by Vaclav Smil
Bosch came to BASF in 1899 directly after graduating from Leipzig University and eventually was put in charge of BASF’s nitrogen fixation research. That goal eluded him as it did so many other outstanding synthetic chemists of the time. But when Haber demonstrated his bench-top process to BASF, it was Bosch who was in charge of turning it into a profitable commercial operation. I have already related in chapter 1 how in March 1909 Bosch’s understanding of steel metallurgy persuaded the BASF leadership to proceed with the commercialization of Haber’s process. But before any large-scale production of ammonia could begin, Bosch and his team had to solve a number of unprecedented engineering challenges, including the failure of the first scaled-up converters. These 2.5-m-long experimental tubes (heated electrically from the outside and filled with the catalyst) exploded after about 80 hours of operation under high pressure. Fortunately, Bosch anticipated such a mishap and placed them in reinforced concrete chambers.
Examination of failed converters revealed the total loss of elasticity as they became hard and brittle after being subjected concurrently to high temperature and high pressure. Bosch’s first approach was to fit the pressure tube with a soft inner lining, but his eventual, and better, solution was to contain high temperature within an inner wall of soft (low-carbon) steel and to force a mixture of pressurized cold hydrogen and nitrogen into the space between the inner and outer walls. Consequently, the inner shell was subject to equal pressure from both sides, and the strong outer steel shell was under high pressure but it remained much cooler. With this solution, converter sizes were increased to 4 m and 1 t in the first pilot plant in 1912, and units 8 m long weighing 3.5 t were installed in the first commercial process in 1913.
Perhaps the most notable challenge among other engineering problems that had to be overcome before setting up the entire operation was the production of hydrogen (nitrogen was derived from Linde’s air liquefaction). In 1912 Bosch and Wilhelm Wild patented their Wasserstoffkontaktverfahren, a catalytic shift reaction that transforms CO and steam into CO2 and hydrogen. The second major set of challenges involved the search for the best and inexpensive catalyst. Alwin Mittasch (1869-1953) undertook a systematic testing of all metals known to have catalytical abilities in pure form or as binary (e.g., Al-Mg, Ba-Cr, Ca-Ni) or ternary catalysts, as well as more complex mixtures (Mittasch 1951). Magnetite (Fe3O4) from the Gallivare mines in northern Sweden supported the highest yield, and Mittasch then sought the best possible combination with catalytic promoters. The first patent for such mixed catalysts was filed on January 9, 1910.
Nothing illustrates the thoroughness and efficacy of Mittasch’s exhaustive search better than the fact that most commercial catalysts used in ammonia synthesis during the 20th century were just slight variations on his basic combination that relied on magnetite with additions of Al2O3, K2O, CaO, and Mg. These promoted iron catalysts are also extraordinarily stable, able to serve for up to 20 years without deactivation. Only recently did Kellogg, Brown & Root introduce their advanced ammonia process (KAAP), which is not based on the classical magnetite catalyst but instead a precious metal, ruthenium, with co-promoters (Smil 2001).
Construction of the first ammonia plant at Oppau near Ludwigshafen began on May 7, 1912, and the production started on September 9, 1913, with the gas used as a feedstock for the synthesis of ammonium sulfate fertilizer. But less than a year after the plant’s completion, Oppau’s ammonia was diverted from making fertilizer to replacing Chilean nitrate, whose imports were cut off by the British naval blockade. There is no doubt that the Haber-Bosch synthesis was one of the factors that helped to prolong WWI. Blockaded Germany could do without Chilean nitrates that were previously used for producing explosives, and its troops had enough ammunition to keep launching new offensives for nearly four years, until the spring of 1918. In order to satisfy this large new wartime demand, the second, much larger, ammonia plant was completed at Leuna near Halle in 1917, and when the war ended Germany was the only country with a considerable capacity to produce inexpensive inorganic nitrogen fertilizer.
But the Haber-Bosch process, and its variants introduced during the 1920s, had a limited impact on the world’s food production before the 1950s as only a few countries were relatively intensive users of inorganic fertilizers and as the economic downturn of the 1930s and WWII set back the industry. Global synthesis of ammonia remained below 5 Mt until the late 1940s, and while several European countries had fairly high average rates of fertilizer applications already before WWI, in the United States more than one-third of all farmers did not use any fertilizer nitrogen even by the late 1950s. But then the situation changed rapidly, particularly as nitrogen fertilizers became the key nutrient that unlocked the yield potential of new cultivars everywhere except in the conflict-torn and mismanaged economies of the sub-Saharan Africa.
Importance of Synthetic Ammonia
While the importance of electricity or internal combustion engines for the modern society is obvious, even reasonably educated urbanites do not appreciate the essential role played by nitrogen fertilizers, and even most scientists are not aware of the extent to which the global civilization depends on the Haber-Bosch synthesis of ammonia. Global production of ammonia nearly doubled during the 1950s, further quadrupled by 1975, and then, after a brief period of stagnation that began during the late 1980s, it rose to nearly 130 Mt by the end of the 20th century. During the late 1990s, the global output of ammonia and sulfuric acid was virtually identical, but because of ammonia’s much lower molecular weight (17 vs. 98 for H2SO4), the gas is the world’s leading chemical in terms of synthesized moles.
Both the scale and the efficiency of the process have become far superior to the initial performance, above all thanks to the combination of innovations introduced during the 1960s. Replacement of reciprocating compressors by centrifugal machines cut the consumption of electricity by more than 90% and led to larger, and more economical, plants. Almost complete displacement of coal by natural gas as both the fuel and the feedstock (source of hydrogen) further lowered the energy cost of ammonia synthesis. During the late 1990s, about two-thirds of ammonia, or an equivalent of about 85 Mt of nitrogen a year, were used by fertilizer industry (figure 4.18), but in contrast to the pre-1960 period, when the gas was a feedstock for making a variety of compounds, most of it now is used for the synthesis of urea.
Unlike the gaseous ammonia, urea is a solid compound, containing 45% nitrogen (more than any other nitrogen fertilizer) and is produced in small granules that are easily stored, shipped, and applied to fields. Only small shares of nitrogenous fertilizers are applied to tree plantations, pastures, and lawns, and the bulk of all applications go to cereals and to oil and tuber crops. A detailed balance of nitrogen flows in the global agroecosystems shows that synthetic nitrogenous fertilizers supplied about half of the nutrient available to the world’s crops, with the other half coming from leguminous crops, organic recycling, and atmospheric deposition (Smil 1999a). Does this also mean—with nitrogen being the leading limiting input in food production—that roughly one-half of humanity is now alive thanks to the Haber-Bosch synthesis? This question cannot be answered without referring to a specific food supply: how many people would not be alive without ammonia synthesis depends on the prevailing diets.
FIGURE 4.18. Global production of nitrogen fertilizers, 1900–2000 (in megatons of nitrogen per year). Pre-1913 output includes ammonium sulfate from coking and cyan-amide and nitrate from the electric arc process. Based on data in Smil (2001).
Detailed accounts of the global nitrogen cycle indicate that about three-quarters of all nitrogen in food proteins available for human consumption comes from arable land (with the rest coming from pastures and aquatic species). If synthetic fertilizers provide about half of all nitrogen in harvested crops, then at least every third person, and more likely two people out of five, get the protein in their diets from the Haber-Bosch synthesis. As with most global averages, such a revelation both overestimates and underestimates
the importance of this great invention. In affluent nations, fertilization helps to produce an excess of food in general and assures high animal food intakes in particular (most of those countries’ crops are fed to animals rather than being eaten directly by people), and they also help to produce more food for export. Consequently, even significant cuts in the amount of applied fertilizers would result in less meaty diets and in lower exports but would not at all imperil the overall adequacy of the food supply. Depending on the meatiness of their diets, no more than 1 in 10 of the world’s 1 billion affluent consumers would then derive their protein from synthetic ammonia.
In contrast, rising fertilizer applications were essential for lifting populous low-income countries from the conditions of bare subsistence and widespread malnutrition. Norman Borlaug, one of the leaders in the development and diffusion of new high-yielding varieties of crops, captured the importance of nitrogen fertilizers in his speech accepting the Nobel Prize for Peace in 1970 (Borlaug 1970): “If the high yielding dwarf wheat and rice varieties are the catalysts that have ignited the Green Revolution, then chemical fertilizer is the fuel that has powered its forward thrust.”
As a result, both China and India have become basically self-sufficient in staple cereals, and (one of the insufficiently appreciated achievements of the 1990s) average per capita food availability in China is now at least as high as in Japan (FAO 2003). This means that the remaining, and not insignificant, extent of India’s and China’s malnutrition (effecting, respectively, about 200 and nearly 140 million people during the late 1990s) is a matter of unequal access to food and not of food shortages (Smil 2000b). Perhaps the best illustration of different degrees of dependence on nitrogen fertilizers is a comparison of the United States and Chinese situation.
In the late 1960s Americans applied just less than 30 kg of nitrogen per hectare of their farmland, while the Chinese rate was less than 5 kg/ha. Then came a stunning reversal of China’s international politics: the country’s return to the United Nations and Kissinger’s secret trip in 1971 were followed by Nixon’s state visit in 1972. The consensus opinion was that this historic shift was motivated almost solely by the need for a strategic partner against the mortal threat of the expansionist USSR: Realpolitik made yesterday’s despised aggressors, raining bombs on Vietnam, today’s valued allies as Mao chatted with Nixon in Zhongnanhai. But such major policy shifts have rarely a single cause, and, as far as I am aware, at the time of China’s opening nobody pointed out a reason ultimately more powerful than the fear of the Soviet hegemony: the need to avert another massive famine.
The world’s greatest and largely man-made famine claimed at least 30 million lives between 1958 and 1961 (Smil 1999b). In its wake, China’s population expanded at an unprecedented rate: with no population controls in place, it grew from 660 million people in 1961 to 870 million by 1972. This addition of more than 200 million people in a single decade represented the fastest population growth in China’s long history and the highest ever national increment in global terms. At the same time, the slowly rising yields could not keep up even with basic food needs: by 1972 China’s average per capita food supply was below the levels of the early 1950s! The only effective solution was to increase rapidly the synthesis of nitrogenous fertilizers—and soon after Nixon’s visit China placed orders for 13 of the world’s largest and most modern ammonia-urea complexes.
Such an order could not be filled without turning to M. W. Kellogg, America’s and the world’s leader in ammonia synthesis: eight of the 13 ammonia plants came from Kellogg, and they fed their product to urea plants delivered by Kellogg’s Dutch subsidiary. Was China’s opening to the world a matter of grand politics and strategic alliances? Undoubtedly—but it was also a matter of basic survival. More purchases of ammonia-urea complexes followed, as did more fertilizer imports: by the early 1980s China became the world’s largest consumer, and a decade later also the world’s largest producer, of fertilizer nitrogen. During the late 1990s, American applications averaged about 50 kg of nitrogen per hectare—but the Chinese rate surpassed 200 kg/ha and, in five of the most intensively cultivated provinces with the total population equal to that of the United States, topped 300 kg/ha! Fertilizer nitrogen already provides about 60% of the nutrient in China’s crops, and as more than 80% of the country’s protein is derived from crops, roughly half of all nitrogen in China’s food comes from inorganic fertilizers.
Similarly high degrees of high existential dependence have been evolving, nationally or regionally, in other land-scarce countries. When these countries reach the limit of their cultivated area, then they must turn, even if they remain largely vegetarian, to higher nitrogen inputs. During the last two generations of the 20th century, India increased its total applications of nitrogenous fertilizers by roughly the same rate as did China (more than 40-fold rise), while Indonesia applied during the late 1990s nearly 25 times as much synthetic fertilizer as it did in 1960 (FAO 2003). With most of the population growth during the next two generations taking place in Asia and Africa, this dependence will have to grow as there is still no practical alternative to supply the needed mass of the most important macronutrient.
While it is not difficult to make plausible scenarios of a world that will eventually function without the two great mainstays of modern civilization—internal combustion engines and electricity generated by the combustion of fossil fuels (the ubiquitous prime mover could be replaced by fuel cells, electricity can be generated by converting direct and indirect solar flows)—there is no substitute for dietary proteins whose production requires adequate nitrogen supplied to crops. During the late 1970s, it appeared that it might be possible to confer the fixation capability possessed by legumes on wheat and rice but, much as with commercial nuclear fusion or with mass-produced electric cars, this goal has remained elusive, and the dependence on the Haber-Bosch synthesis of ammonia will likely extend far into the 21st century, a lasting legacy of one the most important, yet so inexplicably little appreciated, pre-WWI technical advances.
5
Communication and Information
The apparatus … is all contained in an oblong box about 7 inches high and wide, and 12 inches long. This is all there is visible of the instrument, which during the lecture is placed on a desk at the front of the stage, with its mouthpiece toward audience. Not only was the conversation and singing of the people at the Boston end distinctly audible in the Salem Hall, 14 miles away, but Professor Bell’s lecture was plainly heard and applause sent over the wires by the listeners in Boston.
Scientific American of March 31, 1877, reporting on A. G.
Bell’s latest telephone demonstration
Less than a year after Alexander Graham Bell exhibited the first version of his telephone at the Centennial Exposition in Philadelphia in June 1876, he was demonstrating a better design during public lectures. Although much admired, the first device had a limited capacity as it could transmit only over short distances and did so with a much diminished signal; in contrast, the improved device made the first intercity audio communication possible. By the time of the Salem lecture, pictured in the frontispiece to this chapter, the record distance was about 230 km, from Boston to North Conway in New Hampshire. Bell’s telephone was only the first of several fundamental inventions that eventually revolutionized every aspect of modern communication. Almost exactly 10 years after Bell’s first intercity telephone calls came a discovery with even farther reaching consequences.
FRONTISPIECE 5. Alexander Graham Bell lecturing on his telephone to an audience in Salem, Massachusetts, on February 12, 1877, and a group in the inventor’s study in Boston listening to his explanations. The early apparatus was housed in an oblong box about 18 cm wide and tall, and about 32 cm long (inset on the right). Reproduced from the cover of Scientific American, March 31, 1877.
What Heinrich Hertz succeeded in doing between 1886 and 1888 was to generate, send, and for the first time to receive electromagnetic waves whose frequencies ‘rang
e themselves in a position intermediate between the acoustic oscillations of ponderable bodies and the light-oscillations of the ether’ (Hertz 1887:421). He generated sparks by an induction coil, sent electromagnetic waves across a room where they were reflected by a metal sheet, and then measured their frequency (distance between their crests) by observing, under microscope, tiny sparks that could be seen on the other end of the room across a small gap of a receiving wire loop. Expressed in units that honor his name, these broadcasts had frequencies of 50–500 megahertz (MHz), or 6 m to 60 cm (Aitken 1976). Lower frequencies of this range are now used for FM radio and broadcast TV; the higher ones for garage door openers, medical implants, and walkie-talkies.
Has there been any other physical experiment that was so simple—a few batteries, coils, and wires positioned in a 14-m-long lecture room—yet eventually brought such a wealth of amazing spin-offs? Hertz pursued this research only in order to confirm Maxwell’s theoretical conclusions about the nature of electromagnetic waves and could not foresee any use for these very rapid oscillations. That perception changed soon after his premature death in 1894, and his fundamental discovery was first transformed into wireless telegraphy and soon afterward into broadcasts of voice and music. And more wonders based on those rapid oscillations were to follow during the 20th century: television, radar, satellite telecommunication, cellular telephony and, most recently, wireless WWW.
But the story does not end here as the Age of Synergy revolutionized every kind of communication, a term that I use in the broadest sense in order to embrace all forms of printed, visual, and spoken information as well as the means and nontechnical requirements of its large-scale diffusion. Consequently, in this chapter I examine first not only the progress in flexible and rapid printing of large editions of books and periodicals but also the new techniques that were introduced to meet the rising demand for printing paper. When describing the invention of the telephone, I first explain its telegraph pedigree, and before outlining the early history of wireless communications, I look closer at Hertz’s experimental breakthrough.
