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Srceo3-Based Protonic Conductors for Hydrogen Production and Separation by Water Gas Shift, Steam Reforming, and Carbon ...

Permanent Link: http://ufdc.ufl.edu/UFE0024942/00001

Material Information

Title: Srceo3-Based Protonic Conductors for Hydrogen Production and Separation by Water Gas Shift, Steam Reforming, and Carbon Dioxide Reforming Reactions
Physical Description: 1 online resource (170 p.)
Language: english
Creator: Li, Jianlin
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2009

Subjects

Subjects / Keywords: co2, hydrogen, membrane, permeation, production, protonic, reactor, reforming, separation, srceo3, srm, wgs
Materials Science and Engineering -- Dissertations, Academic -- UF
Genre: Materials Science and Engineering thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Hydrogen has been considered as an ideal energy carrier for a clean and sustainable energy future. New ceramic membranes have potential to reduce the syngas (a mixture of hydrogen and carbon monoxide) cost by 30-50% and incorporate hydrogen production and separation into one unit. SrCe_(1-x-y)Zr_(y)Eu_(x)O_(3-delta) has been investigated to maximize hydrogen production and enhance stability. 10 at% europium was used to fabricate tubular micro-cracking free membranes. 20 at% zirconium was used to enhance the stability of SrCe_(0.9)Eu_(0.1)O_(3-delta). Supported SrCe_(0.7)Zr_(0.2)Eu_(0.1)O_(3-delta) thin film membranes on NiO-SrCe_(0.8)Zr_(0.2)O_(3-delta) substrates were developed. Hydrogen permeation flux through these membranes was proportional to the transmembrane Hydrogen partial pressure gradient with a 1/4 dependence and controlled by bulk diffusion. A maximum Hydrogen permeation of 0.23 and 0.21 cm^3/cm^2 min was obtained for the 33 mu m thick SrCe_(0.7)Zr_(0.2)Eu_(0.1)O_(3-delta) membrane at 900 oC with 100% H2 and 97% H2/3% H_2O as the feed gases, respectively. Hydrogen permeation was stable under wet H_2, and conditions of WGS reaction, steam reforming of methane (SRM), and carbon dioxide reforming of methane (CDRM). Thermodynamic equilibrium calculations were carried out for WGS reaction and SRM. Hydrogen production and separation through WGS reaction, SRM and CDRM with SrCe_(0.7)Zr_(0.2)Eu_(0.1)O_(3-delta) membranes were investigated. In situ removal of hydrogen through hydrogen membranes moves the reaction toward the products side resulting in higher conversion and hydrogen yield. 77% and 44% increase in the CO conversion for the WGS reaction was achieved compared to the thermodynamic calculation data under 900 oC with H_2O/CO = 1/1 and 2/1, respectively. 73% and 42% enhancement in the hydrogen production was achieved simultaneously. For the SRM, the hydrogen membrane increased both the CH_4 conversion and total hydrogen production by 15% at 900 ^oC compared to the conventional reactor with only Ni catalyst. Whereas the H_2/CO in the syngas product from the SRM is too high to produce liquid fuels through the Fischer-Tropsch process, it is too low from the CDRM. However, an appropriate value can be obtained by combining the SRM and CDRM. The H_2/CO between 700 oC to 900 ^oC, for instance, is between 1.9-1.7 and 2.5-2.0 for CH_4/CO_2/H_2O = 2/1/1 and 2/1/1.5, respectively.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Jianlin Li.
Thesis: Thesis (Ph.D.)--University of Florida, 2009.
Local: Adviser: Wachsman, Eric D.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2010-02-28

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2009
System ID: UFE0024942:00001

Permanent Link: http://ufdc.ufl.edu/UFE0024942/00001

Material Information

Title: Srceo3-Based Protonic Conductors for Hydrogen Production and Separation by Water Gas Shift, Steam Reforming, and Carbon Dioxide Reforming Reactions
Physical Description: 1 online resource (170 p.)
Language: english
Creator: Li, Jianlin
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2009

Subjects

Subjects / Keywords: co2, hydrogen, membrane, permeation, production, protonic, reactor, reforming, separation, srceo3, srm, wgs
Materials Science and Engineering -- Dissertations, Academic -- UF
Genre: Materials Science and Engineering thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Hydrogen has been considered as an ideal energy carrier for a clean and sustainable energy future. New ceramic membranes have potential to reduce the syngas (a mixture of hydrogen and carbon monoxide) cost by 30-50% and incorporate hydrogen production and separation into one unit. SrCe_(1-x-y)Zr_(y)Eu_(x)O_(3-delta) has been investigated to maximize hydrogen production and enhance stability. 10 at% europium was used to fabricate tubular micro-cracking free membranes. 20 at% zirconium was used to enhance the stability of SrCe_(0.9)Eu_(0.1)O_(3-delta). Supported SrCe_(0.7)Zr_(0.2)Eu_(0.1)O_(3-delta) thin film membranes on NiO-SrCe_(0.8)Zr_(0.2)O_(3-delta) substrates were developed. Hydrogen permeation flux through these membranes was proportional to the transmembrane Hydrogen partial pressure gradient with a 1/4 dependence and controlled by bulk diffusion. A maximum Hydrogen permeation of 0.23 and 0.21 cm^3/cm^2 min was obtained for the 33 mu m thick SrCe_(0.7)Zr_(0.2)Eu_(0.1)O_(3-delta) membrane at 900 oC with 100% H2 and 97% H2/3% H_2O as the feed gases, respectively. Hydrogen permeation was stable under wet H_2, and conditions of WGS reaction, steam reforming of methane (SRM), and carbon dioxide reforming of methane (CDRM). Thermodynamic equilibrium calculations were carried out for WGS reaction and SRM. Hydrogen production and separation through WGS reaction, SRM and CDRM with SrCe_(0.7)Zr_(0.2)Eu_(0.1)O_(3-delta) membranes were investigated. In situ removal of hydrogen through hydrogen membranes moves the reaction toward the products side resulting in higher conversion and hydrogen yield. 77% and 44% increase in the CO conversion for the WGS reaction was achieved compared to the thermodynamic calculation data under 900 oC with H_2O/CO = 1/1 and 2/1, respectively. 73% and 42% enhancement in the hydrogen production was achieved simultaneously. For the SRM, the hydrogen membrane increased both the CH_4 conversion and total hydrogen production by 15% at 900 ^oC compared to the conventional reactor with only Ni catalyst. Whereas the H_2/CO in the syngas product from the SRM is too high to produce liquid fuels through the Fischer-Tropsch process, it is too low from the CDRM. However, an appropriate value can be obtained by combining the SRM and CDRM. The H_2/CO between 700 oC to 900 ^oC, for instance, is between 1.9-1.7 and 2.5-2.0 for CH_4/CO_2/H_2O = 2/1/1 and 2/1/1.5, respectively.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Jianlin Li.
Thesis: Thesis (Ph.D.)--University of Florida, 2009.
Local: Adviser: Wachsman, Eric D.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2010-02-28

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2009
System ID: UFE0024942:00001


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PAGE 9

in situ

PAGE 10

in situ

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In situ

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in situ

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xx

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Fabrication of supported tubular thin film membranes: Sr Ce0.9Eu0.1O3membrane reactors for H2 production through WGS reaction: Stability improvement of SrCe0.9Eu0.1O3:

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H2 permeation properties of the SrCe0.7Zr0.2Eu0.1O3thin film membrane s: SrCe0.7Zr0.2Eu0.1O3based H2 transport WGS reactor : SrCe0.7Zr0.2Eu0.1O3membrane reactors for H2 production through SRM :

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SrCe0.7Zr0.2Eu0.1O3membrane reactor for H2 production through CDRM:

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2.1 Hydrogen Production Technologies 2.1.1 Thermochemical Processes Steam methane reforming (SMR) : kJmol Ho kJmol Ho Partial oxidation:

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kJmol Ho Coal gasification: Other thermal processes: 2.1.2 Electrolytic Processes Electrolysis: 2.1.3 Photolytic Processes Photolytic methods:

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2.2 Hydrogen Separation Membranes

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2.3 Proton Conducting Materials

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2.4 Structure of SrCeO3

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2.5 Proton Transport in SrCeO3 OH NH OOH O O OOH OVOH OV X OO OOH OOH

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CeeCe

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2.6 Hydrogen Permeation dx d Fz dx d FzFz RT CD Jk k k k k k k k Kk k dx d ez dx d ez eJ zIik k k k kk k i i i idx d ez t dx d OH ettt

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i i i i k k k k kdx d z t z dx d ez j OeO e O Oddd eHH e H Hddd dx d t dx d tt d t jH H O He O tot O O O O OP RT O OPd RT d O O H HP P P P H OH tot O e HO totPdtt F RT Pdttt F RT L O O H HP P P P H eOH tot O OH totPdttt F RT Pdtt F RT L 2.7 Hydrogen Membrane System Design

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-6 -5 -4 -3 -2 -1 0 0.5 1 1.5 2 2.5Log ( S/cm)1000/T (K-1)BaZrO3BaCeO3SrTiO3SrCeO3CaZrO3SrZrO3PH2O=30 hPa

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20304050607080Intensity (a.u.)(0 1 1) (2 1 1) (1 2 1) (3 1 1) (0 2 2) (1 2 2) (0 3 7) (4 0 2) (2 3 1) (3 1 3) (4 2 2) (1 1 6) (0 4 4) (4 0 4)2 (o)

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3.1 Introduction

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3.2 Fabrication of Supported Thin Film Membranes 3.2 .1 Materials Synthesis 3.2.2 NiO -SCZ82 Slurry for Support

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3.2.3 SrCe0.7Zr0.2Eu0.1O3Thin Film Membranes on NiO SCZ82 Support

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2030405060 70802 (o)Intensity (a.u.)(4 2 2) (0 3 7) (0 2 2) (2 1 1) (4 0 2) (0 1 1) (1 1 6) (4 0 4) (1 2 2) (2 3 1) (0 4 4)SCZ82 SCZE721(1 2 1) (3 1 1) (3 1 3)

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0 5 1031 1041.5 1042 1042.5 1040 0.10.20.30.40.50.6Viscosity (cP)Shear Rate (s-1)

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4.1 Introduction oH

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in situ 4.2 Experimental

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4.3 Results and Discussion 4.3.1 Thermodynamic Calculation

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4.3.2 Experimental Conversion in situ

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in situ in situ in situ

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in CO out COF F out COF in COF in situ

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4.3.3 H2 Production in situ in situ in CO out HF F out HF in COF in situ

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4.4 Conclusions

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0 0.1 0.2 0.3 0.4 0.5 550600650700750 800 850900950Mole FractionTemperature (oC) CO2H2H2O CO CH4C 0 0.1 0.2 0.3 0.4 0.5 550600 650 700750800850900950Mole FractionTemperature (oC) H2O CO2CO CH4C H2

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0 0.1 0.2 0.3 0.4 0.5 550600 650 700 750 800850900950 CO2H2CO H2OMole FractionTemperature (oC) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 550600 650 700 750 800850900950 CO2H2CO H2OMole FractionTemperature (oC)

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0 0.1 0.2 0.3 0.4 0.5 550600 650 700 750 800850900950 CO2H2CO H2OMole FractionTemperature (oC) 0 0.1 0.2 0.3 0.4 0.5 550600 650 700 750 800850900950 CO2H2CO H2OMole FractionTemperature (oC)

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0 0.1 0.2 0.3 0.4 0.5 550600 650 700 750 800850900950 CO2H2CO H2OMole FractionTemperature (oC) in situ

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0 20 40 60 80 100 550600 650 700 750800 850 900 950XCO (%)Temperature (oC) in situ

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0 0.1 0.2 0.3 0.4 0.5 0.6 550 600650700750 800850900950 0 0.01 0.02 0.03 0.04 0.05H2 Production (cm3/min)Temperature (oC)H2 Flux (cc/cm2min) in situ in situ

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0 20 40 60 80 100 550 600 650700750 800 850900 950 0 2 4 6 8 10Temperature (oC)H2 yield (%)H2/COpermeated H2H2 in reactor side effluent total H2 yield reactor side effluent H2/CO ratio in situ

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5.1 Introduction

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5.2 Experimental

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5.3 Results and Discussion 5.3.1 Stability u nder W et CO Conditions

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OB OArr rr t Ar Br Or

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5.3.2 Decomposition Mechanism

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CeO SrCO CO SrCeO 5.3.3 Hydrogen Permeability

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5.4 Conclusions

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0 5 10 15 20Lattice Parameters (A)a c b Zr (at%) Lattice Parameter (A)6.15 6.10 6.05 5.95 6.00 5.90 8.65 8.60 8.55 8.50 8.40 8.45

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02468 10 12H2 Production (cm3/min)Time (hrs)SrCe0.9Eu0.1O3 (1.8 %/hr) SrCe0.7Zr0.2Eu0.1O3 (2.4*10-3 %/hr) 0.25 0.20 0.15 0.10 0.05

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6.1 Introduction 6.2 Experimental 6.2.1 Membrane Fabrication

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6.2.2 Membrane Morphology 6.2.3 Membrane Permeation 6.3 Result and Discussion 6.3.1 Heat Treatment

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6.3.2 Flow Rate Effect on H2 Permeation 6.3.3 H2 Permeation as a Function of Thickness

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H H OO O O OO OP P H eV OH t P P O V OH t OHPdttt F RT Pd tt F RT L J 6.3.4 Effect of Temperature, H2 and H2O Partial Pressure in the Feed Side on H2 Permeation f HPP HP P H f H OHPP L JO

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6.3.5 Activation Energy

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6.3.6 Long Term Stability 6.4 Conclusions

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10 15 20 25 30 35 5 10 15202530 354045Flow Rate (cm3/min)JH2 (cm3/cm2min) Percentage (%)0.05 0.15 0.10 0.20 0.30 0.25

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0.010.02 0.030.04 0.050.06JH2 (cm3/cm2 min)1/Thickness ( m-1)24.3% H248.5% H272.8% H297.0% H20.40 0.35 0.30 0.25 0.20 0.15 0.10

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0.15 0.2 0.25 0.3 0.350.40.450.50.55 0 0.04 0.08 0.12 0.16 0.2 0.24J H2 (cm3/min)PH2f 1/4-PH2p 1/4 (atm1/4)J H2 (cm3/cm2 min)900 oC 850 oC 800 oC 750 oC 700 oC0.20 3.0 2.0 1.0 1.5 0.5 0 2.5 0.2 0.3 0.40.50.6 0 0.04 0.08 0.12 0.16 0.2 0.24J H2 (cm3/min)PH2f 1/4-PH2p 1/4 (atm1/4)J H2 (cm3/cm2 min)900 oC 850 oC 800 oC 750 oC 700 oC0.20 3.0 2.5 2.0 1.5 1.0 0.5 0

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650700750800 850900950 dry H2 3% H2O+H2 10% H2O+H2 30% H2O+H20 0.04 0.08 0.12 0.16 0.2 0.24J H2 (cm3/min)Temperature (oC)J H2 (cm3/cm2 min)0.20 3.0 2.5 2.0 1.5 1.0 0.5 0

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7 .1 Introduction 7.2 Experimental

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7.3 Results and Discussion 7.3.1 Heat Treatment of the Membranes 7.3.2 H2O/CO Effect on CO Conversion

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in situ in situ 7.3.3 H2O/CO Effect on H2 Production

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7.3.4 H2O/CO Effect on H2 Production and H2/CO

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7.3.5 Flow Rate Effect on WGS Reaction 7.3.6 CO Concentration Effect on WGS Reaction

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7.3.7 Long Term Stability 7.4 Conclusions

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0 0.1 0.2 0.3 0.4 0.5 650 700 750 800 850 900950Mole FractionCO2H2CO H2O CH4Temperature (oC)CO2H2CO H2O CH4H2O/CO=1/1 650700750800850900950 0 0.1 0.2 0.3 0.4 0.5 CO2H2H2O CO CH4Temperature (oC)H2O/CO=1.5/1Mole Fraction

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0 0.1 0.2 0.3 0.4 0.5 650 700 750 800 850 900950Mole FractionCO2H2CO H2O CH4Temperature (oC)CO2H2CO H2O CH4H2O/CO=2/1

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40 50 60 70 80 90 100 650700 750800850900 950XCO (%)Temperature (oC)2/1 1.5/1 1/1 H2O/CO Thermodynamic data (2/1) Thermodynamic data (1/1)

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0 2 4 6 8 10 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 650700 750800850900950H2 Production (cm3/min)H2 permeation thermodynamic H2 production H2 total production H2 flow in reactor side effluentTemperature (oC)H2 Flux (cm3/cm2 min) 0 2 4 6 8 10 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 650700750800850900950H2 Production (cm3/min)Temperature (oC)H2 Flux (cm3/cm2 min)H2 ptotal roduction H2 flow in reactor side effluent H2 permeation

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0 2 4 6 8 10 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 650700 750800850900950H2 Production (cm3/min)H2 permeation thermodynamic H2 production H2 total production H2 flow in reactor side effluentTemperature (oC)H2 Flux (cm3/cm2 min)

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0 20 40 60 80 100 0 0.8 1.6 2.4 3.2 4 4.8 5.6 6.4 650700750800 850900950H2 yield (%)Temperature (oC)total H2 yield H2 in feed side effluent H2/CO ratio in feed side effluent permeated H2thermodynamic H2/CO ratio thermodynamic H2 yieldH2/CO4.0 0 20 40 60 80 100 650700 750 800 850 900 950 0 2 4 6 8 10Temperature (oC)H2 yield (%)H2/COpermeated H2H2 in reactor side effluent H2 total yield H2/CO ratio in reactor side effluent

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0 20 40 60 80 100 0 5 10 15 650700750800850900950H2 yield (%)Temperature (oC)H2 total yield H2 in reactor side effluent H2/CO ratio in reactor side effluent permeated H2thermodynamic H2/CO ratio thermodynamic H2 yieldH2/CO

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0 5 10 15 20 0 2 4 6 8 10 80 85 90 95 100 1020 304050 6070H2 Production (cm3/min)Total Flow Rate (cm3/min) permeated H2H2/CO in reactor side effluent H2 in reactor side effluent total H2CO conversionH2/CO XCO (%)

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0 5 10 15 20 0 2 4 6 8 10 80 85 90 95 100 5 1015 20253035H2 Production (cm3/min)XCO (%) CO Concentration (%)H2/COpermeated H2H2/CO in reactor side effluent total H2H2 in reactor side effluent CO conversionSolid symbol--900 oC Hollow symbol--850 oC

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8.1 Introduction HCOCHOH oH HCOCOOH oH HCOCHOH oH

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8.2 Experimental

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in CH out CH in CH CHF FF X out CO out CO out CO COFF F S out CO out CO out CO COFF F S in CH out HF F yield H out CO out HFFCOH iX iS in iF out iF 8.3 Results and Discussion 8.3.1 Thermodynamic Calculation Results

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K RT G HCOOHCH JTTT Go HCOOHCO JT Go HCCH JTTT Go OHOH JT Go

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8.3.2 Experimental Results 8.3.2.1 Influence of CH4/H2O on the SRM cm Fin CH cm Fin Ar

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8.3.2.2 Influence of CH4 c oncentration on the SRM

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8.3.2.3 Influence o f total flow rate on the SRM 8.3.2.4 Influence of the H2 membrane reactor on the SRM cm Fin CH cm Fin OH in situ

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in situ 8.3.2.5 Long term stability cm Fin CH cm Fin OH 8 .4 Conclusions

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0 20 40 60 80 100 300400 500600 700800 90010001100XCH4 (%)Temperature (oC)CH4/H2O 1/3 1/1 1/2 0 20 40 60 80 100 300400 500600 700800 90010001100XCH4 (%)Temperature (oC)CH4/H2O/Ar 1/3/4 1/1/4 1/2/41/2/4

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0 20 40 60 80 100 300400 500600 700800 90010001100XCH4 (%)Temperature (oC)CH4/H2O/Ar 1/2/9 1/2/4 1/2/3 1/2/1 1/2/0 CH4 & H2O Concentration increasing

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70 75 80 85 90 95 100 650700750800 850900950XCH4 (%)Temperature (oC)1/1/4 1/2/4 1/2/4 1/3/4 1/3/4 1/1/4 CH4/H2O/Ar Experimental Thermodynamic calculation

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10 20 30 40 50 60 70 80 90 2.5 3 3.5 4 4.5 5 5.5 6 650700750800850 900950SCO & SCO2 (%)H2/COTemperature (oC) 1/1/4 1/1/4 1/2/4 1/2/4 1/2/4 1/3/4 1/3/4 1/3/4 1/1/4 CH4/H2O/Ar 6.0 5.0 4.0 3.0

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650700750 800850900950H2 Production (cm3/min)1/1/4 1/1/4 1/1/4 1/2/4 1/2/4 1/2/4 1/3/4 1/3/4 1/3/4 CH4/H2O/ArTemperature (oC)12 11 10 9 8 2 1 0.20 0.16 0.18 0.14 0.12 0.10 0.08 0.06H2 Permeation (cm3/cm2 min)

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65 70 75 80 85 90 95 3.2 3.4 3.6 3.8 4 4.2 4.4 5 10 1520253035XCH4 & SCO (%)H2/COCH4 Concentration (%)XCH4 SCO4.0 H2/CO Solid symbol-900 oC Hollow symbol-850 oC 0 10 20 30 40 50 60 5 101520 2530 35 0 0.8 1.6 2.4 3.2 4 4.8H2 Production (cm3/min)CH4 Concentration (%)Solid symbol-900 oC Hollow symbol-850 oC H2 Permeation Total H2H2 in reactor side effluentH2 Permeation (cm3/cm2 min)4.0

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70 75 80 85 90 95 0 10 20 30 40 50 60 203040506070XCH4 & SCO (%)H2 Production (cm3/cm2 min)Total Flow Rate (cm3/min)XCH4SCOH2 permeation H2 in reactor side effluent Total H2 CH4/H2O=1/2 & 900 oC 65 70 75 80 85 90 0 10 20 30 40 50 60 203040506070XCH4 & SCO (%)H2 Production (cm3/cm2 min)Total Flow Rate (cm3/min)XCH4SCOH2 permeation H2 in reactor side effluent Total H2 CH4/H2O=1/2 & 850 oC

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60 65 70 75 80 85 90 0 10 20 30 40 50 60 203040506070XCH4 & SCO (%)H2 Production (cm3/cm2 min)Total Flow Rate (cm3/min)XCH4SCOH2 permeation H2 in reactor side effluent Total H2 CH4/H2O=1/2 & 800 oC 60 65 70 75 80 85 0 10 20 30 40 50 60 203040506070XCH4 & SCO (%)H2 Production (cm3/cm2 min)Total Flow Rate (cm3/min)XCH4SCOH2 permeation H2 in reactor side effluent Total H2 CH4/H2O=1/2 & 750 oC

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55 60 65 70 75 80 0 10 20 30 40 50 60 203040506070XCH4 & SCO (%)H2 Production (cm3/cm2 min)Total Flow Rate (cm3/min)XCH4SCOH2 permeation H2 in reactor side effluent Total H2 CH4/H2O=1/2 & 700 oC 20 304050 6070H2/COTotal Flow Rate (cm3/min)700 oC 750 oC 800 oC 850 oC 900 oC CH4/H2O=1/2 6.0 5.5 5.0 4.0 3.0 4.5 3.5

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0 20 40 60 80 100 4 4.5 5 5.5 650700750800850900 950XCH4 & SCO (%), H2 Production (cm3/min)H2/COXCH4XCH4Total H2 production Total H2 production SCOSCOXCH4H2/CO H2/CO 4.0Temperature (oC)Thermodynamic XCH4

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9.1 Introduction 9.1.1 Carbon Dioxide Reforming of Methane (CDRM) HCO COCH oH

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9.1.2 Membrane Reactors for the CDRM in situ

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9.1.3 Reaction Mechanism and Kinetics aHaCCH aOaCOgCO aCOaOaC gCOaCO gHaH HCH CH HCH CH HCH CH HCCH HxCOOCHx COOCO

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HCHCH OH COHCO OH CHOCH HCHCH HCHCH xH CCHx xH COOCHx xH COCOCHx HH OH OH CHCH COCO CHCOCHCO rPKPKPPKKKR

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9.2 Experimental in CH out CH in CH CHF FF X in CO out CO in CO COF FF X

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out CH in CH out H HFF F S out CO in CO out CH in CH out CO COFFFF F S out CO out HFFCOH iX iS in iF out iF 9.3 Results and D iscussion 9. 3.1 CH4/CO2 Effect on C onversion, H2/CO and H2 P roduction cm Fin CH HCCH oH CCOCO oH

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OHCOCOH oH

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9.3.2 Flow Rate Effect on C onversion, H2/CO and H2 P ro duction

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9. 3.3 CH4/CO2/H2O Effect on XCH4, XCO2, H2/CO and H2 P roduction in situ HCOCHOH oH cm Fin CH cm Fin CO

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9.4 Conclusions

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40 50 60 70 80 90 100 650700750800850900 950XCH 4 & XCO 2 (%)CH4/CO2Solid line-XCH4Dashed line-XCO 21/2 1/2 1/1.5 1/1.5 1/1 1/1Temperature (oC)

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92 93 94 95 96 97 98 99 100 650700750800850 900950SH2 & SCO(%)Temperature (oC)CH4/CO2 Solid line-SH2Dashed line-SCO1/2 1/1.5 1/1 1/2 1/1 1/1.5

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650700750800850 900950H2 production (cm3/min)Temperature (oC)CH4/CO2H2 permeation solid symboltotal H2 production hollow symbolH2 in reactor side effluent 1/2 1/2 1/2 1/1.5 1/1.5 1/1.5 1/1 1/1 1/1 18 14 15 16 17 11 12 13 10 3 2 1

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650700 750800850900 950H2/COTemperature (oC)1/1 1/2 1/1.5 CH4/CO21.00 0.95 0.90 0.85 0.80 0.75

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50 55 60 65 70 75 80 85 90 93 94 95 96 97 98 99 100 2025303540 455055XCH 4 & XCO 2(%)SH2 & SCO (%)Total flow rate (cm3/min)XCH4 900oC XCH4 850oC XCO 2 900oC XCO 2 850oC SH2 850 oC SH2 900 oC SCO 900 oC SCO 850 oC CH4/CO2=1/1.5

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0.82 0.83 0.84 0.85 0.86 0.87 0.88 202530354045 5055H2/COTotal flow rate (cm3/min)850 oC 900 oC CH4/CO2=1/1.5

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8 9 10 11 12 13 14 20 2530 354045 5055H2 production (cm3/min)H2p percentage of total H2 production (%)H2 permeation solid symbol--900oC hollow symbol--850oC H2 in feed side effluent CH4/CO2=1/1.5 H2 total productionTotal flow rate (cm3/min) H2p fraction 35.0 30.0 25.0 20.0 15.0 10.0 3.5 3.0 2.5 2.0 1.5

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10 20 30 40 50 60 70 80 90 650700750800850 900950XCH 4 & XCO 2 (%)Temperature (oC)XCH 4XCO 22/1/1.5 2/1/1 2/1/1 2/1/1.5 CH4/CO2/H2O

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2 3 4 5 6 7 8 30 35 40 45 50 650700750 800850900950H2 production (cm3/min)Temperature (oC)H2/COH2 permeation H2 total production H2 in feed side effluent H2/CO solid symbol--2/1/1 hollow symbol--2/1/1.5 CH4/CO2/H2O 2.6 1.5 2.0

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10.1 Conclusions

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10.2 Future Work

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30 28 submitted 167 156 Accepted 138 178 125 18 26 440 25 93 241 10

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12 86-88 125 3-4 57 62 138 150 150 149 164 152 159 125 40 125 154-155 33

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44 79 162-163 4 30 79 352 5 336 120 submitted 18-19 176 88 21 70-71 69 77 61 97 97

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8688 125 68 136-137 130 70-71 100 110 148 Accepted 48

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27 23 152 44 119 28 210 51 10 to be submitted submitted 9 30 47 51 177 61 140 97 143 42

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178 145 148 27 146 A32 94 158 submitted 46 149 submitted 29 109

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36 36 18 15 10 119 82 36 118-222 233 67 220 111 158

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22 30 10 48 10 255 274 272 31 33 28 89 15 16 33 33 144 279 358

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77 9 48 55 to be submitted 108 24 44 311 224 247 34 119