Chapter 27. Badische (Fertilizers)

 

My chief subject is of interest to the whole world—to every race—to every human being. It is of urgent importance to-day, and it is a life and death question for generations to come. I mean the question of food supply. Many of my statements you may think are of the alarmist order; certainly they are depressing, but they are founded on stubborn facts. They show that England and all civilised nations stand in deadly peril of not having enough to eat. As mouths multiply, food resources dwindle. Land is a limited quantity, and the land that will grow wheat is absolutely dependent on difficult and capricious natural phenomena. I am constrained to show that our wheat-producing soil is totally unequal to the strain put upon it. After wearying you with a survey of the universal dearth to be expected, I hope to point a way out of the colossal dilemma. It is the chemist who must come to the rescue of the threatened communities. It is through the laboratory that starvation may ultimately be turned into plenty.

 — William Crookes, The Wheat Problem, 1898 AD [1]

27.1.

I don't believe it! A chapter that actually has something to do with air. I suppose the Author will give it to Samson, who will probably find some roundabout way to work solubility into the discussion. Or how about Lucifer? A little fire and brimstone? No, no, let me guess. The Author will probably assign the chapter to Unktomi, who will undoubtedly earthify the place.

Well, now that you mention it, Crooke's little introductory bit does mention land and soil and such. See, plants need a bunch of elements to grow, hydrogen and oxygen and carbon being at the top of the list. Plants have no trouble getting these things; hydrogen and oxygen come from water and carbon comes from carbon dioxide in the air. From hydrogen and oxygen and carbon they make sugar and from sugar they make cellulose. And what with plants being mostly cellulose and cellulose coming from air and water, I can't blame you for not seeing where the earthification would come in. But besides cellulose, plants need to make proteins and to do that they need nitrogen. Now, you might think plants would have no trouble getting nitrogen, what with the air being 80% nitrogen and all. But most plants can't take nitrogen from the air; they have to get it from the soil. So folks have been using nitrogen-rich dung as a fertilizer since God was a child and it seems to me that earthification is exactly what this chapter needs.

I knew—

Of course, to get from the soil into the roots of the plant, nutrients must be soluble in water. There are two water-soluble nitrogen ions: ammonium and nitrate. Ammonia was traditionally supplied by stale urine. Nitrates were traditionally extracted from manure and solublized with potash. So you see, without these soluble nutrients plants would be up a creek.

I knew it was—

Being mere creatures of water and earth and air you undoubtedly failed to appreciate the lessons of Tu-Chhun. The precious nitrates of which you speak are not merely nutrients for vegetables; they feed the arsenals which protect us all from invasion and insurrection. Any society which fails to safeguard its nitrates will inevitably succumb to one which does. Crookes was well aware of this in 1898 and his call for nitrogen fixation was couched in terms of starvation and plenty to make it palatable to those incapable of keeping in the heat and withstanding it.

I knew it was too good to be true. You three are completely missing the point. There you are, surrounded by a virtually unlimited supply of atmospheric nitrogen, but because you don't know how to "fix" it, to convert nitrogen into ammonia or nitrates, you're left to wallow in the dung-heap.

Saltpeter (potassium nitrate) had been the oxidizer of choice for explosives since the invention of gunpowder. In 1846, however, two new explosives burst on the scene; nitrocellulose from the reaction of cotton with sulfuric and nitric acids was discovered by a true Athanor, Christian Schönbein; nitroglycerin from the reaction of glycerine with sulfuric and nitric acids was discovered by another Athanor, Ascanio Sobrero. Nitrocellulose became the basis of smokeless gunpowder, as all of its combustion products are gases. Nitroglycerin remained a laboratory curiosity because of its spectacular sensitivity to shock until a third Athanor, Alfred Nobel, learned to stabilize nitroglycerin with silica. We patented this dynamite, in 1866 and from that time, nitric acid became strategically important as an oxidizer.

Of course, nitric acid was made from saltpeter and sulfuric acid, like it shows in Equation 18-4. Sulfuric acid continued to be manufactured by the lead chamber process, but beginning in 1888 Badische Anilin und Soda Fabrik (BASF) began making it by the more efficient contact process.[2] So acid was as big a business as ever, and saltpeter too, extracted in the traditional way from dung. But from about 1840 folks started importing sodium nitrate mined from huge deposits in Chile, which was exporting over a million tons of the stuff by 1902. But what with wars and famines and population explosions and all, the old-fashioned sources of nitrates weren't going to last forever. Pretty soon everybody and his dog were looking for a way to make nitric acid from something other than saltpeter.

There was ammonia, of course. Available from stale urine in the early days, ammonia became increasingly available in the nineteenth century as a by-product of the manufacture of coke and coal gas. Ammonia could be reacted with sulfuric acid to produce a dandy water-soluble fertilizer, ammonium sulftate. In 1902 Wilhelm Ostwald perfected the oxidation of ammonia over a platinum catalyst to produce nitric acid. From ammonia and nitric acid you get ammonium nitrate, the most important fertilizer of the twentieth century, which would usher in an era of unprecedented—

Hold on there, cowboy, you're getting ahead of yourself. Crookes knew all about dung and urine and coal gas and after adding them all up he figured they weren't going to be enough for the industrialized world, much less for the backwaters. Funny story; a fellow named Thomas Willson was trying to smelt calcium from lime long about 1892. It didn't work. Instead of the metal, calcium, he got something that looked like dirt but which turned out to be calcium carbide. When he threw it in the river, up from the water came a bubblin' gas. Acetylene, that is. Acetylene became all the rage for welding and such, which gave Union Carbide its start in 1898.

Fascinating to a hillbilly, I'm sure, but we're talking about fertilizer.

I was just coming to that. So in 1898 Adolph Frank and Nikodem Caro reacted calcium carbide with atmospheric nitrogen in a high-temperature furnace to produce calcium cyanamide, which turned out to be a nifty fertilizer. Pretty soon everybody and her dog were making cyanamid by the Frank-Caro process. American Cyanamid got started that way long about 1907. World production of cyanamid grew from about 7000 tons in 1907 to 120,000 tons in 1913.[3]

The route from cyanamid to nitric acid was not straightforward, however. In 1909 Fritz Haber of BASF reacted hydrogen with atmospheric nitrogen at high temperature and pressure over an osmium catalyst to produce ammonia. The laboratory process was scaled up by BASF engineer Carl Bosch and by 1912 a pilot plant was producing a ton of ammonia per day.

…and just in the nick of time, for Germany. In 1913 Germany imported approximately half of its nitrogen from Chile, a source which became unavailable at the outbreak of WWI due to a successful British blockade. As a consequence, German agricultural and military demands for fixed nitrogen were in direct competition. At the beginning of the war domestic nitrogen came predominantly from the coking of coal; by the end of the war half of German nitrogen production came from the Haber-Bosch process and Germany was nearly self-sufficient in nitrogen. With superiority in fixed nitrogen and aniline dyes, BASF came to dominate German chemicals by the end of the war, and German chemicals dominated the—

Yeah, yeah; almost makes you forget that Germany lost the war, doesn't it? Imported Chile saltpeter, ammonium sulfate from coal gas, and cyanamid were good enough for poor old Britain, France, and the United States. Just imagine if they'd had the Haber-Bosch process. Oh, yeah, I forgot; they did get it—after the war!

In other words, even in the face of German defeat the Haber-Bosch I-dea conquered its competitors during the general economic slump which followed the war. For example, while American Cyanamid assets fell by 8% from 1918 to 1921, BASF assets quadrupled.[5] BASF began the twenty-first century as the third largest chemical company in the world.[6]

And Haber was awarded the Nobel Prize in 1919. Twenty-one tumultuous years after Crookes' challenge to the chemical community, virtually unlimited quantities of fertilizer could be manufactured from thin air.

Fertilizers, yes; but it is a mistake to forget that the same chemicals that improve agricultural efficiency so dramatically can have other dramatic effects. The truck bomb that leveled the Murrah Federal Building, for example, was probably filled with ammonium nitrate fertilizer and fuel oil.

I don't believe it; we finally agree about something. At least I don't have to worry about you revealing the secret of high explosives.

Quite the contrary, it is not in the interest of a free society for that particular secret to be kept. An ignorant population is the most vulnerable to attack; in the land of the blind, the one-eyed chemist is king.

Notes

[1]

Reference [9], pp. 6-7.

[2]

Reference [52], p. 85.

[3]

Reference [61], p. 102.

[4]

Reference [61], p. 203.

[5]

Reference [61], p. 254.

[6]

Reference [54], July 29, 2002, p. 16.