超临界流体中CO和H_2吸附过程的Monte Carlo模拟

Monte Carlo Simulation of Adsorption Process of CO and H_2 in Supercritical Fluids

利用MonteCarlo(MC)方法,研究了一氧化碳和氢气在不同密度正己烷中的等温吸附情况.模型考虑了正己烷密度对一氧化碳和氢气在催化剂表面吸附量与吸附速率的影响.结果表明,主要有三个因素会影响溶质的吸附量:当溶剂密度低于其临界密度时,体系压力是影响溶质吸附量的主要因素;当体系处于超临界区时,超临界溶剂的溶解能力以及溶质和溶剂之间的竞争吸附是影响溶质吸附量的主要因素.在一定范围内增加溶剂的密度(压力)可以提高溶质在催化剂表面的吸附速率.

The Monte Carlo method was employed to investigate the adsorption isotherm of carbon monoxide and hydrogen in n-hexane with different densities. The model took into account the effects of n-hexane density on the adsorption amount and adsorption rate of carbon monoxide and hydrogen on the catalyst surface. From the simulation results, the adsorption amount of the solutes is influenced by several factors, such as the system pressure and the competitive adsorption between the solvent and solutes. When the hexane density is lower than its critical density, the increase of the system pressure can evidently enhance the adsorption of CO and H-2. However the increase of the solute adsorption becomes slow due to the competitive adsorption of the solvent when the system is in its supercritical state.