Reactivity Investigation on Iron-Titanium Oxides for a Moving Bed Chemical Looping Combustion Implementation
Affiliation(s)
Université de Technologie de Compiègne, Laboratoire de Transformation Intégrée de la Matière Renouvelable,. Université de Technologie de Compiègne, Laboratoire de Transformation Intégrée de la Matière Renouvelable.
Université de Technologie de Compiègne, Laboratoire de Transformation Intégrée de la Matière Renouvelable,. Université de Technologie de Compiègne, Laboratoire de Transformation Intégrée de la Matière Renouvelable.
ABSTRACT
Ilmenite-type natural ore which is constituted mainly of iron-titanium oxide is an interesting candidate as an oxygen carrier in chemical looping combustion (CLC) process. Its reactivity was investigated using methane as reducing gas and air as oxidizing gas. Experiments were carried out in a coupled thermogravimetric–thermo differential analyzer (TGA-DTA). When temperature increases from 700℃ to 1000℃, the reaction rate increases by 50 times while the oxygen transfer capacity passes from 1.8% to 12%. TG-DT analyses showed that the overall mass loss due to ilmenite reduction reached at most 12%. It corresponds to 87% of theoretical mass loss due to the transformation of Fe2TiO5 into Fe and TiO2. It is established that the reduction for the iron-titanium oxides occurs in two steps: Fe2TiO5→ FeTiO3→ Fe + TiO2. The titanium reduction from the state TiO2 to the stage Ti3O5 was observed as well. This behavior is supported by XRD analysis. Subsequent oxidation of the reduced mineral led to recover the starting oxide. The stability of iron-titanium oxides was established over 35 looping cycles of oxidation-reduction, with an increase of 5% of oxygen transfer capacity and reactivity in the first 5 cycles and after that, ilmenite reactivity remained constant. At high temperatures, catalytic effect of ilmenite on methane decomposition leading to carbon deposition is observed. The deposited carbon participates in the reactivity of the oxide.
Cite this paper
D. Campos, J. Belkouch, M. Hazi and A. Ould-Dris, "Reactivity Investigation on Iron-Titanium Oxides for a Moving Bed Chemical Looping Combustion Implementation," Advances in Chemical Engineering and Science, Vol. 3 No. 1, 2013, pp. 47-56. doi: 10.4236/aces.2013.31005.
D. Campos, J. Belkouch, M. Hazi and A. Ould-Dris, "Reactivity Investigation on Iron-Titanium Oxides for a Moving Bed Chemical Looping Combustion Implementation," Advances in Chemical Engineering and Science, Vol. 3 No. 1, 2013, pp. 47-56. doi: 10.4236/aces.2013.31005.
References
[1] IPCC, “Contribution of Working Group I to the 4th Assessment Report of the Intergovernmental Panel on Climate Change,” In: S. Solomon, et al., Eds., Climate Change 2007: The Physical Science Basis, Cambridge University Press, Cambridge, 2007, p. 996. [2] I. Dincer, “Environmental Impacts of Energy,” Energy Police, Vol. 27, No. 14, 1999, pp. 845-854. doi: 10.1016/j.bbr.2011.03.031 [3] M. Ishida, D. Zheng and T. Akehata, “Evaluation of a Chemical-Looping-Combustion Power-Generation System by Graphic Exergy Analysis,” Energy, Vol. 12, No. 2, 1987, pp. 147-154. doi:10.1016/0360-5442(87)90119-8 [4] J. Adanez and L. F. de Diego, “Selection of Oxygen Carriers for Chemical-Looping Combustion,” Energy & Fuels, Vol. 18, No. 3, 2004, pp. 371-377. doi: 10.1021/ef0301452 [5] P. Gayan, L. Dediego, F. Garcialabiano, J. Adanez, A. Abad and C. Dueso, “Effect of Support on Reactivity and Selectivity of Ni-Based Oxygen Carriers for Chemical-Looping Combustion,” Fuel, Vol. 87, No. 12, 2008, pp. 2641-2650. doi:10.1016/j.fuel.2008.02.016 [6] K. Sedor, M. Hossain and H. Delasa, “Reactivity and Stability of Ni/Al2O3 Oxygen Carrier for Chemical-Looping Combustion (CLC),” Chemical Engineering Science, Vol. 63, No. 11, 2008, pp. 2994-3007. doi:10.1016/j.ces.2008.02.021. [7] M. Johansson, T. Mattisson and A. Lyngfelt, “Investigation of Fe2O3 with MgAl2O4 for Chemical-Looping Combustion,” Industrial & Engineering Chemistry Research, Vol. 43, No. 22, 2004, pp. 6978-6987. doi:10.1021/ie049813c [8] H.-B. Zhao, L.-M. Liu, D. Xu, C.-G. Zheng, G.-J. Liu and L.-L. Jiang, “NiO/NiAl2O4 Oxygen Carriers Prepared by Sol-Gel for Chemical-Looping Combustion Fueled by Gas,” Fuel, Vol. 36, No. 3, 2008, pp. 261-266. doi:10.1016/S1872-5813(08)60020-1 [9] M. Johansson, T. Mattisson and A. Lyngfelt, “Creating a Synergy Effect by Using Mixed Oxides of Iron- and Nickel Oxides in the Combustion of Methane in a Chemical-Looping Combustion Reactor,” Energy, Vol. 56, No. 4, 2006, pp. 2399-2407. doi:10.1021/ef060068l [10] M. Rydén, A. Lyngfelt, T. Mattisson, D. Chen, A. Holmen and E. Bjorgum, “Novel Oxygen-Carrier Materials for Chemical-Looping Combustion and Chemical-Looping Reforming; LaxSr1-xFeyCo1-yO3-δ Perovskites and Mixed-Metal Oxides of NiO, Fe2O3 and Mn3O4,” International Journal of Greenhouse Gas Control, Vol. 2, No. 1, 2008, pp. 21-36. doi:10.1016/S1750-5836(07)00107-7 [11] E. Jerndal, T. Mattisson and A. Lyngfelt, “Investigation of Different NiO/NiAl2O4 Particles as Oxygen Carriers for Chemical-Looping Combustion,” Energy, Vol. 94, No. 10, 2009, pp. 665-676. doi:10.1021/ef8006596 [12] A. Abad, J. Adanez, F. Garcialabiano, L. Dediego, P. Gayan and J. Celaya, “Mapping of the Range of Operational Conditions for Cu-, Fe-, and Ni-Based Oxygen Carriers in Chemical-Looping Combustion,” Chemical Engineering Science, Vol. 62, No. 1-2, 2007, pp. 533-549. doi:10.1016/j.ces.2006.09.019 [13] E. Jerndal, T. Mattisson and A. Lyngfelt, “Thermal Analysis of Chemical-Looping Combustion,” Chemical Engineering Research and Design, Vol. 84, No. 9, 2006, pp. 795-806. doi:10.1205/cherd05020 [14] H. Leion, A. Lyngfelt, M. Johansson, E. Jerndal and T. Mattisson, “The Use of Ilmenite as an Oxygen Carrier in Chemical-Looping Combustion,” Chemical Engineering Research and Design, Vol. 86, No. 9, 2008, pp. 1017-1026. doi:10.1016/j.cherd.2008.03.019 [15] H. Leion, T. Mattisson and A. Lyngfelt, “Use of Ores and Industrial Products as Oxygen Carriers in Chemical-Looping Combustion,” Energy & Fuels, Vol. 23, No. 4, 2009, pp. 2307-2315. doi:10.1021/ef8008629 [16] J. Adanez, A. Cuadrat, A. Abad, P. Gayan, L. F. de Diego and F. Garcia-Labiano, “Ilmenite Activation during Consecutive Redox Cycles in Chemical-Looping Combustion,” Energy & Fuels, Vol. 24, No. 2, 2010, pp. 1402-1413. doi:10.1021/ef900856d [17] A. R. Bidwe, F. Mayer, C. Hawthorne, A. Charitos, A. Schuster and G. Scheffknecht, “Use of Ilmenite as an Oxygen Carrier in Chemical Looping Combustion-Batch and Continuous Dual Fluidized Bed Investigation,” Energy Procedia, Vol. 4, 2011, pp. 433-440. doi:10.1016/j.egypro.2011.01.072 [18] M. M. Azis, E. Jerndal, H. Leion, T. Mattisson and A. Lyngfelt, “On the Evaluation of Synthetic and Natural Ilmenite Using Syngas as Fuel in Chemical-Looping Combustion (CLC),” Chemical Engineering Research and Design, Vol. 88, No. 11, 2010, pp. 1505-1514. doi:10.1016/j.cherd.2010.03.006 [19] J. Nell, “An Overview of the Phase-Chemistry Involved in Theproduction of High-Titanium Slag from Ilmenite Feedstock,” Journal of the South African Institute of Mining and Metallurgy, Vol. 100, No. 1, 2000, pp. 35-44. [20] R. A. Briggs and A. Sacco, “The Oxidation of Ilmenite and Its Relationship to the FeO-Fe2O3-TiO2 Phase Diagram at 1073 and 1140 K,” Vol. 24, No. 6, 1993, pp. 1257-1264. doi:10.1007/BF02668194 [21] M. Johansson, T. Mattisson and A. Lyngfelt, “Use of NiO/NiAl2O4 Particles in a 10 kW Chemical-Looping Combustor,” Industrial & Engineering Chemistry Research, Vol. 45, No. 17, 2006, pp. 5911-5919. doi:10.1021/ie060232s [22] P. Kolbitsch, J. Bolhàr-Nordenkampf, T. Proll and H. Hofbauer, “Operating Experience with Chemical Looping Combustion in a 120 kW Dual Circulating Fluidized Bed (DCFB) Unit,” International Journal of Greenhouse Gas Control, Vol. 4, No. 2, 2010, pp. 180-185. doi:10.1016/j.ijggc.2009.09.014 [23] J. Bolhàr-Nordenkampf, T. Proll, P. Kolbitsch and H. Hofbauer, “Performance of a NiO-Based Oxygen Carrier for Chemical Looping Combustion and Reforming in a 120 kW Unit,” Energy Procedia, Vol. 1, No. 1, 2009, pp. 19-25. doi:10.1016/j.egypro.2009.01.005 [24] C. Linderholm, A. Abad, T. Mattisson and A. Lyngfelt, “160 h of Chemical-Looping Combustion in a 10 kW Reactor System with a NiO-Based Oxygen Carrier,” International Journal of Greenhouse Gas Control, Vol. 2, No. 4, 2008, pp. 520-530. doi:10.1016/j.ijggc.2008.02.006 [25] P. Kolbitsch, T. Proll and H. Hofbauer, “Modeling of a 120 kW Chemical Looping Combustion Reactor System Using a Ni-Based Oxygen Carrier,” Chemical Engineering Science, Vol. 64, No. 1, 2009, pp. 99-108. doi:10.1016/j.ces.2008.09.014 [26] C. Linderholm, T. Mattisson and A. Lyngfelt, “Long-Term Integrity Testing of Spray-Dried Particles in a 10 kW Chemical-Looping Combustor Using Natural Gas as Fuel,” Fuel, Vol. 88, No. 11, 2009, pp. 2083-2096. doi:10.1016/j.fuel.2008.12.018 [27] A. Cuadrat, A. Abad, J. Adánez, L. D. Diego, F. García-Labiano and P. Gayán, “Behaviour of Ilmenite as Oxygen Carrier in Chemical-Looping Combustion,” Fuel Processing Technologie, Vol. 94, No. 1, 2012, pp. 101-112. doi:10.1016/j.fuproc.2011.10.020 [28] A. Abad, J. Adánez, A. Cuadrat, F. García-Labiano, P. Gayán and L. F. de Diego, “Kinetics of Redox Reactions of Ilmenite for Chemical-Looping Combustion,” Chemical Engineering Science, Vol. 66, No. 4, 2011, pp. 689-702. doi:10.1016/j.ces.2010.11.010 [29] A. Ould-Dris, Y. Molodtsof and J. F. Large, “A Classification and Design Method for Moving Bed Flow in Pipes,” Powder Technology, Vol. 87, No. 1, 1996, pp. 49-57. doi:10.1016/0032-5910(96)80758-3 [30] M. L. Vries, I. E. Grey and J. D. Fitz Gerald, “Crystallographic Control in Ilmenite Reduction,” Metallurgical and Materials Transactions B, Vol. 38, No. 2, 2007, pp. 267-277. doi:10.1007/s11663-006-9015-0 [31] C. Kucukkaragoz and R. Eric, “Solid State Reduction of a Natural Ilmenite,” Minerals Engineering, Vol. 19, No. 3, 2006, pp. 334-337. doi:10.1016/j.mineng.2005.09.015. [32] P. Pourghahramani and E. Forssberg, “Effects of Mechanical Activation on the Reduction Behavior of Hematite Concentrate,” International Journal of Mineral Processing, Vol. 82, No. 2, 2007, pp. 96-105. doi:10.1016/j.minpro.2006.11.003 [33] G. Flamant, D. Gauthier, M. Rivot, A. Rouanet and F. Sibieude, “Mécanismes de Réduction de L’ilménite Naturelle par le Méthane dans un Réacteur à Lit Fluidisé,” Powder Technology, Vol. 51, No. 3, 1987, pp. 251-260. doi:10.1016/0032-5910(87)80026-8 [34] C. V. Stevens, “Thermochemical Processing of Biomass: Conversion into Fuels, Chemicals and Power,” John Wiley & Sons, Hoboken, 2011, p. 348. [35] A. Cuadrat, A. Abad, F. García-Labiano, P. Gayán, L. F. de Diego and J. Adánez, “Ilmenite as Oxygen Carrier in a Chemical Looping Combustion System with Coal,” Energy Procedia, Vol. 4, 2011, pp. 362-369. doi:10.1016/j.egypro.2011.01.063 [36] A. Cuadrat, A. Abad, F. García-Labiano, P. Gayán, L. F. de Diego and J. Adánez, “The Use of Ilmenite as Oxygen-Carrier in a 500 Wth Chemical-Looping Coal Combustion Unit,” International Journal of Greenhouse Gas Control, Vol. 5, No. 6, 2011, pp. 1630-1642. doi:10.1016/j.ijggc.2011.09.010 [37] A. Cuadrat, A. Abad, F. García-Labiano, P. Gayán, L. F. de Diego and J. Adánez, “Effect of Operating Conditions in Chemical-Looping Combustion of Coal in a 500 Wth Unit,” International Journal of Greenhouse Gas Control, Vol. 6, 2012, pp. 153-163. doi:10.1016/j.ijggc.2011.10.013 [38] N. Berguerand and A. Lyngfelt, “Design and Operation of a 10 kWth Chemical-Looping Combustor for Solid Fuels—Testing with South African Coal,” Fuel, Vol. 87, No. 12, 2008, pp. 2713-2726. [39] N. Berguerand and A. Lyngfelt, “The Use of Petroleum Coke as Fuel in a 10 kWth Chemical-Looping Combustor,” International Journal of Greenhouse Gas Control, Vol. 2, No. 2, 2008, pp. 169-179.
[1] IPCC, “Contribution of Working Group I to the 4th Assessment Report of the Intergovernmental Panel on Climate Change,” In: S. Solomon, et al., Eds., Climate Change 2007: The Physical Science Basis, Cambridge University Press, Cambridge, 2007, p. 996. [2] I. Dincer, “Environmental Impacts of Energy,” Energy Police, Vol. 27, No. 14, 1999, pp. 845-854. doi: 10.1016/j.bbr.2011.03.031 [3] M. Ishida, D. Zheng and T. Akehata, “Evaluation of a Chemical-Looping-Combustion Power-Generation System by Graphic Exergy Analysis,” Energy, Vol. 12, No. 2, 1987, pp. 147-154. doi:10.1016/0360-5442(87)90119-8 [4] J. Adanez and L. F. de Diego, “Selection of Oxygen Carriers for Chemical-Looping Combustion,” Energy & Fuels, Vol. 18, No. 3, 2004, pp. 371-377. doi: 10.1021/ef0301452 [5] P. Gayan, L. Dediego, F. Garcialabiano, J. Adanez, A. Abad and C. Dueso, “Effect of Support on Reactivity and Selectivity of Ni-Based Oxygen Carriers for Chemical-Looping Combustion,” Fuel, Vol. 87, No. 12, 2008, pp. 2641-2650. doi:10.1016/j.fuel.2008.02.016 [6] K. Sedor, M. Hossain and H. Delasa, “Reactivity and Stability of Ni/Al2O3 Oxygen Carrier for Chemical-Looping Combustion (CLC),” Chemical Engineering Science, Vol. 63, No. 11, 2008, pp. 2994-3007. doi:10.1016/j.ces.2008.02.021. [7] M. Johansson, T. Mattisson and A. Lyngfelt, “Investigation of Fe2O3 with MgAl2O4 for Chemical-Looping Combustion,” Industrial & Engineering Chemistry Research, Vol. 43, No. 22, 2004, pp. 6978-6987. doi:10.1021/ie049813c [8] H.-B. Zhao, L.-M. Liu, D. Xu, C.-G. Zheng, G.-J. Liu and L.-L. Jiang, “NiO/NiAl2O4 Oxygen Carriers Prepared by Sol-Gel for Chemical-Looping Combustion Fueled by Gas,” Fuel, Vol. 36, No. 3, 2008, pp. 261-266. doi:10.1016/S1872-5813(08)60020-1 [9] M. Johansson, T. Mattisson and A. Lyngfelt, “Creating a Synergy Effect by Using Mixed Oxides of Iron- and Nickel Oxides in the Combustion of Methane in a Chemical-Looping Combustion Reactor,” Energy, Vol. 56, No. 4, 2006, pp. 2399-2407. doi:10.1021/ef060068l [10] M. Rydén, A. Lyngfelt, T. Mattisson, D. Chen, A. Holmen and E. Bjorgum, “Novel Oxygen-Carrier Materials for Chemical-Looping Combustion and Chemical-Looping Reforming; LaxSr1-xFeyCo1-yO3-δ Perovskites and Mixed-Metal Oxides of NiO, Fe2O3 and Mn3O4,” International Journal of Greenhouse Gas Control, Vol. 2, No. 1, 2008, pp. 21-36. doi:10.1016/S1750-5836(07)00107-7 [11] E. Jerndal, T. Mattisson and A. Lyngfelt, “Investigation of Different NiO/NiAl2O4 Particles as Oxygen Carriers for Chemical-Looping Combustion,” Energy, Vol. 94, No. 10, 2009, pp. 665-676. doi:10.1021/ef8006596 [12] A. Abad, J. Adanez, F. Garcialabiano, L. Dediego, P. Gayan and J. Celaya, “Mapping of the Range of Operational Conditions for Cu-, Fe-, and Ni-Based Oxygen Carriers in Chemical-Looping Combustion,” Chemical Engineering Science, Vol. 62, No. 1-2, 2007, pp. 533-549. doi:10.1016/j.ces.2006.09.019 [13] E. Jerndal, T. Mattisson and A. Lyngfelt, “Thermal Analysis of Chemical-Looping Combustion,” Chemical Engineering Research and Design, Vol. 84, No. 9, 2006, pp. 795-806. doi:10.1205/cherd05020 [14] H. Leion, A. Lyngfelt, M. Johansson, E. Jerndal and T. Mattisson, “The Use of Ilmenite as an Oxygen Carrier in Chemical-Looping Combustion,” Chemical Engineering Research and Design, Vol. 86, No. 9, 2008, pp. 1017-1026. doi:10.1016/j.cherd.2008.03.019 [15] H. Leion, T. Mattisson and A. Lyngfelt, “Use of Ores and Industrial Products as Oxygen Carriers in Chemical-Looping Combustion,” Energy & Fuels, Vol. 23, No. 4, 2009, pp. 2307-2315. doi:10.1021/ef8008629 [16] J. Adanez, A. Cuadrat, A. Abad, P. Gayan, L. F. de Diego and F. Garcia-Labiano, “Ilmenite Activation during Consecutive Redox Cycles in Chemical-Looping Combustion,” Energy & Fuels, Vol. 24, No. 2, 2010, pp. 1402-1413. doi:10.1021/ef900856d [17] A. R. Bidwe, F. Mayer, C. Hawthorne, A. Charitos, A. Schuster and G. Scheffknecht, “Use of Ilmenite as an Oxygen Carrier in Chemical Looping Combustion-Batch and Continuous Dual Fluidized Bed Investigation,” Energy Procedia, Vol. 4, 2011, pp. 433-440. doi:10.1016/j.egypro.2011.01.072 [18] M. M. Azis, E. Jerndal, H. Leion, T. Mattisson and A. Lyngfelt, “On the Evaluation of Synthetic and Natural Ilmenite Using Syngas as Fuel in Chemical-Looping Combustion (CLC),” Chemical Engineering Research and Design, Vol. 88, No. 11, 2010, pp. 1505-1514. doi:10.1016/j.cherd.2010.03.006 [19] J. Nell, “An Overview of the Phase-Chemistry Involved in Theproduction of High-Titanium Slag from Ilmenite Feedstock,” Journal of the South African Institute of Mining and Metallurgy, Vol. 100, No. 1, 2000, pp. 35-44. [20] R. A. Briggs and A. Sacco, “The Oxidation of Ilmenite and Its Relationship to the FeO-Fe2O3-TiO2 Phase Diagram at 1073 and 1140 K,” Vol. 24, No. 6, 1993, pp. 1257-1264. doi:10.1007/BF02668194 [21] M. Johansson, T. Mattisson and A. Lyngfelt, “Use of NiO/NiAl2O4 Particles in a 10 kW Chemical-Looping Combustor,” Industrial & Engineering Chemistry Research, Vol. 45, No. 17, 2006, pp. 5911-5919. doi:10.1021/ie060232s [22] P. Kolbitsch, J. Bolhàr-Nordenkampf, T. Proll and H. Hofbauer, “Operating Experience with Chemical Looping Combustion in a 120 kW Dual Circulating Fluidized Bed (DCFB) Unit,” International Journal of Greenhouse Gas Control, Vol. 4, No. 2, 2010, pp. 180-185. doi:10.1016/j.ijggc.2009.09.014 [23] J. Bolhàr-Nordenkampf, T. Proll, P. Kolbitsch and H. Hofbauer, “Performance of a NiO-Based Oxygen Carrier for Chemical Looping Combustion and Reforming in a 120 kW Unit,” Energy Procedia, Vol. 1, No. 1, 2009, pp. 19-25. doi:10.1016/j.egypro.2009.01.005 [24] C. Linderholm, A. Abad, T. Mattisson and A. Lyngfelt, “160 h of Chemical-Looping Combustion in a 10 kW Reactor System with a NiO-Based Oxygen Carrier,” International Journal of Greenhouse Gas Control, Vol. 2, No. 4, 2008, pp. 520-530. doi:10.1016/j.ijggc.2008.02.006 [25] P. Kolbitsch, T. Proll and H. Hofbauer, “Modeling of a 120 kW Chemical Looping Combustion Reactor System Using a Ni-Based Oxygen Carrier,” Chemical Engineering Science, Vol. 64, No. 1, 2009, pp. 99-108. doi:10.1016/j.ces.2008.09.014 [26] C. Linderholm, T. Mattisson and A. Lyngfelt, “Long-Term Integrity Testing of Spray-Dried Particles in a 10 kW Chemical-Looping Combustor Using Natural Gas as Fuel,” Fuel, Vol. 88, No. 11, 2009, pp. 2083-2096. doi:10.1016/j.fuel.2008.12.018 [27] A. Cuadrat, A. Abad, J. Adánez, L. D. Diego, F. García-Labiano and P. Gayán, “Behaviour of Ilmenite as Oxygen Carrier in Chemical-Looping Combustion,” Fuel Processing Technologie, Vol. 94, No. 1, 2012, pp. 101-112. doi:10.1016/j.fuproc.2011.10.020 [28] A. Abad, J. Adánez, A. Cuadrat, F. García-Labiano, P. Gayán and L. F. de Diego, “Kinetics of Redox Reactions of Ilmenite for Chemical-Looping Combustion,” Chemical Engineering Science, Vol. 66, No. 4, 2011, pp. 689-702. doi:10.1016/j.ces.2010.11.010 [29] A. Ould-Dris, Y. Molodtsof and J. F. Large, “A Classification and Design Method for Moving Bed Flow in Pipes,” Powder Technology, Vol. 87, No. 1, 1996, pp. 49-57. doi:10.1016/0032-5910(96)80758-3 [30] M. L. Vries, I. E. Grey and J. D. Fitz Gerald, “Crystallographic Control in Ilmenite Reduction,” Metallurgical and Materials Transactions B, Vol. 38, No. 2, 2007, pp. 267-277. doi:10.1007/s11663-006-9015-0 [31] C. Kucukkaragoz and R. Eric, “Solid State Reduction of a Natural Ilmenite,” Minerals Engineering, Vol. 19, No. 3, 2006, pp. 334-337. doi:10.1016/j.mineng.2005.09.015. [32] P. Pourghahramani and E. Forssberg, “Effects of Mechanical Activation on the Reduction Behavior of Hematite Concentrate,” International Journal of Mineral Processing, Vol. 82, No. 2, 2007, pp. 96-105. doi:10.1016/j.minpro.2006.11.003 [33] G. Flamant, D. Gauthier, M. Rivot, A. Rouanet and F. Sibieude, “Mécanismes de Réduction de L’ilménite Naturelle par le Méthane dans un Réacteur à Lit Fluidisé,” Powder Technology, Vol. 51, No. 3, 1987, pp. 251-260. doi:10.1016/0032-5910(87)80026-8 [34] C. V. Stevens, “Thermochemical Processing of Biomass: Conversion into Fuels, Chemicals and Power,” John Wiley & Sons, Hoboken, 2011, p. 348. [35] A. Cuadrat, A. Abad, F. García-Labiano, P. Gayán, L. F. de Diego and J. Adánez, “Ilmenite as Oxygen Carrier in a Chemical Looping Combustion System with Coal,” Energy Procedia, Vol. 4, 2011, pp. 362-369. doi:10.1016/j.egypro.2011.01.063 [36] A. Cuadrat, A. Abad, F. García-Labiano, P. Gayán, L. F. de Diego and J. Adánez, “The Use of Ilmenite as Oxygen-Carrier in a 500 Wth Chemical-Looping Coal Combustion Unit,” International Journal of Greenhouse Gas Control, Vol. 5, No. 6, 2011, pp. 1630-1642. doi:10.1016/j.ijggc.2011.09.010 [37] A. Cuadrat, A. Abad, F. García-Labiano, P. Gayán, L. F. de Diego and J. Adánez, “Effect of Operating Conditions in Chemical-Looping Combustion of Coal in a 500 Wth Unit,” International Journal of Greenhouse Gas Control, Vol. 6, 2012, pp. 153-163. doi:10.1016/j.ijggc.2011.10.013 [38] N. Berguerand and A. Lyngfelt, “Design and Operation of a 10 kWth Chemical-Looping Combustor for Solid Fuels—Testing with South African Coal,” Fuel, Vol. 87, No. 12, 2008, pp. 2713-2726. [39] N. Berguerand and A. Lyngfelt, “The Use of Petroleum Coke as Fuel in a 10 kWth Chemical-Looping Combustor,” International Journal of Greenhouse Gas Control, Vol. 2, No. 2, 2008, pp. 169-179.