Also
known as "laughing gas", nitrous oxide ( N2O) is a non-flammable
gas, used in surgery and dentistry for its anesthetic and analgesic effects.
Under room conditions and atmospheric pressure, it is a colorless gas with a
pleasant, slightly sweet odor and taste.
Though it is non-flammable, it supports combustion. It is moderately
soluble in water, alcohol and oils. At higher temperature the gas decomposes
into nitrogen and oxygen. Nitrous oxide plants are nitrous oxide generating
plants which are supposed to be very safe and economical. An important
advantage of these plants is they are efficient generation system which
reduces power consumption and adds on to safety. The gas manufactured in
such plants is usually stored in liquid state which can be directly filled
into cylinders.
Manufacturing Process
When ammonium nitrate is heated, nitrous oxide is produced. Heating is done
either electrically or by using gas. In the process, ammonium nitrate is
decomposed to give a combination of nitrous oxide and super heated steam.
The reaction is as
NH
4NO
3 --------- N
2O + 2H
2O
The reaction needs to be handled very cautiously. If temperature of ammonium
nitrate is allowed to go beyond a certain point then it is decomposed into
different gases. Usually the ammonium nitrate should be a heated to a
temperature of 250 Deg C. During this process, impurities are produced.
These impurities include ammonium nitrate fumes, nitrogen & other
nitrogen oxides. The steam & impurities are removed by using caustic
soda and sulphuric acid in sequence or by scrubbing with water. The nitrous
oxide with some nitrogen is stored in the gas balloon. Here nitrous oxide is
compressed with a compressor, dried in a drier and then refrigerate when it
becomes liquid. Liquid Nitrous oxide is stored in storage vessels. Pure
liquid nitrous oxide is then filled into cylinders by weight.
Nitrous Oxide Production Process
- Nitrous Oxide is a chemical compound of Nitrogen and Oxygen
- It is color less
- It is non flammable and nontoxic gas.
- It has a slight sweetish taste & odor.
- Nitrous oxide is distributed as a compressed liquid in cylinders in
the same way as oxygen, nitrogen etc.
- The pressure in nitrous oxide cylinders is somewhere around 50 Bars
at 20 degree C.
- The gas remains stable and comparatively remains an un-reactive
chemical compound at ordinary temperatures. At higher temperatures, it
is transformed into nitrogen and oxygen. · It supports combustion
and hence organic substances like oil and greases must be kept away from
the gas.
Uses of Nitrous Oxide
- The main use of nitrous oxide gas is for anesthetic purposes.
- It is used as a carrier gas in laboratory instruments.
- Nitrous oxide is used as a propellant in aerosols and food stuff.
- Nitrous oxide has also become a propellant for high quality perfumes
and cosmetics.
- It is used for Cryosurgery.
- This is considered as an oxide gas for atomic absorption in
spectrophotometer.
- It is also used as a fuel oxidant for racing vehicles.
Equipment
The nitrous oxide gas plants consists the following equipment:
- Primary Scrubber
- Primary Condenser
- Ammonium nitrate melting and decomposition pots
- Gas Cooler
- Mist Separator
- Water scrubber
- Acid and alkali scrubber
- Final Scrubber
- Pumps
- Gas holder/Balloon
- Refrigerator unit
- Liquid storage vessels
- High Pressure Dryers
- Cylinder filling unit/weighing scale
- Set of valves and pipelines
- Cooling Tower with pump
Nitrous
Oxide Plant
