Molecular simulation for methanol synthesis in supercritical n-hexane

摘要

A computer model based on the Monte Carlo method for methanol synthesis from CO and H_2 in supercritical n-hexane was investigated. The model took into account the effect of methanol aggregation on the synthesis reaction and converted Monte Carlo steps to real time according to Boltzman equation. The results indicated that TOF (turnover frequency) and conversion number (defined as the ratio of the total number of methanol molecules produced by reaction over the total number of carbon monoxide impinging on the surface) increased with methanol aggregation number (MAN) at the same reaction condition, and MAN mainly influenced methanol re-adsorption. We also simulated the influence of mole fraction of n-hexane on the reaction under different MAN and found that conversion number increased monotonously with the mole fraction of n-hexane. Each TOF versus n=hexane mole fraction curve had a maximum, and the maximum shifted towards higher n-hexane concentration as the MAN increased.