This proceedings book contains papers presented at the 15th European Symposium on Computer Aided Process Engineering (ESCAPE-15), held in Barcelona, Spain, from May 29-June 1, 2004. These proceedings consist of two volumes, which include the contributed papers organised in five classes paralleling the five themes of the Symposium. A complementary CD-ROM contains all the papers presented at the symposium.The ESCAPE (European Symposium on Computer Aided Process Engineering) series brings the latest innovations and achievements by leading professionals. The series acts as a forum for engineers, scientists, researchers, managers, and students from academia and industry to present and discuss progress being made in research and application of CAPE.ESCAPE-15 has focused on recent developments of New Systems Methodologies and Computer Aided Applications in Process Engineering in general and in the following areas of chemical engineering in particular:Computing methods for CAPE Modelling and simulation Process and product design Process operation and control Integrated approaches in CAPE