Intermediate Topic 1076 of 1102 Biochemistry, Environment & Industry

Chlorine Industry

Produced by electrolysis for PVC, solvents and water treatment.

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In-depth explanation of Chlorine Industry

Chlorine is produced mainly by the electrolysis of concentrated brine, which yields chlorine gas at the anode, hydrogen at the cathode and sodium hydroxide in solution. The chlor-alkali process can use mercury, diaphragm or membrane cells, and membrane cells are now preferred because they avoid mercury emissions and are energy efficient. Chlorine is used to make PVC and other chlorinated chemicals, solvents, pharmaceuticals, bleaches and water disinfectants. Because it is produced together with sodium hydroxide, demand for the two co-products must be balanced. Chlorine is a toxic gas, so handling it requires strict safety controls.

Going deeper: Chlorine Industry

Key ideas: Chlor-alkali process: electrolysis of brine, 2NaCl plus 2H2O gives Cl2 (anode) plus H2 (cathode) plus 2NaOH. Cells: membrane cell (modern, pure product, energy efficient), diaphragm cell, mercury cell (phased out due to mercury pollution). Chlorine goes to PVC, solvents and water treatment, NaOH to paper, soap and aluminium.

Common mistakes and connections: Mistake: expecting sodium at the cathode; in aqueous solution water is reduced instead of Na+. Products must be kept apart, as Cl2 plus NaOH gives bleach (NaOCl). Uses about 2.5 MWh per tonne Cl2. Links to electrolysis, selective discharge and water chlorination.

Visualization of Chlorine Industry

Electrolysis of brine gives chlorine at the anode and hydrogen with sodium hydroxide at the cathode, the chlor-alkali process. The interactive lesson shows this as a live animation or chart.

Worked example and use case

Chlorine gas from brine electrolysis is used to make vinyl chloride for PVC pipes.

Frequently asked questions about Chlorine Industry

What is Chlorine Industry?

Produced by electrolysis for PVC, solvents and water treatment.

Is Chlorine Industry a beginner, intermediate or advanced topic?

Chlorine Industry is a intermediate topic in Biochemistry, Environment & Industry. It builds on the vocabulary of beginner topics in this area.

What should I learn before Chlorine Industry?

Study these earlier topics in Biochemistry, Environment & Industry first: Coal, Sulfuric Acid Industry, Ammonia Industry.

What comes after Chlorine Industry?

The next topics in Biochemistry, Environment & Industry are Paper Industry and Soap Making.

Can I practise Chlorine Industry with quizzes?

Yes. The interactive lesson includes a self-check question on Chlorine Industry, and the Biochemistry, Environment & Industry quiz draws on every topic in this area.

Where Chlorine Industry fits in Biochemistry, Environment & Industry

Chlorine Industry is topic 101 of 127 in Biochemistry, Environment & Industry.