fixing atmospheric nitrogen but it’s energy costs again were high—at best 130
GJ t
−15
—due to the electricity requirements and the production of the coke.
By 1915, the cost
12 of producing ammonium sulphate from cyanamide in the
UK was just £4. 13 s ton
−1
. Even so, Germany became a major player and by
1918 thirty-five cyanamide plants produced 325,000t fixed nitrogen per
annum
5 dominating the world’s production (Fig. 3.2).
3.4 Early Academic Progress Fixation
by Synthesis: The Combination
of Elemental Nitrogen and Hydrogen
Both the electric arc and the cyanamide processes provided fixed nitrogen, but
both were expensive. The simplest chemical route to nitrogen fixation was
long known to be through the synthesis of ammonia according to;
N 2ðgÞ þ 3H 2ðgÞ 2NH 3ðgÞ
Fig. 3.2 A schematic Illustrating the cyanamide process, from Manuals of Chemical
Technology
12 1915
3 Germany and ‘Fixation’
87