Task 3.0 -- Advanced power systems: Subtask 3.18 -- Ash behavior in power systems. Semi-annual report, June 1--December 31, 1997

Advanced power systems such as integrated gasifier combined cycle systems and fluidized bed systems are at the forefront of power industry research because of the need for increased efficiency and the reduction of greenhouse gases. Ash behavior in power systems can have a significant impact on the design and performance of these systems. The Energy and Environmental Research Center (EERC) has developed a focused research initiative aimed at filling gaps in the understanding of fundamental mechanisms of ash behavior, which has relevance to commercial application and marketable products associated with advanced power systems. This program develops methods and means to better understand and mitigate adverse coal ash behavior in advanced power systems and can act to relieve the US reliance on diminishing recoverable oil resources and other greenhouse-producing fossil fuels. Subtask 3.18 is structured as three tasks. Task 1 pertains to summarizing the critical issues in ash behavior, especially for advanced power systems. Task 2 focuses on fundamental ash sintering and viscosity-ash composition relationships that are critical for developing a better mechanistic understanding of ash deposit formation and for predicting ash behavior. Task 3 is aimed primarily at determining the role of the ash chemistry and phase relationships for specific ash interactions in advanced power systems. The role of sulfides in the formation of ash deposits in gasification systems and the factors that influence alloy corrosion in supercritical boilers will be specifically analyzed. Task results to date are presented