MULTICOMPONENT HIGH-PRESSURE ADSORPTION EQUILIBRIA ON CARBON SUBSTRATES - THEORY AND DATA

We explore the two-dimensional equation of state representation of the multicomponent adsorption isotherm, building on the research of de Boer, Kobayashi and Leland. We formulate the representation so that knowledge of surface area is unnecessary. For wet coal substrates at high pressure, we find that the EOS representation may be more accurate than either the ideal adsorbed solution theory of Prausnitz and Myers or the generalized Langmuir theory. The calculation of multicomponent adsorption equilibria requires the simultaneous solution of the fugacity equations together with the mole balance equations; this equilibria computation is non-trivial. We introduce a path-continuation approach, namely a pressure, a loading and a composition homotopy, to solve the complex adsorption equilibrium equations. The homotopy parameter is naturally embedded in the problem. This distinguishes our homotopies from others.