The industrialization of electrochemistry
Michael Faraday (1791–1867) had a modest upbringing. He was 14 years old when he began his bookbinding apprenticeship. The young Faraday read a multitude of works that he received for binding and thus educated himself in the sciences as well as in literature and art. A customer at the bookbinding workshop noticed the curious apprentice and mentioned him to his father, who then took Faraday with him to several lectures given by electrochemistry pioneer Humphry Davy. Shortly after, Faraday began working for Davy.
As his assistant, Faraday traveled with Davy across Europe, as they carried out experiments together and met numerous influential scientists. Back in England, Faraday continued training as a chemist and in 1833 became a professor of chemistry. During this time, he investigated the basic laws of electrolysis. These formed the basis of electrochemistry and, in the second half of the century, enabled the development of an electrochemical industry which manufactured products such as chlorine, hydrogen, aluminum, magnesium, sodium, and potassium in its plants located at hydroelectric power stations.
Solvay’s soda ash
The industrial production of soda ash (sodium carbonate) had been possible since the development of the Leblanc process at the end of the 18th century. However, the synthesis required expensive raw materials and produced large amounts of the byproduct hydrogen chloride, which is toxic to the environment in which it is introduced. The produced hydrogen chloride escapes from industrial stacks and kills surrounding vegetation, and is also lethal to aquatic life when added to water.
During the second half of the 19th century, the Belgian Ernest Solvay (1838–1922) occupied himself with the issue. Solvay, who came from an industrialist family, had little formal education but was familiar with chemical procedures thanks to his work at his uncle’s and father’s factories. He developed the process for manufacturing soda ash, which was named after him and only has one byproduct – the harmless calcium chloride (CaCl2).
In 1861, Ernest Solvay and his brother Alfred began soda ash production in their own small factory in Brussels. By continuously adjusting the process, they became increasingly successful and continued to expand. Solvay, who had become very wealthy, became active in furthering scientific research and charitable causes. He also showed his sense of social responsibility in his factories: he established an eight-hour workday, paid holiday leave, a social security system, and a pension for his employees – long before it was legally mandatory.
The periodic table of elements
There had already been 64 chemical elements discovered by 1868. However, there was as of yet no clear system of regulating which particular atom combinations formed new molecules. Sorting the elements based on their atomic mass had not offered a solution up to this point.
Dmitri Mendeleev (1834–1907) recognized a pattern here: when elements are sorted by their atomic mass, certain elemental properties are periodically repeated – specifically, after every eight elements. Mendeleev therefore retained the arrangement in ascending order of atomic mass, but then also sorted the elements that had the same properties below one another. Whenever properties were repeated after fewer than eight elements, he left open gaps to be filled with elements that had not yet been discovered. Mendeleev arranged the transition elements, which did not fit with his «octet rule», into their own column. This resulted in the first periodic table of elements in 1869.
From aniline to aspirin
Organic chemistry, which now went far beyond the synthesis of artificial urea, had become a significant and rapidly growing industry. The tar dye companies BASF, Bayer, and Hoechst, all of which were founded in the 1860s, grew so rapidly that they were employing thousands of people even before the turn of the century. From the end of the 19th century, the tar dye industry also developed synthetic organic medicinal products. Bayer, for example, patented the byproduct-free synthesis of acetylsalicylic acid in 1898 and marketed the product under the name «Aspirin» from the beginning of the 20th century.
In basic research, chemists began devoting themselves to increasingly complex organic molecules. Emil Fischer (1852–1919) investigated biologically significant molecules such as sugars and amino acids. In 1890, he used glycerin as a basis for synthesizing three sugars: glucose, fructose, and mannose. He later researched proteins. During this period, he discovered new amino acids and shed light on the type of bond which connects them to one another: an amide bond which he gave the name «peptide bond» .
First World War: Artificial fertilizer and warfare agents
The use of fertilizer had been common practice throughout agriculture ever since Liebig proved that it would improve yield. The nitrogen needed by plants for growth was added to fertilizers largely in the form of guano. This consists of the weathered excrement of seabirds which forms meter-thick layers over many years, particularly on the beaches of South America, where there are low levels of precipitation. In order to meet the high demand for food – and thus for fertilizer – entire shiploads of guano were being imported to Europe.
However, the import of guano could not keep pace with the rapid growth of population indefinitely, so at the end of the 19th century, researchers began looking for a way to fix nitrogen from the air. The German chemist Fritz Haber (1868–1934) eventually found a solution in 1909 and, with his ammonia synthesis, prevented the famine prophesied in the western world. Unfortunately, this development also enabled Germany’s production of warfare agents during the First World War, as ammonia could be used to create ammonium nitrate, which was then used in ammunition.
In the Haber-Bosch process, ammonia is produced as a result of a reaction between hydrogen and nitrogen. Fritz Haber achieved synthesis at a high temperature and a high pressure level, and with the aid of a catalyst. Carl Bosch (1874–1940) developed the industrial implementation of the process. For this purpose, he developed specific equipment made of state-of-the-art materials which could withstand both high pressure and temperature levels.
In 1914, the First World War broke out. The nations involved, as well as neutral states, faced blockades in their trade routes and had to become largely self-sufficient. Thanks to governmental structuring and aid, this led to a boom in industrial research across the globe. Numerous reputable scientists were actively involved in the war or supported it, including Fritz Haber, Walther Nernst, and Emil Fischer. In addition to the Haber-Bosch process, the pressure to create innovations that prevailed before and during the war also resulted in the first synthetic rubber as well as mustard gas and the toxic gas phosgene. Chlorine gas, which is produced during ammonia synthesis, was also used as a warfare agent during World War One.
What if . . .
. . . the Haber-Bosch process didn’t exist? Without the nitrogen fertilizer produced using the Haber-Bosch process, there would likely be a lot fewer people on Earth: the population growth of around 1.6 billion in 1900 to nearly 8 billion today would not have been possible without yield improvements brought about by artificial nitrogen fertilizers. Agriculture is still dependent on it today: without this process, the planet would only be able to provide enough food for half the population .
Chemistry since WWI
Following the armistice agreement in 1918, the German chemical industry – which had been world-leading until then – lost all of its patents and had to reveal numerous production secrets in order to satisfy the reparation demands of the victorious Allied Powers . This meant that the German chemical industry had to relinquish its place at the top. Although it experienced another upswing toward the beginning of the Second World War, today’s leaders in the chemical industry are the USA and France. During the post-war period, polymer chemistry and pharmaceutical chemistry were the fields that saw particular advancement and brought about countless products which are still essentials today. Among these are polymers, including synthetic fibers such as nylon and polyester, and artificially produced vitamins and hormones.
The time around the turn of the 20th century saw rapid advancement in chemistry, both in fundamental research as well as in industry – and to a great extent, it is the relationship between the two which enabled this progress. Numerous processes developed during this time period, including the Haber-Bosch and Solvay processes, have remained the methods of choice in the production of chemicals – in this case ammonia and soda ash, respectively – to this very day.
 The Components of Life: From Nucleic Acids to Carbohydrates; 1st ed., Rogers, K., Ed.; Britannica Educational Publishing/Rosen Educational Services: New York, 2011; p 59.
 Erisman, J. W., Sutton, M. A., Galloway, J., Klimont, Z., and Winiwarter, W. (2008) Nat. Geosci. 1, 636–639.
 Kricheldorf, H. R. Menschen und ihre Materialien: Von der Steinzeit bis heute; 1st ed., Wiley-VCH Verlag & Co. KGaA: Weinheim, 2012; p 111.