Cyclohexane on oxidation gives cyclohexanol and cyclohexanone(alcohol and ketone) with
20% cyclohexane remains unreacted.
Unreacted(excess) Oxygen is drawn out from the product.
The mixture obtained at the outlet of reactor 1 is introduced in the distillation column where distillate consists of cyclohexane and water is completely removed.
K.A mixture consisting of ketonic,alcoholic group and water is the bottom product
The K.A mixture is oxidized in the presence of nitric acid as oxidizing agent.
This oxidation results into the formation of 94% adipic acid alongwith Nox,salicylic acid ,gluteric acid(as by products),water and excess HNO3.
The product from reactor 2 is then expanded from high pressure due to which Nox are separated from mixtue.
The Nox are then absorbed in Absorber.
Absorber is used to convert the oxides of nitrogen into Nitric acid.
Air is introduced alongwith water to form Nitric acid in two steps.
Formation of NO2 from NO
Formation of Nitric acid by reaction of water and NO2.
For Enhancing the concentration of Adipic acid upto 95%.
Upto 98% purity of adipic acid is achieved.
Crystals of Adipic acid are obtained with small amount of mother liquor(HNO3,Gluteric acid and salicylic acid).
The mother liquor is separated from crystals here by adding water.
The crystal is washed by water.
The excess water is then removed by dryer.
Dryer is used to remove the water used for washing away the mother liquor.
If water removal is not done then the crystal may remain impure and cause brittlness,not suitable for handling and transportation.