Soda ash, also known as sodium carbonate, is an inorganic compound that is widely used across the globe. It has a long history of use, dating back to ancient civilizations where it was used to make glasses and clothes. Initially, soda ash was produced from the ash of a plant that grew in sodium-rich soils. However, with the advent of the Industrial Revolution, the method of production changed to a more industrial manufacturing process.
There are several methods used to produce soda ash today, including the extraction from trona, the LeBlanc process, the Solvay process, and the Hou process. The extraction of soda ash from trona, also known as natural soda ash production, is commonly used in the United States and Turkey. Trona can be found in lake brines or mineral deposits, and the largest deposits are located in Wyoming, USA, and Ankara, Turkey. Trona extraction accounts for more than 30% of global soda ash production.
The process of natural soda ash production involves injecting heated water into the trona deposits to create a brine solution. From there, the brine undergoes filtration, crystallization, separation, and drying to form the soda ash. Another method, the Solvay process, also known as the ammonia-soda process or synthetic soda ash process, uses brine, limestone, and ammonia as the main raw materials. It accounts for more than 70% of soda ash production worldwide and consists of four main processes: ammoniation, carbonation, and calcination.
In 1930, Chinese scientist Hou Debang developed a new method for producing soda ash known as the Hou process. This process uses carbon monoxide to produce carbon dioxide instead of limestone, resulting in the elimination of calcium chloride as a byproduct. Ammonia chloride becomes the byproduct of this process instead. Despite its success, scientists and engineers continue to work on developing new methods that increase the efficiency of soda ash production while also considering environmental safety.