Haber, ammonia and a complex legacy

Nitrogen is vital to plant life, and nitrogen-based fertilizers were essential for crops to produce more food in the early 20th century. Even if there is only limited usable nitrogen on the earth’s surface, the atmosphere is an inexhaustible source that can be tapped. Binding nitrogen from the air was a long-awaited goal of chemists – which the German chemist Fritz Haber finally achieved.

Born into a wealthy German-Jewish family in 1868, Haber showed an inclination towards chemistry at an early age. Haber studied at several universities and received his doctorate in organic chemistry in 1891. During his time as a lecturer at a Karlsruhe polytechnic, Haber studied physical chemistry.

Growing anti-Semitism

In 1901 Haber married Clara Immerwahr, a brilliant chemist and the first woman to receive a doctorate from the University of Wroclaw. Even if, like Haber, she converted from Judaism to Christianity, the couple was nonetheless exposed to anti-Semitism (discrimination against Jews).

At the turn of the century, it was rumored more and more often, especially among scientists, that the world could not meet the growing food needs of the growing population. While at that time it was known that nitrogen-based fertilizers could increase crop yields and thus meet the pending demand, the fixation of nitrogen from the air had not yet been achieved.

Fix nitrogen

Atmospheric nitrogen is fairly inert, which means it doesn’t easily react with other chemicals to form compounds. Nitrogen fixation is the process by which molecular nitrogen in the air is converted to ammonia or other related nitrogen compounds either in the soil, in water systems, or even industrially.

It was Haber who developed a method in which nitrogen gas was reacted directly with hydrogen gas under high pressure and a catalyst to produce ammonia. On September 27, 1910, Haber received a US patent for the production of ammonia.

In cooperation with the German chemist and engineer Carl Bosch of the chemical company BASF, the process for the production of ammonia from atmospheric nitrogen was scaled. The Haber-Bosch process was born, which made it possible to produce large quantities of ammonia.

“Bread from Nowhere”

The resulting ammonia could be used industrially, creating huge amounts of fertilizers. Agricultural fertilizers greatly increased crop yields, eased famine fears, and produced enough food to meet humanity’s growing needs. “Bread out of air”, which literally meant “bread out of nowhere”, was the popular German catchphrase at the time for this miraculous turning point.

Haber always wanted to prove his patriotism and therefore intervened in the German cause during the First World War. He experimented with chlorine gas and developed a new weapon, poison gas, which he believed would shorten the war.

Haber supervised the first use of his methods in Ypres, Belgium, in 1915 and was promoted to captain in the German army. The night he celebrated his promotion at a party at his home in Berlin, Clara, who condemned her husband’s gun work and became frustrated with life at home, died by suicide.

His wife’s suicide did not delay his deployment as he rushed back to the war front. But many others began to express their views on Haber’s wartime role and what they saw as an advertisement for a barbaric weapon. When he was awarded the Nobel Prize in Chemistry in 1918 for the synthesis of ammonia from its elements, of course, that didn’t go down well with everyone.

Escape from Germany

While Haber continued to patriotize, he felt that he was still caught in the web of anti-Semitism. When the Nazis came to power he was still perceived as a Jew and his position soon became untenable. He fled Germany and went into exile, but found neither work nor a place to stay and died in 1934 of a heart attack.

In addition to the poison gas, Haber’s research was later further developed into the cyclone process. This was used by the Nazis to kill millions of people in their concentration camps, including some of Haber’s own extended relatives.

Despite the importance of his work producing ammonia, which still helps agriculture around the world, Haber left a complicated legacy, largely due to his efforts on the war front. The theoretical physicist Albert Einstein, who was born in Germany, summarized the life of his friend and his relationship with his homeland as follows: “Haber’s life was the tragedy of the German Jew – the tragedy of unrequited love.”