Making of ammonia from its elements

Fertilisers, fibers, plastics, nitric acid (explosives), household cleaners, detergents

N 2 and H 2 Ammonia

To produce ammonia: 1. Increase pressure (it will tend to decrease the number of moles of gas) 2. Decrease temperature (it will tend to increase temperature)

* Increasing pressure increases the frequency of successful collisions * Compromise: Construction of strong pipes to maintain high pressures is not economical. Pressure needs to be lessened

* Lower temperature produces the highest yield of ammonia (~90%) but at a very slow rate (months!) as there is insufficient kinetic energy for a collision * Compromise: Use slightly higher temperatures to yield smaller amounts quickly.

* Catalysts speed the forward and reverse reaction. * It does not change the position of equilibrium * Compromise: A catalyst makes it possible to use lower temperatures

1. Increase reactants (but must maintain 1:3 ratio) 2. Pressure: 25 MPa (25,000 Pa) 3. Temperature: 400 o C 4. Magnetite Catalyst 5. Product is removed

Yield of ammonia: ~15–20% per cycle. After 5–6 cycles about 98% of the reactants are converted to ammonia.

Efficiency and safety