Increasing environmental awareness and regulations have placed new requirements on process design for advanced power systems, and increased the need for sophisticated simulation and design tools for examining pollution prevention options. The current research project is designed to address those needs. It builds on an earlier project sponsored by the U.S. Department of Energys Morgantown Energy Technology Center (DOE/METC) to develop enhanced modeling capabilities built around the ASPEN process simulator used by METC to analyze the performance of advanced power generation systems. The goals of the current project are to, (1) develop and implement new methodological capabilities in the areas of process optimization and synthesis; (2) develop and implement new performance and cost models of selected processes and process components for advanced power generation; and (3) to demonstrate the application of these new design methods and engineering models in the context of selected advanced power systems of interest to DOE/METC. This Topical Report is one in a series of reports summarizing the results of this project. Sequential modular chemical process simulators, such as FLOWTRAN, ASPEN, or PROCESS have been widely used for the design of new and existing chemical processes. Recently, DOE has begun to use the ASPEN simulator to model advanced energy systems. These flowsheeting programs contain very detailed models for calculating mass and energy balances as well as for sizing and costing. This report deals with the development of a process synthesis capability built around the sequential modular simulator ASPEN using the mathematical programming approach, which requites the solution of a Mixed Integer Nonlinear Programming (MINLP) problem. A users manual for the new ASPEN MINLP Process synthesizer is provided in Appendix B.