106 THE ROYAL SOCIETY OF CANADA 



seems unlikely that much ethylene could be obtained in this way. 

 It is also probable that any ethylene found results from the decom- 

 position of ethane present rather than from the reaction of methane or 

 its decomposition products with carbon. The best conditions should 

 be: (i) the absence of hydrogen, (ii) temperature below 800°C. It 

 is recognized that in the carbonization of coaP the highest yields of 

 olefines are found at retort temperatures of 400-500°C. 



Again m.ethane and acetylene heated at high pressures to 200- 

 350°C. combine to form propylene, using suitable catalysts. There- 

 fore, if the natural gas used contained considerable quantities of 

 ethane, acetylene formed by its decomposition might react with 

 methane and so produce propylene. 



Experimental 



The arrangement of apparatus was usually: 



^ , . . ^ heated quartz train of 



natural gas mixmg fiow , . . , 



c ,. J — , , ■ — ■ — tube contammg^ — -absorption — 



irom cylmder chamber gauge , , , 



^ * catalyst bottles 



gasometer. 



In the first set of experiments a fused quartz tube 46 cm long, and 

 1.7 cm. diameter was used. This was replaced by a transparent 

 quartz tube 1 . 2 cm. diameter. In the later experiments rapid cooling 

 of the gases after issuing from the catalyst zone was obtained by 

 fitting a copper condenser internally in the quartz tube, reaching 

 almost to the catalyst. 



The tube was heated in an electric combustion furnace and the 

 temperature of the catalyst recorded by a platinum, platinum- 

 rhodium thermocouple. 



Catalyst 



A mixture of pumice, carbon black and copper oxide in the ratio 

 by weight of 1 :1 :5 was used as catalyst. The reduction of the copper 

 oxide commenced at 400°C. and was complete at 500°C. and hence 

 in the experiments over 500°C. the reaction was between finely 

 divided copper, carbon, methane and ethane. 



Analytical Control 



The initial and final gases were analysed for carbon dioxide, 

 oxygen, hydrogen, unsaturated hydrocarbons, methane and ethane 

 in a modified Burrell gas analysis apparatus. Partial analyses were 

 made in an Orsat apparatus. 



*V. B. Lewes, "The Carbonization of Coal," pp. 112-134, 1917. Van Nostrand. 



