Manufacture of Ammonia by Haber’s Process
Hydrogen doesn’t react with Nitrogen at ordinary temperature . But when the mixture of pure Nitrogen and Hydrogen in ratio 1:3 by volume is heat at 450°C under a pressure 200-900 atm in presence of Fe and Mo as catalyst Ammonia gas is obtaine .
N2 + 3H2 ———–> 2NH3 + 22.4Kcal
Effect of concentration :
If increase in concentration of Hydrogen and Nitrogen equilibrium shift in forward direction and vice-versa . That is higher concentration favors the formation of ammonia .
Effect of Temperature :
The given reaction is exothermic reaction . If increase in temperature equilibrium shifts in backward direction . That is lower temperature favors the formation of ammonia .
Effect of Pressure :
There are four volume in reactant side but only two volume in product side . If increase in pressure equilibrium shift in forward direction . That is higher pressure favors the formation of Ammonia .
Effect of catalyst :
In absence of catalyst (Fe / Mo) chemical reaction is very slow . Therefore , use of positive catalyst (Fe / Mo) increase the rate of reaction .
A mixture of pure and dry Nitrogen and Hydrogen in the ratio 1 : 3 by volume is compress to (200 – 900) atm pressure are take in catalyst chamber in presence of catalyst Fe and Mo . The chamber is initially heated to about 450°C . Under this reaction , Nitrogen combines with Hydrogen in catalyst chamber by converting 15% of mixture to Ammonia . Then resulting Ammonia , Hydrogen and Nitrogen are pass through condenser (Refrigerator) is collected into receiver called liquor Ammonia . The uncombined Hydrogen and Nitrogen are recycle and reprocess .