The Manufacture of Nitrate Nitrogen Fertilizers

This presentation provides an overview of the manufacture of nitrate nitrogen fertilizers. It covers the history of nitrate nitrogen fertilizers, the production process of sodium nitrate, and the physical, chemical, and safety environment of the production process. It also includes information on the storage and safe handling of sodium nitrate crystals. References for further reading are provided.

 Nitrate nitrogen fertilizers have their nitrogen compound
chemically bonded in nitrate form. This form of nitrogen is
incidentally the one that is most preferred by plants.
 The most common types of Nitrate nitrogen fertilizers
include; Sodium nitrate, Calcium nitrate, Potassium nitrate
which contains 16%, 15.5% and 13% of Nitrogen (N)
respectively (Masclaux, 2010, p.1143).
The raw material for its production is Nitrate ore or Caliche
For synthetic sodium nitrate, the following raw materials
are used ; (Pokorny, 1977, p.24).
 soda ash
 sodium hydroxide
 sodium chloride
 ammonia
 nitric acid
The basic concept of the process involves first oxidizing
ammonia with help of a platinum catalyst at 1 atmosphere
(Pokorny, 1977, p.93).
The nitrogen oxide fumes are first cooled by use of a waste-
heat tank at 210- 270 degrees Celsius.
The gases are then directed into an absorber chamber
whereby further cooling takes place in addition to a chemical
reaction with a sodium carbonate solution. (Winsock, 2001,
p.431).
Na2 CO3 + NO + NO2 → 2NaNo2 + CO2
Na2 CO3 + 2NO2 + NaNO2 → NaNo2 + CO2
The fumes produced in the absorber chamber are washed
and then compressed to a pressure of about 0.4 MPa.
They are then directed into a second absorption chamber so
that the remnant nitrogen oxide is reabsorbed back into a
countercurrent stream of sodium carbonate that has been
freshly dissolved into water.
•The resultant solution in the second absorber is chemically
treated in an abatement unit before being re-circulated into the
first absorption chamber. (Hayes & Britton, 2019)
•The solution from the first absorption chamber which is the
parent liquor is poured into a column reactor whereby a
chemical treatment by use of Nitric acid takes place in order
to change sodium nitrite into sodium nitrate. (Robinson,
2019).
2NaNO2 + 2HNO3 → 2NaNO3 + NO2 + NO + H2O
•The sodium nitrate solution obtained is then crystallized and
then dried in a rotating drum. The crystals are packaged and
stored inside moisture resisting bags.
Masclaux-Daubresse, C.,
Daniel-Vedele, F.,
Dechorgnat, J., Chardon, F.,
Gaufichon, L., & Suzuki, A.
(2010).
Pokorny L, Maturana I,
Bortle WH (2006). Sodium
nitrate and nitrite. In: Kirk-
Othmer Encyclopedia of
Chemical Technology, 5th
Ed, New York, John Wiley
& Sons [online version].
Sebilo, M., Mayer, B.,
Nicolardot, B., Pinay, G., &
Mariotti, A. (2013). Long-
term fate of nitrate fertilizer
in agricultural
soils. Proceedings of the
National
Wisniak, J., & Garces, I.
(2001). The rise and fall of
the salitre (sodium nitrate)
industry. Indian journal of
chemical technology, 8(5),
427-438.
The Manufacture of Nitrate Nitrogen Fertilizers
[Insert Name, Name of Department, Name Of University
NO + NO2
1st Absorber
Chamber
2NaNo2 + CO2
Abatemen
t unit
Primary
Centrifuge
Filtration and
evaporation
Storage
Rotating
drum
Column
Reactor
Sodium Nitrate Crystals
Na2 CO3
Ammonia + Platinum
catalyst
2nd Absorber
Chamber
Na2 CO3
HNO3
Introduction History
The Production Process (Sodium Nitrate)
References
Production Process Flow diagram
Sodium Nitrate
Crystals
Nitrate Ion
structure
Physical, Chemical and Safety Environment
Safe storage of crystals in water
resistant bags.
Oxidation Of Ammonia Using Platinum Catalyst At 1 Atm
Waste heat
tank
NO + NO2
NO + NO2 At 250 °C
NO + NO2 Gases
Compressor at 0.4
Mpa
NO + NO2 Gases
compressed at 4 Mpa
• Always wear chemical goggles
and adequate skin cover.
• Inspect equipment before each
day's work and correct any
abnormal conditions.
• Water is the first aid treatment of
choice when ammonia gets into
the eyes or on the skin. In case of
mishap, flush affected areas for
15 minutes and get medical help
as soon as possible.
• Make sure all valves, lines, and
connections are secure in order
to reduce the chance of either
leaks or being doused during
The first commercially exploited source was
India, providing the British Empire with a
reliable supply. Until the early part of the
twentieth century, there were no known
methods for the chemical synthesis of nitrates
nowadays; most nitrates are produced from
ammonia synthesized from atmospheric
nitrogen.