Development of an empirical force field CRACK for n-alkanes that allows for classical molecular dynamics simulations investigating the pyrolyrsis reactions
A novel empirical force field CRACK was developed for n-alkane thai allowed for covalcnl bond breaking and forming, and can be used to investigate the pyrolysis of alkanes by classical molecular dynamics simulation (MD). The shape of CRACK potential-energy curve was for the pyrolysis reactions, with a deep harmonic well, an activation energy barrier and another shallow Lennard-Jones well. To validate CRACK force field, classical MD was performed 10 simulate the pyrolysis reactions of n-octane and n-decane. The defined pyrolytic temperature Tp could be adjusted by the displacement constant de in accord with the pyrolysis energy barrier presented by CRACK. Tp of n-octane was found higher than that of n-decane at the same de is consistent with the pyrolysis fundamentals. The results of time histories of pyrolysis reactions and of distribution of pyrolysis product revealed thai CRACK force field certainly reflected Ihe recombination between different molecules. The microscopic pyrolysis kinetics was discussed and the pyrolysis reaction was found to reach its equilibrium within the simulation time 100ps. The evaluated rate constant in apparent first order increased with the elevated temperature or the decreased value of de. The distribution of he pyrolysis products was analyzed in details and was compared with the experimental data. The results demonstrate that CRACK force field can he applied to predict the product distribution at least qualitatively by MD.
Kailiang Yin Qing Xia Duanjun Xu Yajing Ye Chenglung Chen
Deparment of Chemical Engineering, Jiangsu Polytechnic University, Changthou 213016, PR China;Depart Deparment of Chemical Engineering, Jiangsu Polytechnic University, Changthou 213016, PR China Department of Chemistry, Zhejiang University, Hangzhou 310027, PR China Stale Key Laboratory of Solidification Processing, Northwestern Polytechnic University, Xian 710072 Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan 80424, China
国际会议
杭州
英文
197-204
2007-04-01（万方平台首次上网日期，不代表论文的发表时间）