The impact of H2O on the combustion of n-pentane: A reactive molecular dynamic simulation study

Abstract A series of reactive molecular dynamic simulations (ReaxFF MD) are performed to investigate the impact of H2O on the combustion of n-pentane. The results indicated that the presence of H2O molecules has a significant impact on the consumption rate of n-pentant during the combustion process, H2O molecules promote the combustion of n-pentane at lower temperatures, but inhibit combustion at higher temperatures. The lower content of H2O molecule promotes the combustion of n-pentane, but the higher content of H2O molecule is opposite. The early stage of the combustion process of n-pentane is mainly the pyrolysis reactions of n-pentane, the whole reaction system starts from the endothermic reactions, whereafter, the O2 and H2O molecules participate in the combustion reactions, resulting in the violent combustion of n-pentane. Four stages can be found during the combustion process of n-pentane and the first three stages involve the decomposition of n-pentane. C2H5, H, O, OH and CH3 radicals, and C2H4 molecules are generated in the first stage·H2O molecules participate in the combustion reactions of n-pentane in the second stage, CH2 and HO2 radicals, H2 and CH2O molecules are formed in this stage. N-pentane is completely consumed and CO molecules are generated in the third stage. This study is conducive to the safety of n-pentane used in the field of organic Rankine cycle.