Ammonia Facts for Kids

Stuctural formula of ammonia. N is nitrogen and H is hydrogen. The lines show that the atoms are joined by chemical bonds.

A picture to show simply how the atoms may fill space. The blue is nitrogen and the white is hydrogen.

Ammonia is a chemical. Its formula is NH₃ (not to be confused with Ammonium that has a formula of NH4⁺). It is made from nitrogen and hydrogen atoms.

Properties
Uses of ammonia
Ways it can be made
Ammonia in fish tanks
Manufacture of ammonia
Related pages
Images for kids
See also

Properties

It is a gas at room temperature
It is colourless
It has a strong, sharp smell
It is a base
It is an alkali
It is harmful when drank or inhaled
It dissolves in water to form a solution called household ammonia

Uses of ammonia

Making nitric acid from which many other things are made
Preparing wood pulp
Dissolved in water, it is household ammonia, used in cleaning (such as glass)
Refrigeration (making things cold)
Creating fertilizers such as Ammonium nitrate to use on farms

Ways it can be made

Many organic nitrogen compounds are in animal waste, including urine and guano. In the 19th century the Distillation (boiling for separation) of nitrogenous vegetable and animal waste was the main source of ammonia. During the 20th century the Haber process using high temperature and pressure with catalysts (things that make reactions faster) became the main source.

Ammonia in fish tanks

Ammonia is toxic. If a goldfish tank is dirty from their waste, the fish can suffer from ammonia burns which cause black spots or patches on their body. The tank must be large enough and have a filter.

Manufacture of ammonia

Production trend of ammonia between 1947 and 2007

Because of its many uses, ammonia is one of the most highly produced inorganic chemicals. Dozens of chemical plants worldwide produce ammonia. The worldwide ammonia production in 2004 was 109 million metric tonnes. China produced 28.4% of the worldwide production (increasingly from coal as part of urea synthesis) followed by India with 8.6%, Russia with 8.4%, and the United States with 8.2%. About 80% or more of the ammonia produced is used for fertilizing agricultural crops.

Before the start of World War I, most ammonia was obtained by the dry distillation of nitrogenous vegetable and animal waste products, including camel dung, where it was distilled by the reduction of nitrous acid and nitrites with hydrogen; in addition, it was produced by the distillation of coal, and also by the decomposition of ammonium salts by alkaline hydroxides such as quicklime, the salt most generally used being the chloride (sal-ammoniac) thus:

2 NH₄Cl + 2 CaO → CaCl₂ + Ca(OH)₂ + 2 NH₃

Today, the typical modern ammonia-producing plant first converts natural gas (i.e., methane) or liquefied petroleum gas (such gases are propane and butane) or petroleum naphtha into gaseous hydrogen. The process used in producing the hydrogen begins with removal of sulfur compounds from the natural gas (because sulfur deactivates the catalysts used in subsequent steps). Catalytic hydrogenation converts organosulfur compounds into gaseous hydrogen sulfide:

H₂ + RSH → RH + H₂S (g)

The hydrogen sulfide is then removed by passing the gas through beds of zinc oxide where it is adsorbed and converted to solid zinc sulfide:

H₂S + ZnO → ZnS + H₂O

Catalytic steam reforming of the sulfur-free feedstock is then used to form hydrogen plus carbon monoxide:

CH₄ + H₂O → CO + 3 H₂

In the next step, the water gas shift reaction is used to convert the carbon monoxide into carbon dioxide and more hydrogen:

CO + H₂O → CO₂ + H₂

The carbon dioxide is then removed either by absorption in aqueous ethanolamine solutions or by adsorption in pressure swing adsorbers (PSA) using proprietary solid adsorption media.

The final step in producing the hydrogen is to use catalytic methanation to remove any small residual amounts of carbon monoxide or carbon dioxide from the hydrogen:

CO + 3 H₂ → CH₄ + H₂O

CO₂ + 4 H₂ → CH₄ + 2 H₂O

To produce ammonia, the hydrogen then reacts with nitrogen (derived from process air) using a magnetite catalyst under high pressure to form anhydrous liquid ammonia. This step is known as the ammonia synthesis loop (also referred to as the Haber-Bosch process):

3 H₂ + N₂ → 2 NH₃

Hydrogen required for ammonia synthesis could also be produced economically using other sources like coal or coke gasification, less economically from the electrolysis of water into oxygen + hydrogen and other alternatives that are presently impractical for large scale production. At one time, most of Europe's ammonia was produced from the Hydro plant at Vemork, using electrolysis.

Images for kids

Ball-and-stick model of the diamminesilver(I) cation, [Ag(NH
3)
2]+
Ball-and-stick model of the tetraamminediaquacopper(II) cation, [Cu(NH
3)
4(H
2O)
2]²⁺
Jabir ibn Hayyan
This high-pressure reactor was built in 1921 by BASF in Ludwigshafen and was re-erected on the premises of the University of Karlsruhe in Germany.
A train carrying Anhydrous Ammonia.
Household ammonia
Ammoniacal Gas Engine Streetcar in New Orleans drawn by Alfred Waud in 1871.
The X-15 aircraft used ammonia as one component fuel of its rocket engine
The world's longest ammonia pipeline (roughly 2400 km long), running from the TogliattiAzot plant in Russia to Odessa in Ukraine
Hydrochloric acid sample releasing HCl fumes, which are reacting with ammonia fumes to produce a white smoke of ammonium chloride.
Ammonia occurs in the atmospheres of the outer giant planets such as Jupiter (0.026% ammonia), Saturn (0.012% ammonia), and in the atmospheres and ices of Uranus and Neptune.

Ammonia facts for kids

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