Bergius process

The Bergius process emerged in 1913 because Germany had plenty of coal and almost no petroleum—a resource constraint that would twice reshape global history. Friedrich Bergius, working at a private laboratory in Hanover after completing his PhD at Leipzig in 1907, discovered that hydrogen under extreme pressure could convert coal into liquid fuel.

The adjacent possible aligned precisely in 1913. On September 9 of that year, BASF's ammonia synthesis plant at Ludwigshafen went into operation—the world's first industrial high-pressure chemical process. Fritz Haber had cracked ammonia synthesis at 500°C and 2,900 psi in 1909, and Carl Bosch had spent four years scaling it. The high-pressure engineering, catalysis knowledge, and industrial hydrogen production that made ammonia synthesis possible were exactly what Bergius needed. BASF obtained its ammonia patent on March 8, 1913; Bergius patented coal hydrogenation the same year.

The process operates at 200-700 atmospheres and 400-600°C, forcing hydrogen into coal molecules to produce synthetic gasoline. Iron sulfide catalysts present in coal itself drive the reaction. Single-stage operations yield 45-50% liquid fuel by weight; optimized two-stage processes reach 65-75%. Bergius sold his patent to BASF, where Carl Bosch and chemist Matthias Pier refined it through the 1920s.

IG Farben formed in 1925 partly to finance the enormous capital requirements of coal hydrogenation. The first commercial plant opened at Leuna on April 1, 1927, producing 'Leuna-Benzin.' But the economics never worked without intervention. The Great Depression transformed the technology into a financial drain until December 14, 1933, when the Nazi regime signed the 'Gasoline Agreement'—guaranteeing prices and purchase volumes in exchange for expanded production.

By early 1944, twelve Bergius plants produced over 3 million metric tons of synthetic fuel annually—21.5 million barrels. More than 92% of Germany's aviation gasoline came from synthetic sources; over 50% of all petroleum was coal-derived. The Leuna works alone sprawled across 3 square miles with 250 buildings and 35,000 workers, including 10,000 prisoners. It became the most heavily defended industrial target in Europe. Allied strategic bombing beginning May 12, 1944 systematically destroyed production. By February 1945, Leuna produced just 1,000 tons—0.5% of peak output. A German general later wrote: 'Lack of petrol meant the end of the war and the end of the Third Reich.'

Fischer-Tropsch synthesis, developed in 1923-1926, offered a parallel path through indirect liquefaction at lower pressures. Today, Fischer-Tropsch dominates coal-to-liquids production, especially in South Africa's Sasol plants. The Bergius process is no longer commercially operated—the last plant at Bottrop, Germany closed in 1993. But the principle persists in modern direct coal liquefaction research, particularly in China, where coal abundance and oil dependence echo the resource constraints that created the process.