IECM Technical Documentation: Chemical Looping Combustion for Pre-combustion CO2 Capture September 2012 Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed therein do not necessarily state or reflect those of the United States Government or any agency thereof. IECM Technical Documentation: Chemical Looping Combustion for Pre-combustion CO2 Capture RES Activity No. 0004000.2.672.241.003: The Role of Simulation and Modeling in Accelerating CO2 Capture Technology Prepared for: National Energy Technology Laboratory Department of Energy Pittsburgh, PA 15236 www.netl.doe.gov Prepared by: Hari C. Mantripragada Edward S. Rubin Carnegie Mellon University Pittsburgh, PA 15213 www.iecm-online.com September 2012 Table of Contents Chemical Looping Combustion 1 Objectives of this Report ........................................................................................................... 1 Introduction ............................................................................................................................... 2 Oxygen Carriers .......................................................................................................... 3 Reactor Design ............................................................................................................ 4 CLC Applications ........................................................................................................ 5 Thermodynamic Analysis of CLC Reactions .......................................................................... 10 Equilibrium Constant Solution Method ..................................................................... 10 Adiabatic Temperature .............................................................................................. 12 Air Reactor Calculations ........................................................................................... 13 Fuel Reactor Analysis................................................................................................ 19 Methods for Calculating Solids Inventory ................................................................. 30 Reactor Design .......................................................................................................... 32 IGCC power plant using CLC ................................................................................................. 34 Gas turbine and compressor calculations .................................................................. 34 CO2 Purification Unit ................................................................................................ 35 Calculation procedure ................................................................................................ 38 Case Studies ............................................................................................................................. 40 Base Case .................................................................................................................. 40 Results ....................................................................................................................... 41 Conclusion ............................................................................................................................... 48 References ............................................................................................................................... 48 Integrated Environmental Control Model - Technical Documentation Table of Contents v List of Figures Figure 1. Chemical looping combustion process: Oxygen carrier is oxidized in the air reactor and reduced in the fuel reactor. .......................................................................................................................................................................... 2 Figure 2. Typical process flow diagram of CLC process with interconnected fluidized beds (1) high velocity riser air reactor, (2) cyclone for particle separation and (3) fuel reactor (Fang et al, 2009) ...................................................... 5 Figure 3. Example of application of CLC to power generation – a simple cycle power plant where hot exhaust from air (oxidation) and fuel (reduction) reactors are expanded in air and CO2 turbines, respectively (Brandvoll and Bolland, 2004). ............................................................................................................................................................................ 6 Figure 4. Example of a CLC combined cycle power plant. Steam is produced using the hot exhaust from air and CO2 turbines in a heat recovery steam generator (HRSG) (Naqvi and Bolland, 2007). ....................................................... 7 Figure 5. Conceptual design of combined gasification and combustion of solid fuels using chemical looping (Rizeq et al, 2003). ............................................................................................................................................................................ 8 Figure 6. ALSTOM's Ca-based CLC process (Andrus et al, 2009). ..................................................................................... 8 Figure 7. Different applications of ALSTOM's chemical-looping concept using solid fuels (Andrus, 2009) ..................... 9 Figure 8. Chemical looping with oxygen-uncoupling (Mattisson et al, 2009). .................................................................... 9 Figure 9. Schematic of chemical looping combustion ........................................................................................................ 14 Figure 10. Variation of equilibrium constant for the oxidation reaction Ni + 0.5O2 <=> NiO, with temperature ............. 14 Figure 11. Inlet and outlet flows of the air reactor.............................................................................................................. 14 Figure 12. Variation of heat of reaction of Ni + 0.5O2 NiO, with temperature ............................................................. 16 Figure 13. Variation of adiabatic reaction temperature of AR as a function of inlet OC temperature at different inlet air temperatures. Pure NiO is assumed. x=0, z=0. ........................................................................................................... 18 Figure 14. Variation of adiabatic reaction temperature of AR as a function of inlet air temperature and inlet OC temperatures. Pure NiO is assumed. x=0, z=0. ........................................................................................................... 18 Figure 15. Variation of adiabatic temperature of AR as a function of inlet air temperature and inlet OC temperature. 40% NiO in the OC, x=0, z=0............................................................................................................................................. 18 Figure 16. Variation of adiabatic temperature in AR as a function of excess air ratio (x) and excess NiO ratio (z) at fixed inlet temperature of 400oC and inlet OC temperature of 900oC ................................................................................. 19 Figure 17. Equilibrium constants for reactions between CO and NiO and H2 and NiO as a function of temperature ....... 22 Figure 18. Variation of specific heat (Cp) of different components with temperature ....................................................... 27 Figure 19. Variation of equilibrium constant expressions with temperature ...................................................................... 27 Figure 20. Variation of equilibrium constant expressions with temperature ...................................................................... 27 Figure 21. Adiabatic FR temperature as a function of inlet fuel temperature and inlet OC temperature. z=0, pure NiO as OC .............................................................................................................................................................................. 28 Integrated Environmental Control Model - Technical Documentation List of Figures vi Figure 22. Adiabatic FR temperature as a function of inlet OC temperature and inlet fuel temperatures. z=0, pure NiO as OC .............................................................................................................................................................................. 29 o Figure 23. Adiabatic fuel reactor temperature as a function of excess NiO (z) at inlet OC temperature = 1200 C. xMeO = 40% ............................................................................................................................................................................. 29 Figure 24. Regression lines for solids inventory for different fuels at Xox values very close to 1. Data from Abad et al (2007) and Mattison et al (2007) were used in estimating