Advanced Gas Shift Membrane Reactor (DE-FC26-05NT42453)

T. H. Vanderspurt1, S. C. Emerson1, Z. Dardas1, S. Opalka1, R. Radhakrishnan1, S. Seiser1, S. Tulyani1, H. Wen1, & R. Willigan1, W. Huang2,T. B. Flanagan3, D. Wang3

16 May 2006

1) United Technologies Research Center, East Hartford, CT 2) QuesTek Innovations, Evanston, IL 3) Metal Hydride Technologies Inc., Burlington, VT

This presentation does not contain any proprietary, confidential, or otherwise restricted information Project ID: PD 17 Overview

Timeline Barriers ƒ Start – July 2005 ƒ Hydrogen, Fuel Cells and Infrastructure ƒ End – June 2007 Technologies Program Multi-Year ƒ 95% Complete Research, Development and Demonstration Plan Budget ƒ Section 3.1.4.2.3: Separations and Other Cross-Cutting ƒ Total Project Funding Barriers (DOE Office of Energy Efficiency ƒ DOE share - $849k and Renewable Energy) ƒ Contractor share - $212k ƒ M. Impurities ƒ Funding Received in FY06 ƒ Hydrogen from Coal – Research, ƒ $205k Development, and Demonstration Plan ƒ Funding for FY07 ƒ Section 5.1.5 Technical Barriers – Central ƒ $340k Production Pathway (DOE Office of Fossil Energy) ƒ D. Impurity Intolerance/Catalyst Durability ƒ I. Poisoning of Catalytic Surfaces ƒ Q. Impurities in Hydrogen from Coal Partners ƒ QuesTek Innovations LLC ƒ Metal Hydride Technologies

2 Objectives

ƒ Identify through Atomistic and Thermodynamic modeling a suitable Pd-Cu tri-metallic alloy membrane with high stability and commercially relevant hydrogen permeation in the presence of and trace amounts of sulfur.

ƒ Identify and synthesize a Water Gas Shift (WGS) catalyst with a high operating life that is sulfur and chlorine tolerant at low concentrations (0.004 atm at 42 atm total pressure) of these impurities.

3 Concept

Separation mechanism

H2 2H

H2, CO, CO2, H2O, N2 WGS catalyst Water Gas Shift Catalyst Pd-Cu alloy (Modeling & Experimental)

Coal Gas CO2, H2O, etc. > 99.99% H2

Pd Membrane Alloy (Modeling)

ƒ Process intensification by removing equilibrium limitations on water gas shift

(WGS) reaction & producing >99.99% pure H2 ƒ Atomistic and thermodynamic modeling of sulfur tolerant Pd-Cu tri-metallic alloys ƒ WGS catalyst with a high operating life that is sulfur and chlorine tolerant

4 UTRC Catalyst Discovery Approach

Atomistic catalyst design, synthesis, characterization, reaction studies & kinetic analysis Conceptual Catalyst Design Catalyst Synthesis Quantum Mechanical Atomistic Modeling for advanced catalyst design ⇔ ⇔ ⇔

High active surface area Nanocrystalline structure ~100% NM dispersion

Characterization Kinetic Expressions Derived Superior Performance 0.32 1.4%Pt/Ce Zr Mo O 1.5CO, 33H O, 13.9CO , 30.3H From Reaction Data 0.30 0.665 0.285 0.05 2 2 2 2 1.8%Pt/Ce0.6Zr0.4O2 UT02D 1.5CO, 33H2O, 13.9CO2, 30.3H2 0.28 0.26 Catalyst B 0.24 0.22 0.20 + 0.18 = 0.16 0.14 0.12 Rate, (Moles CO/Sec)/Moles Pt Catalyst A 0.10 0.08 0.06 0.04 4000 3000 2000 1000 210 220 230 240 250 260 270 280 Temperature, C Wavenumbers (cm-1) 5 High Permeability Alloy Design

Seek to maximize H permeability: permeability = diffusivity x PdCu B2 ordered bcc 303 K

fcc+H2

Predicted lattice dynamics for p a B2+H r 2 (PA) a diffusivity & thermodynamics -e ½ q u il P ib r iu B2+fcc+fcc m B2+fcc+H2 fcc+fcc

H/(Pd+Cu) Pd-Cu-H Section T= 303 K P=105 Pa

Assessment, and validation Modeling of phase of thermodynamic model behavior and properties against literature data PdCu bcc H diffusion activation barriers Thermodynamic H solubility lower than those in fcc PdCu. Design measurements more stable ternary bcc PdCuTM phase. 6 Accomplishments

7 Pd0.44Cu0.56 B2 Alloy H Solubility Measurements Dilute H solubility regime Partial molar quantities measured from Δ pressure from van’t Hoff plot using Sievert’s apparatus at fixed concentrations

ΔH°=3.54 kJ/mol H ΔS°=- 60.8 J/K mol H

o ∆SH =∆SH +R ln (r /(β-r)) where β = 6 interstitial sites

H solubility is small and endothermic: solubility increases with temperature, contrary to H behavior in other Pd alloys. Thus, increased solubility at a fixed diffusivity yields higher permeability.

8 Thermodynamic Modeling: H Solubility in PdCu B2

B2 + fcc + H2 Ks= 1/slope 673 K = Δ[H/(Cu+Pd)]/ΔP0.5

B2 + H2

B2 Pd0.47Cu0.53

1bar 10bar 43.8bar 100C B2 150C 200C 250C B2 B2 + 300C + fcc + B2 + fcc 350C fcc H2

Pd-Cu boundaries independent of P. ModeledBilateral H narrowing solubility ofin the B2 H solubility ↑ & B2 range shifts to PdPd-Cu0.47Cu B20.53 phaseB2 phase boundaries increases with temperature. lower Cu compositions with ↑ PH2 . with increasing temperature. Thermodynamic modeling delineates boundaries for max. H

solubility in high diffusivity Pd0.47Cu0.53 B2 phase. 9 Comparison FP Predictions & Experiment 400 °C 100 °C 25 °C 10-6 Predicted 10-7 Pd0.5Cu0.5 (bcc) -8 Völkl (1978) -1 10

.s Pd0.47Cu0.53 (bcc) 2 10-9 10-10 10-11 Piper (1966) Völkl (1978) Pd Cu (bcc) Pd Cu (fcc) 0.475 0.0.525 10-12 0.47 0.53 Quantum-correctedQuantum-corrected diffusion diffusion equation equation (Jiang, (Jiang, 2004): 2004): -13 10 n 2 kTB Da=−exp ⎣⎡ ()Δ+ Hact Δ ZPEkT/ B ⎦⎤ -14 6 h Diffusion Coefficient / m 10 [ΔHact+ ΔZPEH ] = 0.07 eV, n=4 equivalent paths -15 [ΔHact+ ΔZPEH ] = 0.07 eV, n=4 equivalent paths 10 a=1.5a=1.5 Å Å jump jump length length 10-16 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 T-1 / K-1 Good experimental vs. predicted Diffusion Coefficient agreement.

10 Prediction of H Permeability in Pd0.47Cu0.53 400 °C 100 °C 25 °C 10-6 D JKPP=−κ ()ss0.5 0.5 Hs22l HH122 -0.5 10-7 .Pa QDK= κ -1 s .s -1

10-8 0.5 Ks= Sievert’s constant (1/ Pa ) κ = conversion factor (moles H/m3) for (1/ V) when [H//metal] =1, 10-9 with ΔV=1.77 x 10-24 m3 /mole H

Permeability / mol.m Permeability from Baranowski et al. (1971) D = diffusivity (m2/s) 10-10 0.001 0.002 0.003 0.004 T-1 / K-1 Bulk H permeability (Q) predicted from our experiments, & thermodynamic assessments in agreement with Ma et al. (2003).

11 Pd-Cu-Transition Metal Ternary Assessments

PdCuTM (TM= transition metal) ternary assessments with TM= G5 and J6, showing poor solubility of J6. PdCuG5 PdCuJ6

Fcc+B2+J6 G5

Fcc+B2+NbPd2 J6 B2+fcc+W Fcc+B2+G5Pd2

Fcc+B2+G5Pd Fcc+B2+NbPd22 Fcc+B2+J6B2+fcc+W

B2+G5PdB2+NbPd22 B2+J6B2+W Fcc+B2 B2B2 B2+fcc fc c+W B2+fcc B2B2 Fcc+B2 Fcc+J6

G5 shows maximum solubility of 1.5 atomic % in PdCu B2 phase.

12 Predicted H Solubility for Selected Ternary Alloy

B2 + fcc + G5Pd + H 2 2 673 K

B2 + G5Pd2 + H2

100C G5 B2 + H2 150C 200C B2 Pd0.47Cu0.52G50.01 250C 1 bar 10 bar 43.8 bar 300C 350C B2+ fcc B2 +fcc +H2

B2+fcc+G5Pd G5 2 B2+fcc+G5Pd2+H2 1% G5 addition widens B2 region Predicted H solubility in the while maintaining H solubility. Pd0.47Cu0.52G50.01 B2 phase.

Pd0.47Cu0.52G50.01 ternary alloy less susceptible to phase separation with thermal cycling and compositional fluctuations.

13 Diffusivity and Permeability of Selected Alloy

Comparison at AWGSMR Conditions: 400 °C and 43.8 bar.

H Predicted Typical Predicted Composition solubility, Diffusivity, experimental Permeability, Q Ks D Permeability, Q Pa0.5 m2.s-1 mol.s-1.m-1.Pa-0.5 mol.s-1.m-1.Pa-0.5

-5 -9 -8 Pd0.47Cu0.52G50.01 1.17×10 9.69×10 1.11×10

-5 -8 -8 Pd0.47Cu0.52 (bcc) 1.25×10 6.30×10 7.89×10

-9 Pd0.77Cu0.23 (fcc) ≈ 4×10

Selected alloy is predicted to have at least twice the permeability of the best candidate fcc phase, with thermal and chemical stability.

14 Sulfur Resistance of Ternary Alloy

Pd Cu G5 H S

Optimal

H2S binding configurations predicted at ground state

H2S on Pd8Cu7G5 (110) H2S on Pd8Cu8 (110) • G5 ternary element preferentially substitutes for subsurface Cu.

•H2S binding is ≈10 kJ/mole weaker on the Pd8Cu7G5 B2 (110) surface compared to binding on PdCu B2 (110) surface. Ternary alloy predicted to have the sulfur resistance comparable to fcc PdCu alloys with the higher permeability of bcc PdCu alloys.

15 Results: Lower Sulfur Binding Energy Predicted Low CO Binding Energy Preferred For 42 atm, high CO partial press. Coal Gas

CO, eV H2O, eV H2S, eV

TiO2 - Anatase -0.32 -0.64 -1.93 TiO2 - Rutile -0.09 -1.16 -0.90

Ti0.96J60.04O2 -0.34 -0.72 -2.09

Ce0.5Zr0.4J60.1O2 -0.63 -0.74 -2.14

Ce0.5Zr0.4E40.1O2 -0.97 -1.01 -2.43

Ce0.33Zr0.33E40.33O2 -0.01 -0.83 -0.29

Pt O J6 Ti S H CO, eV H2S, eV H2S/Pt/J6-Doped TiO2 Anatase(101) Pt / TiO2 - Anatase -1.67 -2.37 Binding Energy: -2.02 eV/H2S Pt / Ti0.96J60.04O2 -0.97 -2.02

Pt / Ce0.5Zr0.4J60.1O2 -1.74 -3.66

Pt / Ce0.33Zr0.33E40.33O2 -0.32 -1.84 The electronic structure of doped oxides modifies that of Pt

monolayer thus lowering CO, H2S binding energies to Pt.

16 Catalyst Test Results Consistent with Modeling

RATE DATA AT 400 C - Normalized to 2% Pt 3.1%Pt-1.6%Re / Ce Zr E4 O 1.4 80 h 0.36 0.33 0.31 2 100 h + Sulfur 100 120 h (post shutdown) 1 atm 1.2 90 140-180 h (~5 atm) 1 atm repeat 80 1.0 21 atm -1 42 atm 70 0.8 60 50

0.6

TOR in s TOR in 40 0.4 30

Conversion / % 20 0.2 10 0.0 0 ABCDE Catalyst Sample 220 240 260 280 300 320 340 360 380 400 420 Temperature / C % Pt % Re 7.2% CO, 7.8% CO2, 6% H2, 39.2% H2O

A Pt/Re-Ce0.36Zr0.33E40.31O2 3.1 1.6

B Pt/Re-Ce0.52Zr0.39E40.09O2 2.3 1.2 ƒ High Pressure, high CO operation very challenging C Pt/Re-Ce0.36Zr0.22E40.42O2 3.4 1.7 D Pt/Re-Ce E6 J6 O 0.69 0.25 0.05 2 2.8 1.4 ƒ Remaining effort focused

E Pt/Re-Ti0.9J60.1O2 3.6 1.8 on Sulfur durability run.

17 Future Work

ƒ (Apr-Jun ’07) Complete evaluation and durability tests of final set of catalysts and deliver final report.

18 Advanced Membrane Reactor Water Gas Shift Summary

Relevance Lower cost high purity H2 production from precleaned coal gas: Eliminates need for: 1) complete sulfur scrubbing, 2) separate H2 extraction/purification train and retentate gas is >90% CO2 on a dry basis.

Approach ƒ Atomistic and thermodynamic modeling to design high stability BCC Pd-Cu based trimetallic alloy with commercial relevant permeance. ƒ Design synthesize and test catalyst tailored to needs of advanced membrane reactor

Accomplishments

ƒ Two “stabilized” BCC alloys Pd0.5Cu(0.5-x)G5x and Pd0.5Cu(0.5-x)J6x investigated. ƒ Permeance, stability, and composition of Pd0.5Cu(0.5-x)G5x predicted ƒ WGS catalyst family potentially resistant to H2S identified

Issues ƒ Completing 1500-h durability run at high pressure

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