In recent years there has been a convergence of trends in chemical reaction engineering and chemistry which have set the stage for significant advances in kinetic and thermodynamic modeling of processes. New analytical chem­ istry methods, new mathematical methods, and new computational tools facilitate a more fundamental approach and a deeper understanding of chemical reactions in complex mixtures with very large numbers of com­ pounds, such as petroleum fractions. This fortunate state of affairs has stimulated important new work both in academia and industrial research labs. The purpose of the workshop that led to this book was to bring together researchers at the forefront ofthis field to review the state of the art, stimulate communication and cooperation between industry and academia, and develop a cohesive picture of research trends and future directions. The chapters of the book have been organized into four main areas: • Continuous mixtures, where the very large numbers of discrete com­ pounds present are regarded as making up a continuum, • Structure-activity relationships, where the nature and rates of the reac­ tions that a particular molecule undergoes are correlated with its chemical structure, thus allowing the kinetics of very large numbers of compounds to be described by a few parameters, • Kinetic analysis, where mathematical techniques are applied to analyze the behavior of kinetic networks, and • Thermodynamics, emphasizing the practical and computational aspects of chemical equilibrium in complex mixtures.