3. Introduction
Ammonia is a compound of nitrogen and
hydrogen with the formula NH 3 . Ammonia is
a colourless gas with a distinct pungent smell.
Biologically, it is a common nitrogenous
waste, particularly among aquatic organisms
4. Raw Materials
Hydrogen in the form of H₂
Nitrogen in the form of N₂
Hydrogen is obtained by reacting natural gas (mostly
methane) with steam, or from cracking oil fractions.
Nitrogen is obtained from the air.
6. HABER’S
PROCESS
• The Haber process (sometimes
referred to as the Haber-Bosch
process) is an industrial procedure for
obtaining ammonia from nitrogen an
d hydrogen in the gaseous state. The
Haber method is done under high
temperature and pressure conditions
and can be described by the following
reverse reaction:
• N2(g)+3 H2(g)⇌2 NH3(g)
7. Process :
1. First, we take nitrogen gas from the air and combine it
with hydrogen atom obtained from natural gas in the ratio 1:3
by volume.
2. The gases are passed through four beds of catalyst, with
cooling takes place in each pass. This is done to maintain
equilibrium constant.
3. While different levels of conversion occur in each pass where
unreacted gases are recycled.
4. Normally an iron catalyst is used in the process, and the whole
procedure is conducted by maintaining a temperature of
around 400 – 450oC and a pressure of 150 – 200 atm.
5. The process also involves steps like shift conversion, carbon
dioxide removal, steam reforming, and methanation.
6. In the final stage of the process, the ammonia gas is cooled
down to form a liquid solution which is then collected and
stored in storage containers.
9. Conditions for
Haber’s process
• Minimizing cost of production by ensuring
• (a) The capital cost of the plant is not too
high,
• (b) The starting materials are cheap;
• Maximizing yield of products by
• (a) Shifting the equilibrium position in the
desired direction
• (b) Increasing the value of the equilibrium
constant,K,for the process concerned;
10. Reaction
Rate and
Equilibrium
• The Haber process for the synthesis of
ammonia is based on the reaction of
nitrogen and hydrogen. The chemical
reaction is given below. Notably, in this
process, the reaction is an exothermic
reaction one where there is a release
of energy.
• N2(g) + 3H2(g) → 2NH3(g)
11. Electrochemical
Synthesis of
Ammonia:
• The dominant process for ammonia synthesis
is the Haber-Bosch (H-B) process which
involves the production of H2 from the steam-
reforming of natural gas, or coals, which
concurrently produces enormous amounts of
CO2. This is followed by extensive purification
of this H2, before its reaction with N2 at 400–
500 °C and at elevated pressures (about 150
bar) over a Fe-based catalyst [1,2]. Ever since
its discovery, the H-B process has been
gradually improved upon. The improvements
consisted primarily in searching for more
active catalysts which would allow operation at
lower pressures and temperatures.
12. Biological
Problems /
Difficulties:
• Temperature: Toxicity of ammonia (as total ammonia)
increases as temperature increases (U.S. EPA 1999).
• pH: Ammonia concentration and toxicity increases as pH
increases, although less ammonia is required to produce
toxic effects at lower pH (IPCS 1986, Wurts 2003).
• Dissolved oxygen: Oxygen is consumed as ammonia is
oxidized (nitrification), and low oxygen levels increase
ammonia levels by inhibiting nitrification.
• Season: Total ammonia-nitrogen concentration in surface
waters tends to be lower during summer than during
winter. This is due to uptake by plants and decreased
ammonia solubility at higher water temperatures (IPCS
1986).
• Ionic strength: Tolerance to ammonia can increase with
an increase in ionic strength or salinity (Sampaio et al.
2002).
• Sediments: Fine sediments tend to generate ammonia
due to low oxygen levels and high organic matter.
13. Backup Option : GREEN AMMONIA
• What is Green Ammonia?
• Green ammonia refers to ammonia, which has been produced through a process that is 100% renewable and carbon-free. One way of making
Green Ammonia is by using the hydrogen from water electrolysis and nitrogen separated from air. These two elements are then fed into the
Haber process. In the process, nitrogen and hydrogen react together in high pressure and temperature to produce Ammonia.
• Currently, ammonia making is not a green process. It is now made from methane. It is called Steam Methane Reforming (SMR) process. Around
90% of carbon dioxide is produced from SMR process.
15. Uses of Ammonia :
As a FERTILIZER
• •About 90 percent of ammonia produced is
used in fertilizer to help sustain food
production for billions of people around the
world. Specially ammonium sulphate has many
profound properties that plays a vital role in
plants growth and also in controlling soil
salinity.
16. Household uses
• Ammonia is one of the main ingredients in a lot of household cleaning products. It is used as a cleaning
agent and can be used to remove stains or clean mirrors, tubs, sinks, windows and more. Some other uses
include antimicrobial agent or an antiseptic, and ammonia is also used as a fuel.
18. Risk factors while
working with ammonia
• At room temperature,ammonia is a
colorless,highly irritating gas with a
pungent,suffocating odor.
• In pure form,it is known as
anhydrous ammonia and is
hygroscopic (readily absorbs
moisture).
• Ammonia has alkaline properties and
is corrosive.
• Ammonia gas dissolves easily in water
to form ammonium hydroxide,a caustic
solution and weak base.
