January 29, 1920] 



NATURE 



569 



it is unliliely that low-temperature carbonisation 

 will have any considerable influence on the main 

 result, and attempts to utilise peat and sewage 

 afford no certain promise of success. Although 

 our existing processes have admittedly shown 

 themselves to be a national asset of the greatest 

 value in times of war, they need to be supple- 

 mented, in a time of national emergency, by 

 methods which will render this country indepen- 

 dent of external supplies of nitrates. 



The cost of power is, of course, a vital factor 

 in connection with the establishment of any syn- 

 thetic process of nitrogen fixation; and to this 

 question the Committee necessarily devoted great 

 attention and with special regard to the conditions 

 of the United Kingdom. It has considered such 

 water-power schemes as appeared practicable, and 

 the cost of obtaining electrical energy from coal. 

 The comparison is complicated by the many com- 

 plex factors involved, and especially by the uncer- 

 tainty concerning the future cost of coal and 

 labour. At the same time, it offers an estimate 

 of the cost of a particular water-power scheme 

 which it has investigated, but of which it 

 gives no details, and it is of opinion that for 

 a power of more than 28,000 continuous kilo- 

 watts the running cost, under post-war conditions, 

 would be 393'. per full kilowatt-year, inclusive of 

 capital charges. The only possible chance of 

 obtaining electrical energy from coal at a cost 

 which would compare with this would be by direct 

 firing at a power station operating on a very large 

 scale. This with coal at lox. per ton and an 

 annual load factor of 97*5 per cent, works out 

 at about a,'^. per kilowatt-year of 8540 hours. 



After careful consideration of the main features 

 of the various nitrogen fixation processes and of 

 the ammonia oxidation process, in the light of 

 British conditions and requirements, the Com- 

 mittee concludes that (a) tiie arc process, in spite 

 of certain disadvantages, viz. its large power re- 

 quirements, its low electro-chemical efficiency, and 

 the costly character of its chemical plant, would 

 compete with the retort process of obtaining nitric 

 acid so long as the cost of electrical energy was 

 below 9/. per kilowatt-year. (b) The calcium 

 cyanamide process affords a cheaper marketable 

 form of combined nitrogen, so long as electrical 

 energy is below 5Z. per kilowatt-year, than any 

 other established fixation process, and gives a 

 solid nitrogenous fertiliser as a primary product. 

 The manufacture may be combined with that of 

 calcium carbide and crude cyanides, and, as the 

 raw materials are cheap and abundant in this 

 country, there is good ground for assuming that 

 it would be successful with us, in spite of the rela- 

 tively high cost of electrical energy. The Com- 

 mittee is of opinion that a steam-power station 

 of 30,000-kw. maximum load is the minimum size 

 that would be justifiable under British conditions, 

 (c) The Haber process, with pure hydrogen at 

 25. 6d. per 1000 cu. ft., is capable of producing 

 ammonia at a cost below that of any ammonia 

 process as yet established. The Committee, of 

 course, had no opportunity of inquiring into the 

 NO. 2622, VOL. 104] 



Claude process, the details of which have only 

 recently become known. Both these processes are 

 the most promising of all the synthetic methods 

 of making ammonia and ammonium sulphate. It 

 is too soon to express any definite opinion as to 

 their relative merits as commercial processes, but 

 it is certain that both of them have a great future. 



The ammonia •oxidation process for making 

 nitric acid, although probably not in its final form, 

 can even now furnish concentrated acid at a lower 

 cost than the retort process from Chile nitrate, 

 and ammonia oxidation converters are well 

 adapted for use in the chamber process of making 

 oil of vitriol. It is not unlikely that such con- 

 verters will soon supersede the wasteful system 

 of nitre-pots. 



It should be stated, however, that the last word 

 has not been said in favour of existing by-product 

 processes. It is pointed out that improvements 

 in the metallurgical coke industry, such as the 

 more rapid replacement of beehive ovens by re- 

 covery ovens, and improvements in the existing 

 practice in gasworks, both large and small, 

 would do much to augment the yield and recovery 

 of by-product ammonia, and the Committee was 

 unanimouslv of opinion that energetic measures 

 should be taken to ensure that industries making 

 such a large annual demand upon our coal re- 

 serves should be made to utilise them to the 

 maximum advantage, and it indicates in outline 

 what these measures should be. The waste that 

 has hitherto taken place in the potentiality of coal, 

 as regards both its energy and its products, is a 

 national scandal that ought no longer to be 

 tolerated. Its continuance would be the strongest 

 argument that the advocates of nationalisation 

 could adduce. 



Considerations of space prevent any attempt 

 to deal with many other points which have en- 

 gaged the attention of the Committee, and are 

 set out in detail in its voluminous report, such 

 as the question of the nitrogen problem as it 

 affects other parts of the Empire. The Dominions 

 beyond the seas are rich in latent resources in 

 coal and other raw materials, and some of them 

 possess exceptional water-power facilities, acces- 

 sible to the seaboard and capable of easy develop- 

 ment. Nor have we been able to devote much 

 space to the question as it affects national defence. 

 It must be evident, however, from past experi- 

 ence that, notwithstanding our maritime 

 supremacy, the military situation has been, as the 

 Committee states, fundamentally changed. We 

 must no longer be dependent upon Chile nitrate 

 for the manufacture of explosives. We agree 

 with the Committee that a wise policy in regard 

 to defence can well go hand in hand with a sound 

 economic policy. 



The Committee recommends that : — 



I. The calcium cyanamide process should be 

 established in Great Britain without delay, either 

 by private enterprise (supported, if necessary, by 

 the Government) or as a public work, and that 

 the scale of manufacture should be suflficient to 

 produce 60,000 tons of cyanamide per annum. 



