ADSORPTION EQUILIBRIA OF SUB-CRITICAL AND SUPER-CRITICAL FLUIDS IN CARBONACEOUS MATERIALS

摘要

In this paper, we present an overview of a number of techniques used to characterize the adsorption equilibria of sub- and super-critical fluids in nonporous carbon black and porous activated carbon. Tools such as the grand canonical Monte Carlo simulation (GCMC), Density Functional Theory (DFT), Molecular Layer Structure Theory (MLST) of Ustinov and Do, and enhanced molecular layering and pore filling proposed by Do and his co-workers will be discussed. Although the GCMC provides the brute force calculation of molecular interactions and its results have been used as a benchmark for other techniques to compare with, its extremely time consuming computation makes the other techniques more appealing to engineers and experimentalists. Despite the ever-increasing computing power of today personal computer, the advantage of simpler methods is warranted for their role in solving practical problems. Furthermore, added to this advantage is the good performance in terms of the prediction power of the simpler methods. All these tools will be discussed in this paper regarding their applications to adsorption of super and sub-critical fluids in carbonaceous materials, such as graphitised thermal carbon black and activated carbon.