Potential Candidate for an Advanced Catalytic Gasification Process

摘要

Under the Department of Energy/University Coal Research (DOE/UCR)program, a team consisting of Clark Atlanta University (CAU), The University of TennesseeSpace Institute (UTSI), and Georgia Institute of Technology (GIT), carried out a successfulbench scale program, in which they identified three candidate eutectic salt mixtures to improvethe gasification performance of Illinois #6 coal. These candidate eutectic mixtures wereevaluated in a thermal gravimetric analyzer (TGA) as well as in a high-pressure, hightemperature differential fixed-bed set up. Gasification performance of Illinois #6 coal wasstudied under steam, CO_2, and steam/H_2 atmospheres. Major process variables including methodof catalyst impregnation, temperature, pressure, reacting gas flow rate and composition, catalystloading and candidate eutectic salt mixtures were evaluated. Experiments were also carried outusing different solvents to efficiently recover, reactivate and recycle spent catalyst mixtures.These extraction techniques were then compared based on their economics and extractionefficiency. Kinetic rate expressions were also developed from the bench scale fixed-bed data foruse in future design applications. Gasified chars of different carbon conversion levels, andungasified coal/catalyst samples were studied using x-ray diffraction and SEM analysis. Theseanalyses provided the information on various forms of catalyst compounds present duringgasification as well as overall catalyst mobility. Major findings from this DOE/UCR study arepresented here. Some important benefits and certain critical issues that need to be resolved priorto commercialization of this concept are also discussed in this paper.For further development of this and/or other potential candidate gasification concepts, athree step, 7-year program has been developed. This program will address unresolved issues incommercialization of a suitable advanced gasification process. The Southeast Consortium forAdvanced Gasification System (SeCAGS) has been formed to advance such technologies.SeCAGS members at present include the University of Tennessee Space Institute (UTSI),Tennessee State University (TSU), the University of Tennessee at Chattanooga (UTC), and theTennessee Valley Authority (TVA). It is believed that development of a suitable advancedgasification process would fulfill the National Energy Policy’s mandate to develop a reliable,affordable and environmentally safe energy source for America’s future. Successfulimplementation would mean a clean and abundant source of electricity generation and reduceddependence on foreign oil.