(515g) Study of Wyoming PRB Coal for Application of Solid Fueled Chemical Looping Combustion with TGA-MS

Yi Zhang, Jeffery T. Slone, Aurora M. Rubel, James K. Neathery, Fang Liu, Chunli Han, Liangyong Chen and Kunlei Liu*

University of Kentucky, Center for Applied Energy Research

Lexington, KY 40511-8410

Abstract: Since Wyoming coal is used to generate electricity in 38 states and represents 55% of the coal used in the US, a feasibility study of the application of chemical looping combustion technology to Wyoming coal would benefit its use in the future carbon constrained world. Wyoming PRB coal was acquired from a local power plant in the State of Kentucky. The coal was first pyrolyzed at 500-600 ºC to remove volatiles and tar to obtain char, which was served as the solid fuel in experiments reported in this paper. The purpose to remove volatiles and tar from coal was to minimize the potential agglomeration of oxygen carriers (OCs) inside reducer, and volatiles and tar produced would be introduced into reducer as part of fluidization media in the CLC process. In this work, a variety of oxygen carriers (OC) were premixed with PRB char with char-to-char ratio of 10:90 (weight based), tested in a thermogravimetric analyzer coupled with a mass spectrometer and a water vapor generator (TGA-MS-WVG). The TGA temperature was ramped up to 950 ºC at heating rate of 10 ºC/min. The weight change and its changing rate were used to quantify the degree of fuel conversion and reactivity of the OCs. Tested OCs include commercially available catalysts such as fused iron, Wustite and pure Fe₂O₃ powder and housed-made synthetic OCs such as freeze-granulated Fe₂O₃/Al₂O₃(50:50),  NiO/Al₂O₃(50:50) and CuO/Al₂O₃(50:50).  The carbon conversion rate and reactivity were calculated and compared.