

Section IIÏ, 1922 [105] Trans. R.S.C. 



The Formation of Unsaturated Hydrocarbons from Natural Gas* 



By R. T. Elworthy, B.Sc. 



In a book^ on "Rubber, Its Chemistry and Synthesis," Dubosc 

 and DeBoistesselin refer briefly to a method of preparing ethylene 

 and propylene by passing methane over carbon impregnated with 

 copper oxide at 400-450°C. The proportions obtained v^^ere approxi- 

 mately : 



Ethylene 36 per cent. 



Propylene 42 



Higher olefins and hydrogen 21 



but no figures are given showing what fraction of the methane was 

 changed. 



If a considerable percentage of ethylene could be formed, in 

 view of the developments in the industrial use of this gas, this reaction 

 might be of importance. 



The following paper outlines some experiments carried out to 

 see what yields of unsaturated hydrocarbons could be obtained in 

 this way. 



Many observers have studied the decomposition of the simple, 

 hydrocarbons by heat. Berthelot, as a result of exhaustive work, 

 claimed that acetylene was always the ultimate product of decom- 

 position. V. B. Lewes, working chiefly on ethylene, agreed that this 

 gas is primarily resolved by heat into methane and acetylene. Bone 

 and Coward,^ however, disproved Berthelot's theories. They showed 

 that methane is the most stable of the lower hydrocarbons decom- 

 posing slightly at 800°C., but rapidly at 1100°C., into its elements 

 hydrogen and carbon, and that the efïect of heat on ethane and 

 ethylene is a loosening of hydrogen with the fugitive formation of 

 :CH2 and :CH. These radicles eventually combine giving ethylene, 

 acetylene or methane if much hydrogen is present or they may be 

 decomposed into their elements. Rollings and Cobb\ studying the 

 effect of heat on various gases in contact with coke, confirmed these 

 results, finding that ethane decomposed slowly at 800°C., forming 

 ethylene and methane, and that ethylene was broken down rapidly 

 at 1100°C. giving methane and hydrogen. From these statements it 



* 



Published by permission of the Director, Mines Branch. 

 ^Published by C. Griffin and Co., London, p. 253. 

 2Jour. Chem. Soc. Trans. 93, 1197, 1908. 

 'Jour. Inst. Gas Engineers, 1914. 



