Using thermodynamic models to present adsorption of Nanostructures at high pressure

Adsorption models are used to simulation and design of adsorption processes. Due tothe variety of nanostructure usage in these processes, development of the gas adsorptionmodels is necessary. In this study, van der Waals and Peng - Robinson equations havebeen modified to describe the behavior of fluids in a Nano pore. Two models have beenoffered by using the modified equations and their standard equations to predict highpressure adsorption of pure gases. The results show that the model based on modifiedvan der Waals equation do not have acceptable results at lower pressure than 5MPa butresults at higher pressure than 5MP are better and average deviation from experimentaldata at this range is 3.31%, when as the precision of the second model in the most casesare acceptable at pressure range 1MPa to 12MPa and average deviation is 6.41%.Checking the effect of adsorbent pore diameter shows the amount of adsorptiondecreases with increasing pore diameter. In addition, the vapor pressure of carbondioxide in Nano pore has been studied. The results display that in constant temperaturethe vapor pressure of the fluid in bulk state is more than the Nano pore and the vaporpressure also decreases with decreasing pore diameter. At the end, the results show thatthe critical temperature of the fluid in Nano pore decreases with decreasing porediameter.

Keywords:

Adsorption , Nano pore , Van der Waals equation , Peng Robinson equation