Slide 1

DOE EERE

Fluid Phase H2 Storage Material Development

Tessui Nakagawa, Biswajit Paik, Benjamin Davis, Troy Semelsberger, Tom Baker, Larry Sneddon

2012 Annual Merit Review, May 17th

Los Alamos National Laboratory

LA-UR 12-20427

This presentation does not contain any proprietary or confidential information

Project ID # ST040

Slide 2

DOE EERE

Timeline • Project Start Date: Oct 1st 2010 • Project End Date: 2014 • Percent Complete: 45%

Budget • Total Project Funding:

•DOE share: $ 330 •Contractor share: $ 0

•Funding received in FY11: 400k •Funding for FY12: 330k

Barriers •Barriers Addressed

•Weight/Volume •Efficiency •Durability/Operability •Discharging Rates •H2 purity

Partners •LANL (lead) •University of Ottawa •UPenn (consulting)

Overview

Slide 3

DOE EERE

NH

HH

B

H

H Hδ+ δ−

NH

HH

B

H

H Hδ+ δ−

Ammonia Borane

H2

Relevance and Overall Objectives

Relevance

Materials with excellent H2 storage capacity and efficient regeneration are required for transportation, stationary, and portable power applications. 2017 system target = 5.5 wt. %; ultimate 7.5 wt. %

Objectives

Develop ammonia-borane (~15 wt. % usable H2)/ionic liquid mixtures that have sufficient H2 capacity, release kinetics, stability, and fluid phase properties. Work with Hydrogen Storage Engineering Center of Excellence (HSECoE) to ensure compatibility with system designs.

Slide 4

DOE EERE

Approach #1 Technical Limitation: Ammonia borane mixtures can form insoluble products after extensive H2 release Our Method: Implement strategies to prevent or forestall phase change, define usable temperatures/times to guide HSECoE 2012 Goals: 1) Development solubility quantification method and screen ILs 2) Design additives which prevent solid formation

Reactant NH

H H

BH

H H

NH

HR

BH

H H

B NB

NBN NH

BNHHBNB

HNB

NB

NHBNHB

n

NHBH

NHBN

BNHB

NHB

R

R

NHBH

RHB N

BNB

N NBH

NHBNHB

R

R

RHB N

R

R

+ H2

Product

Solubility screening and additives will be used to address phase change

Prevent extensive polymer formation Impart solubility

Slide 5

DOE EERE

Approach #2

Knowledge Gap: Many ionic liquids, many AB fuel blend possibilities. Our Method: survey fuel blends to meet DOE targets for hydrogen release rates, capacity, stability, and H2 purity while maintaining fluid phase 2012 Goals: 1) Use solubility measurements -> Maximize capacity 2) Continue short/long term stability -> ensure minimal H2 loss 2) Develop impurity quantification method and use -> provide HSECoE with guiding data

1. 2. 3.

Selection Criteria

Slide 6

DOE EERE

Additive Development

Approach #1 Accomplishments

Slide 7

DOE EERE

• CHSCoE originally explored alkylamine boranes to solubilize AB

• In 2011 UPENN evaluated amine additives and substituted borazines to maintain fluid phase

AB/IL + 5% dipentylamine solid (2.2 eq. H2 released) AB/IL + 5% trimethylborazine solid (2.3 eq. H2 released)

85

C

85

C

Additive Development Previous Approach

Slide 8

DOE EERE

Additive amine-boranes have 3-4 wt. % usable H2 and maintain fluid phase

Analogous syntheses by Framery, E.; Vaultier, M. Heteroatom Chem, 2000, 11, 218-225.

Liquid Liquid

Picture @ Room Temperature Hexyl is Liquid = 0 C Hexyl is Solid = -40 C

Accomplishments 2012: New Additives Synthesized

US Provisional Patent Application Number 61/615650

Picture @ Room Temperature

Me2S BH3+-20 C

THF

99%

R NH2 RH2N BH3

R = hexyl, methoxypropyl

130 C, 12 h

closed vessel99%

HB

NBH

N

BHN

RR

R

Slide 9

DOE EERE

140

C

20 wt. %AB in hexylAB (6.0 wt. % H2) transforms from a slurry to liquid upon dehydrogenation

Additives Can Impart Favorable Fluid Properties

Accomplishments 2012: Additives/AB Mixtures Yield Fluid Products

US Provisional Patent Application Number 61/615650

Picture @ Room Temperature

Slide 10

DOE EERE

0

0.002

0.004

0.006

0.008

0.01

0.012

1 2

Accomplishments 2012: H2 Release Before Phase Change in AB/IL/additive Mixtures

Temp 90°C

More H2/g of fuel is released in AB/IL/additive mixtures before phase change

AB/IL/Additive (23 wt. % AB) MethoxypropylAB additive

Control (no additive)

H2 (

mol

es)/M

ass o

f Fue

l (g)

Slide 11

DOE EERE

Ammonia Borane Ionic Liquid Survey

Approach #2 Accomplishments

Slide 12

DOE EERE

Accomplishments 2012: Ammonia Borane/Polyborazylene Solubility Measurements

0 2 4 6 80.00E+000

1.00E+010

2.00E+010

3.00E+010

Y=4.8790E9x+1.3477E9Peak

are

a (c

ount

s)

Concentration (M)

Baseline correctionEquation y = a + b*

Weight No WeigResidual Sum of Squares

1.88711E18

Adj. R-Sq 0.99714Value Standard

bc Intercept 1.3477 4.38825E

bc Slope 4.2790 8.65757E

Polyborazylene (PB) solubility properties depend on the route

of formation

NMR solubility quant method completed, initial selection of ionic liquids assessed

11B NMR quantification method only ‘sees’ dissolved species

AB

Wt.%

Dis

solv

ed

uOttawa will provide a PB from metal catalyzed

decomposition of AB for us to test

05

101520253035

0.7 0.3 0.4

17 17 20

24 20

32

AB PB

Slide 13

DOE EERE

Ionic Liquid As Received

(ppm)

Dried (ppm)

EmimEtOSO3

1600 80

DmimDmp

4000 250

EmimAcetate

1500 100

BmimCl

10,000 320

BmimOTf 450 < 30

Drying Methods Implemented, Solubility of AB Improves

Due to ionic nature, some ILs will absorb several wt. % H2O if exposed to atmosphere

Accomplishments 2012: Water Impurities can alter AB solubility

AB

Wt.%

Dis

solv

ed

010203040

17 20 23.5 19 32

27 32 31 23.5

31

4.4

Wet/As Received ILs Dried ILs

Slide 14

DOE EERE

AB solubility measured in binary ILs, improves in some cases

Accomplishments 2012: Ammonia Borane Solubility in Binary Ionic Liquids

0

5

10

15

20

25

30

20 23.5

19 17

29.5 29.5 28.5

26 28.6

22.5

1:1 Binary w/ EmimEtOSO3 (as received)

Individual (as received)

1:1 Binary w/ EmimEtOSO3 (dried)

AB

Wt.%

Dis

solv

ed

Slide 15

DOE EERE

Stability improves with dry IL; More accurate, longer term studies initiated

0 2 4 6 80.0

0.1

0.2

0.0

3.3

6.7

Con

sum

ed (%

of t

otal

H2 i

n AB

)

IoLiLyte-wet (0.16 H2/AB) IoLiLyte-dry (0.10) 30AB70EmimCl (0.02) 50AB50EmimCl (0.02) 30AB70BmimCl (0.04) 50AB50BmimCl (0.04) 10AB90Tetraglyme (0.03)

Yiel

d (m

ol H

2/AB)

Time (days)

Accomplishments 2012: Stability Measurements Continued

Burette Measurements

More sensitive Parr reactor Measurements initiated

Slide 16

DOE EERE

Accomplishments 2012: Quantification Methods Developed, Validated, Initial Results

Quant Method Completed, Initial Results to Guide HSECoE

Evolved Gas Analysis Equipment

0

10

20

30

40

50

60

70

80

90

100

% o

f Mas

s Lo

st

Unaccounted

Hydrogen

Ammonia

Borazine

Diborane

Slide 17

DOE EERE

Collaborations

External Collaborators Effort Contact H2 Codes and Standards General Guidance C. Padro (LANL)

University of Ottawa Additive Development T. Baker

University of Pennsylvania AB/IL Formulations Larry Sneddon

Chemical Hydrogen System Architect System Designs Troy Semelsberger (LANL)

SSAWG Technical Collaboration G. Ordaz (DOE) H2 Storage Tech Team General Guidance Ned Stetson (DOE) Argonne National Laboratory Independent Analyses R. Ahluwalia Applied Energy Office General Guidance Kevin Ott (LANL)

Slide 18

DOE EERE

Synthesize, design, and test new additives FY12 Measure AB/IL/additive liquid range FY12, FY13 Synthesize/evaluate new additives Continue solubility assessments and AB stability in new ionic liquids FY12 Solubility tests with new classes of ionic liquids FY12 Test uOttawa PB/real spent fuel solubility FY12 Initiate long term stability measurements FY12 Milestone: complete solubility survey Continue AB/IL impurity evaluation FY12, FY13 Identify trends and tailor to HSECoE needs Interface with HSECoE FY12, FY13 Upscale candidate materials for HSECoE component validation

Proposed Future Work

NR CH3

N RR

R

R

P RR

R

R

Slide 19

DOE EERE

Additive Development

•New additives synthesized •AB/additive slurries remain fluid after prolonged heating

Solubility Measurements

•Method Development Complete •Water impurities identified, measured, and removed •Effect of water on solubility observed •Binary solubilities measured

Impurity Quantification

•Method development complete •Measurements on AB and AB/IL •HSECoE guidance

Summary

Optimizing AB fuel blends for HSECoE use

Slide 20

DOE EERE

Technical Back-Up Slides

Slide 21

DOE EERE

Ionic Liquid Abbreviation

EmimEtOSO3 (Iolilyte)

DmimDmp

EmimAcetate

BmimCl

TbmpMs

BmimOTf

EmimDep

Ionic Liquid Nomenclature

Cyphos IL 101

Slide 22

DOE EERE

Previously examined ILs CHSCoE

CHSCoE IL

bmimCl

bmmimCl

bmimI

bmimBF4

bmimPF6

mmimMeSO4

emmimEtSO4

bmimOTf

emmimOTf

pmmimTf3C

Limitations: -> only imidazolium cations

-> only 1:1 ratio compositions -> ILs were dried no H2O quant

Slide 23

DOE EERE

NMR was calibrated for boron loading using BF3-etherate standards When applied to a different boron species of known concentration, an excellent

approximation of boron concentration was calculated

0 2 4 6 80.00E+000

1.00E+010

2.00E+010

3.00E+010

Y=4.8790E9x+1.3477E9Peak

are

a (c

ount

s)

Concentration (M)

Baseline correctionEquation y = a + b*

Weight No WeigResidual Sum of Squares

1.88711E18

Adj. R-Sq 0.99714Value Standard

bc Intercept 1.3477 4.38825E

bc Slope 4.2790 8.65757E

NMR Quantification Methodology

Slide 24

DOE EERE

Full List of AB/IL Combinations Examined