The Main Parts of Nitrous Oxide Plant
This decomposition of ammonium nitrate in water can start at temperatures around 210°C (410°F) depending on reactor design, concentration and purity of ammonium nitrate catalysers and stabilizer It would take a relatively long time to naturally reach the thermal equilibrium set point (generally between 250°C and 255°C (482°F and 491°F)). To accelerate the starting process the ammonium nitrate solution is heated in the reactor to approximately 240°C (464°F).
The gas leaving the reactor is water saturated and passes through a condenser for removal of the condensate.
The condensed water contains ammonium nitrate and nitric acid and can be reused. It should be purified before discharge, according to national regulations.
- Purification towers (Water, Sodium Hydroxide & Acid Scrubber)
The gas leaving the condenser contains impurities produced by decomposition of the ammonium nitrate. The purification is carried out in absorption towers by washing the gas with chemical solutions re-circulated by pumps in a closed circuit
Gas from Purification Towers has condensate moisture that can be extracted in Moisture Separator
The gasholder if used can be either a gasometer (water sealed bell) or a gas bag (balloon). It acts as a compensator for the variations between the gas production from the reactor and the consumption by the compressor in order to ensure a constant gas flow to the compressor.
Product is fed to the compressor either directly or from the gas holder, A Three stage non lubricated reciprocating compressor increases the Nitrous Oxide pressure up-to working pressure . Cooling coils and condensate traps are located at each stage, and the entire assembly of the compressor, with its coils and traps, is submerged in water for maximum cooling of the Nitrous Oxide gas due to heat of compression
The drying unit removes by adsorption the water vapour from the compressed gas. The unit contains two or more adsorbers filled with alumina, silica-gel or molecular sieve. The adsorbers are connected in a parallel arrangement allowing continuous operation, with one line in adsorption mode and the other in regeneration mode.
For regeneration the adsorber shall be depressurised; the gas is returned to the gasholder or should be used. Regeneration is accomplished by means of hot hydrocarbon-free gas.
- High Pressure Buffer Storage
Nitrous oxide is Stored in Three number of pressure vessels or pressure tanks at a pressure of 15 Bars for buffer for liquefaction unit.