reading the alchemy of air

alchemy_coverThe development of mass agriculture spurred both population growth and the fear that population would one day outpace food production. In the 2nd century AD, Carthaginian theologist Tertullian fretted about overpopulation, and the possibility that humans could have sex with supernatural beings. In 1798, Thomas Malthus laid out the mathematical inevitability of mass starvation (“Malthusian catastrophes”). And in the last half-century, The Population Bomb predicted dwindling food sources, Soylent Green envisioned our future cannibalistic dystopia, and The Running Man depicted future food riots. In between (1898), William Crookes warned that with arable land being tapped out, only a synthetic fertilizer and increased crop yields could prevent our deprived future—in his words, “starvation may be averted through the laboratory.”

Why the focus on synthetic fertilizer? Plants require nitrogen, but can’t just pull it straight from the air, despite Earth’s nitrogen-rich atmosphere. For plants to access nitrogen, it must be chemically “fixed.” Nitrogen fixing is a natural process that occurs in compost and manure, but at the time Crookes was speaking, there was no artificial method for fixing nitrogen.

Because nitrogen couldn’t be synthetically fixed, natural sources have been almost priceless commodities throughout history. In the Middle Ages, for example, petermen scoured the country for saltpeter with royal license to seize it by force. Later, the English actually farmed saltpeter by seeding trenches with sewage and urine. Swedish farmers paid taxes in saltpeter, and high-quality nitre near the Ganges was one principal economic reason for the British colonization of India.

By the mid 1800s, the world’s greatest source of fixed nitrogen was seabird guano from the uninhabited islands near Chile and Peru. Guano access sparked wars (read more here), enslavement, and like any good commodity, a speculation bubble that burst in 1890. But the world was using up that guano faster than the birds could lay it down, and by the late 1800s, the bottom of the world’s shit barrel was within scraping distance.

The synthetic fertilizer Crookes thought could save humanity was scientific legerdemain; a 19th-century analog to transmuting lead into gold: fixing nitrogen from the air to make fertilizer. Or, in parlance: turning air into bread.

Haber and apparatus. I do not trust pince-nez glasses.
Haber and apparatus. I do not trust pince-nez glasses.

Fritz Haber, a German Jewish chemist (1868-1934), cracked the code. If there is a fundamental aspect of Haber’s personality, it is unstinting national pride. And to him, fixing nitrogen was not a humanitarian effort to cure world hunger, but insurance that the English could not cut off Germany’s access to Chilean guano—or that if they did, Germany could still farm. A staggering amount of world history hinges on waste products.

What Haber discovered wasn’t so much how to fix nitrogen, but how to do so practically. At the time, an actual chemical process for fixing nitrogen was known: at high temperatures and pressures (1200+ degrees C and 200+ atmosphere), the triple bonds of atmospheric nitrogen could be broken to produce ammonia. The problem was that the resultant ammonia was cooked off, and that’s assuming your pressure vessel did not explode first. Haber did not solve the problem with a deep insight or clever reconceptualization; he simply chipped away at it, making minor reductions to the pressure/temperature requirements. By 1908, he had a working tabletop model. It produced droplets of ammonia.

Enter Carl Bosch, head of the massive German chemical/dye concern BASF. Bosch had made his mark(s) by predicting the need for a synthetic indigo dye, then spending 15 years and billions of dollars to develop it—a long con that paid off. BASF had also been dabbling unsuccessfully at the nitrogen fixing problem; they had bought a hydroelectric power plant to work on a doomed, preposterously expensive arc-electricity approach.

Bosch bought Haber’s prototype machine, but he needed to make it work on a massive scale. Haber’s model still required high pressures and temperatures, so scaling it up meant developing new types of steel, new high-pressure valves, fittings, and tanks, finding a suitable catalyst (Haber used osmium, one of the rarest metals on earth), and coming up with a way to produce huge amounts of hydrogen needed as input. They overcame all of it. Haber wrote his scientific paper on the process in 1910, and by 1913 BASF was producing tons of ammonia every hour using the Haber-Bosch process.

•     •     •

If you’ve heard this story before, it’s almost assuredly because of this dramatic irony: fixed nitrogen is also used in gunpowder and explosives. This fact was not neglected by Germany’s military, who by 1916 were using more than 20,000 tons of fixed nitrogen every month to sate the war machine. Nitrogen was crucial to the war: as Haber predicted, the German and English navies were fighting for guano access near Chile (even with the plant producing nitrogen for the military, farmers still needed fertilizer). Some historians estimate that the synthetically produced nitrogen extended the war by up to a year—without it, Germany would have been forced to surrender sooner.

Carl Bosch
Carl Bosch

When Bosch—less jingoistic than Haber—unexpectedly found himself running a defense contractor, he promised to drink himself “into the biggest high of my life.” Haber, meanwhile, tried to enlist but was instead put in charge of a research institute portentously surrounded by barbed wire. His big idea was poison gas (chlorine) that aimed to kill—no “irritant” half-measures for Haber, who figured his super-weapon would save lives by ending all war. Of course it didn’t—he forgot about gas masks—and in any case his moral calculus made no accounting for psychological trauma.

(Gassed soldiers weren’t the only to suffer from that Deutschland uber alles single-mindedness. His first wife, Clara Immerwahr, was the first German woman to earn a PhD in chemistry; Haber and social conventions conspired to make her a housewife. Feeling trapped and aghast at Haber’s development and use of poison gas, she shot herself with his service revolver, and the suicide was covered up.)

Haber fled Germany after the war, concerned he would be tried for war crimes. While on the run, he won the Nobel in 1919, which infuriated, well, pretty much everyone else. He returned to the institute when charges didn’t materialize, at one point developing a chemical to delouse buildings (it was Zyklon B; even his good deeds were made evil). He then obliterated the line between genius and insanity with a plan to pay off German war debts by extracting GOLD FROM THE SEA. Working off claims that ocean water contained a non-trivial amount of gold and other minerals, Haber spent years developing a way to pull trace gold from water. Only then did he go out and scoop up some seawater, where he found that, yes, those claims were wrong, and the water was gold-free.

When Hitler took over, Haber’s “patriotic” deeds were rendered moot. Lacking the requisite racial purity, Haber left Germany and his institute was gutted. His second marriage had failed, his country deserted him, and he was sickly: “I am fighting with diminishing strength against my four enemies: sleeplessness, the financial demands of my divorced wife, my increasing disquiet about the future, and the feeling of having made serious mistakes in my life.” His national pride died just before he did, in 1934: “my most important goals in life are that I not die as a German citizen…”

•     •     •

Back to Bosch. With two BASF plants under French control after WWI, Bosch tried to keep his industrial magic secret by letting the plants idle and refusing to talk. Despite having no leverage whatsoever, he convinced the French to license the fixing process—we can only assume they also left the meeting shirtless and with a deed to the Brooklyn Bridge. The sequence repeated a few years later when Germany stopped paying its war debts and France repossessed the plants. This time playing hardball, the French held BASF board members hostage for more than a year trying squeeze Bosch, who still refused to crack. He was like Bartleby the High-Pressure Industrial Chemist.

The plants remained important. In 1921, angered workers barricaded themselves in the factory for ten days; thirty workers were killed when a police artillery attack ended the standoff. An explosion later that year killed 561 people and left 7000 homeless. Bosch started drinking.

In the mid-1920s BASF was resorbed into the collusory oligopoly IG Farben. Concerns about peak oil were growing, and Bosch’s plan was to develop synthetic gasoline. He was slowed by new oil fields discovered in Oklahoma and the Great Depression, but eventually succeeded. In the early 1930s, Hitler was a big fan—most people didn’t grasp why at the time—and strong-armed Farben/Bosch into increasing output and selling all of their synthetic gas to the government, making the company officially an arm of the party.

Bosch raised enough hackles about that to be booted out the side door of both Farben and the country. He more or less drank himself to death by 1940, less than a decade after winning a Nobel for his part nitrogen fixing process. He didn’t see the synthetic gas plant become so crucial to Germany that Allied forces spent more than a year straight trying to bomb it into submission; he also didn’t see many of his former colleagues convicted of war crimes.

File photo: Haber-Bosch process
File photo: Haber-Bosch process

Oceans of ink have been spilled over the dichotomy of Haber: feeding the world but also the military, preventing starvation and developing poison gas, all without the fleeting morsels of satisfaction you might get from Bosch’s apparent torment over what he’d done or enabled. Nitrogen fixing wasn’t all sunshine and kittens, either: Chile and Peru were devastated when the value of their primary export plummeted, and all that extra nitrogen injected into the ecosystem gives us giant algal blooms and ocean dead zones. Then again, the Haber-Bosch process feeds ~⅓ of the world. Maybe best not to try sorting it out.


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