Abstract

                                It has been mentioned in Part II of this series that the synthetic process for ammonia was first worked out on a commercial scale in 1913 by Haber and Bosch and plants were erected at Oppau and later at Leuna (Meresburg) in Germany to carry on the process on a large scale. These two factories, between them, are now equipped to fix nearly a million tons of nitrogen per year. The working details of the Haber Process were kept a close secret even after the close of the War, but the principles underlying it were success- fully developed into commercial practice independently in other countries, e. g. in America, France, Italy and England. The chief of these modified processes are those of Claude (France), Casale (italy), Fauser (Italy), Mont Cenis (Germany) and F. N. R. L. (U. S. A.). The main differences betwaen these methods lie in: (a) the source from which hydrogen is obtained; (b) the method of separating oxygen from the nitrogen of the air; (c) method of purifying hydrogen and nitrogen; (d) nature of catalyst used; (e) tempera- ture of reaction; (f) pressure employed; and (g) method of removing ammo- nia from the system.

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