Sodium carbonate is an alkaline powder familiar to many generations of laundry workers as washing soda. However, this is a versatile substance with myriad other uses. Most notably, in this age of the skyscraper, it forms glass when heated then rapidly, cooled with sand and calcium carbonate. On a more grisly note, sodium carbonate is used in taxidermy to strip away flesh from bone. It is also a common food additive.
Traditionally, sodium carbonate was sourced from mining and from the ashes of plant matter (hence its other name, soda ash). Throughout the industrial era, efforts were made to find a synthetic process to produce the compound, which was in great demand for textiles and glass. The first attempt was made in 1790 by Frenchman Nicolas Leblanc (1742-1806), who found a way to convert salt into sodium carbonate using sulfuric acid, limestone, and coal. The method worked, and was used by industry for seventy years.
The Leblanc method had two drawbacks: expensive reactants and pollution. In 1861, Belgian chemist Ernest Solvay (1838-1922) worked out a more efficient process that bears his name and is still used today. Carbon dioxide is bubbled through a mixture of ammonia and salt water to form ammonium chloride and baking soda. The latter is then filtered out and heated to produce sodium carbonate.
Ernest and his brother Alfred founded their own company in 1863, and production of sodium carbonate began in 1865. It took until the end of that century for them to perfect it, but Solvay's process, which was more viable for large-scale commercial production, finally replaced the Leblanc process and came to dominate industry. Three-quarters of the world's sodium carbonate is now produced by Solvay's method, with the rest being mined.
