Sulfuric acid is a highly corrosive, colorless to slightly yellow liquid that is soluble in water. It is one of the most important industrial chemicals, used mainly in fertilizer production. It is manufactured through two main processes - the contact process and the lead chamber process. The contact process involves burning sulfur to produce sulfur dioxide, catalytically oxidizing the sulfur dioxide to sulfur trioxide, and hydrating the sulfur trioxide to produce sulfuric acid. Wastewater treatment uses sulfuric acid to neutralize pH and remove particles, odors, and pathogens.

1. Guided By : Savan Prajapati
Kajal Sareriya
SULPHURIC ACID

2. SULFURIC ACID
 Sulfuric acid (H2SO4) is a highly corrosive strong mineral acid.
 It is a colorless to slightly yellow viscous liquid which is soluble in water
at all concentrations.
 It is one of the most important heavy industrial chemicals due to it has a
number of large-scale uses particularly in the phosphate fertilizer industry.
About 60 % of the sulfuric acid produced is utilized in fertilizer
manufacture.
MANUFACTURE
The Industrial manufacture of sulfuric acid is done mainly by two processes
1. The Lead Chamber process
2. The Contact process
3. DCDA process

3. THE CONTACT PROCESS
Raw Materials
Basis: 1000kg sulfuric acid (100%)
Sulfur dioxide or pyrite (FeS2) = 670kg
Air = 1450-2200Nm3
Reactions
S + O2 SO2 ΔH = - 71.2kcals
2SO2 + O2 2SO3 ΔH = - 46.3kcals
SO3 + H2O H2SO4 ΔH = - 31.1kcals
SO3 +H2SO4 H2S2O7 (Oleum)

5. The steps in this process are as follow.
1. Burning of sulfur
2. Catalytic oxidation of SO2 to SO3
3. Hydration of SO3
1. Burning of sulfur
Burning of sulfur in presence of dry air is carried out in sulfur pyrite
burner. As SO2is needed for the catalytic oxidation and prevention of
corrosion, dry air is used in the combustion process. If sulfur contains
carbonaceous impurities, the molten material has to be filtered to avoid
poisoning the catalyst.

6. Catalytic oxidation of SO2 to SO3
The catalyst used is vanadium pentoxide (V2O5) and the pressure and
temperature maintained is 1.2-1.5 and 500-600oC respectively
atmospheres. At this stage 30% catalyst converts about 80% of SO2.
The converter product is cooled by heat exchange at 300C stage where
total yield is fed to a second stage.
Where total yield is increased to 97% by operating at 400-450oC for
favorable equilibrium.
High yield product gases are cooled to 150oC by water and air heat
exchangers and absorbed in oleum fed.

7. 

8. WASTEWATER TREATMENT
Wastewater treatment is a very important process that must be
done in order to protect the people and animals living in our
environment. As the most commonly used acid around the world,
sulfuric acid is often used to bring the pH level of wastewater
back to normal.
The major benefits of using sulfuric acid to treat wastewater are
as follows:
 Solid particles with chemicals such as ferric chloride,
polymers, and alums will be eliminated.
 The wastewater will be brought back to a neutral pH level,
which is a process known as neutralization.
 Offensive odors found in wastewater will be controlled and
prevented.

9.  Pathogens that can spread diseases are destroyed through
disinfection.
 Water and sludge are separated through chemical
treatment which makes it easier to remove the sludge.
