Calcium carbide and acetylene manufacturing process

Calcium carbide is a very useful chemical in industrial applications and domestic uses. We can prepare acetylene gas by the production of calcium carbide. In this lesson we discuss about preparation of calcium carbide and acetylene gas and then their uses in chemical industry and domestic purposes.


Calcium carbide and acetylene

  • Calcium carbide - CaC2
  • Acetylene gas - C2H2

Preparation of calcium carbide

Raw materials

  • Limestone / Calcium carbonate (CaCO3)
  • Coke (C)
  • Water is required to production of acetylene gas

Production Process

Steps of production, reactions and physical conditions are discussed in this section.


Calcium carbonate decomposition | CaCO3 = CaO + CO2

Calcium carbonate is heated into higher temperature and take calcium oxide (CaO). CaCO3 decomposes into CaO and CO2 above 8250C.
calcium carbonate decomposition

Calcium oxide and coke reaction | CaO + C = CaC2 + CO

Produced CaO and coke are heated at temperature around 20000C in an electric arc furnace. Calcium carbide and carbon monoxide are produced in this step.
calcium carbide manufacturing reaction


Preparation of acetylene from calcium carbide


Calcium carbide and water reaction | CaC2 + H2O = HCCH + Ca(OH)2

Add calcium carbide into water. You can see a smoke is coming out of water. This smoke is the acetylene gas which is highly flammable. Acetylene's IUPAC name is ethyne. Which is an organic compound and belongs to alkyne group.


Acetylene gas is an organic compound and belongs to alkyne group.

Preparation of acetylene from calcium carbide


Calcium carbide production process

Following figure shows, how CaC2 and acetylene gas is manufactured by starting from raw materials and what are the physical conditions you should maintain to get higher yield.

Calcium carbide manufacturing process

Carbide compounds can be prepared from strontium and barium metals too.


Uses of acetylene gas

  • to produce oxyacetylene flame for welding industry.
  • Produce polymers
  • to ripen fruits

Preparing calcium cyanamide

Calcium cyanamide(CaNCN) is a fertilizer. Calcium carbide is heated with nitrogen gas stream in 10000C to manufacture calcium cyanamide.

calcium cyanamide preparing


Problems of calcium carbide manufacturing process

Calcium carbide plant causes to environmental pollution.

  • Corol and limestone are used to take CaO. This causes to coastal erosion.
  • Energy required for preparing CaC2 is higher than getting energy by the combustion of C2H2.
  • Generated heat causes to increase the temperature of environment.
  • Cannot transport ethyne (C2H2) easily.
  • Storing ethyne is difficult.


Calcium carbide in rippening foods

Calcium carbide is a prohibitted compound to rippen foods in most countries.



What is the colour of calcium carbide?

Pure calcium carbide is colourless. But pieces of technical-grade calcium carbide are grey or brown colour because existing of calcium oxide, calcium phosphate, calcium sulfide, calcium nitride and silicon carbide.



Calcium carbide to ethyne

Ethyne is the IUPAC name of acetylene. Add water to calcium carbide. It gives ethyne gas which has two carbon atoms and two hydrogen atoms.



Related Tutorials to Calcium Carbide and Acetylene Gas