TOPIC 12 – Sulfur
· SOURCES OF SULFUR:
Sulfide ores.
A by-product from the removal of sulfur from petroleum and natural gas.
Found in its elemental state underground in the USA, Mexico and Poland.
· USES OF SULFUR DIOXIDE:
As a bleach in the manufacture of wood pulp for paper.
As a preservative for foods and drinks by killing bacteria.
· USES AND PURPOSES OF DILUTE SULFURIC ACID:
Used as a catalyst in many organic reactions.
Also used to clean the surface of metals.
· USES AND PURPOSES OF CONCENTRATED SULFURIC ACID:
Used in car batteries, making phosphate fertilisers, soaps and detergents.
It is also used to make acid drain cleaners and in the production of paints and dyes.
Powerful oxidising agent.
Powerful dehydrating agent.
· THE CONTACT PROCESS:
STAGE 1 – oxidation of sulfur. ( S + O2 -> SO2 )
STAGE 2 – oxidation of sulfur dioxide to sulfur trioxide using a catalyst (V 2O5). ( 2SO2 + O2 ⇌ 2SO3 )
Stage 2 Conditions – Temperature = 450°C , Pressure = 2 atm.
STAGE 3 (I) – SO3 is absorbed into a 98% sulfuric acid solution to form oleum. ( SO 3 + H2SO4 -> H2S2O7 )
STAGE 3 (II) – Oleum is added to water to form concentrated sulfuric acid. ( H 2S2O7 + H2O -> 2H2SO4 )
· SOURCES OF SULFUR:
Sulfide ores.
A by-product from the removal of sulfur from petroleum and natural gas.
Found in its elemental state underground in the USA, Mexico and Poland.
· USES OF SULFUR DIOXIDE:
As a bleach in the manufacture of wood pulp for paper.
As a preservative for foods and drinks by killing bacteria.
· USES AND PURPOSES OF DILUTE SULFURIC ACID:
Used as a catalyst in many organic reactions.
Also used to clean the surface of metals.
· USES AND PURPOSES OF CONCENTRATED SULFURIC ACID:
Used in car batteries, making phosphate fertilisers, soaps and detergents.
It is also used to make acid drain cleaners and in the production of paints and dyes.
Powerful oxidising agent.
Powerful dehydrating agent.
· THE CONTACT PROCESS:
STAGE 1 – oxidation of sulfur. ( S + O2 -> SO2 )
STAGE 2 – oxidation of sulfur dioxide to sulfur trioxide using a catalyst (V 2O5). ( 2SO2 + O2 ⇌ 2SO3 )
Stage 2 Conditions – Temperature = 450°C , Pressure = 2 atm.
STAGE 3 (I) – SO3 is absorbed into a 98% sulfuric acid solution to form oleum. ( SO 3 + H2SO4 -> H2S2O7 )
STAGE 3 (II) – Oleum is added to water to form concentrated sulfuric acid. ( H 2S2O7 + H2O -> 2H2SO4 )
