Industrial chemical processes, assignment energy balance presentation for Prof Halimaton Hamdan class. group no.20(akmal, suri,charmine.c.j).

1. Additional Info – Q8

4. Manufacture of Sulfuric Acid (H2SO4) Most of the sulfuric acid manufactured is produced using the Contact Process. Combustion Chamber(combustion of sulfur) Converter(conversion of sulfur dioxide) Absorption Tower(sulfur trioxide absorbed into the sulfuric acid mist Hydration of Oleumto produce sulfuric acid

5. The Contact Process is a process involving the catalytic oxidation of sulfur dioxide, SO2, to sulfur trioxide, SO3. Step I Solid sulfur, S(s), is burned in air to form sulfur dioxide gas, SO2 S(s) + O2(g) -----> SO2(g) Step II The gases are mixed with more air then cleaned by electrostatic precipitation to remove any particulate matter

6. Step III The mixture of sulfur dioxide and air is heated to 450oC and subjected to a pressure of 101.3 - 202.6 kPa (1 -2 atmospheres) in the presence of a vanadium catalyst (vanadium (V) oxide) to produce sulfur trioxide, SO3(g), with ayieldof 98%. 2SO2(g) + O2(g) -----> 2SO3(g)( exothermic reaction) Step IV Any unreacted gases from the above reaction are recycled back into the above reaction

7. Step V Sulfur trioxide, SO3(g) is dissolved in 98% (18M) sulfuric acid, H2SO4, to produce disulfuric acid or pyrosulfuric acid, also known as fuming sulfuric acid or oleum, H2S2O7. SO3(g) + H2SO4 ------> H2S2O7 This is done because when water is added directly to sulfur trioxide to produce sulfuric acid SO3(g) + H2O(l) -----> H2SO4(l) the reaction is slow and tends to form a mist in which the particles refuse to coalesce.

8. Step VI Water is added to the disulfuric acid, H2S2O7, to produce sulfuric acid, H2SO4 H2S2O7(l) + H2O(l) -----> 2H2SO4(l)

9. Uses of Sulfuric Acid (H2SO4) Sulfuric acid is the electrolyte used in lead-acid batteries (accumulators) Sulfuric acid is important in the production of fertilizers such as ammonium sulfate (sulfate of ammonia), (NH4)2SO4, and superphosphate, Ca(H2PO4)2, which is formed when rock phosphate is treated with sulfuric acid. Sulfuric acid is used to remove oxides from iron and steel before galvanising or electroplating Concentrated sulfuric acid (18M) is used as a dehydrating agent, that is, to remove water, since it has a tendency to form hydrates such as H2SO4.H2O, H2SO4.2H2O, etc. Sulfuric acid is often used to dry neutral and acidic gases such as N2, O2, CO2 and SO2 Sulfuric acid will "suck" water out of carbohydrates and some other organic compounds which contain oxygen and hydrogen. For example, sulfuric acid will "suck" water out of sucrose, C12H22O11(s), (cane sugar) to produce a spongy mass of carbon: C12H22O11(s) + 11H2SO4 -----> 12C(s) + 11H2SO4.H2O