Section III, 1919 [187] Trans. R.S.C. 



The Adsorption of Gases by Carbonized Lignites 

 By Stuart McLean, M.A. 



Presented by Prof. E. F. Burton, F.R.S.C. 



(Read May Meeting, 1919.) 



The term "adsorption" is applied to that property possessed by 

 charcoals, lignites and other porous bodies of absorbing gases that are 

 in contact with them. For charcoals the phenomenon has been 

 shown to consist of a condensation of the gas upon its surface, which 

 takes place rapidly, requiring only a few minutes to reach the maxi- 

 mum, and a slow diffusion of the gas into the interior. Some authori- 

 ties- claim that, in a few cases, they have found evidence that chemical 

 action accompanies the process or that some of the gas is adsorbed 

 permanently. 



The object of the first series of experirnents to be described below 

 was to investigate the amount of gas adsorbed by a sample of carbon- 

 ized lignite and how that amount varies with the pressure of the gas 

 and the temperature of the lignite. A second series of experiments 

 was undertaken to determine the nature of the process, especially 

 to find out whether, or not, any chemical action or permanent 

 adsorption takes place. 



The lignites for these experiments were prepared by Mr. E. 

 Stansfield of the Department of Mines, Ottawa, Ontario. Their 

 densities were found by the volumenometer method', the apparatus 

 being filled with helium because that gas is not adsorbed at ordinary 

 temperatures. Before each experiment the samples of lignite were 

 heated to a temperature sufficient to free them from any previously 

 absorbed gas and while hot, the apparatus containing them was 

 exhausted. 



A diagram of the apparatus used in the first experiments is shown 

 in Fig. 1; The lignite is contained in the tube X which may be shut 

 off from the rest of the apparatus at B. The gas used was measured in 

 the graduated tube K and admitted at E. The mercury reservoir 

 N was so arranged that it could be easily raised, thereby forcing all 

 the gas in the tube K into the apparatus. The stop-cock B was then 



1 McBain, Phil. Mag. 18, 1909. Page 916. 



2 Arrhenius: Theories of Solutions. 



Rhead and Wheeler, J. Chem. Soc. 103, 1913. Page 641. 

 ' McLean: Proc. Roy. Soc. of Canada. 1919. 



