Chemical Looping Technology and CO 2 Capture

Transcription

1 Chemical Looping Technology and CO 2 Capture by L. S. Fan Department of Chemical and Biomolecular Engineering The Ohio State University Columbus, Ohio May 3, 2011

2 Chemical Looping for Hydrogen Production or Combustion CO 2 H 2 O Metal H 2 Metal Oxide H 2 O C x H y

3 Chemical Looping for Fossil Fuel Conversions Two typical types of looping reaction systems Oxygen Carrier (Type I) Me/MeO, MeS/MeSO 4 CO 2 Carrier (Type II) MeO/MeCO 3 1 st International Conference on Chemical Looping, Lyon, France, March (2010). 1 st Meeting of High Temperature Solids Looping 3 Cycle Network, Oviedo, Spain, September (2009).

4 Historical Development of Chemical Looping Technologies for Fossil Energy Conversions Technologies Lane Process and Messerschmitt Process Lewis and Gilliland Process IGT HYGAS Process CO 2 Acceptor Process Time Early Twentieth Century 1950s 1970s 1970s Looping Media Fe/FeO/Fe 3 O 4 Cu 2 O/CuO FeO/Fe 3 O 4 CaO/CaCO 3 Reactor Design Fixed bed Fluidized bed Staged fluidized bed Fluidized bed IGT Process Lane Process Lewis and Gilliland Process 4 CO 2 Acceptor Process

5 IGT Steam Iron HYGAS Process MO=> M M=> MO Gas Conversion (%) Solid inlet 80% Fe3O4-20% FeO 95% FeO- 5% Fe Temperature ( o C) Reactor Fluid Bed Fluid Bed Poor solid phase conversions: Used only about 25% oxygen capacity of the particles. Low gas phase conversions: Used iron ore: Low reaction rates Only about 40% efficient Poor Thermo The process not geared towards making pure CO 2 5

6 CO 2 Capture from Fossil Energy Technological Solutions Source: José D. Figueroa, National Energy Technology Laboratory (NETL), USDOE

7 Exergy Analysis on Hydrogen Production Substance Enthalpy of degradation Exergy Exergy Rate (ε) Energy/Exery Loss Additional Energy Input Final Product Carbon kj/mol kj/mol 0 Heat Loss 48.8 kj Exergy Loss H 2 + CO Partial oxidation kj /Gasification kj ε = kj Heat Loss 36 kj Exergy Loss H 2 +CO kj Water Gas Shift kj ε = 0.82 I I. Contional Process Exergetic Efficiency 322.9/407.7 = 79.2% ε 1 Fe 3 O (0.395 mol) kj 71.9 kj ε = Fe kj Partial oxidation kj ε = kj Exergy Loss 77.8 kj thermal 380 K 12.41kJ Exergy H 2 + Fe 3 O kj kj ε = 0.82 II. Chemcial Looping Process Exergetic Efficiency 396.9/( )=94.5% ε = 0.16 II 7

8 Chalmers University of Technology Gaseous Fuel CLC Up to 99% gaseous fuel conversion; Satisfactory (Ni) particle performance; Solids inventory: kg/mw th ; Solids circulation rate: 4 kg/s MW th 8 Photo Courtesy of Professor Anders Lyngfelt

9 OSU Syngas Chemical Looping Process To Steam Turbine Raw Syngas Candle Filter Hot Gas Cleanup Purge Makeup Fe 2000 psi CO 2 (with H 2 S, Hg, HCl) H 2 (450 PSI) Coal BFWFly Ash BFW Sulfur Byproduct Fuel Reactor Fe 2 O 3 H 2 Reactor Steam O 2 Hot Syngas Air Oxidation Hot Spent Air Fe 3 O 4 Compressor Air Compressor Air Gas Turbine Generator State-of-the-art N 2 Thomas, T., L.-S. Fan, P. Gupta, and L. G. Velazquez-Vargas, Combustion Looping Using Composite Oxygen Carriers U.S. Patent No. 7,767,191 (priority date 2003). 9

10 Discussions on Alternative Coal Direct Chemical Looping Reducer CO 2 /H 2 O Fe 2 O 3 Coal/ biomass Zone 1 Zone 1 Zone 2 Zone 2 Coal/ biomass Zone 3 Zone 4 Enhancing Gas Fe Thomas, T., L.-S. Fan, P. Gupta, and L. G. Velazquez-Vargas, Combustion Looping Using Composite Oxygen Carriers U.S. Patent No. 7,767,191 (priority date 2003) Fan, L.-S., P. Gupta, L.G. Velazquez-Vargas, Systems and Methods of Converting Fuels WO 2007/ (2006)

11 Scale Solid Conversion (%) Gas Conversions (%) Syngas Chemical Looping Process Development Maximum Operating Temperature Determined Reactor Performance Confirmed 50 Particle 45 Reactivity Confirmed Solid H2 CO Axil Position (inch) Bench Scale Tests Sub-Pilot SCL Integrated Tests Particle Fixed Bed Tests Time

12 PCO2/PCO FeO x FeO x CO 2 /H 2 O CO 2 /H 2 O Chemical Looping Reactor Design (x>y) Fluidized Bed v.s. Moving Bed FeO x FeO x CO 2 /H 2 O CO 2 /H 2 O 11.11% Maximum Solid Conversion 50.00% > U mfv Gas Velocity < U mfv (X>Y) Small 1.E+07 Particle Size Large (X>Y) FeO y CO/H 2 1.E+06 Fe 2 O 3 FeO y CO/H 2 Fluidized Bed 1.E+05 1.E+04 (x>y) Fe Moving Bed The Selected 3 O 4 Reactor Type 1.E+03 Fluidized Bed Moving Bed FeO y CO/H 2 Fluidized Bed 1.E+02 1.E+01 1.E+00 1.E-01 Moving Bed FeO Temperature (C) Fe FeO y CO/H 2 Moving Bed 12

13 Gasifier Syngas Chemical Looping in CTL Applications I H 2 Reactor Fuel Reactor N 2 CO 2 H 2 Air Gas Phase Particulate removal H 2 S Removal H 2 /CO=2 F-T reactor Product separation Liquid Fuel H 2 /CO = 0,5 Coal/ O 2 HRSG N 2 13

14 Reactor 3 Syngas Chemical Looping in CTL Applications II Sequestrable CO 2 MeO x Biomass and F-T byproduct MeO y (y < x) Reactor 1 Reactor 2 H 2 O H 2 O (Cooling) Steam to Reactor 2 CO 2 Byproduct to Reactor 1 F-T and Product Upgrade Liquid Fuel Product Steam from F-T H 2 O H 2 rich gas C + H 2 O/O 2 H 2 + CO 2 /Heat MeO z (y<z x) Air (Optional) 3H 2 + CO 2 -(CH 2 )- + 2H 2 O 14

15 Cathode Anode SOFC Reactor 3 Reactor 1 Reactor 2 Chemical Looping Integrated with Fuel Cell I Steam rich exhaust to Reactor 2 Sequestrable CO 2 and H 2 O MeO x Oxygen lean air to Reactor 3 Biomass Electric Power MeO y (y < x) H 2 rich gas Oxygen lean air from SOFC cathode (Optional) Compressed Air C + H 2 O/O 2 H 2 + CO 2 /Heat 2H 2 + O 2 2H 2 O + Electricity MeO z (y<z x) 15

16 Circulating Fluidized Bed Systems Single Loop High Density CFB System (Kirbas et al., 2007) Two Loop High Density CFB System (Kulah et al., 2008) Kirbas G, Kim SW, Bi X, Lim J, Grace JR. Radial Distribution of Local Concentration Weighted Particle Velocities in High Density Circulating Fluidized Beds. Paper presented at: The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering; May 13-17, 2007; Vancouver, Canada. Kulah G, Song X, Bi HT, Lim CJ, Grace JR. A NOVEL SYSTEM FOR MEASURING SOLIDS DISPERSION IN CIRCULATING FLUIDIZED BEDS. Paper presented at: 9th International Conference on Circulating Fluidized Beds; May, 13 16, 2008; Hamburg, Germany. 16

17 Particle Type Ni Cu Fe Type of Data Particle Type Lab Scale NiO/ MgAl 2 O 4 CFB 120 kw NiO/ MgAl 2 O 4 Lab Scale CFB 10kW Lab Scale kg/s or 14,000 36,000 ton/hour CFB 300W Moving Bed -H 2 25 kw CuO/ Fe 2 O 3 / Fe 2 O 3 / Al 2 O 3 CuO/Al 2 O 3 MgAl 2 O 4 Al 2 O 3 Composite Fe 2 O 3 Air Flow MWth and 10% Excess (mol/s) Volumetric Air Flow Rate at 1 atm and 900 ºC (m 3 /s) Particle Circulation 1000 MWth (kg/s) Reducer Solids Inventory (tonne) total Oxidizer Solids Inventory (tonne) n/a Total Medium Particle Size (μm) Particle Density (g/cm 3 ) Ut (m/s) Uc (m/s) Use (m/s) Typical Riser Superficial Gas Velocity (m/s) Bed Area Turbulent Section (if Required) at 1 atm (m 2 ) Bed Area Required for Riser Section at 1 atm (m 2 ) Corresponding Riser Diameter (m) Solids Flux at 1 atm (kg/m 2 s) Number of Beds Needed given 8 m ID Riser 3.23 <1 Number of Beds Needed given 1.5 m ID Riser Ug for a Single 1.5 m ID Riser at 1 atm (m/s) Ug for a Single 8 m ID riser at 1 atm (m/s) (Ug < Ut; N/A) Required Pressure for a Single 1.5m ID Riser (atm) Solids Flux for a Single 1.5 m ID Riser (kg/m 2 s) Required Pressure for a Single 8 m ID Riser (atm) 3.23 < 3,000 ton/hour Solids Flux for a Single 8 m ID Riser (kg/m 2 s) Ug < Ut; N/A

18 Oxygen Carrier Selection Primary Metal Fe Ni Cu Mn Co Potential Supports Al 2 O 3, TiO 2, MgO, Bentonite, SiO 2, etc Cost + ~ Oxygen Capacity 1 (wt %) Thermodynamics for CLC + ~ Kinetics/Reactivity Melting Points + ~ + + Strength + ~ ~ ~ Environmental& Health ~ ~ Hydrogen Production + 1. Maximum theoretical oxygen carrying capacity; 2. Reactivity with CH 4 ; 3. Mn 3 O 4 is the highest oxidation state based on thermodynamics, although not thermodynamically favorable, Mn is assumed to be the lowest oxidation state

19 Recyclability of Commercial Fe2O3

20 Force (N) Performance of Composite Fe 2 O Cycle Pellet Reactivity Cycle Pellet Strength Fresh 10 Cycles 100 Cycles 20

21 Pellet Reaction Mechanism Ionic Diffusion for Unsupported Iron 21

22 Pellet Reaction Mechanism Ionic Diffusion for Supported Iron Partially oxidized Fe with support Pt mapping Pt Epoxy Resin Pellet bulk phase Pt 22

23 Structures of Iron Oxide FeO Fe 3 O 4 NaCl Type oxygen close-packed cubic pattern iron occupy all octahedral interstices inverse Spinel Type octahedral interstices 1/2 occupation rate tetrahedral interstices 1/8 occupation rate

24 Role of Support Oxidation of Fe and Fe/TiO 2 Simulation Oxygen anion transfer in Wüstite and Ilemnite Energy barrier for O 2- can be reduced after support addition

25 Comparisons with other HT sorbents Wt % CO 2 capture (g-co 2 / g-sorbent) PCC a LC a Li 4 SiO 4 b PbO c CaO (microns) d dolomite e Theoretical capacity Number of cycles ( a current work; b Toshiba Corpn., c Kato et al, 1999; d Barker, 1973; e Harrison et al, 2001, d Barker, 1974)

26 Atomic Investigation of CO 2 Adsorption on CaO Front View Side View (100) Simulation: Vienna Ab-Initio Simulation Package (VASP) Surface structure: semi-infinite model (110) Adsorption energy of CO 2 molecules on various CaO surfaces Surface (100) (110) (111) (111) Adsorption energy (ev) :O :Ca : C Relaxed adsorption images of CO 2 molecule on CaO surfaces extremely stable configuration may prohibit a further transformation of the intermediate (CaO CO 2 ) into the calcium carbonate

27 Microscopic The main peak breadth (FWHM) of the sorbents before/after hydration 800 C 900 C 1000 C 1100 C 1200 C 1300 C Before After The intensity of the first three planes on the CaO surface of various sorbents before and after hydration 800 C 900 C 1000 C 1100 C 1200 C 1300 C XRD spectra of the sintered sorbents (a) sintered (b) hydrated Before hydration After hydration fraction of (111) and (100) increase! (110) decrease! (111) (200) (220) (111) (200) (220)

28 OSU CCR Process CARBONATOR CALCINER BOILER HYDRATOR

29 % Capture capacity Hydrated sample capture capacity 60 OSU CCR Process y = x R² = before hydration (Calcined) After hydration Cycle number

30 CCR Process Demonstration

31 Calcium Looping Sub-pilot Unit for Hydrogen production

32 Comparison Among Gaseous Chemical Looping, Direct Coal Chemical Looping and Traditional Coal to Hydrogen/Electricity Processes Assumptions used are similar to those adopted by the USDOE baseline studies.

33 My Graduate Students and Research Associates Ted Thomas Himanshu Gupta Puneet Gupta Alissa Park Mahesh Iyer Luis Velazquez-Vargas Bartev Boghos Sakadjian Danny Wong Fanxing Li Shwetha Ramkumar Liang Zeng FuChen Yu Deepak Sridhar Ray Kim Fei Wang Zhenchao Sun S. Rao William Wang Songgeng Li Andrew Tong Nihar Phalak Siwei Luo Yao Wang Niranjani Deshpande 33

34 Government Agencies and Industrial Corporations U. S. Department of Energy Ohio Coal Development Office U. S. Department of Defense Clear Skies Noblis/Metritek CONSOL Energy PSRI AEP Duke Energy Babcock & Wilcox Air Products Shell CRI/Criterion First Energy Carmeuse Lime and Stone LittleFord Day Southern Company 34