New Technology Trends for Improved IGCC System Performance

The application of gas turbine technology to IGCC systems requires careful consideration of the degree and type of integration used during the system design phase. Although gas turbines provide the primary output and efficiency gains for IGCC systems, as compared with conventional coal-fired power generation systems, they are commercially available only in specific size ranges. Therefore, it is up to the IGCC system designer to optimize the IGCC power plant within the required output, efficiency, and site conditions by selecting the system configuration carefully, particularly for air separation unit (ASU) integration incorporated with oxygen blown gasification systems. An IGCC system, based on a generic, entrained flow, oxygen blown gasification system and a GE STAG 109FA combined cycle has been evaluated with varying degrees of ASU integration, two fuel equivalent heating values and two gas turbine firing temperatures to provide net plant output and efficiency results. The data presented illustrate the system flexibility afforded by variation of ASU integration and the potential performance gains available through the continued use of gas turbine advances. Emphasis is placed on system design choices that favor either low initial investment cost or low operating cost for a given IGCC system output.