Industrial and applied chemistry

Production of H₂SO₄, NH₃ (Haber–Bosch), HNO₃, NaOH

Four foundational industrial routes show how reaction equilibrium, catalysis, separations and recycle combine in continuous chemical manufacture.

IntuitionFrom reactions to process flowsheets

A plant is more than a large reaction vessel. Feed preparation, heat exchange, catalytic conversion, product recovery and recycle must work as a coupled system. The four routes here make that systems view concrete.

SchoolSchool foundations: balancing and conservation

Industrial equations are balanced descriptions of atom conservation, not full process diagrams. For example, ammonia synthesis consumes three moles of hydrogen per mole of nitrogen; real plants must also supply pure feeds, remove heat and separate product.

UndergraduateContact process: sulfuric acid

Sulfur is burned to SO₂, which is oxidised over a vanadium catalyst to SO₃. Because this oxidation is exothermic and equilibrium-limited, the converter uses staged catalyst beds and interstage cooling; absorbing SO₃ into concentrated acid avoids an unhelpful aerosol from direct hydration.

UndergraduateHaber–Bosch: ammonia synthesis

Purified nitrogen and hydrogen react over an iron-based catalyst at elevated pressure and temperature. The synthesis is exothermic, so lower temperature favors equilibrium yield, while higher temperature accelerates approach to equilibrium. Industrial operation balances these effects, removes ammonia by cooling and condensation, and recycles unreacted gas.

UndergraduateOstwald and chlor-alkali routes

The Ostwald process oxidises ammonia to nitric oxide over a platinum–rhodium gauze, then oxidises NO to NO₂ and absorbs it in water to make nitric acid. Brine electrolysis makes chlorine at the anode and hydrogen plus sodium hydroxide at the cathode compartment; membrane cells limit mixing of these products.

ResearchResearch frontier