This paper is on a number of general aspects in the preliminary design of reactive separations. It provides a method for easy identification of reaction processes that can be improved by application of reactive separation. The method is based on analyzing chemical reactions by making a distinction between intensive and extensive concentration requirements for the involved chemical substances. Conflicting concentration requirements are indicators for a potentially attractive application of reactive separation. Here, the focus is mainly on improving the performance of the reaction process. Guidelines are given for the selection of a suitable separation technology on the basis of the intensive and extensive concentration assessment, together with a checklist on various practical issues. Further, a method for conceptual process design of a multi-stage counter-current reactive separation process is given, which is guided by the extraction factors of all relevant reaction ingredients. Thus, the technical feasibility of such a reactive separation process can be assessed in an early stage of the development. The resulting process concept is a good starting point for more detailed process development work. (C) 2003 Published by Elsevier Science Ltd.