With the growth in industries including soaps, detergents, pulp & paper, and aluminum, the demand for caustic soda has increased significantly all around the world. The global caustic soda market will be registering an average annual rate of 5 percent. The market for caustic soda is dominated by the Asia Pacific region especially India and China. It is estimated that the North American market will grow at a faster pace even beyond 2024.
What is caustic soda?
Caustic soda is the common name of sodium hydroxide (NaOH). It is corrosive and caustic in nature and derives its common name from this property. It is a waxy and white solid in its pure form and forms aqueous solutions easily as it readily absorbs water.
Caustic soda is widely used in soaps, candles, homemade biodiesel, paper industries, frosting glass, and has numerous food and chemical applications. It should be kept in sealed containers as it reacts with water very quickly. The growth in demand for caustic soda in India will be driven primarily by the expanding textile industry.
Processes Involved in the production of Caustic Soda
A variation of electrolytic chloralkali process is used in the production of caustic soda. One of the most popular methods of producing caustic soda is through the Castner-Kellner process.
Following are the various steps involved in the Castner-Kellner process: –
- Principle – By the electrolysis of NaCl (aqueous solution), NaOH (caustic soda) is prepared.
- Equipment – Castner-Kellener cell which is a rectangular steel tank lined with ebonite. Titanium is at the anode. Cathode is the layer of mercury at the tank’s bottom.
- Ionization of NaCl- 2NaCl e-2Na + 2Cl-
- As the current flows through the brine, migration of negative and positive ions takes place towards their respective electrodes.
- Reaction at Cathode-
- 2Na+ +2e- à2Na
- Na + Hg àNa/Hg
- Na+ ions are discharged due to high voltage.
- Reaction at anode-
- 2Cl-à Cl2 + 2e-
- Formation of NaOH
- The amalgam thus formed moves to other chambers, where it reacts with water and results in the production of NaOH in liquid state. Evaporation of this solution results in the formation of solid NaOH or caustic soda.
- 2Na/Hg + 2H2O à 2NaOH + H2 +2Hg
The caustic soda thus produced is very pure.
Industrial applications and increasing demand for caustic soda
Caustic soda is used in various industries and the demand is expected to grow further. It is predicted that more than 266,000 tons of caustic soda will be manufactured in 2020 by GACL and NALCO, which are the two biggest manufacturers for caustic soda in Asia. Caustic soda has various industrial applications including:
- An extensive application is in industries of household products like soaps and detergents. It is used in the production of raw materials to clean drains and ovens.
- Production of various chemicals also use caustic soda due to its reactive and corrosive nature. The chemicals can be both organic and inorganic in nature.
- Caustic soda is also used in various other industries in the production of alumina, pulp & paper, textiles, and water treatment. The rising use of tissue papers in homes has increased the demand for pulp and paper industries. The demand for caustic soda has also increased in the paper industry due to the increased use of printing and writing paper.
- With technological investment and increased development, the demand for caustic soda in the textile industry is also increasing.
- It easily reacts with aluminum and zinc because of its strong alkali nature and reactivity. This results in demand for caustic soda in metallurgical applications as well.
- The development of alumina extraction industry has also led to the growth of the global caustic soda market.
- The use of caustic soda is also associated with the automotive industry because of its use in the smelting of alumina. Alumina is widely used in cars as it results in lightweight vehicles.
Caustic soda is used mostly in the pulping and bleaching process of the paper and pulp industry. It is also used in de-inking of waste paper and water treatment. The major end-use industry application of caustic soda is in the production of alumina from bauxite. It is also utilized in the manufacturing of many chemicals. It is used to produce solvents, synthetic fibers, plastics, coating, dyes and pharmaceuticals acting as an intermediate or a reactant in the process. It is also used in the saponification and in the manufacturing of surfactants for detergents.
Market forecast of Caustic Soda
The global caustic soda market is predicted to grow at a CAGR of 5 percent by the year 2020 to reach $2.42 billion.
The global caustic soda market will expand rapidly in the coming years. The Asia Pacific region has been the dominant region for consumption of caustic soda and it has been estimated that it will grow further in the next few years due to high demand across the textile industry in countries like China, India, Taiwan, and Vietnam. China is the hub for the chemical processing industry in the Asia Pacific region and is also the biggest producer and consumer of caustic soda globally. China is closely followed by India as the second biggest consumer of caustic soda in the Asia Pacific region, but the demand growth in India slowed down significantly due to demonetization in the years 2016-2017.
Organic and inorganic chemical formulations in 2017 formed 21 percent of the overall caustic soda demand globally. Demand for caustic soda in the North American market is also predicted to grow in the next few years. This is due to an increased demand for household products. The Middle East and Africa will grow at a moderate rate whereas Latin America will observe slower growth rates over the next few years.
Low water levels in the European region has resulted in a reduction in the quantity of caustic soda produced.
Caustic soda is a highly corrosive substance and has a harmful impact on the environment. This acts as a huge impediment in the growth of the caustic soda market. Another significant constraint in the expansion of the caustic soda market is the high cost of investment in setting up a manufacturing plant. In such cases, importing caustic soda is much cheaper as compared to manufacturing, which results in a fall in supply of caustic soda from domestic suppliers.