Optimization of IGCC Processes with Reduced Order CFD Models Yidong Lang 1,2 , Stephen E. Zitney 2 and Lorenz T. Biegler* 1,2 1 Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 2 Collaboratory for Process & Dynamic Systems Research, National Energy Technology Laboratory, Morgantown, WV Abstract Integrated gasification combined cycle (IGCC) plants have significant advantages for efficient power generation with carbon capture. Moreover, with the development of accurate CFD models for gasification and combined cycle combustion, key units of these processes can now be modeled more accurately. However, the integration of CFD models within steady-state process simulators, and subsequent optimization of the integrated system, still presents significant challenges. This study describes the development and demonstration of a reduced order modeling (ROM) framework for these tasks. The approach builds on the concepts of co-simulation and ROM development for process units described in earlier studies. Here we show how the ROMs derived from both gasification and combustion units can be integrated within an equation-oriented simulation environment for the overall optimization of an IGCC process. In addition to a systematic approach to ROM development, the approach includes validation tasks for the CFD model as well as closed-loop tests for the integrated flowsheet. This approach allows the application of equation-based nonlinear programming algorithms and leads to fast optimization of CFD-based process flowsheets. The approach is illustrated on two flowsheets based on IGCC technology. Keywords: Co-simulation, PCA, Reduced Order Modeling, IGCC, Process Optimization, CFD 1. Introduction It is critical for the energy industries to reduce carbon emissions from power generation. For fossil fuel plants, integrated gasification combined cycle (IGCC) processes have been recognized as a core technology that allows more efficient capture of carbon dioxide. The main components of IGCC include air separation, coal gasification, synthesis gas cleanup, electricity generation with combined cycles, and carbon capture and storage. Using these components, IGCC processes produce electricity more efficiently than conventional plants and convert almost all carbon into carbon dioxide and hydrogen-rich fuel, which makes it easier to capture CO 2 for sequestration. Consequently, simulation and optimization of IGCC processes have become more important, and it is expected that optimization of process design and operation for IGCC will lead to significant economic and environmental benefits. As shown in Figure 1-1, the gasfier and the gas-turbine-combustor are key units of the IGCC process, but these cannot be modeled accurately with conventional process