Interaction between aromatics and n-alkane for in-situ combustion process

Abstract In this research, the effect of p-quaterphenyl and cumene hydroperoxide on tetracosane combustion was investigated using accelerating rate calorimetry (ARC). Two obvious reaction processes were identified as induction period and ignition period for tetracosane combustion. p-Quaterphenyl showed a strong suppression on tetracosane combustion: prolonged induction period, suppressed the reaction rate of intense exothermic reaction, and delayed the occurrence of ignition period. Cumene hydroperoxide also exhibited a delay effect in ignition period, but it can slightly promote the exothermic reaction in reduction period and shortened the duration of induction period due to the presence of hydroperoxide group. We find that the Arrhenius zero-order kinetic model ( ln k ∗ = ln A − E a R 1 T ) fitted experimental data reasonably well in induction period, while nth-order reaction model ( d α d t = A ∗ f ( α ) ∗ exp ( − E a R ∗ T ) , where f ( α ) = ( 1 − α ) n ) is more suitable for estimating kinetics in the ignition period as the intense exothermic process is dependent of both hydrocarbons and oxygen concentration. However, when there is a strong interaction between tetracosane and p-quaterphenyl during their co-combustion, nth-order reaction model cannot be applied well for ignition period, instead, Ginstling-Brounshtein diffusion model ( 1.5 / ( ( 1 − α ) 1 / 3 − 1 ) ) fitted much better with experimental data, indicating that diffusion might play an important role in ignition period. This means that the interaction between components should be considered when simulating crude oil combustion in in-situ combustion (ISC) process, and coupling diffusion to reaction-kinetic model to control mass transfer might be necessary and helpful for its precise simulation.