69 



genation, using the gas in the nascent state, the sulphur may be 

 taken out of an organic molecule and converted into HgS. The 

 value of this type of hydrogenation was occasionally recognised 

 long ago, and one of the earliest attempts to apply the princ pie to 

 the removal of sulphur from oils was patented by M. Schiller 

 (U.S.A. patent No. 580652, 1897). The same k : nd of hydrogena- 

 tion was used in the earlier cited process of using ammonia at high 

 temperatures, when it dissociates and yields hydrogen in the 

 nascent state, which, acting upon the sulphur, brings about the 

 desired augmentation of H 2 S. Unfortunately the very elegant 

 methods of hydrogenation by catalysis, in the presence of nickel, 

 platinum or palladium, cannot be well applied in our case owing 

 to the poisonous action of the sulphur on the catalyst. But even 

 this side of the problem cannot be considered hopeless, and some 

 antidote may yet be devised and the problem solved. Altogether, 

 the elimination of sulphur from Kimmeridge oil by means of hydro- 

 genation of one type or other appears decidedly promising. In 

 some cases the hydrogenation by nascent hydrogen may be used 

 to reduce a refractory sulphur compound to one more easily 

 attacked by the usual refining methods. 



Various methods are employed for eliminating sulphur by 

 chemical methods. The main idea of those in actual use, after the 

 determination of the kind of sulphur bodies present in the oil, is 

 to adopt the proper chemical treatment to convert them into a gas 

 or a solid or otherwise into a compound easily separated. The 

 Frash process will serve as an example. When Frash began work 

 in 1885, Ohio oil, owing to its sulphur content, was sold at 17 

 cents, a barrel, whereas Pennsylvanian oil fetched 2 dollars 25 cents. 

 After two years' research he succeeded in developing his process. 

 It consists essentially in treating the oil with copper oxide ; this 

 combines with the sulphur and can be readily separated as the 

 sulphide which on roasting yields the oxide again for further use. 



The chemistry of the action of inorganic sulphur compounds 

 and elementary sulphur on hydrocarbons is practically as old as the 

 development of organic chemistry itself. Recently this question 

 has been taken up again. It is an extremely strange coincidence 

 that in the last few years — the war period in fact — just when in- 

 creased attention was being paid in this country to the sulphur 

 question in connection with Kimmeridge shale derivatives, on the 

 Continent, on the other side of the fighting line, some very in- 

 teresting papers have been published on the action of sulphur on 

 the different classes of hydrocarbons. These papers throw a very 

 clear light on the Kimmeridge problem, and it is the purpose of 

 the last few paragraphs of our present paper to give a short 

 description of the work done. 



We have already mentioned the cracking effect of sulphur on 

 paraffins and how the unsaturated fragments resulting from the 

 action take up some sulphur and produce sulphur compounds. 

 About 1909 Engler took up the study of the action of sulphur on 



