U. Hegde and R. Balasubramaniam

National Center for Space Exploration Research, Glenn Research Center, Cleveland, Ohio

S.A. Gokoglu

Glenn Research Center, Cleveland, Ohio

Heating-Rate-Coupled Model for Hydrogen 

Reduction of JSC–1A 

NASA/TM—2010-216256

April 2010

AIAA–2010–1546
NASA STI Program . . . in Profi le

Since its founding, NASA has been dedicated to the 

advancement of aeronautics and space science. The 

NASA Scientifi c and Technical Information (STI) 

program plays a key part in helping NASA maintain 

this important role.

The NASA STI Program operates under the auspices 

of the Agency Chief Information Offi cer. It collects, 

organizes, provides for archiving, and disseminates 

NASA’s STI. The NASA STI program provides access 

to the NASA Aeronautics and Space Database and 

its public interface, the NASA Technical Reports 

Server, thus providing one of the largest collections 

of aeronautical and space science STI in the world. 

Results are published in both non-NASA channels 

and by NASA in the NASA STI Report Series, which 

includes the following report types:

• TECHNICAL PUBLICATION. Reports of 

completed research or a major signifi cant phase 

of research that present the results of NASA 

programs and include extensive data or theoretical 

analysis. Includes compilations of signifi cant 

scientifi c and technical data and information 

deemed to be of continuing reference value. 

NASA counterpart of peer-reviewed formal 

professional papers but has less stringent 

limitations on manuscript length and extent of 

graphic presentations.

• TECHNICAL MEMORANDUM. Scientifi c 

and technical fi ndings that are preliminary or 

of specialized interest, e.g., quick release 

reports, working papers, and bibliographies that 

contain minimal annotation. Does not contain 

extensive analysis.

• CONTRACTOR REPORT. Scientifi c and 

technical fi ndings by NASA-sponsored 

contractors and grantees.

• CONFERENCE PUBLICATION. Collected 

papers from scientifi c and technical 

conferences, symposia, seminars, or other 

meetings sponsored or cosponsored by NASA.

• SPECIAL PUBLICATION. Scientifi c, 

technical, or historical information from 

NASA programs, projects, and missions, often 

concerned with subjects having substantial 

public interest.

• TECHNICAL TRANSLATION. Englishlanguage translations of foreign scientifi c and 

technical material pertinent to NASA’s mission.

Specialized services also include creating custom 

thesauri, building customized databases, organizing 

and publishing research results.

For more information about the NASA STI 

program, see the following:

• Access the NASA STI program home page at 

http://www.sti.nasa.gov

• E-mail your question via the Internet to help@

sti.nasa.gov

• Fax your question to the NASA STI Help Desk 

at 443–757–5803

• Telephone the NASA STI Help Desk at

 443–757–5802

• Write to:

 NASA Center for AeroSpace Information (CASI)

 7115 Standard Drive

 Hanover, MD 21076–1320
U. Hegde and R. Balasubramaniam

National Center for Space Exploration Research, Glenn Research Center, Cleveland, Ohio

S.A. Gokoglu

Glenn Research Center, Cleveland, Ohio

Heating-Rate-Coupled Model for Hydrogen 

Reduction of JSC–1A 

NASA/TM—2010-216256

April 2010

AIAA–2010–1546

National Aeronautics and

Space Administration

Glenn Research Center

Cleveland, Ohio 44135

Prepared for the

48th Aerospace Sciences Meeting

sponsored by the American Institute of Aeronautics and Astronautics

Orlando, Florida, January 4–7, 2010
Acknowledgments

The authors gratefully acknowledge the support of this work by the In-Situ Resource Utilization Project which is a part of the 

NASA Exploration Technology Development Program. U. Hegde and R. Balasubramaniam were supported under NASA Contract 

No. NNC08BA08B with the National Center for Space Exploration Research. The authors greatly appreciate the encouragement 

and insights offered by K. Sacksteder and D. Linne of NASA Glenn Research Center, and useful discussions with E. SantiagoMaldonado of NASA Kennedy Space Center during the course of this work. The authors also thank L. Oryschyn and A. Paz of 

NASA Johnson Space Center who conducted the experiments and arranged for access to experimental data utilized for the model 

validation efforts.

Available from

NASA Center for Aerospace Information

7115 Standard Drive

Hanover, MD 21076–1320

National Technical Information Service

5301 Shawnee Road

Alexandria, VA 22312

Available electronically at http://gltrs.grc.nasa.gov

Level of Review: This material has been technically reviewed by technical management. 
NASA/TM—2010-216256 1

Heating-Rate-Coupled Model for Hydrogen Reduction of JSC–1A 

U. Hegde and R. Balasubramaniam 

National Center for Space Exploration Research 

Glenn Research Center 

Cleveland, Ohio 44135 

S.A. Gokoglu 

National Aeronautics and Space Administration 

Glenn Research Center 

Cleveland, Ohio 44135 

Abstract 

A previously developed and validated model for hydrogen reduction of JSC-1A for a constant 

reaction-bed temperature is extended to account for reaction during the bed heat-up period. A quasisteady approximation is used wherein an expression is derived for a single average temperature of 

reaction during the heat-up process by employing an Arrhenius expression for regolith conversion. 

Subsequently, the regolith conversion during the heat-up period is obtained by using this representative 

temperature. Accounting for the reaction during heat-up provides a better estimate of the reaction time 

needed at the desired regolith-bed operating temperature. Implications for the efficiency of the process, as 

measured by the energy required per unit mass of oxygen produced, are also indicated. 

Introduction 

A major objective of lunar in-situ resource utilization (ISRU) (Refs. 1 to 3)is production of oxygen 

from lunar regolith. Mare basalts containing oxygen include olivine, ilmenite, and pyroxene (Ref. 4). 

Energy has to be supplied to remove the oxygen, i.e., the associated chemical reactions are endothermic. 

Free energy considerations show that the iron containing minerals require the least energy input for this 

purpose (Ref. 5). Various technologies have been proposed for the chemical conversion. These include 

ilmenite reduction by hydrogen, molten electrolysis, and carbothermal reduction using methane (Refs. 6 

and 7). The reduction processes involve gas-solid reactions. Such systems are well developed for earth 

applications but mainly for the purpose of metal extraction, as opposed to water vapor and oxygen 

extraction for lunar applications. In addition, in the lunar context, the reactor must interface with the other 

sub-system processes such as upstream regolith extraction and beneficiation and downstream electrolysis 

and phase separation in a way that establishes the most favorable balance between efficiency, robustness, 

and equivalent system mass. A need exists, therefore, to establish an analytical framework to couple these 

sub-systems together. The building blocks of this framework are the individual sub-system models. The 

development of a generalized analytical model of the chemical reactor sub-system has been discussed in 

an earlier paper and the model has been validated against experimental data from reduction of JSC-1A, a 

lunar regolith simulant (Ref. 8). 

The model is formulated in terms of the following overall steps: (i) inflow of pure hydrogen into the 

regolith containing reactor, (ii) reaction of hydrogen with the iron oxide portion of the regolith, and (iii) 

outflow of left-over hydrogen and produced water vapor. Step (ii) is the gas-solid reaction step which is 

the key to the conversion. Results of regolith particulate analysis conducted on Apollo-returned samples 

(Ref. 6) suggest that the particles are not completely solid but have some porosity that would enable gases 

to diffuse into the particles, i.e., the iron oxide portion can be essentially completely converted with the 

reduced iron remaining behind in the particulates. It may also be noted that JSC-1A has significant glass 

content with iron oxide dispersed in the glass phase. The diffusion of gases in the glass phase is expected 

to be the controlling feature for the reduction process. These observations support utilization of a 
NASA/TM—2010-216256 2

“shrinking core” diffusion-reaction model (Ref. 9) for the gas-solid reduction process. This model is then 

coupled with the inflow/outflow of gases to complete the reactor sub-system model. 

Two key parameters appear in the model: (i) a diffusion time related to the diffusion of gases in the 

interior of the regolith particles, and (ii) a residence time of the gases in the reactor. It is found that for 

high levels of conversion or for a relatively small ratio of residence time to diffusion time, the governing 

parameter is the diffusion time. Validation of the model was conducted by comparison to experiments 

carried out at Pacific Northwest National Laboratory (PNNL) (Ref. 10) and at Lockheed Martin (Ref. 11). 

A factor F, which is related to the diffusion times for different particle sizes, is derived from the model 

formulation and is defined as follows: 

2

0

)1(

6 a pr

D

k

kc F

+ρ = (1) 

Using the PNNL data for JSC-1A in conjunction with the model, the factor F- is correlated to the 

temperature by an Arrhenius expression: 

8808.2 10761 )log( −−= TF (2) 

The above expression appears to work well in the temperature range of 873 to 1273 K, i.e., in between 

600 and 1000 °C. 

It may be noted that the model assumes a constant operating temperature during the reduction 

process. This implies that it considers a situation where the regolith is brought up to the desired operating 

temperature prior to initiating the hydrogen flow and the reduction process. In order to extend the 

applicability of the model, it is useful to incorporate reaction during the regolith heat-up stage as well. In 

fact, current configurations being tested by NASA envision hydrogen flow through the reactor and 

associated reduction during heat-up. If significant reduction takes place during the heat-up then it may be 

possible to increase the energy efficiency of the process, i.e., the amount of water (or oxygen) produced 

per unit energy input. 

In the next section, the methodology to incorporate reaction during heat-up is described. The Results 

and Discussion section first presents comparison of the model with experimental results provided by 

NASA Johnson Space Center (JSC). Then, the model is exercised to present the effects of heat-up time 

and operating temperature of the regolith bed on the water production. Finally, theoretical results on 

impact of reduction during heat-up on the energy efficiency of oxygen production in the reactor are 

described in the Results and Discussion section. 

Nomenclature 

c0 molar concentration of hydrogen at inlet to regolith bed (moles/m3) 

D effective intra-particle gas diffusion coefficient (m2

/s) 

k equilibrium constant 

L length of regolith bed (m) 

r regolith particle radial coordinate (m) 

rp regolith particle radius (m) 

t time (s) 

tD intra-particle diffusion time (s) 

tR reactor residence time (s) 

T temperature (K) 

Th heater temperature (K) 

Ti minimum temperature for reduction (K) 
NASA/TM—2010-216256 3

Tr final operating temperature (K) 

< T > average temperature during heat-up (K) 

u velocity through reactor (m/s) 

α particle conversion fraction 

ε void fraction in regolith bed 

ρa molar concentration of iron oxide in regolith (mol/m

3

) 

τ time constant for regolith-bed heat-up (s) 

Model Description 

The shrinking core formalism utilized in the model is schematically depicted in Figure 1. Conversion 

proceeds from the exterior particle surface inward. As the reaction progresses into the interior of the 

particle, the reactant and product gases must diffuse through the particle matrix structure formed after the 

conversion. 

The equation for the conversion fraction α (related to the fraction of iron oxide converted) at a given 

time, t, is given by (Ref. 8) 

⎥

⎥

⎦

⎤

⎢

⎢

⎣

⎡

α−−

α−

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛

ε−+

−=−α−−α−

u

L

r

D

Ft

p ])1(1[

]1[ )1(31

1]1[2]1[3

3/1

3/1

2

3/2 (3) 

where the factor F is given by Equation (1). For the case when the residence time, L/u, of the gases is 

small compared to the diffusion time, rp

2

/D, of gases in the particle matrix the equation for α becomes 

(Ref. 8) 

 1]1[2]1[3 −=−α−−α− Ft 3/2 (4) 

Figure 1.—Shrinking core model configuration. 

 Radius of reaction surface 

 Particle radius, rp

Unreacted core 
NASA/TM—2010-216256 4

As noted earlier, the model assumes a fixed operating temperature. In order to account for reaction 

during heat- up, it may be assumed that the conversion during the heat-up process is the summation of a 

sequence of quasi-steady reduction steps with increasing temperature. This is valid as long as the particle 

is assumed to be at a uniform temperature at each sequential step as far as the gas diffusion process is 

considered, i.e., the intra-particle thermal conductivity is much larger than the intra-particle gas 

diffusivity, D, which appears to be the case. Equation (4) indicates that during each of these sequential 

steps the rate of conversion, dα/dt, is proportional to the F corresponding to the sequential temperature. 

An average rate of conversion during the heat-up period may then be defined by using an appropriate 

average for F that may be utilized in Equation (4). 

Let the heat-up begin at time t =0. Experimentally, it has been found that there is no discernible 

reduction until the regolith (simulant) temperature reaches a certain value. For JSC-1A this temperature is 

in the range 873 to 923 K (i.e., 600 to 650 °C). Let, in general, this minimum temperature for reduction be 

denoted as Ti and the corresponding time for the regolith to reach this temperature be ti. The reduction 

period is then given by (t–ti). 

In previous work it was shown that, for a temperature Th of a coaxial heater, the time needed to raise 

the regolith bed from a temperature Ti to T is given by (Ref. 12) 

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛

−

− −=τ

ih

h

TT

TT

t log/ (5) 

where the time constant τ depends, among other quantities, on the mass and specific heat of the regolith. 

When the heater temperature is raised in steps between the initial and final temperatures, as is generally 

the case, the regolith- bed temperature rise is almost linear in time as shown in an example scenario in 

Figure 2 in non-dimensional form. 

Figure 2.—Heater temperature profile and corresponding calculated regolith bed temperature. 
NASA/TM—2010-216256 5

The discussion above indicates that the time-average value of F or log(F) may be obtained by simply 

averaging it over the temperature range Ti to Tr. The average for log(F) becomes 

8808.2 1

)(

10761 )log( − − −>=< ∫ dT

TTT

F

Tr

Ti ir

 (6) 

so that 

8808.2

)(

log10761

)log( − −

⎥

⎦

⎤ ⎢

⎣

⎡

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛

−>=<

ir

i

r

TT

T

T

F (7) 

Comparing Equations (2) and (7) yields an average temperature for log(F) during the heat-up period 

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛

− >=<

i

r

ir

T

T

TT T

log

 (8) 

With the approximation that log<F> is roughly equal to <log(F)> in the temperature range of interest, 

the same value of the average temperature may be utilized for F. 

Figure 3 plots < T > versus Tr for JSC-1A. It is seen that the variation of < T > in the temperature 

range of interest is essentially linear. For cases where the residence time is comparable to the diffusion 

time, Equation (1) may be first used to obtain the appropriate average value of the diffusion coefficient 

D from the averaged value of F with the equilibrium constant, k, being evaluated at < T >. Then, 

Equation (3), which incorporates the ratio of the residence and diffusion times, may be utilized. 

It may be noted that while the analysis herein has been carried out for JSC-1A, a similar methodology 

may be employed for other simulants whose reduction is described by the shrinking core model with an 

Arrhenius expression for F. 

Figure 3.—Average value of temperature during heat-up as a function of the final operating temperature. 
NASA/TM—2010-216256 6

Results and Discussion 

As noted earlier, the constant-temperature reduction model (i.e., not including reaction during heatup) has been validated against experiments. In these experiments, physically bound water was first baked 

off at high temperatures (above 600 °C) in the presence of an inert gas (e.g., argon or helium) until the 

detectable humidity at the reactor outlet was negligible. Subsequently, the simulant was brought up to the 

operating temperature in the presence of the inert gas by raising the heater temperature. The time taken 

for this step also helped assure that the simulant bed was close to the heater temperature. At this point, the 

hydrogen flow was initiated. In this manner, the water production due to hydrogen reduction at the 

operating temperature was unambiguously determined. It would be useful to have similar validation 

experiments for reaction during heat-up where all of the bound water is baked off prior to initiating the 

hydrogen flow and the simulant temperature is well characterized. Because of schedule constraints in 

hardware development, these tests have not been conducted. However, some test results are available 

where hydrogen flow is present during the bound water bake-off and simulant-bed heat-up process. First, 

the model results will be compared to this data to assess the model applicability. 

The experiment was conducted at NASA JSC in a cylindrical laboratory reactor of inner diameter 

0.021 m with a JSC-1A batch size of 10 grams. Based upon non-reacting tests with JSC-1A in the same 

reactor, it is estimated that the bound water amount for this sample size is about 0.04 grams. By the time, 

the heater reached the 650 °C mark, measurements showed that about 0.02 grams of bound water had 

been removed (ignoring the small amount of water that would be produced by hydrogen reduction in this 

lower temperature regime) leaving an estimated 0.02 grams of bound water to come out during the 

hydrogen reduction process in addition to that formed by reaction. The heater profile for this test run with 

the final operating temperature of 1080 K (approximately 807 °C) is plotted in Figure 4 (only the portion 

beyond 650 C is shown which is considered here). The experimental values of the water out, expressed as 

a conversion fraction are shown in Figure 5. Two curves are shown: one (red), where the bound water is 

included in the conversion fraction, and the other (green), where the bound water is subtracted out from 

the measured water in a linear fashion with time over the duration of the experiment. Thus, at the end of 

the experiment, the two experimental curves differ by the 0.02 grams of estimated bound water which 

translates to a difference of approximately 0.07 in the conversion fraction. 

The model prediction is also shown in Figure 5. In general, the model prediction is between the two 

data curves with and without the estimated bound water removal. There is some overprediction of the 

water out at short times, i.e., at lower temperatures during the heat-up process which may be due to < T > 

being higher than the initial temperature. However, it appears that the cumulative water out, i.e., the 

conversion fraction, at the end of the heat-up period is reasonably well represented by the model. 

Figure 4.—Time profile of heater temperature from experiment. 
NASA/TM—2010-216256 7

Figure 5.—Experimental and predicted values of conversion fraction for the heater temperature 

profile of Figure 4. 

Within the restrictions of the model, the conversion fraction during heat-up depends upon the heat-up 

time and the final steady-state operating temperature. The effects of both of these factors are considered 

next using predictions from the model. Figure 6 plots the conversion fraction as a function of heat-up time 

to a final operating temperature of 1273 K (i.e., 1000 °C). In order to make the discussion general, it is 

assumed that the reactions are not constrained by hydrogen availability; this allows the use of Eq. (4) 

without detailed knowledge of the reactor geometry and simulant batch size with results being presented 

in terms of conversion fraction. The heat-up time here is measured from the stage where the regolith 

temperature reaches 873 K which, as previously noted, is close to the temperature where measurable 

reduction begins to occur. As may be expected, as the heat-up time increases, the conversion fraction also 

increases, although the correspondence is not linear. Thus, at shorter heat-up times, the rate of conversion, 

given by the slope of the curve, is faster. This occurs because during the initial stage of conversion the 

outer layers of the regolith particles are being reduced so that the effects of slower intra-particle diffusion 

are limited. However, once these outer layers are reduced, intra-particle diffusion effects become more 

important and the rate of conversion is reduced. 

The effect of the final operating temperature on the conversion fraction during heat-up is shown in 

Figure 7 for a fixed heat-up time of two hours. As before, the heat-up time is measured after the initial 

reduction temperature of 873 K is reached. In contrast to the non-linear dependence on heat-up time, the 

dependence on the final operating temperature is nearly linear. Thus, Figures 6 and 7 together show that 

the conversion fraction during heat-up may be increased by both increasing the heat-up time as well as by 

increasing the final operating temperature. 

If heat losses from the reactor are well-controlled, then the energy required to bring the regolith to the 

operating temperature depends mainly on the mass of regolith and its specific heat. If these factors are 

fixed, then increasing the heat-up time reduces the power requirement for the fixed total energy so that if 

power is a constraint, then increasing the heat-up time may be a viable option. However, an influencing 

factor is the amount of oxygen that needs to be produced in a given time. As Figure 6 shows there is a 

diminishing rate of conversion with increase in heat- up time which would prohibit arbitrary increase in 

the heat-up time. On the other hand, while the conversion fraction for a fixed heat-up time may be 

increased by increasing the final operating temperature, as shown in Figure 7, this increases the overall 

energy and power requirements. 
NASA/TM—2010-216256 8

Figure 6.—Conversion fraction as a function of heat-up time for a final operating temperature of 

1273 K. 

Figure 7.—Conversion fraction during heat-up as a function of final operating temperature. The 

heat-up time is 2 hr. 

The manner in which reaction during heat-up impacts the overall conversion is shown in Figure 8. 

The figure plots conversion fraction as a function of reaction time at the operating temperature (1273 K) 

for three cases: with no reaction during heat-up, one-hour reaction during heat-up, and two-hour reaction 

during heat-up. For the case with no reaction during heat-up, the conversion fraction starts at zero at time 

zero and then increases as shown in previous work. Initially, the conversion rate is high as the outer layers 

of the particles are reduced and then the conversion rate drops as intra-particle diffusion becomes 

important. For the one-hour and two-hour reaction times during heat-up, a finite conversion has taken 

place by the time the operating temperature is reached. However, by this time, the conversion rate has 

reduced since reduction is now taking place in the interior of the particles. As a result, after one to 2 hr 

of conversion at the operating temperature, the conversion fractions for all three cases are very close to 

each other. 

It has been proposed to utilize the energy efficiency of the process, defined as the cumulative amount 

of oxygen produced per unit energy input, as a tool for evaluating the performance of a given reactor 

configuration and operation timeline (Ref. 13). The cumulative amount of oxygen produced may be 

calculated from the conversion fraction; for JSC-1A, a conversion fraction of unity implies production of 

2.8 percent water by weight, or equivalently, 2.49 percent oxygen by weight. The cumulative energy input 

is given by the sum of the energy needed to heat-up the regolith and the heat losses. An example set of 

calculations for the ratio of oxygen produced to energy input as a function of reaction time are presented 
NASA/TM—2010-216256 9

in Figure 9. Since the heat loss depends upon the reactor configuration and insulation characteristics, a 

specific reactor configuration and batch size needs to be chosen for the calculations. In the example here, 

the inner diameter of the reactor is 0.13 m and its external heat-loss surface area is approximately 0.4 m2

. 

The heat loss to the surroundings is assumed to be by radiation, which is appropriate for a lunar 

configuration. 

In Figure 9, the time origin refers to the time when the reactor reaches the operating temperature 

(1273 K in this case). For the case of reaction during heat-up, some oxygen has already been produced by 

this time (see also Fig. 8). Thus, in this case, the energy efficiency is positive at time zero, in contrast to 

the case with no reaction during heat- up for which no oxygen has been produced. The difference in the 

energy efficiencies for the two cases decreases with increase in reaction time at the operating temperature. 

This suggests that the increase in energy efficiency with reaction during heat-up needs to be balanced 

against associated additional complexity of the reactor design and operational procedures. 

Figure 8.—Conversion fraction during reaction at an operating temperature of 1273 K for different 

heat-up times. 

 

Figure 9.—Oxygen produced per unit energy input as a function of reaction time at the final 

operating temperature. 
NASA/TM—2010-216256 10

Conclusion 

A previously developed model for hydrogen reduction of JSC-1A has been enhanced by adding the 

capability to account for conversion during the simulant heat-up period. The predicted value of the 

conversion at the end of the heat-up period, utilizing a suitably derived average temperature, is in 

satisfactory agreement with available data. The conversion fraction during heat-up increases with the 

heat-up time and final steady-state operating temperature. However, there is a diminishing rate of 

conversion with increase in heat-up time, as well as in overall energy and power requirements, with 

increase in the final temperature. The energy efficiency of the process, defined as the cumulative amount 

of oxygen produced per unit energy input, is generally higher with reaction than with no reaction during 

heat-up although the difference becomes small for longer reaction times. The model finds application in 

overall reactor system analysis studies. 

References 

1. Sanders, G.B., Larson, W.E., Sacksteder, K.R., and Mclemore, C., “NASA In-Situ Resource 

Utilization (ISRU) Project-Development & Implementation,” AIAA Paper No. 2008–7853, AIAA 

SPACE 2008 Conference & Exposition, San Diego, CA, September 2008. 

2. Larson, W.E., Sanders, G.B., Sacksteder, K. R., Simon, T. M., and Linne, D. L., “NASA’s In-Situ 

Resource Utilization Project: A Path to Sustainable Exploration,” IAC–08–A3.2.B13, International 

Astronautical Congress, Glasgow, Scotland, October 2008. 

3. Sanders, G.B., Larson, W.E., Sacksteder, K.R., Simon, T.M., and Linne, D.L., “Open Architecture for 

Lunar Surface Systems-Challenges & Opportunities In Design, Integration, And Partnerships,” IAC–

08–D3.2.1, International Astronautical Congress, Glasgow, Scotland, October 2008. 

4. Heiken, G. H., Lunar Sourcebook, Cambridge University Press, NY, 1991. 

5. Taylor, L.A., and Carrier, W.D. III, “Production of Oxygen on the Moon: Which Processes are Best 

and Why,” AIAA Journal, 30, (12), 2858–2863, (1992). 

6. McKay, D.S., and Allen, C.C., “Hydrogen Reduction of Lunar Materials for Oxygen Extraction on 

the Moon,” AIAA Paper No. 96–0488, American Institute of Aeronautics and Astronautics, 

Washington, DC, 1996. 

7. Rice, E.E., Hermes, P.A., and Musbah, O. A., “Carbon Based Reduction of Lunar Oxides for Oxygen 

Production,” AIAA Paper No. 97–0890, American Institute of Aeronautics and Astronautics, 

Washington, DC, 1997. 

8. Hegde, U., Balasubramaniam, R., and Gokoglu, S., “Development and Validation of a Model for 

Hydrogen Reduction of JSC–1A,” NASA/TM—2009-215618, May 2009. 

9. Levenspiel, O., Chemical Reaction Engineering, Wiley, NY, 1972. 

10. Dagle, R., Holladay, J., Wilcox, W., and Wegeng, R., “Application of Microtechnology to NASA: 

Regolith Reduction Task Update,” Pacific Northwest National Laboratory Report, Project# 52199, 

August 2007. 

11. Clark, D.L., “Integrated In-Situ Resource Utilization for Human Exploration-Propellant Production 

for the Moon and Beyond,” Monthly Report, Lockheed Martin LOP–2005–0102, August 2007. 

12. Hegde, U., Balasubramaniam, R., and Gokoglu, S., “Analysis of Thermal and Reaction Times for 

Hydrogen Reduction of Lunar Regolith,” NASA/TM—2009-215623, May 2009. 

13. Linne, D., Gokoglu, S., Hegde, U., Balasubramaniam, R., and Santiago-Maldonado, E., “Component 

and System Sensitivity Considerations for Design of a Lunar ISRU Oxygen Production Plant,” AIAA 

Paper No. 2009–1391, January 2009. 
REPORT DOCUMENTATION PAGE Form Approved 

OMB No. 0704-0188 

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the 

data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this 

burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. 

Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB 

control number. 

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 

1. REPORT DATE (DD-MM-YYYY)

01-04-2010 

2. REPORT TYPE

Technical Memorandum 

3. DATES COVERED (From - To)

4. TITLE AND SUBTITLE

Heating-Rate-Coupled Model for Hydrogen Reduction of JSC-1A 

5a. CONTRACT NUMBER

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

Hegde, U.; Balasubramaniam, R.; Gokoglu, S., A. 

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

WBS 387498.04.01.05.02.03 

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration 

John H. Glenn Research Center at Lewis Field 

Cleveland, Ohio 44135-3191 

8. PERFORMING ORGANIZATION

 REPORT NUMBER

E-17242 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration 

Washington, DC 20546-0001 

10. SPONSORING/MONITOR'S

 ACRONYM(S)

NASA 

11. SPONSORING/MONITORING

 REPORT NUMBER

NASA/TM-2010-216256 

12. DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified-Unlimited 

Subject Category: 31 

Available electronically at http://gltrs.grc.nasa.gov 

This publication is available from the NASA Center for AeroSpace Information, 443-757-5802

13. SUPPLEMENTARY NOTES

14. ABSTRACT

A previously developed and validated model for hydrogen reduction of JSC-1A for a constant reaction-bed temperature is extended to 

account for reaction during the bed heat-up period. A quasi-steady approximation is used wherein an expression is derived for a single 

average temperature of reaction during the heat-up process by employing an Arrhenius expression for regolith conversion. Subsequently, the 

regolith conversion during the heat-up period is obtained by using this representative temperature. Accounting for the reaction during heatup provides a better estimate of the reaction time needed at the desired regolith-bed operating temperature. Implications for the efficiency of 

the process, as measured by the energy required per unit mass of oxygen produced, are also indicated.

15. SUBJECT TERMS

Hydrogen reduction; ISRU; Lunar regolith simulant; Lunar regolith; Lunar simulant 

16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

 ABSTRACT

UU 

18. NUMBER

 OF 

 PAGES

16 

19a. NAME OF RESPONSIBLE PERSON

STI Help Desk (email:help@sti.nasa.gov) 

a. REPORT

U 

b. ABSTRACT

U 

c. THIS 

PAGE

U 

19b. TELEPHONE NUMBER (include area code)

443-757-5802 

Standard Form 298 (Rev. 8-98)

Prescribed by ANSI Std. Z39-18