Helium Recovery from Rocket Test Systems - Hawaii Natural Energy ...

HAWAI‘I NATURAL ENERGY INSTITUTE
School of Ocean & Earth Science & Technology – University of Hawai‘i at Mānoa
Helium Recovery from Rocket Test Systems
Periods of Performance:
One Year (Phase I)
Two Years (Phase II)
Team Partner(s)
Sierra Lobo, Inc.
Project Funding:
National Aeronautic and Space
Administration (NASA) via
STTR to Sierra Lobo, Inc. for
Kennedy (KSC) and Stennis
Space Centers (SSC)
$30,000 (Phase I) KSC
$30,000 (Phase I) SSC
$200,000 (Phase II) SSC
Contact Information:
Michael Angelo
Research Associate, HNEI
808-593-1714
mangelo@hawaii.edu
Richard Rocheleau
Director, HNEI
808-956-8346
rochelea@hawaii.edu
Links:
HNEI
http://www.hnei.hawaii.edu
STTR - Small Business
Technology Transfer
http://www.sbir.gov/about/abou
t-sttr
Sierra Lobo, Inc.
http://www.sierralobo.com/pag
es/default.aspx
Related Projects:
Airborne Contaminants and
Fuel Cell Performance
Hydrogen for GM Equinox Fuel
Cell Electric Vehicles
Project Description and Goals
Through National Aeronautic and
Space Administration (NASA)
funding under a contract with Sierra
Lobo, Inc. the Hawai‘i Natural
Energy Institute (HNEI) is
investigating the feasibility of using a
proton exchange membrane fuel cell
system (PEMFCS) to separate
gaseous helium (GHe) from gaseous
hydrogen (GH2) to attain GHe purity
levels > 99.995 %. The overall goal
is to develop a separation system that
is more energetically efficient and
cost effective than commonly used
separation methods such as cryogenic
distillation.
Project Benefits
GHe is the only suitable gas for
purging GH2 boil-off from liquid
hydrogen (LH2) rocket fuel lines due
to its chemical inertness and low
boiling point, which enable it to
remain in the gas phase during the
purging process. However, helium is
a finite and scarce resource and
extremely large quantities are used at
rocket launching and testing facilities
worldwide. For example, according
to NASA, a single launch countdown
for the Space Shuttle required one
million standard cubic feet of GHe.
Using a PEMFCS will enable
separation of the GH2, which due to
its combustibility is considered a
contaminant in the purge gas, to
attain high purity GHe which will be
recaptured and reused, thereby
reducing NASA’s GHe usage.
http://www.hnei.hawaii.edu/ Phone: (808) 956-8890 – Fax: (808) 956-2336
1680 East-West Road, POST 109 – Honolulu, Hawai‘i 96822
An Equal Opportunity/Affirmative Action Institution
A PEMFCS is an attractive separation
technology compared to cryogenic
distillation because off-the-shelf
components can be used to make the
system comparatively low cost. The
electrochemical separation process is also
energetically more efficient and operating
temperatures are much closer to ambient
(e.g., 60 ºC). It is an environmentally clean
technology having no emissions in this
application other than GH2, which can
either be recaptured for reuse or burned in
air to form water vapor.
Status and Accomplishments
HNEI proposed operating a PEMFCS in an
electrolytic mode with a power supply to
drive the electrochemical reaction to
separate the GH2 and GHe stream. This
type of operation is illustrated in the figure
on the following page and is commonly
referred to as hydrogen pump operation.
This operating method was preferred over
normal “fuel cell” (galvanic cell) operation
because it eliminates cross contamination
of gaseous nitrogen present in air, which
would permeate across the membrane and
result in an additional purge gas
contaminant. GH2 and GHe are separated
by the electrochemical transport of
hydrogen across the proton exchange
membrane (PEM). As shown in the figure,
GH2 is oxidized at the anode to form
protons (H + ) which are subsequently
transported across the PEM. The protons
are reduced on the cathode to reform GH2
which then exits the cell via pressure
driven flow. The PEM acts as a separation
barrier between the gases.

HNEI has demonstrated in two Phase I Small Business
Technology Transfer (STTR) projects for Kennedy
Space Center (KSC) and Stennis Space Center (SSC)
that a laboratory-scale PEMFCS operated as a helium
pump is capable of obtaining GHe streams with less
than 50 parts per million (ppm) GH2 remaining from
inlet streams initially consisting of 1% GH2 (dry-gas
basis). Additional work currently in progress will
evaluate performance of a pilot-scale system that is 20
times larger than the previous system with inlet streams
of up to 10% GH2. Similar results have been obtained.
A differential-reactor-based model was developed
during the Phase I work to determine the mass transport
coefficient of GH2 in the PEMFCS operating at its
limiting current to approximate the flow conditions and
system size required to attain < 50 ppm GH2 with up to
10% GH2 at the inlet. The process was observed to be
well modeled as diffusion limited at steady state with
respect to the inlet GH2 concentration.
An example of the ability of the model to predict the
fraction of GH2 removed by the PEMFCS is given in
the adjacent figure for the laboratory-scale system.
Experimental data is represented by the squares and the
fraction of hydrogen predicted to be removed from the
model shown by the circles. The model fit well to the
experimental data. It also predicted the flow conditions
Hawai‘i Natural Energy Institute – Helium Recovery from Rocket Systems
for the pilot-scale system to more than 70 % of the
expected performance.
0.850
0.0 0.2 0.4 0.6 0.8 1.0
Future research activities include optimization of the
operating conditions for the pilot-scale system to
determine system durability at those conditions.
Reports and Publications
� M. Angelo, K. Bethune, and R. Rocheleau, “The
Sizing and Evaluation of a PEMFCS to Separate
Hydrogen and Helium,” In preparation for
submission to Chem. Eng. Sci.
� M. Angelo, K. Bethune, and R. Rocheleau,
“Calculating H2 Mass Transport Coefficients at
Different Operating Conditions using a Hydrogen
Pump Configuration.” to be presented at the 222 nd
Electrochemical Society, Honolulu, HI, USA, Oct. 7-
12 th , 2012.
� M. S. Angelo, M. S. Haberbusch, C. T. Nguyen, K. P.
Bethune, and R. E. Rocheleau, “The Use of Proton
Exchange Membrane Fuel Cell Technology to
Recover Gaseous Helium from Rocket Testing
Systems,” ECS Trans. 41 (1), 1943 (2011).
� Final Report entitled “Integration Study of an
Innovative Helium Recovery System for the NASA
Stennis Space Center,” (2011).
� Final Report entitled “Integration Study of an
Innovative Helium Recovery System for the NASA
Kennedy Space Center,” (2010).
REVISION DATE: 06/2012 HELIUM RECOVERY PROJECT
Fraction of hydrogen removed
1.050
1.025
1.000
0.975
0.950
0.925
0.900
0.875
1 % GH 2
R.H. = 100 %
Experimental data
Model prediction (1 %)
Fraction of Vol. flow used to determine
mass transport coefficients