A model library for spatially distributed membrane reactor models is presented. The structure of the library is guided by a general modelling concept for the systematic formulation of chemical engineering process models. Therefore, the building blocks in the library can also be used to model related processes like fixed bed reactors or adsorption columns. The library is implemented in the process modelling tool (PRoMoT), whose key features are presented. The use of the library is illustrated by the example of the selective oxidation of hydrocarbons in two types of membrane reactors. (C) 2003 Elsevier Ltd. All rights reserved.