This document summarizes the contact process for producing sulfuric acid. It involves three main steps: 1) sulfur is burned to produce sulfur dioxide, 2) the sulfur dioxide is converted to sulfur trioxide in the presence of a catalyst, and 3) the sulfur trioxide is dissolved in concentrated sulfuric acid to produce oleum, which is then diluted with water to form concentrated sulfuric acid. The major raw materials are sulfur, air, and water. Sulfuric acid has many industrial uses such as fertilizer and metal production.

2. Alishay baig ………..16381507-011
Urwa zubair………….16381507-033
Rehman Ali…………...16381507-014

3. Industry Of Suphuric AciD

4.  Molecular formula :
 H2SO4
 Chemical Names :
 Sulphuric acid/oil of vitriol/dihydrogen sulphate/king of chemicals
 Molecular weight :
 98 g/mol
 Boiling point :
 340

5. Sulfuric acid is a colorless oily liquid.
 It is soluble in water with release of heat.
 It is corrosive to metals.

6. There are two method of prepartaion :
1. Contact process
2. Lead chamber process

7.  Contact process consist three stages .
1. Preparation of sulfur dioxide.
2. Conversion of sulphur dioxide into sulfur
trioxide.
3. Conversion of sulfur trioxide formed into
concentrated H2SO4.
 The major raw material are :
1. Sulphur
2. Air
3. Water

8. Step 1: Preparation of sulphur dioxide:
 SO2 is prepared by burning sulphur in the
presence of excess air at 100 c in sulphur burner
so that the product combines with oxygen.
 S(s) + O2 (g) → SO2(g)

9. Cooled the gases through cooler pipes.
Passed through coarse coke filter.
Then passes through cotterell electrostatic
mist precipitator.

10. Step 2: Preparation of sulphur trioxide:
 when sulphur dioxide reacts with oxygen at
a temperature of 400°C – 450°C and a
pressure of 1.5-1.7 atm in the presence of
N2O5 / vanadium pentaoxide / Asbestos as
a catalyst. This reaction is reversible in
nature.
 2SO2(g) + O2(g) ⇌ 2SO3(g)

11. Cooled the gas
And passed through absorption chamber
Unreacted gas get back to catalytic
converter called chamber.

12. Step 3: Preparation of concentrated
sulphuric acid:
The cooled sulfur trioxide is dissolved in
98% sulfuric acid in the absorption tower.
 The acid is sprayed over the SO3 and
produces an oily liquid called oleum.
H2SO4 + SO3(g) → H2S2O7

13. Oleum tower is made up of brick- lined
steel.
This is preferable over directly dissolving
sulfur trioxide in water as this forms
sulfuric acid mists, due to the large heat of
dissolution (130 kJ/mol), which are hard to
control and difficult to store. Also it is
difficult to separate the sulfuric acid gas
from others such as nitrogen

14.  water is mixed with oleum to produce 98%
sulfuric acid
H2S2O7 + H2O → 2H2SO4

16. In Industries:
It is used in the production of phosphoric
acid which is in turn used to make
phosphate fertilizers.
It is used in the manufacturing of metals
such as copper, zinc etc.
It is used in the making of fibers.
Used in acidic drain cleaners.

17. As a Catalyst:
Used as a catalyst in the manufacturing
process of nylon.
Used in the Manheim process in the
manufacturing of HCl.
Used in petroleum refining.

18. Overview
This process contain several steps.
Carried out in large lead lined chamber.
SO2 is obtained by burnig suphur in
burner.
S + O2 → SO2
4 FeS2 + 11 O2 → 2 Fe2O3 + 8 SO2

19. It is also obtained from gysum. Because
gypsum is available in pakistan .
Sulphur dioxide passes through lead
chamber in the presence of O2, NO, NO2
along with steam.
SO2 is converted into H2SO4.
Acid is 60-70% H2SO4.

20. The plant employed in this process consist
of :
1. Pyrite burners
2. Nitre pots
3. Glover towers
4. Lead chambers
5. Gay-lussac tower
6. Coolers
7. Purification of acid chamber

21. Combustion of sulphur or sulphites is
carries ourt in a machenical furnace or the
flash roaster.
Here the S is coverted into SO2.

22. Contain the mixture of NaNO3 and H2SO4 .
Tower is about 15 into 50 feet .
Lined with acid proof cement.

23. oxide of nitrogen is obtained by heating
NaNO3 and concentrated H2SO4.
 NaNO3 + H2SO4 (concentrated) ——-> NaHSO4 + HNO3
 4 HNO3 —–> 2H2O + NO2 + O2
 4 HNO3 ——> 2H2O + 4NO + 3O2

24. Major Function of glover rower are :
1. Cooling the gases coming from pyrite burner
2. Conversion of some SO2 into SO3.
3. Concentrate the dilute acid.
4. Recovery of oxides of nitrogen from gay-lussac
tower.
5. Cleaning the burner gases.

25. Box like room made up of sheet lead.
No. of chmaber contain between 3-12.
The gases from previous chamber enter in
lead chamber at 99 *C
Chamber controlled through gase colour
changes and through temprature.

26. Afford space and time for reaction.
Conversion of SO2 into SO3.
To radiate heat produced by chemical
reaction.
Furnished surface for condensation of the
acid mist formed.

27. Filled with tile with tile packing.
Provide maximum area for contact.
Also recover oxides of nitrogen coming
from gases coming from lead chamber.

28.  Consist No. of tanks ( at least three ).
 Set in series made up of sheet leads.
 Coils of lead pipes have cooled water in it.
 Firstly acid from glover tower enter the first
cooler at 130-150 *C
 The temprature of acid remains only 30-4- *C
at the end.

29. Chamber acid usually used for
1. Fertillizers
2. Pickling of iron
3. In paints etx
 Chamber acid contain small amount of
lead, oxides of nitrogen, iron or aluminium
dissolved from tower.

30. Dossolved oxides of nitogen are removed
by adding 0.2-0.5 % ammonium sulphate
and heating .
 (NH4)2SO4 + NO + NO2 ——-> 3N2 + H2SO4 + 3H2O