Temperature Extrapolation of Molecular Dynamics Simulations of Complex Chemistry to Microsecond Timescales Using...

Area of Science:

• Chemical Engineering
• Computational Chemistry
• Materials Science

Background:

• Molecular dynamics (MD) simulations are crucial for understanding complex chemical processes like hydrocarbon pyrolysis.
• MD simulations are computationally intensive, limiting their application to nanoseconds, which is insufficient for low-temperature systems requiring longer equilibration times.

Purpose of the Study:

• To develop a method for constructing temperature-dependent kinetic models of hydrocarbon pyrolysis.
• To overcome the timescale limitations of MD simulations at low temperatures by extrapolating from high-temperature data.

Main Methods:

• Utilizing information from high-temperature molecular dynamics simulations of pyrolyzing systems.
• Developing a kinetic model based on high-temperature, high-reactivity data.
• Extrapolating the developed kinetic model to predict behavior at lower temperatures.

Main Results:

• The method accurately predicts the time evolution of small molecules and the characteristics of long carbon chains over a wide temperature range.
• Extrapolation accuracy can be enhanced by increasing the volume of simulation data used for training.
• The kinetic model shows similar compositional trends to experimental results.

Conclusions:

• The developed method enables microsecond-long simulations by extrapolating kinetic models from high-temperature MD data.
• This approach provides detailed kinetic and mechanistic insights into hydrocarbon pyrolysis.
• The model's predictive accuracy and applicability can be improved with additional simulation data.