Friedrich Bergius

German chemist

• Born: October 11, 1884
• Birthplace: Goldschmieden, near Breslau, Germany (now Wrocław, Poland)
• Died: March 30, 1949
• Place of death: Buenos Aires, Argentina

Bergius discovered how to obtain liquid hydrocarbon fuels by hydrogenation of coal and how to obtain synthetic sugar from wood cellulose. The fuels made by his processes aided Germany during World War II, and Bergius’s methods form the basis for the modern synthetic fuels industry.

Early Life

Friedrich Bergius (FREE-drihk BEHR-gee-ehs) was born to well-educated parents. He gained early experience in chemistry, working first in a small chemical plant owned by his father and later in a larger plant in Mulheim/Ruhr. He studied at the Universities of Breslau and Leipzig. At Leipzig, Bergius worked under the direction of Arthur Hantzsch, who had also influenced the work of Nobel laureate Alfred Werner twenty years earlier. He was granted the Ph.D. in chemistry in 1907 and proceeded to Berlin for a year of postdoctoral work with Walther Hermann Nernst, who was one of the most prominent physical chemists in German academic circles at that time.

Bergius now had his first opportunity to attempt high-pressure reactions in the laboratory. He also participated in research on the nitrogen/hydrogen/ammonia equilibrium in Nernst’s laboratory. After leaving Berlin, Bergius spent a further semester at Karlsruhe in association with the future Nobel laureate Fritz Haber. There, Bergius gained further experience in the application of high-pressure reaction techniques. He was not satisfied with the existing techniques and apparatus, and he saw the need for improvements.

Bergius’s first published research was a doctoral dissertation on the use of 100 percent sulfuric acid as a solvent. He began his affiliation with the Hannover Institute of Technology in 1909 and was free to pursue his developing interest in high-pressure reactions. His research was conducted partly at the institute and partly at a private laboratory he established. As his projects reached pilot-plant scale, further facilities were acquired. Early work included a study of the lime/oxygen/calcium peroxide equilibrium, which was undertaken in the hope of finding a better process for manufacturing hydrogen peroxide, but which actually was important mainly because it required the refinement of high-pressure valves, fittings, stirred autoclaves, and other equipment that was of great use later. Bergius and his coworkers also patented a method of using caustic soda to convert chlorobenzene into phenol (needed for the manufacture of plastic). This patent was one of many German patents confiscated by the Allies after World War I and became the basis of the manufacture of phenol by Dow Chemical Company.

As early as 1911, Bergius became interested in the nature and origin of coal one of Germany’s most plentiful natural resources. The studies that he made of the coal-forming process (the virtually untranslatable German word is Inkohlung) led to the achievements for which he is most famous and for which he was awarded (jointly with Carl Bosch) the 1931 Nobel Prize in Chemistry.

Life’s Work

Bergius, like Bosch and Haber, sought to apply the academic principles of physical chemistry to the solution of industrial chemical problems. His goal was not only to understand chemical reactions in an academic manner but also to develop practical industrial methods for large-scale economical production. His efforts were applied mainly in three areas: the production of pure, inexpensive hydrogen; the liquefaction of coal and peat; and the conversion of cellulose-containing by-products into sugar and starch. Bergius’s interests were motivated by a desire to benefit humanity in general and by a desire to help Germany end its dependence on foreign sources for food and fuel. Bergius’s success in each of these areas came partly from his energy and persistence in overcoming an array of obstacles and partly from his ability to bring to bear the newest technology, particularly the use of high pressures.

The production of hydrogen from the reaction between steam and coke (the water-gas reaction) produced impure hydrogen. Bergius modified this reaction by performing the process at high pressure and developed purification methods for the hydrogen. He also found it possible to manufacture pure hydrogen by means of a reaction between water and iron. Ultimately, this proved cheaper than the use of the water-gas reaction. Modifications of the water-gas reaction and of the iron-water reaction were explored in which the use of high pressure kept the water liquid at high temperatures.

Coal hydrogenation had been performed in small laboratory experiments as early as 1869 by Marcelin Berthelot in France. Bergius improved on the earlier method by switching to high-pressure conditions instead of the relatively low pressures that were obtained by Berthelot. Using a few grams of powdered coal moistened with petroleum to form a paste and treated with high-pressure hydrogen gas, Bergius was able to obtain promising yields of liquid and gaseous hydrocarbons. Use of a rotating autoclave, which was especially developed for the purpose, permitted successful reactions on the scale of five liters, but problems remained.

The hydrogenation reaction was heat-releasing and thus needed to be conducted in a controlled manner to prevent overheating, which reduced the yield of hydrocarbons and produced useless coke. Attempts to hydrogenate coal in larger batches brought many problems. Overheating became more difficult to control in large reactors, and the batch process was inefficient and needed to be made continuous. As the size and complexity of the apparatus increased, so did the expense of the research, and Bergius sought financial backing from various industrial sources. Eventually, Bergius left his relatively small private laboratory in Hannover and began to assemble a modern high-pressure facility in Essen. By that time, he had conducted many studies on the production of hydrogen and on the hydrogenation of oil and coal and had obtained the first of his many patents. Hundreds of different samples of coal of various kinds were tested to determine which types were most suitable for hydrogenation. Soft coal and lignite (common in Germany) were well suited, but hard anthracite coal was poorly suited for liquefaction.

The coal hydrogenation reaction, when scaled up, involved formidable material-handling problems. The coal was ground to a powder and mixed with oil to form a paste. This paste was preheated and pressed into the reactor by a cylindrical ram. Products were continually removed from the reacting mixture during hydrogenation.

The development site in Rheinau/Mannheim employed about 150 workers and was exceedingly expensive to maintain. It became obvious that better capitalization was needed, which could come only from affiliation with a larger company. Bergius sold his patents to Badische Anilin und Soda Fabrik (BASF), a major corporation, which continued to develop coal hydrogenation at a plant in Leuna. Much further development was needed to create the synthetic fuel industry that existed in Germany by the 1940’s (twelve production facilities were eventually brought into operation), but Bergius’s direct contributions were over. He turned his attention to another area: the production of synthetic food.

Chemically, starch, cellulose, and glucose (also known as dextrose) are closely related, since starch and cellulose are composed of many glucose units linked together one pattern of linkage leading to starch and another to cellulose. Although ruminants can digest cellulose as well as starch, humans can digest only starch (or glucose). Strong acids (such as hydrochloric acid, which humans have in their digestive tracts) can eventually break down cellulose into sugar but only at high temperatures. Bergius devoted years of effort to the perfection of the method of converting sawdust, straw, or other agricultural wastes into edible material by hydrochloric acid treatment. Great care and ingenuity were needed to ensure recycling of reactants and the greatest efficiency in the use of heat. An extensive account of this work was published in 1931 as “Die Herstellung von Zucker aus Holz und ähnlichen Naturstoffen” (the preparation of sugar from wood and other natural materials).

Bergius resided in Heidelberg in the late 1920’s and was awarded an honorary degree by the university in 1927. In Hannover, a street was named for him, and the university awarded him an honorary degree. Even Harvard University chose to award him an honorary degree in 1936. In Heidelberg, the Bergius household became a meeting place for artists and writers. Among those who came was Gustav Stresemann, a leader in the National Liberal Party and chancellor (1923) who had done much to rejuvenate German industry after World War I by negotiating with the Allies over the question of reparations.

Once again, however, Bergius’s research began to suffer from lack of funding. He sold his home, threw all of his personal fortune into the research effort, and even made a personal appeal to President Paul von Hindenburg for support to keep his work going. Ironically, it was only the rise of Adolf Hitler and his preparations for war that finally stimulated meaningful support from the government for the so-called food from wood project. Bergius worked during the war years in Berlin but saw his facilities destroyed by air raids. At the end of the war, the Allies captured numerous documents pertaining to German scientific research. Scholars are still studying these documents, and it may be that additional details of Bergius’s research activities may appear. Bergius spent the postwar years until his death in an attempt to find suitable employment and scope for his further plans. He went first to Italy, then to Turkey, Switzerland, and Spain. He left Europe in 1947 to become a scientific adviser to the Argentine government and died in Buenos Aires in 1949.

Significance

Although his life was rich in achievements, Bergius spent the latter part of his life in circumstances that did not permit him to be as creative as he might have been. The economic chaos in Germany in the 1920’s made it so difficult to obtain funding for his research that in 1925 he sold most of his patents to BASF. From that time on, Bergius was excluded from further work on coal liquefaction, the field that he had pioneered.

Turning to cellulose conversion, Bergius again did fundamental work and developed an economically viable process, but only after spending vast sums including major amounts of his own money. Unfortunately, the commercial interest in his process did not materialize to any great extent. After World War II, having lost his laboratory and sources of funding, he became a sort of scientific refugee and traveled to many countries as a consultant until his death.

Bibliography

Bergius, Friedrich. “Chemical Reactions Under High Pressure.” In Chemistry, 1922-1941. River Edge, N.J.: World Scientific, 1999. Bergius’s Nobel lecture is reprinted in this volume, which includes biographies of the laureates.

‗‗‗‗‗‗‗. “An Historical Account of Hydrogenation.” In Proceedings of the World Petroleum Congress 2. London: Offices of the Congress 1934. Bergius tells what trains of thought led him to develop his coal- and oil-hydrogenation processes. There are nineteen illustrations, mostly showing diagrams of reactors or photographs of process equipment.

Deutch, John M., and Richard K. Lester. Making Technology Work: Applications in Energy and the Environment. New York: Cambridge University Press, 2004. A good introduction to the key technologies in alternative and synthetic fuels, including the use of coal. For advanced students.

Stranges, Anthony N. “Friedrich Bergius and the Rise of the German Synthetic Fuel Industry.” Isis 75, no. 279 (1984): 643-667. This article traces the growth of the German synthetic fuel industry, concentrating on the period 1910-1925. Includes an extensive list of references to works by and about Bergius.

‗‗‗‗‗‗‗. “Friedrich Bergius and the Transformation of Coal Liquefaction from Empiricism to a Science-Based Technology.” Journal of Chemical Education 65, no. 9 (1988): 749-751. This article discusses Bergius’s place in the application of the highly theoretical ideas of Nernst and the other founders of chemical thermodynamics.

Szöllösi-Janze, Margit, ed. Science in the Third Reich. New York: Berg, 2001. A collection of social science and historical essays examining the scientists and sciences of Nazi Germany.