Accurate physical models are currently unavailable for predicting rates of slag buildup in a gasifier and ash deposition in a syngas convective cooler. Demonstration plants have experienced problems such as lower carbon conversion and plugging of syngas coolers with fly ash. These issues reduce plant heat rate, place additional strain on solids handling and grey water circuits, and reduce the overall reliability of the gasifier. Research in this area will focus on establishing how iron and vanadium oxide content, as well as oxidation state, impact slag viscosity and is aimed at negating plugging and fouling throughout the syngas cooling system. It will lead to increased capabilities for predicting gasifier performance and further determine the impacts and limits of using various coal grades and petcoke in entrained gasifiers. In addition, development of computational simulation tools will reduce uncertainty associated with the use of low-rank coal and mixed feeds. Results of this work will aid in gasifier design and performance relative to the use of these fuels, allowing for fuel flexibility in current and future gasification facilities.
More information on NETL-supported R&D in conversion and fouling is available at the Gasifier Optimization page; also see a study on IGCC availability and costs that includes aspects of conversion, fouling and slagging.