Industrial processes are procedures involving
chemical,
physical,
electrical, or
mechanical steps to aid in the manufacturing of an item or items, usually carried out on a very large scale. Industrial processes are the key components of heavy industry.
Calcination –
Limestone, which is largely composed of fossilized
calcium carbonate (CaCO3), breaks down at high temperatures into useable
calcium oxide (CaO) and carbon dioxide gas (CO2), which gets released as a
by-product. This chemical reaction, called calcination, figures most prominently in creating
cement (the paste within
concrete). The reaction is also important in providing calcium oxide to act as a chemical
flux (removal of impurities) within a
blast furnace.
CaCO3(s) → CaO(s) + CO2(g)
Steel
Smelting – Inside a
blast furnace,
carbon monoxide (CO) is released by combusting
coke (a high-carbon derivative of
coal) and removes the undesired oxygen (O) within
ores. CO2 is released as a by-product, carrying away the oxygen and leaving behind the desired pure metal. Most prominently,
iron smelting is how
steel (largely iron with small amounts of carbon) is created from mined
iron ore and coal.
Hall–Héroult process – Aluminium oxide (Al2O3) is smelted with coke (C) in a high-temperature
electrolysis reaction, yielding the desired pure aluminium (Al) and a mixture of CO and CO2.
Al2O3(s) + 3 C(s) → 2 Al(s) + 3 CO(g)
2 Al2O3(s) + 3 C(s) → 4 Al(s) + 3 CO2(g)
Fertilizer
Haber process – Atmospheric nitrogen (N2) is separated, yielding ammonia (NH3), which is used to make all synthetic
fertilizer. The Haber process uses a
fossil carbon source, generally
natural gas, to provide the CO for the
water–gas shift reaction, yielding
hydrogen (H2) and releasing CO2. The H2 is used to break the strong triple bond in N2, yielding
industrial ammonia.
CH4(g) + H2O(g) → CO(g) + 3 H2(g)
CO(g) + H2O(g) → H2(g) + CO2(g)
N2(g) + 3 H2(g) → 2 NH3(g)
Other chemical processes
Disinfection – chemical treatment to kill bacteria and viruses