Advanced Natural Gas Fuel Tank Project - EERE

Advanced Natural Gas Fuel Tank Project 

California Energy Commission Contract #500-08-022 

Peter Pfeifer 

University of Missouri, Columbia 

Natural Gas Vehicle Technology Forum 

San Francisco 

October 25, 2011 

© The University of Missouri

• Project Objectives: 

– Adsorbed Natural Gas (ANG) Tank 

– Storage capacity 200 V/V at 500 psi 

– Conformable, lightweight 

• Earlier Work 

Presentation Outline 

• Technical Accomplishments: Storage Capacity 

• Technical Accomplishments: Tank Hardware 

• Market Projections 

© The University of Missouri 

2

Project Overview I 


3

Project Overview II 


4

Timeline 

• Project start date: 

May 28, 2009, nominally 

January 1, 2011, effectively 

• Project end date: 

December 31, 2012 

• Percent complete: 40% 

Subcontractors 

DBHORNE, LLC, Atlanta 

MRIGlobal, Kansas City 

Buckley Engineering, LLC, Kansas City 

Budget 

CEC: $1,000,000 

SoCalGas: $310,068 

U. Missouri (MU): $307,584 

Project Overview III 

Project Personnel, U. Missouri, Alliance for 

Collaborative Research in Alternative Fuel 

Technology (ALL-CRAFT, http://allcraft.missouri.edu): 

Physics: P. Pfeifer, C. Wexler, J. Romanos, 

N. Chada, E. Dohnke, T. Rash, Y. Soo 

Chemical Engineering: G. Suppes, A. Tekeei 

Mechanical Engineering: Y. Lin, H. Xu 

Office of Technology Management & Industry 

Relations: B. Maland 

Project Advisory Committee: 

Christian Bach – EMPA, Zurich 

Michael Eaves – Clean Energy, CA 

Doug Horne – DBHORNE LLC, GA 

Diane Lewis – The Lewis Chemical Co., GA 

Henry Mak – Southern California Gas Co., CA 

Steven Ragan – Jacobi Carbon Co., LA 

Tom Sewell – Tulsa Gas Technologies, OK 

Mike Veenstra – Ford, Dearborn, MI 


5

Project Overview IV 

Project Objectives: 

• Develop low-pressure storage technology for NG, based on high-performance 

adsorbent materials discovered at MU (1st generation carbons): carbon made from waste 

corncob, “sponge for NG” 

• Adsorbed Natural Gas (ANG) Tank 

• Storage capacity 200 V/V at 500 psi 

• Low pressure (500 psi) � conformable, lightweight tank; reduced fueling costs 

Tasks: 

• Develop 2nd generation carbon adsorbents, with target capacity of 200 V/V 

• Design/build “Advanced Flat-Panel Tank Assembly” 

– Assembly = computer-controlled test bed in laboratory (not on vehicle), filled 

with best monolithic carbon, operating at ambient temperature 

– Specs: capacity for light-duty NGV with 300-mile driving range @ 30 miles/gge; 

operation over full range of fuel delivery parameters of current light-duty NGVs 

– Offer to tank/automobile manufacturers for testing and demonstration 

• Evaluate performance of, and market, flat-panel tank assembly 

Q1: Is high volumetric or high gravimetric capacity more attractive? Different carbons for 

two targets! 

Q2: Can we reach LNG density? In nanopores, yes! 

• Develop cost estimates for flat-panel ANG tank for passenger cars, 

and ANG tanks for fueling stations 


6

Why ANG? 

� Current light-duty NGVs: NG stored as 

compressed natural gas (CNG) in steel or 

composite cylinders. 

� Barrier (consumer acceptance): 

• Heavy, non-conformable tanks due to high 

pressure (3600 psi) 

• Loss of passenger or trunk space 

• Limited driving range 

ANG seeks to offer alternative, consumerattractive 

technology for storage and 

transport of NG 

Low pressure (500 psi) enables thin tank 

walls and conformable tank geometry 

CNG tank: Honda Civic GX 

CNG tank in trunk 


7

Earlier Work 


8

Atlanta Gas Light Adsorbent Research 

Group (AGLARG), 1997: 

AGLARG Project 

Adsorbent: monolithic activated carbon 

(briquettes) from peach pit; 

included extensive demonstration project 

© AGLARG 1997 

© AGLARG 1997 

4 tanks in bed of 

NG Dodge Dakota 


9

NREL: “Missouri 

Hockey Puck” 

Monolith has surface 

area that could cover 

much of MU campus 

ALL-CRAFT ANG Tank 2007 

U. Missouri (ALL-CRAFT): 

• Carbon monoliths from 

corncob; NSF Project 

PFI-0438469, 2004-07 

http://www.nsf.gov/news 

/news_summ.jsp?cntn_i 

d=108390&org=NSF&fr 

om=news 

• Tank field-tested in 

Kansas City, 2007-09 


10

Performance of AGLARG and ALL-CRAFT tank 

• Target pressure for flat tank: 35 bar (35 atm, 500 psig *); without adsorbent, 

pressure would have to be 150 bar, much more than what a flat tank can bear 

• ANG, DOE target: 118 g/liter (vol. CH 4 at 25 o C & 1 bar, per vol. of tank: 180 V/V) 

• CNG at 25 o C & 250 bar (3600 psig): 190 g/liter 

• LNG at –161 o C &1 bar: 423 g/liter 

• DOE target 

achieved! 

*) 500 psi: 

pressure in NG 

pipelines 

DOE target; best ALL-CRAFT carbon 

AGLARG capacity 

Adsorbent Filled Tank (ANG) 

Empty Tank (CNG) 

11 

© ALL-CRAFT 2007 


11

ANG Projects 

Y. Ginzburg, Proceedings of the 23 rd World Gas Conference, Amsterdam, 2006: 

PROJECT AGLARG 

(Atlanta 

Gas Light 

Adsorbent 

Research 

Group) 

EU FP5 

LEVINGS 

program 

(FIAT) 

OAK 

RIDGE 

NATIONAL 

LAB. 

(ORNL) 

HONDA 

MOTORS 

UNIVERSITY OF 

PETROLEUM 

CHINA (UPC) 

Brazilian 

Gas 

Technology 

Center 

(CTGÁS) 

ALL-CRAFT (U. Missouri) 

Years 1990-1999 1997-2000 ? -2000 From 2000 1994-95 From 2000 Current (since 2007) 

Investigation 

method 

Chrysler 

B-van, 

Dodge 

Dakota 

Truck 

FIAT Marea, 

On-board, 

field testing 

Laboratory 

Investigations 

Tank 

development 

Adsorbent 

laboratory 

tests 

Car XIALI 

713IU 

On-board, field 

testing 

Laboratory 

investigation 

on full-size 

prototype 

Laboratory investigation , Adsorbent 

optimization , field testing. 

Pressure (bar) 35-40 35-40 35 35 50 125 35-40 35 250 

Tank uptake 

V/V 

Tank delivery 

V/V 

to engine 

Adsorbent 

price 

Vessel (tank) 

design 

features 

150 in 

laboratory 

condition 

123 150 155 100 

110 

170 

180 

130-150 Intragran. cap.: 

202V/V 

Monolith. cap.: 

161 V/V 

142 107 - - - - - - - 

Prohibitive High, but 

about 10 

times less 

than 

AGLARG 

Multicell 

of 

extruded 

aluminum 

Multicell of 

steel tubes 

Supposedly 

very high 

Small 

laboratory 

vessel of 

volume 

0,05 L. 

Supposedly 

similar to 

AGLAG 

- - TBD 

Multicell - Cylindrical 

form with 

volume 30 

liters 

Intragran. cap.: 

337 V/V 

Monolith. cap.: 

TBD 

Cylindrical tank (2007) 

Flat tank (2012) 

3 rd generation ANG tank (201x) 


12

Technical Accomplishments 

Storage Capacity 

© The University of Missouri 13

Corncob 

MU Carbons 

H3PO4 activation KOH activation 

High-surface- 

Binder Monolith 

Char 

(briquette, 

area carbon pellet) 

� Abundant and inexpensive raw 

material: corncob 

� Large scale production is 

economic and feasible 

� No special handling under inert 

atmosphere is needed 


14

MU Carbons: Nanospace Engineering 

Width: 2 nm Width: 1 nm Width: 0.75 nm 

In narrow, sub-nm pores, van der Waals potentials overlap; create deep potential wells and high 

storage density 

Activation 

mechanism 

Oxidation of carbon with KOH/H 2O 

produces CO and CO 2 

• Intercalation of metallic potassium into 

the graphitic lattice 

• Expansion of the lattice by 

intercalated potassium 

• Rapid removal of intercalate from the 

carbon sheet 

High specific surface areas (up to 3,000 m 2 /g), porosities, 

sub-nm (

Best Performers to Date 

4.0K-790C 

Best gravimetric storage 

capacity, at 35 bar 

• At 35 bar and 22 °C, ANG volumetric storage 

capacity is 5 times higher than CNG 

• Even at 250 bar and 22 °C, ANG volumetric 

storage capacity is 20% better than CNG. 

• Additional improvement from carbon 

densification (see below) 

4.0K-790C 

Amount delivered 

22 o C 2.5K-700C 

Best volumetric storage 

capacity, at 35 bar 

x 5 


16

Carbon densification: powders, pellets, and briquettes 

Controllable carbon density 

� At constant excess adsorption, volumetric storage capacity increases, and gravimetric 

storage capacity decreases, with increasing carbon density (decreasing porosity) 

� Densification can increase volumetric storage capacity by a factor of two 


17

Manual methane test 

fixture 

Adsorption Measurements in Laboratory 

Methane detector 

Dosing volume 

Vacuum gauge indicator 

Test tank (inside glove box) 

Oxygen and moisture indicator 

Automated methane test fixture, 2011 

Methane test fixture (Sievert apparatus) 

� Large samples: (~30 to 500g: Briquettes) 

� Temperature: 297 K 

� Pressure: 0-300 bar 


18

Technical Accomplishments 

Tank Hardware 


19

ALL-CRAFT ANG Tank 2012 (under construction) 

Next generation ANG tank: 

- Optimal design for low pressure NG 

storage 

- Flexibility to investigate higher 

pressure and lower temperature 

storage 

- Several 40-liter (internal volume) tanks 

will be fabricated 

- Thermal management 


20

ALL-CRAFT ANG Tank 2012: Finite-Element Analysis 

Optimal design: almost all the stress on chambers and end 

caps in range 40-300 MPa 


21

ALL-CRAFT ANG Tank 2012: Filled with Carbon 

Tank cross section 

Carbon pellets 

Carbon powder 

40-liter flat-panel tank 

4 of these: 250 mi driving range 

0.405 m 

0.171 m 


22

Market Projections 


ANG vs. CNG: Tank Volume and Mass I 

Carbon with best volumetric storage capacity (0.70 g/cm 3 , 200 V/V): 

Outside volume: ANG tank ≈ CNG tank; mass 20% lower 

ANG 500 

Driving Range = 200 miles @ 30 mpg 

NG Capacity = 6.7 GGE 

Aluminum Tank (16,000 psi allowable stress) 

Volume Occupied by Tank = 37 gal 

Inside Volume of Tank = 34 gal 

Mass of Tank + Carbon = 250 lbs 

Carbon Steel Tank (30,000 psi allowable stress) 




CNG 3,600 






Mass of Tank = 320 lbs 






ANG vs. CNG: Tank Volume and Mass II 

Carbon with best gravimetric storage capacity (0.34 g/cm 3 , 148 V/V) 

Outside volume: ANG 30% larger than CNG; mass 30% lower 

ANG 500 











CNG 3,600 












ANG vs. CNG vs. Gasoline: Fuel Costs 

Significance of minimal fueling investment when compared to gasoline 

$3.50 

$3.00 

$2.50 

$2.00 

$1.50 

$1.00 

$0.50 

$ 

Cost Comparison for 1 GGE 

ANG CNG Gasoline 

• Compression costs at refueling stations drop 

• Home refueling costs drop because home compressor will be 

cheaper and filling is faster 

Station Cost 

Vehicle Cost 

Fuel Cost 


Early Market Applications 

Hub and Spoke Fleets Forklifts 

• Large Market 

– Forklifts are a multi-Billion dollar market 

– 200,000 forklifts manufactured each year 

– Toshiba, Kawasaki Heavy Industries, Nissan 

Motor 

• Good Fit for ANG 

– No need to deliver gasoline. Instead, just tap 

into NG line and add a moderate compressor 

– Weight of tank is not an issue (it’s a benefit!!!) 

– CNG is NOT a good fit here 


Conclusions: 

Conclusions I 

Current best performer for volumetric storage capacity (light-duty vehicles): 132 g CH 4/liter 

carbon (2.5K-700C) at 35 bar and 22 o C (200 V/V, 110% of DOE target of 118 g/liter). Is 

500% of CNG at 35 bar and 22 o C. 

Current best performer for gravimetric storage capacity (heavy-duty vehicles): 256 g CH 4/kg 

carbon (4.0K-790C) at 35 bar and 22 o C. Volumetric storage capacity at 250 bar and 22 o C 

is 20% higher than CNG. 

Total tank volume & mass, best volumetric performer (6.7 GGE): 37 gal, 250 lbs 

Total tank volume & mass, best gravimetric performer (6.7 GGE): 50 gal, 230 lbs 

Total tank volume & mass, CNG (6.7 GGE): 38 gal, 320 lbs 

Thermodynamic analysis of CH 4 excess isotherms at 22 o C gives film thickness (~0.4 nm), 

saturated film density (320-440 g/l), comparable to LNG. 

Briquetting can increase volumetric storage capacity by factor of 2 if surface area remains 

constant. 


Natural gas vehicles over time 

First NG vehicle 1910 (USA) with balloon 

tank on trailer 

Current NG vehicle with highpressure 

tank in trunk 

Conclusions II 

Low-pressure, flat-panel 

ANG tank 

NG 

vehicle 

~1930 

(France) 

with 

balloon 

tank on 

roof 

Future NG vehicle with lowpressure 

tank in unused space

Advanced Natural Gas Fuel Tank Project - EERE

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?