4 BULLETIN 37, U. S. DEPARTMENT OF AGEICULTUEE. 



SULPHATE OF AMMONIA. 



Bituminous coal contains 1.2 to 1.34 per cent of combined nitro- 

 gen. In the destructive distillation of coal for the production of 

 coke 33 per cent of this nitrogen is evolved, as shown in Table III. 1 



Table III. — Nitrogen from the production of coke. 



Form in which nitrogen is evolved. 



Amounts, 



Form in which nitrogen is evolved. 



Amounts. 





Per cent. 

 03. 7 

 20.3 



8.1 





Per cent. 

 2.9 





Recoverable as pyridine 



Recoverable as cyanide 



.25 





.3 







Other volatile substances, carbonaceous in character, are, of course, 

 given off, such as gas of high calorific value, coal tar, benzol, etc., 

 and constitute the main distillation products. 



In Table IV the nitrogen of a ton of coal and products resulting 

 from the distillation of that weight have been calculated to pounds 

 of ammonium sulphate. 2 



Table IV 



-Nitrogen per ton of coal and products produced from distillation of a ton 

 of coal. 



Constituent. 



Ammonium 

 sulphate per 

 ton of coal. 



Constituent. 



Ammonium 

 sulphate per 

 ton of coal. 



Coal, 1.3 per cent nitrogen 



Pounds. 

 122.6 



Nitrogen in p vridine 



Nitrogen in cyanide 



Total 



Pounds. 



0.3 

 .4 



Ammonia vield 



Nitrogen left in coke 



Nitrogen in 10,000 cubic feet of gas 



Nitrogen in tar (90 pounds per ton).. . 



25.0 

 78.2 

 12.0 

 3.5 



119.4 

 3.2 







In the main, coal is distilled in this country in that form of coke 

 oven, the beehive oven, which does not admit of the recovery of trie 

 distillation products. Instead, they are allowed to go to waste. So 

 we are indebted to the by-product recovery oven for the main supply 

 of ammonium sulphate. The amount recovered is valued at about 

 $4,000,000, while the recoverable ammonia annually destroyed in 

 the coking processes by the beehive ovens is valued at $22,000,000. 3 



In the manufacture of producer gas by the Mond process, where 

 the distillation takes place in the presence of steam, 80 pounds of 

 ammonium sulphate are obtained per ton of coal. This is four times 

 as much as that obtained from an equal weight of coal in the retort 

 process. 



i Pennock, J. Ind. Eng. Chem., 4, 174 (1912). 

 Pcnnock, loc. cit. 

 ^Parsons, Hearst's Magazine, January, 1913, p. 128. 



