MATERIAL BALANCE CALCULATIONS FOR AMMOINUM SULPHATE MANUFACTURE

Chemical reactions involved for the Ammonium sulphate:-

NH3+H2ONH4OH +8.3 Cal/g mol------(1)

2NH4OH+CO2 (NH4)2CO3 +22 cal/g mol ----(2)

(NH4)2CO3+CaSO4 (NH4)2SO4+CaCO3 + 3.9 cal/g mol-----(3)

Molecular weights(in g/mol):-

NH3=17

H2O=18

NH4OH=35

CO2=44

(NH4)2CO3=96

CaSO4=136

CaCO3=100

(NH4)2SO4=132

If we require to produce 300 tonnes of Ammonium Sulphate.And considering 24 hr operation of the Ammonium sulphate plant.

Then production rate per hour is :-

300 tonnes=300,000kg

Therefore,Ammonium Sulphate produced per hour is =300,000/24

=12,500Kg/hr

And it has been found that the approx. 100 kgs of the Ammonium Sulphate produced is lost in filtration process.

Required production rate=12,400 Kg/hr

Assumptions:-

Considering complete conversion in the (1) and (2) reactions and for reaction (3) conversion is 96%.

Now the Gypsum obtained has the following composition:-

Gypsum composition

Gypsum= 85%

Calcium Carbonate= 10.4%

Insolubles=3.6%

Free moisture= 1%

BASIS:-1-HOUR OPERATION

Gypsum required :

Now if we consider all the reactions to take place stoichiometrically. Then from reaction (3) we have:-

(NH4)2CO3+CaSO4 (NH4)2SO4+CaCO3 + 3.9 cal/g mol-----(3)

136 kg 132 kg

132 kg of ammonium sulphate requires 136 kg of gypsum,

So,1kg of ammonium sulphate requires 136/132= 1.03kg

So, 12500 would require=12500*1.03=12875kg.

As the reaction has 96% conversion and the gypsum is only 85% of the gypsum supplied so Net gypsum required=

12875*1/0.85*1/0.96

=15,778.18 kg

Ammonium carbonate required :

(NH4)2CO3+CaSO4 (NH4)2SO4+CaCO3 + 3.9 cal/g mol-----(3)

96 kg 136kg

96 kg of Ammonium carbonate requires 136 kg of gypsum

So, 1 kg will require = 96/136=0.70

So, 15778.18 will require= 0.70*15778.18=11044.72kg

Aqueous ammonia required:

2NH4OH+CO2 (NH4)2CO3 +22 cal/g mol ----(2)

70kg 96kg

From the reaction (2) we see that the 96 kg of ammonium carbonate requires 70 kg of ammonium hydroxide .

So,11044.72 kg of ammonium carbonate would require:

70/96*11044.72=8053.44kg

Ammonia required :-

NH3+H2ONH4OH +8.3 Cal/g mol------(1)

From this reaction we see that 1mole of ammonia produces ,1 mole of ammonium hydroxide but this is only the half of the actual requirement by reaction (2)

Ammonia of Aq. Ammonia produced =8053.44/2=4026.72kg

Hence ,35 kg of Aq.ammonia requires 17 kg of ammonia

4026.72kg of Aq.ammonia would require:

17/35*4026.72=1955.83 kg

Carbon dioxide required:

From reaction(3)

100 kg of ammonium carbonate requires 44kg of carbon dioxide.

11,044.72 kg of ammonium carbonate would require:

44/100*11,044.72=4859.67 kg

Water required :

35 kg of aq.ammonia requires 18 of water

4026.72kg of aqueous ammonia would require:-

18/35*4026.72=2070.88 kg

Summarising the results obtained above we have:-

RAW MATERIALS AMOUNT(kg/hr) Gypsum 15,778.18 Ammonium Carbonate 11044.72

Aqueous Ammonia 8053.44Ammonia 1955.83 Carbon dioxide required 4859.67

Water required 2070.88