This lesson covers major industrial chemical processes, the catalysts used, operating conditions, and the importance of these processes in manufacturing fertilizers, fuels, and essential chemicals.

1. Core Concepts (Short Notes)

Industrial chemistry involves large-scale chemical production with focus on:

• Efficiency

• Cost-effectiveness

• Safety

• Environmental sustainability

Common themes:

• Use of catalysts

• High temperature & pressure optimization

• Recycling of unreacted materials

• Pollution control

2. Major Industrial Processes

26.1 Haber Process (Ammonia Production)

Reaction: N₂ + 3H₂ ⇌ 2NH₃

Conditions:

• Temperature: 450°C

• Pressure: 200 atm

• Catalyst: Iron (Fe)

Key Notes:

• High pressure favors ammonia formation.

• Moderate temperature balances yield & reaction rate.

• Ammonia used to make fertilizers (urea, ammonium nitrate).

26.2 Contact Process (Sulfuric Acid Production)

Steps:

1. S + O₂ → SO₂

2. 2SO₂ + O₂ ⇌ 2SO₃ (reversible)

3. SO₃ + H₂SO₄ → H₂S₂O₇

4. H₂S₂O₇ + H₂O → 2H₂SO₄

Conditions (Step 2):

• Catalyst: V₂O₅ (vanadium(V) oxide)

• Temperature: 450°C

• Pressure: 1–2 atm

Important: SO₃ is not directly dissolved in water (forms mist).

26.3 Ostwald Process (Nitric Acid Production)

Steps:

1. NH₃ + O₂ → NO (platinum–rhodium catalyst)

2. NO + O₂ → NO₂

3. NO₂ dissolved in water → HNO₃

Conditions:

• Temperature: 900°C

• Catalyst: Pt–Rh gauze

Uses of nitric acid:

• Fertilizers (ammonium nitrate)

• Explosives (TNT)

• Dyes

26.4 Cracking of Hydrocarbons

Breaking long-chain hydrocarbons → shorter alkanes + alkenes.

Types:

• Thermal cracking: high temperature & pressure.

• Catalytic cracking: zeolite catalyst, lower temp.

Products:

• Alkenes for plastics (ethene → polyethylene).

• Petrol components.

3. Polymers & Plastics

26.5 Polymerization

Two types:

• Addition polymerization: monomers with double bonds.

  • Example: ethene → polyethene.

• Condensation polymerization: monomers join with loss of small molecules.

  • Example: nylon, polyester.

26.6 Common Polymers

• Polyethene → bags, bottles.

• PVC → pipes, cables.

• Polystyrene → packaging.

• Nylon → clothing.

Environmental issues:

• Non-biodegradability

• Microplastics

Recycling & biodegradable plastics reduce impact.

4. Catalysts in Industry

Catalysts lower activation energy and increase rate.

Examples:

• Fe → Haber process

• V₂O₅ → Contact process

• Pt–Rh → Ostwald process

• Ni → hydrogenation

Catalysts must be:

• Efficient

• Cheap

• Long-lasting

• Easily replaceable

5. Tips & Tricks for Exams

• Know exact temperatures, pressures, and catalysts.

• Don’t confuse “contact” and “ostwald” processes.

• High pressure always favors fewer gas molecules.

• Catalysts do not affect equilibrium yield—only speed.

• Diagrams of industrial reactors often appear.

• Cracking produces useful alkenes for polymers.

6. Important Points to Remember

• Industrial chemistry is about producing chemicals efficiently.

• Conditions are optimized for balance between rate & yield.

• Recycling unreacted gases increases efficiency.

• Polymers have huge commercial importance but environmental issues.

Catalysts are crucial for industrial-scale reactions.