AECH 1103 | Topic 5: Fertilizer Industry

Ammonia (NH₃)

It is used mostly to produce fertilizers.

• Colorless: liquid or gas

• Pungent odor (really strong smell)

• Liquefied at 8-10 atm pressure

• Boiling point at -33°C

• Melting Point: -78°C

• Flammable gas

• Toxic

These are the properties of ammonia.

nitrogen, proteins

Fill in the blanks.

Ammonia provides ____________ to plants to make plant ____________.

growth, repair

Fill in the blanks.

Ammonia is necessary for _________ and ___________ of plant cells.

Nitrogen, growth, yields

Fill in the blanks.

_____________ fertilizers promote plant __________ and increase crop __________.

nitrogen, atmosphere

Fill in the blanks.

Plants cannot use _____________ gas directly from _____________ (air).

nitrogen, soluble, compounds, soil

Fill in the blanks.

Plants get _____________ supply by absorbing ___________ nitrogen ___________ from the _______.

ammonium nitrate, ammonium sulfate, urea CO(NH₂)₂

These are examples of ammonia fertilizers.

Reversible Reaction

These are reactions that can go in either direction, and forward and backward reactions take place at the same time.

True

True or False.

Reversible reactions do not go into completion.

True

True or False.

Reversible reactions achieve equilibrium.

Equilibrium

This is achieved when amounts of reactants and products no longer change.

True

True or False.

In a reversible reaction, the amounts of reactants and products at equilibrium can be changed by altering conditions [e.g., temperature and pressure].

Haber Process

This is the process originally used to make explosives and soon became the main source of ammonia to make nitrogen fertilizers.

1908, Fritz Haber

Fill in the blanks.

The Haber Process was invented in ___________ by _____________.

N₂(g) + 3H₂(g) ⇌ 2NH₃(g)

This is the reversible reaction for the Haber process.

Temperature: 450°C

Pressure: 250 atm

Catalyst: Iron catalyst for maximum yield

These are the conditions for the Haber process.

A lower temperature increases the yield of ammonia

This is the relationship between temperature and ammonia.

A lower temperature results in a slower reaction

This is the relationship between temperature and the rate of reaction.

Increasing pressure increases the yield of ammonia

This is the relationship between pressure and ammonia.

Increasing pressure increases the rate of reaction

This is the relationship between pressure and the rate of reaction.

pressure, costly, safety risk

Fill in the blanks.

Maintaining higher __________ is _________ and involves a ___________.

Urea

It is an organic compound of carbon, nitrogen, oxygen, and hydrogen.

(NH₂)₂CO

This is the formula for urea.

• Used worldwide as a fertilizer. Main nitrogen fertilizer used in agriculture (60%).

• For the manufacturing of dermatological products.

• Essential for making feedstock, glue, and commercial products.

• For the manufacturing of urea-formaldehyde resins.

• To produce urea nitrate, which is explosive.

• Automobile

These are the applications of urea.

granules, crystals, solutions/pellets

These are what urea is produced as.

ammonia, carbon dioxide, high pressure, temperature

Fill in the blanks.

Urea is manufactured by reacting _____________ and _____________ into the reactor at ______________ and _______________.

35 atm

This is the pressure at which urea is produced.

135°C

This is the temperature at which urea is produced.

1. Formation of ammonium carbamate.

CO2 + 2NH3 → NH2COONH4

2. Dehydration of ammonium carbamate to produce molten urea.

NH2COONH4 → NH2CONH2 + H2O

These are the two main reactions of urea production.

2NH₂CONH₂ → NH₂CONHCONH₂ + NH₃

(Biuret)

This is the undesirable side reaction taking place in the production of urea.

Biuret

It is a by-product produced during the manufacture of urea.

crops, soil, three quarters, nutrients

Fill in the blanks.

Additives in urea are most commonly used by farmers to grow ___________. However, after they are applied to ________, more than ________ of their ______________ wash away before plants can absorb them.

• Use of slow-release urea

• Coating of urea with water-insoluble sulfur or polymers

These are the solutions for additives in urea.

sulfur, polymer, nitrogen, water

Fill in the blanks.

In a _________ or __________ coated urea, ___________ is released once ____________ penetrates through the coating.

polymer, nitrogen, 10

Fill in the blanks.

In a ____________-coated urea, ____________ release can be delayed for _______ months after application.

True

True or False.

Polymer-coated urea has a higher cost than sulfur-coated urea.

To reduce nitrogen volatilization losses, other additives are also used, which are called urease inhibitors.

This explains the use of inhibitors to reduce nitrogen volatilization.

• Copper (Cu²⁺)

• Boric acid (H₃BO₃)

• NBPT (N-(n-Butyl) thiophosphoric triamide)

These are the inhibitors used to reduce nitrogen volatilization.

3.8 million MT

This is the amount of ammonia produced in QAFCO annually.

5.6 million MT

This is the amount of urea produced in QAFCO annually.