74 



WATER GAS. 



By A. DUFTON, B.A., B.Sc. October 2nd, 1888. 



A gaseous fuel possesses many advantages over a solid one. 

 The gas stove is everywhere appreciated for its convenience, 

 cleanliness and economy in labour. The great extension in the 

 use of the gas engine shows that where only a moderate horse- 

 power is needed the reign of the steam engine is over. The 

 success of gas furnaces in metallurgical and other operations 

 involving a high temperature has been recognized for many years. 

 The manufacture of steel of high quality at a low price became 

 possible only by means of a gas-heated furnace — the temperature 

 necessary being higher than that of a blast furnace and quite 

 unattainable by ordinary means. 



The demand for a gas of low price for heating purposes is 

 steadily increasing. It has been shown that such a gas could 

 be readily made from the coke produced in the manufacture of 

 illuminating gas but this system has not been adopted owing 

 chiefly to the trouble and expense of laying down a second series 

 of service pipes. 



Ordinary Coal Gas produced by the destructive distillation of 

 coal is a complicated mixture containing — 



from 25 to 50 "/o Hydrogen. 



— 35 — 50 — Marsh Gas. 



— 5 — 9 — Carbon Monoxide. 



— 3 — 20 — defines. 



And smaller quantities of other bodies. 



It owes its illuminating value to the olefines, the other con- 

 stituents burning with an almost non-luminous though intensely 

 hot flame. On distillation a ton of coal yields according to its 

 nature and treatment 



from 1,000 to 1,400 lbs. coke) 



— 200— 600 lbs. tar [ 



— 300 — 500 lbs. gas ) 



When carbon burns with an excess of air carbon dioxide 

 results. If the supply of air is insufficient there is formed 

 carbon monoxide, a gas of high calorific intensity. This is the 

 principle of the manufacture of ' Producer Gas ' now so largely 

 used in glass-works and in the Siemens-Martin steel process. 



The composition of Producer Gas is roughly about 



Vols. 

 CO 25) 



H 8 } 35 °/o combustible gases. 

 CHt 2) 



N° 61 I ^^ ^/" incombustible gases. 

 100 



