Ammonia is a product with widespread use.
In 1716, J. Kunckel mentioned formation of ammonia during fermentation. S. Hales, in 1727, noted that if he warms calcium oxide (CaO) with ammonia salt in a retort to allow collecting the gaseous release of water, this does not seemed to give off any gas; by contrast, all the water was drawn into the retort. But it was Joseph Priestley, in 1774, that “discovered” Ammonia. He repeated the same experiment of Hales, only in a pneumatic mercury camera, and got what he called “alkaline air”; which is nothing more than the gaseous ammonia, whose formula is NH3.
Claude Louis Berthollet, in 1784, decomposed the gas by means of an electric spark setting composition as three (3) volumes of hydrogen and one (1) volume of nitrogen. It was the first elemental analysis of ammonia that provided knowledge of the formula.
The first industrial-scale production occurred in 1913 in Germany, using the Haber-Bosch process. The ammonia production process essentially consists in the reaction between nitrogen and hydrogen, under elevated pressure and temperature in the presence of a catalyst, as shown in the following equation:
N2 + 3H2 = 2NH3
Before the advent of synthetic ammonia industry, the main source of the nitrogen consisted of the gases from coal coking operations.
The nitrogen used in the synthesis of ammonia is derived from the air. A wide variety of sources, however, is used to obtain nitrogen required in the process.
The Haber-Bosch process is the main method for obtaining ammonia, but there are many other processes. In laboratories, e.g., ammonia is obtained by heating ammonium chloride with calcium hydroxide, according to the following reaction:
NH4Cl + 2 Ca (OH) 2 = 2NH3 + H2O + CaCl2
2.1 General Information
Name of a chemical substance consisting of a nitrogen and three hydrogen (NH3) atoms. Obtained from the process of atmospheric nitrogen and hydrogen at high temperature and pressure in the presence of a catalyst. Toxic and corrosive gas.
Used as the cooling gas, as the basic component for the manufacture of fertilizers, nitric acid and ammonium nitrate.
Remains in the liquid state at low temperatures and relatively high pressures. It is a colorless gas, but at high concentrations produces visible vapor cloud, presenting strong alkaline reaction. It has characteristic, pungent and penetrating odor.
Corrosive to copper and galvanized surfaces.
It is very soluble in water; at 0 ° C and 760 mm / Hg, a volume of water dissolves approximately 1,300 volumes of gas, and 20 ° C, the same volume of water dissolves 710 volumes of gas. When dissolved in water, heating and is formed ammonium hydroxide (NH4OH).
Anhydrous Ammonia expansion in the air at 0 ° C is approximately 900 times, or 1 liter of ammonia poured equivalent to 900 liters of ammonia gas.
2.3 Technical Data Sheet
Risk number = 268
Class 2 – Compressed gas, liquefied, liquid under pressure or highly cooled
Class 6 – Toxic Substance
Class 8 – Corrosive
UN = 1005 code number
Class or subclass of risk = 2
Description of the class or subclass of risk = Toxic Gas
CAS = 7664-41-7
Stability and Reactivity
3.1 Specific conditions
- a) Stability: Anhydrous Ammonia is stable when stored and used under normal conditions of storage and handling. Above 450 C can decompose releasing nitrogen and hydrogen. Polymerisation does not occur.
- b) dangerous reactions: This product is an alkaline gas and emits heat when reacted with acids. In contact with halogens, boron, 1.2. dichloroethane, ethylene oxide, platinum, nitrogen triclorato can cause strong oxidizers and can cause potentially violent or explosive reactions. In contact with heavy metals such as mercury, results in highly explosive reactions. In contact with chlorine and its compounds may result in the release of cloramida gas. The Anhydrous Ammonia produces significant explosive mixture when in contact with hydrocarbons. The product is also incompatible with acetaldehyde, acrolein, hydrazine, potassium ferrocyanide.
Conditions to avoid: Avoid contact to high temperatures and fire, do not induce reactions with incompatible substances.
3.2 Hazardous decomposition products
NH3 thermal decomposition may produce toxic nitrous gases.
Molecular Weight: 17.03 g / mol
Specific gravity: 0.682 g / cm3
Vapor density: 0.597 g / cm3
Color: Colorless gas
Boiling point: 33,35 ° C
Melting point: -77.7 ° C
Critical temperature: 132.4 ° C
Critical pressure: 111.5 atm.
Vapour pressure: 10 atm. 25.7 ° C
Heat of combustion: – 4440 cal / g
Viscosity: 0,255 cps at -33.5 ° C
Odor: Ammonia, quite pungently
Explosive Limits in Air % by volume: 15-28%
Autoignition Temperature: 850 ° C or 651 ° C (in the presence of iron as a catalyst)
Dissociation temperature: above 400 ° C
Burn rate: 1 mm / min