Characterization of oxygen carriers for chemical-looping combustion

Publisher Summary This chapter analyzes the behavior of the different oxygen carriers with respect to selectivity towards complete oxidation products, durability in the cyclic reactions, and attrition and agglomeration during fluidized bed cyclic reactions. In the multicycle tests in thermogravimetric analyzer (TGA), it was observed that most of the oxygen carriers exhibited high reactivity and excellent chemical stability but the Cu and Ni based oxygen carriers prepared by mechanical mixing underwent a rapid degradation of their mechanical properties as the number of cycles increased. The Ni- and the Fe based oxygen carriers did not agglomerate. The attrition rates of the carriers were usually high in the first cycles due to the rounding effects on the particles and because of the fines sticked to the particles during preparation. Later, the attrition rates due to the internal changes produced in the particles by the successive reduction and oxidation processes decreased, and all carriers showed low attrition rates. The product distribution during the oxidation of the fuel depended on the metal oxide used in the oxygen carrier. Complete conversion of CH 4 to CO 2 and H 2 O was obtained with the oxygen carrier Cu-AI-I.

[1]  Jeong-Hoo Choi,et al.  Oxidation and reduction characteristics of oxygen carrier particles and reaction kinetics by unreacted core model , 2001, Korean Journal of Chemical Engineering.

[2]  H Herzog,et al.  Capturing greenhouse gases. , 2000, Scientific American.

[3]  A. Lyngfelt,et al.  Reactivity of some metal oxides supported on alumina with alternating methane and oxygen - Application for chemical-looping combustion , 2003 .

[4]  Toshihiro Okamoto,et al.  A Fundamental Study of a New Kind of Medium Material for Chemical-Looping Combustion , 1996 .

[5]  A. Lyngfelt,et al.  Comparison of iron-, nickel-, copper- and manganese-based oxygen carriers for chemical-looping combustion , 2004 .

[6]  Ho-Jung Ryu,et al.  Effect of temperature on reduction reactivity of oxygen carrier particles in a fixed bed chemical-looping combustor , 2003 .

[7]  A. Abad,et al.  Selection of Oxygen Carriers for Chemical-Looping Combustion , 2004 .

[8]  Toshihiro Okamoto,et al.  Development of a Novel Chemical-Looping Combustion: Synthesis of a Solid Looping Material of NiO/NiAl2O4 , 1999 .

[9]  D. Zheng,et al.  Evaluation of a chemical-looping-combustion power-generation system by graphic exergy analysis , 1987 .

[10]  Hongguang Jin,et al.  Reactivity Study on Natural-Gas-Fueled Chemical-Looping Combustion by a Fixed-Bed Reactor , 2002 .

[11]  H. Richter,et al.  Reversibility of combustion processes , 1983 .

[12]  A. Lyngfelt,et al.  The use of iron oxide as an oxygen carrier in chemical-looping combustion of methane with inherent separation of CO2 , 2001 .

[13]  Juan Adánez,et al.  Development of Cu-based oxygen carriers for chemical-looping combustion , 2004 .

[14]  Hongguang Jin,et al.  A Novel Chemical-Looping Combustor without NOx Formation , 1996 .

[15]  Hongguang Jin,et al.  A Novel Combustor Based on Chemical-Looping Reactions and Its Reaction Kinetics , 1994 .

[16]  R. Villa.  Ni based mixed oxide materials for CH4 oxidation under redox cycle conditions , 2003 .

[17]  Hongguang Jin,et al.  Development of a Novel Chemical-Looping Combustion: Synthesis of a Looping Material with a Double Metal Oxide of CoO−NiO , 1998 .

[18]  Toshihiro Okamoto,et al.  Kinetic Behavior of Solid Particle in Chemical-Looping Combustion: Suppressing Carbon Deposition in Reduction , 1998 .