This paper studies both the steady-state design aspects and the dynamic controllability aspects of processes in which a fresh feed stream contains significant impurities. The ternary process with the reaction A + B --> C has a flow sheet consisting of two distillation columns, one reactor, and two recycle streams. One of the fresh feeds contains mostly A but can contain varying amounts of an impurity, which is product C. With low impurity levels, it is logical to introduce the fresh feed directly into the reactor; but if the feed contains large amounts of C, it may be more economical to feed this stream into the distillation column that is separating A and C. For the numerical case studied, impurity levels greater than about 30% favor feeding the fresh feed to the column when the reaction is irreversible. When the reaction is reversible, the impurity level at which the fresh feed should be introduced into the column drops to about 20%. Other kinetic and vapor-liquid equilibrium parameter values will affect these impurity levels. Different control structures may be required in the two cases, and the dynamic controllability may also be different. Control schemes are developed that effectively handle both situations. Dynamic simulations show that introducing the impure fresh feed stream into the column gives a Easter dynamic response because it isolates the reactor from disturbances.