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The Solvay Process Explained

Named after Ernest Solvay, a Belgian chemist who developed the process to its modern form in the 1860s, the Solvay process is used in a variety of industries. The Solvay process is an industrially scaled method for producing sodium carbonate, commonly referred to as soda ash.

Sodium carbonate has many chemical uses, including the sodium carbonate test, which is used to detect and distinguish between several types of metal ion. However, the reason to have a large scale chemical process to produce it in high quantities is that soda ash is used in other industries and products such as glass making, water treatment, detergent production and paper making among others. The Solvay process was successful, and remains so, because the ingredients needed to produce the soda ash are very inexpensive. In fact, all that is needed is salt water and limestone which can be found nearly everywhere.

The Process

The industrial Solvay process uses two towers through which brine, usually concentrated sea water, passes. In the first tower, ammonia is allowed to be absorbed by bubbling it through from underneath. In the other tower the ammonia rich brine has carbon dioxide bubbled through it. The net result of the Solvay process is that both soda ash and calcium chloride are output with the soda ash being set aside for further application. Calcium chloride, on the other hand, is regularly used along with other electrolytes in things like sports drinks and bottled mineral water.

Glass Making

One of the most common uses for soda ash produced by the Solvay process is with the manufacturing of soda-lime glass. Nowadays, over half of the soda ash that is made using the process goes into this form of glass making. Bottle glass, which is used for a variety of containers, and window glazing is made by using the material along with calcium carbonate and sand, or silicon dioxide. Flat glass, the sort that is mostly used for windows, is made by a process called floating whilst container glass is crafted by blowing or pressing it. Either type of production method makes durable glass which can be easily recycled into new products, if required.

The Future

The Solvay process was exported to North America in the 1880s in a joint venture which saw the operation of a purpose built plant in New York. Soon afterwards other processes used to produce soda ash died out and the Solvay process was dominant globally. Nevertheless, in the twentieth century North American use of the process ended after natural deposits of sodium carbonate were discovered.

However, it remains as popular as ever elsewhere in the world and shows no sign of decline in any other region