2006 AIChE Annual Meeting

(305c) Microkinetic Model for the Water Gas Shift Reaction on Supported Copper Catalyst

Authors

Yu-Chuan Lin - Presenter, Kansas State University
L. T. Fan, Kansas State University
Shahram R. Shafie, Kansas State University
Keith Hohn, Kansas State University
Botond Bertok, University of Pannonia
Ferenc Friedler, Department of Computer Science, University of Veszprém
Catalytic pathways (mechanisms) of the water gas shift (WGS) reaction have stimulated extensive research because of their enormous theoretical and practical significance; notable among the research efforts are those by Fishtik and his collaborators. At the outset, they have exhaustively identified stoichiometrically feasible reaction routes (RRis), i.e., independent pathways (IPis), by resorting to a linear algebraic approach through the formulation of the stoichiometric matrix of a set of plausible elementary reactions. This is followed by the selection of those RRis (IPis) whose energy diagrams span the moderate range between -25 and 10 kcal/mole as the energetically favorable RRis (IPis). Finally, the RRi (IPi) giving rise to the highest simulated rate of the WGS reaction in idealized CSTR and PFR is claimed to be dominant. The work of Fishtik and collaborators is scrutinized by our graph-theoretic method based on P-graphs (process graphs). It has identified with dispatch and ease on a PC 116 stoichiometrically feasible RRis (IPis), which substantially exceed the the 70 identified by them; moreover, these 116 RRis (IPis) have yielded 5 energetically favorable RRis (IPis). It is indeed the case that the dominant one should be searched among the 5 instead of the 3 RRis (IPis) obtained by Fishtik and his collaborators. The results imply that an efficient and robust approach for determining the potentially dominant RRi (IPi) should involve the exhaustive identification of the stoichiometrically feasible RRis (IPis) with our graph-theoretic method at the outset.