The effect of un-saturates on low-temperature oxidation of crude oil

Low-temperature oxidation (LTO) of four Arabian crudes as well as blends of naphtha with a super-light crude was investigated employing differential thermal analysis. The mass fraction of in-saturates in the reactants varied between 0.2 and 0.9. All reactants showed LTO peaks between 230 and 264degreesC; heat flow at the peak, however, varied widely. The data revealed a clear increase in, LTO-generated heat as the reactant's content of un-saturates increased. The lightest crude with 51.1 degreesAPI gravity and un-saturates fraction of 0.2 showed the least LTO reactivity. It is, therefore, concluded that the un-saturates content of a crude is an influential factor in its LTO tendency and, thus, its potential for spontaneous ignition and other enhanced-recovery techniques that rely on LTO.