Industrial nitrogen fixation

Vladimir N. Ipatieff, The Life of a Chemist Memoirs of Vladimir N. Ipatieff, edited by J. Eudin, et al., and translated by Vladimir Haensel and Mrs. Ralph H. Lusher (Stanford Stanford University Press, 1946), pp. 409-413. Some useful historical information on the nitrogen fixation industry in the USSR will be found in Mathew J. Sagers and Theodore Shabad, The Chemical Industry in the USSR An Economic Geography. ACS Professional Reference Book (Boulder, Co. Westview Press, 1990), esp. pp. 115-117. 

Finally, in 1797, the Frenchman L. N. Vauquelin discovered the oxide of a new element in a Siberian mineral, now known as crocoite (PbCr04), and in the following year isolated the metal itself by charcoal reduction. This was subsequently named chromium (Greek xpco ia, chroma, colour) because of the variety of colours found in its compounds. Since their discoveries the metals and their compounds have become vitally important in many industries and, as one of the biologically active transition elements, molybdenum has been the subject of a great deal of attention in recent years, especially in the field of nitrogen fixation (p. 1035). 

How have agriculture and deforestation changed the global rates of nitrogen fixation and denitrification How can increased agricultural productivity be sustained without using industrially produced fertilizers ... 

Haber, the self-taught upstart in physical chemistry, entered the nitrogen-fixation race in 1903. He had certain strengths. Ever eager to overcome rejection and obstacles, he was a patient researcher who did not give up easily. He had put basic scientific principles to practical use and was intimately familiar with industrial chemistry. One of the keys to making ammonia commercially... 

By now, Haber was cut off from all but a handful of friends and colleagues. Few academic associates visited or sent words of sympathy, although such gestures would have cost them nothing. The chemical industry, which owed Haber much of its success, had allied itself with the Nazis. Carl Bosch, Haber s old colleague in the nitrogen-fixation process, was the only industrialist who tried to help. 

In recent years, most attention has been paid to nitrogen fixation, partly in order to understand the fascinating. process by which a molecule traditionally regarded as being unreactive can be reduced readily to ammonia under mild conditions, and also in the hope of establishing new processes for the industrial production of cheap nitrogen fertilizers. More recently the process of denitrification has been receiving attention, while that of nitrification has been much less studied. 

The problem of nitrogen fixation is one of the most important scientific and technical tasks. The nitrogen and nitrogen-compound-making industry is one of the leading branches of the... 

The chemical unreactivity of the N=N bond is clearly seen when one considers the industrial process of nitrogen fixation. This process, devised by Fritz Haber in 1910 and still used today in fertilizer factories, involves the reduction of N2 in the presence of H2 gas over an iron catalyst at a temperature of 500°C and a pressure of 300 atmospheres. 

Molybdenum is necessary for the reduction of nitrate in the plant, otherwise nitrate will accumulate and interfere with protein synthesis. Nitrogen fixation by legumes is also dependent upon molybdenum. Small amounts of Mo appear to be essential for maximum growth, the high levels found in forages as a result of industrial contamination do not appear to depress feed production (Gardner and Hill-Patch, 1962). 

In addition to the classical Haber process, recent efforts have been directed to finding an alternative economic process for fixing N2 to meet-increasing demands for nitrogeneous fertilizers and others industrial requirements. Thus, numerous results of the recent advances in the Chemistry of Nitrogen Fixation via transition metal complexes have reported (Chatt et al. 1978 A treatise on dinitrogen fixation , Hardy ed. 1979 New trends in the chemistry of nitrogen fixation , Chatt ed.1980). 

---