This paper demonstrates how it is possible to extend the ’attainable region’ concept (Glasser, HiIdebrandt and Crowe [1]) to reactor systems with a larger number of components present. The extended. procedure is demonstrated on the steam reforming reactions, a system that is originally described by three reactions and five components. Further, we address the entire reactor/recycle/separation system. A graphical representation of the process in the composition space is presented. This representation may form the foundation for a new graphical synthesis concept.