Breakdown of Simple Hydrocarbons subjected to a Silent Electric Discharge

Abstract

THE gassing tendencies of insulating oils used in the electrical industry are assessed by measuring the rate of gas evolution or absorption when they are exposed under an atmosphere of hydrogen in an electrodeless discharge tube of the Siemens Evers-type. Previous investigations^1–4 have been confined to the investigation of a wide variety of commercial oils and the effect of additions of aromatic rich oil fractions and other additives chosen for their ability to impart a desirable hydrogen gas absorbing characteristic to the mixture. The different hydrocarbon types present in the oils, paraffins, naphthenes, olefines and aromatics cause the discharge reaction to be a complex competitive process in which the gas evolved by the paraffins and naphthenes is partially or completely absorbed by the olefinic and aromatic fractions. To avoid this complexity and enable a clearer understanding of the reaction processes to be reached, certain pure saturated and unsaturated hydrocarbons representative of the types found in oils have been selected for investigation. The experiments have shown that the discharge reaction is closely related to the corresponding radiolytic breakdown of simple hydrocarbons⁵.