Because of its many uses, ammonia is one of the most highly-produced inorganic chemicals. There are literally dozens of large-scale ammonia production plants worldwide. The worldwide production in 2004 was 109,000 metric tons.^[1] China produced 28.4% of the worldwide production 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. Ammonia is also used for the production of plastics, fibers, explosives, and intermediates for dyes and pharmaceuticals.

Flash point 11°C R/S statement R: ? S: , , , , RTECS number BO0875000 Supplementary data page Structure and properties n, εr, etc. ...

History

Before the start of WWI most ammonia was obtained by the dry distillation of nitrogenous vegetable and animal products; by the reduction of nitrous acid and nitrites with hydrogen; and also by the decomposition of ammonium salts by alkaline hydroxides or by quicklime, the salt most generally used being the chloride (sal-ammoniac). Strathisla whisky distillery in Keith, Scotland Distillation is a method of separation of substances based on differences in their vapour pressures. ... Nitrous acid weak monobasic acid known only in solution and in the form of nitrite salts. ... // Definition The nitrite ion is NO2−. A nitrite compound is one that contains this group, either an ionic compound, or an analogous covalent one. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Calcium oxide (CaO), commonly known as lime, quicklime or burnt lime, is a widely used chemical compound. ... Ammonium chloride or Sal Ammoniac (chemically ammonium chloride (NH4Cl); also nushadir salt, zalmiak, sal armagnac, sal armoniac, and salt armoniack) is, in its pure form, a clear white water-soluble crystalline salt with a biting taste. ...

The Haber process, which is the production of ammonia by combining hydrogen and nitrogen, was first patented by Fritz Haber in 1908. In 1910 Carl Bosch, while working for the German chemical company BASF, successfully commercialized the process and secured further patents. It was first used on an industrial scale by the Germans during World War I. Since then, the process has often been referred to as the Haber-Bosch process. The Haber Process (also Haber-Bosch process) is the reaction of nitrogen and hydrogen to produce ammonia. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ...

Modern ammonia-producing plants

A typical modern ammonia-producing plant first converts natural gas (i.e., methane) or LPG (liquified petroleum gases such as propane and butane) or petroleum naphtha into gaseous hydrogen. The method for producing hydrogen from hydrocarbons is referred to as "Steam Reforming". ^[2] The hydrogen is then combined with nitrogen to produce ammonia. Natural gas, commonly referred to as gas, is a gaseous fossil fuel consisting primarily of methane. ... R-phrases S-phrases , , , Flash point −188°C Autoignition temperature 537°C Explosive limits 5–15% Supplementary data page Structure and properties Thermodynamic data Spectral data UV, IR, NMR, MS Related compounds Related alkanes Ethane Propane Related compounds Methanol Chloromethane Except where noted otherwise, data are given for materials in... 45 kg LPG cylinders Liquified petroleum gas (also called liquefied petroleum gas, liquid petroleum gas, LPG, LP Gas, or autogas) is a mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles, and increasingly replacing fluorocarbons as an aerosol propellant and a refrigerant to reduce damage to... R-phrases S-phrases , , Flash point -104 °C Autoignition temperature 432 °C Explosive limits 2. ... R-phrases S-phrases , , Flash point −60 °C Autoignition temperature 287 °C Explosive limits 1. ... Naphtha is a group of various volatile flammable liquid hydrocarbon mixtures used primarily as feedstocks in refineries for the reforming process and in the petrochemical industry for the production of olefins in steam crackers. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Hydrocarbons are refined at oil refineries and chemical plants In chemistr, a hydrocarbon is any chemical compound that consists only of the elements carbon (C) and hydrogen (H). ... Steam reforming is a method of producing hydrogen from hydrocarbons. ... Flash point 11°C R/S statement R: ? S: , , , , RTECS number BO0875000 Supplementary data page Structure and properties n, εr, etc. ...

Starting with a natural gas feedstock, the processes used in producing the hydrogen are:

• The first step in the process is to remove sulfur compounds from the feedstock because sulfur deactivates the catalysts used in subsequent steps. Sulfur removal requires catalytic hydrogenation to convert sulfur compounds in the feedstocks to gaseous hydrogen sulfide:

H₂ + RSH → RH + H₂S(gas)

• The gaseous hydrogen sulfide is then absorbed and removed by passing it through beds of zinc oxide where it is 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 + 3H₂

• The next step then uses catalytic shift conversion to convert the carbon monoxide to 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 + 3H₂ → CH₄ + H₂O

CO₂ + 4H₂ → CH₄ +2H₂O

To produce the desired end-product ammonia, the hydrogen is then catalytically reacted with nitrogen (derived from process air) to form anhydrous liquid ammonia. This step is known as the ammonia synthesis loop (also referred to as the Haber-Bosch process): General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Atomic mass 32. ... A catalyst (Greek: καταλύτης, catalytēs) is a substance that accelerates the rate (speed) of a chemical reaction (see also catalysis). ... Hydrogenation is a chemical reaction in which unsaturated bonds between carbon atoms are reduced by attachment of a hydrogen atom to each carbon. ... Hydrogen sulfide (hydrogen sulphide in British English), H2S, is a colorless, toxic, flammable gas that is responsible for the foul odor of rotten eggs. ... Zinc oxide is a chemical compound with formula ZnO. It is nearly insoluble in water but soluble in acids or alkalis. ... Zinc sulfide is a chemical compound with the formula ZnS. Zinc sulfide is a white to yellow colored powder or crystal. ... Steam reforming is a method of producing hydrogen from hydrocarbons. ... Carbon monoxide, chemical formula CO, is a colorless, odorless, tasteless, flammable and highly toxic gas. ... The water gas shift reaction is an organic reaction in which water and carbon monoxide react to form carbon dioxide and hydrogen (water splitting) CO + H2O → CO2 + H2 The water gas shift reaction is part of steam reforming of hydrocarbons and is involved in the chemistry of catalytic converters While... Carbon dioxide is an atmospheric gas comprised of one carbon and two oxygen atoms. ... Ethanolamine, or 2-Amino ethanol, is a toxic flammable corrosive colorless viscous liquid with an odor similar to ammonia. ... The Haber Process (also Haber-Bosch process) is the reaction of nitrogen and hydrogen to produce ammonia. ...

3H₂ + N₂ → 2NH₃

The steam reforming, shift conversion, carbon dioxide removal and methanation steps each operate at absolute pressures of about 25 to 35 bar, and the ammonia synthesis loop operates at absolute pressures ranging from 60 to 180 bar depending upon which proprietary design is used. There are many engineering and construction companies that offer proprietary designs for ammonia synthesis plants. Haldor Topsoe of Denmark, Lurgi AG of Germany, and Kellogg Brown & Root of the United States are among the most experienced companies in that field.

References

• ^{^} United States Geological Survey publication
• ^{^}  Twygg, Martyn V. (1989). Catalyst Handbook, 2nd Edition, Oxford University Press. ISBN 1874545367.

See also

• Ammonia

Flash point 11°C R/S statement R: ? S: , , , , RTECS number BO0875000 Supplementary data page Structure and properties n, εr, etc. ...

External links

• Today's Hydrogen Production Industry
• Ammonia: The Next Step includes a detailed process flow diagram.