). Thus 50% caustic comes in contact with ammonia in a countercurrent fashion at 60°C and up to 2500 kPa (25 atm) pressure, the Hquid NH absorbing salt, chlorate, carbonate, water, and some caustic. The overflow from the reactor is stripped of NH, which is then concentrated and returned to the extraction process. The product, about 62% NaOH and devoid of impurities, is stripped free of NH, which is concentrated and recirculated. MetaUic impurities can be reduced to low concentrations by electrolysis employing porous cathodes. The caustic is then freed of Fe, Ni, Pb, and Cu ions, which are deposited on the cathode. 

These disadvantages prompted Ernest Solvay (1838—1922) to develop and commercialize a procedure using ammonia to produce soda ash from salt and limestone. The first plant using the Solvay process was built in 1863 this process or variations are in use in much of the world in the 1990s. 

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