Solvay Process
Sodium carbonate or soda ash is an important industrial chemical.It is used in the manufacturning of glass, soaps,detergents, paper and many other important chemicals. Sodium carbonate is manufactured in a continuous process known as the Solvay process.
◎Raw Materials :-
commercially, sodium carbonate is manufactured in a continuous process that uses :
1) Ammonia
2) Brine (concentrated sodium chloride solution)
3) Lime stone as a source of carbon dioxide and slaked lime,Ca(OH)2
4) H2O(water)
◎Basic Steps :-
Solvay process consists of following steps
☞1) Preparation of ammonical brine:
Ammonical brine is prepared by dissolving ammonia gas in brineAmmonicalbrine is fed into the carbonating tower.
☞2)Carbonation:-
In the carbonating tower, carbon dioxide is passed through Ammonicalbrine.
Following reaction take place in it
CO2+NH3+H2O →NH4CO3
NH4HCO3+NaCl 15℃→ NaHCO3+NH4Cl In the lower compartment of carbonating tower,the temperature of the mixture is lowered to 15℃. At this temperature, NaHCO3 precipitates out.
☞3)Filtration: -
Precipitates of NaHCO4 are separated from the milky solution by filtration. It is used as baking soda.
☞4)Calcinations:-
Sodium hydrogen carbonate is heated to get sodium carbonate.
2NaHCO3 heat→ Na2CO3+CO2+H20
Carbon dioxide released is re-cycled in the process.
☞5)Preparation of Carbon dioxide and slaked lime:-
Carbon dioxide is produced by heating limestone in a kiln.
CaCO3 heat → CaO+CO2
Carbondioxide is fed into the carbonating tower from the top.Equal mounts of lime(CaO) and water are mixed to produce slaked lime, Ca(OH)2
CaO + H2O → Ca (OH)2
Slaked lime is pumped to the ammonia recovery tower.
☞6)Recovery of ammonia: -
Solution containing ammonium chloride produced in the carbonation tower is heated with slaked lime.
2NH4Cl + Ca(OH)2 heat → 2NH3+CaCl+2H2O
Almost all the ammonia is recovered in this process.It is reused in the process.
◎Advantages of Solvay Process: -
★It is a cheap process. The raw materials arr cheap and easily available.
★It is a pollution free process. No harmful products are produced.
★It consumes less fuel .This is because there is no solution to be evaporated.
★Carbon dioxide and ammonia are recovered and re-used in the process.
★It produces pure NaHCO3 and Na2CO3.
Sodium carbonate or soda ash is an important industrial chemical.It is used in the manufacturning of glass, soaps,detergents, paper and many other important chemicals. Sodium carbonate is manufactured in a continuous process known as the Solvay process.
◎Raw Materials :-
commercially, sodium carbonate is manufactured in a continuous process that uses :
1) Ammonia
2) Brine (concentrated sodium chloride solution)
3) Lime stone as a source of carbon dioxide and slaked lime,Ca(OH)2
4) H2O(water)
◎Basic Steps :-
Solvay process consists of following steps
☞1) Preparation of ammonical brine:
Ammonical brine is prepared by dissolving ammonia gas in brineAmmonicalbrine is fed into the carbonating tower.
☞2)Carbonation:-
In the carbonating tower, carbon dioxide is passed through Ammonicalbrine.
Following reaction take place in it
CO2+NH3+H2O →NH4CO3
NH4HCO3+NaCl 15℃→ NaHCO3+NH4Cl In the lower compartment of carbonating tower,the temperature of the mixture is lowered to 15℃. At this temperature, NaHCO3 precipitates out.
☞3)Filtration: -
Precipitates of NaHCO4 are separated from the milky solution by filtration. It is used as baking soda.
☞4)Calcinations:-
Sodium hydrogen carbonate is heated to get sodium carbonate.
2NaHCO3 heat→ Na2CO3+CO2+H20
Carbon dioxide released is re-cycled in the process.
☞5)Preparation of Carbon dioxide and slaked lime:-
Carbon dioxide is produced by heating limestone in a kiln.
CaCO3 heat → CaO+CO2
Carbondioxide is fed into the carbonating tower from the top.Equal mounts of lime(CaO) and water are mixed to produce slaked lime, Ca(OH)2
CaO + H2O → Ca (OH)2
Slaked lime is pumped to the ammonia recovery tower.
☞6)Recovery of ammonia: -
Solution containing ammonium chloride produced in the carbonation tower is heated with slaked lime.
2NH4Cl + Ca(OH)2 heat → 2NH3+CaCl+2H2O
Almost all the ammonia is recovered in this process.It is reused in the process.
◎Advantages of Solvay Process: -
★It is a cheap process. The raw materials arr cheap and easily available.
★It is a pollution free process. No harmful products are produced.
★It consumes less fuel .This is because there is no solution to be evaporated.
★Carbon dioxide and ammonia are recovered and re-used in the process.
★It produces pure NaHCO3 and Na2CO3.
☞Flow sheet diagram of solvay process is made by me that will help you understand this process easily.
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