My students and I are interested in complex chemical systems in which several reactions occur simultaneously. Real systems are almost always of this kind, so it becomes important to understand reactors with complicated chemistry in a systematic way. Current work is proceeding along two related lines: Chemical Reaction Network Theory Reactors with complex chemistry give rise to complicated systems of nonlinear equations that don’t lend themselves to analytic solution. What’s more, increased complexity in the governing equations can give rise to complicated new phenomena that simple textbook reactors don’t admit. Even in the constant temperature case, for example, there can be unstable steady states, multiple steady states, sustained composition oscillations, and wild, chaotic dynamics—things engineers really need to worry about. 

Since each new network of chemical reactions gives rise to its own complicated system of differential equations, it becomes apparent that, in the absence of an overarching theory, we would be forced to study reactors on a case-by-case basis, and each new case would be fraught with terrible analytical difficulties. What’s needed is a way of looking at things from a broader and more general perspective. 

Optimal Reactor Design in the Presence of Complex Chemistry One of the great problems of chemical reaction engineering might be described roughly in the following way: Given a network of chemical reactions and given feed streams of several reactants, how should those reactants be contacted so as to best meet a specified production objective? Very often, problems of this kind are solved by choosing a fixed qualitative design a priori (for example, a combination of CSTRs and plug flow reactors) and then optimizing within this structure. This leaves open the question of what might have been achieved had one chosen a different configuration at the outset. Especially when the chemistry is complex, then, the following question becomes compelling: What is the full range of design outcomes when one considers all possible designs (even those that transcend current imagination)? Work is proceeding on a theory of what is, in fact, attainable and of which reactor configurations yield the outer limits of what is achievable.