SUCCESSFUL CONTINUOUS INJECTION OF COAL INTO GASIFICATION SYSTEM PRESSURES EXCEDING 500 PSI - DOE FUNDED PROGRAM RESULTS

摘要

Under President George W. Bush, the US is pursuing an energy program focused towards commercialization of coal-based power production technologies that offer significant improvements in efficiency and major reductions in emissions. The leaders in this area of technology are Gasification and Pressurized Fluidized Bed Combustors. However, to bring these technologies to mainstream commercial acceptance, certain operational components need to be significantly improved. One of the most pressing areas is solving the ongoing problem of reliable, controlled and cost effective solid fuel feeding into the pressure environment. The Department of Energy (DOE), working through the National Energy Technology Laboratory, has funded research to develop the unique Stamet "Posimetric Solids Pump" to a level able to feed coal into current gasification and PFBC system operating pressures. The research objective is a mechanical rotary device able to continuously feed and meter coal into the pressurized environments of at-least 34 Bar (500 PSI). The DOE research program has comprised an initial phase for design and testing of a device to feed coal into 20 Bar (300 PSI) and a second Phase for feeding into 34 Bar (500 PSI). The first phase target was achieved in December 2003. Since that time, effort has been focused to increase the machines feeding capability to the ultimate pressure target. In January 2005, following further testing, modification and optimization, the Stamet Pump achieved a world-record pressure level for continuous injection of coal, 38 Bar (560 PSI), exceeding the Phase 2 target. To conclude the research program, design optimization to lower power/torque requirements, enhance gas sealing and extend test runs are currently underway. To confirm commercial application of the Stamet Pump, extended testing at a gasifier-operating test facility is anticipated before the conference date. This paper will review and evaluate the successful pump design, design optimizations and results of the Phase 2 testing. The paper will additionally present results of semi-scale commercial testing which should have commenced by the date of the conference.