New insights into the pyrolysis of <i>n</i>-tetradecane using ReaxFF molecular dynamics simulations: Implications for understanding the thermal cracking of subsurface crude oil

The fragmentation of normal alkanes during the cracking oil under geochemical conditions with high thermal stress is important for preservation crude oils in reservoirs and formation gaseous hydrocarbons. In this study, kinetics behavior, mechanisms, products n-tetradecane pyrolysis were investigated using reactive molecular dynamics (ReaxFF MD) simulations at temperatures (2000K∼3000 K). process itself, its main intermediates, kinetic behavior analyzed an atomic/molecular level. Low weight (C 1 –C 5 ) olefins, together H 2 , predominant intermediates simulations. Three distinct stages—a stable stage, initial decomposition, secondary pyrolysis—can be distinguished decomposition process. reactant was exhausted when simulation temperature reaches ∼2250 K, accompanied by a rapid increase hydrocarbons numbers C . yield peaked ∼2500 K then decreased. number CH 4 molecules increased continuously throughout entire because contribution pyrolysis. Arrhenius parameters obtained from ReaxFF MD simulations, on basis first-order analysis n-tetradecane, reasonably consistent experimental data generally agreement results experiments laboratory. reaction mechanism also laboratory whole their individual components. therefore considered to valid approach study subsurface oils.