It is generally held that 1909 was the year of the first successful experimental synthesis of ammonia according to the modern concept. On 2nd of July 1909 Haber was able, in BASF laboratory in Karlsruhe, to synthesize ammonia using for the first time in history a process concept that is the one still used today. This event is documented by a letter, contained in BASF archives, written by Mr. Haber to the company’s directors: Yesterday we began operating the large ammonia apparatus with gas circulation in the presence of Dr. Mittasch and were able to keep its uninterrupted production for about five hours. During this whole time it had functioned correctly and it produced continuously liquid ammonia. Because of the lateness of the hour, and as we all were tired, we had stopped the production because nothing new could be learned from continuing the experiment. All parts of the apparatus were tight and functioned well, so it was easy to conclude that the experiment could be repeated.... The steady yield was 2 cm3/minute and it was possible to raise it to 2.5 cm3/min. This yield remains considerably below the capacity for which the apparatus has been constructed because we have used the catalyst space very insufficiently. This experiment set in train the development of chemical technologies unprecedented in the previous history of the chemical industry.
This year therefore marks the real centenary of the birth not just of the modern synthetic ammonia industry, which solved a fundamental problem in securing food supply, but of much of the modern chemical industry. In the two decades following that first experiment, BASF managed to fully industrialize the process, developing also the right catalyst and all the mechanical design, and built the first plants. Following the paths opened by BASF, in the same period three other companies developed new processes for the ammonia synthesis, contributing to the birth of the modern ammonia industry. This, the first of two papers commemorating this important anniversary, outlines the early history of modern ammonia technology, up to the Second World War, and the industry that was built on it.