GASEOUS FUELS. 1 03 



But 12 kilograms of carbon, in burning, generate only 

 12 X 2473 = 29676 calories. 



To decompose the water, then, there is a shortage of 

 force of 



58084 29676 =i 28408 calories 



for 2 kilograms of hydrogen, or 14204 calories for I kilo- 

 gram. The heat must be furnished by an external source. 

 In other terms, to gasify I kilogram of carbon there must be 

 supplied 



14204 -T- 6 = 2367 calories. 



As may be easily seen, this operation absorbs much heat, 

 and the combustion of the water gas can give only the calo- 

 ries used at first in forming it. The heat necessary for the 

 decomposition of the water is actually taken from that of the 

 preparatory period of the air gasogene, which makes a loss of 

 one third of the total calories. In burning the water gas 

 made under these conditions we utilize a part of the heat 

 which would have been lost by the air gasogene only. 



The decomposition of water by carbon is not as simple as 

 would appear from the equation 



H a O + C = CO + H 3 . 



The lower portion of the fuel of the gasogene undergoes 

 ordinary combustion on account of air being present; while 

 in the upper portion the reaction takes place between the 

 gaseous products formed in the lower portion and the heated 

 carbon. The carbonic acid is then in contact with the heated 

 carbon and is reduced to carbonic oxide : 



C -} CO, = 2CO. 



