Oxidative Reforming of Biodiesel Over
Molybdenum (IV) Oxide
Jessica Whalen, Oscar Marin Flores, Su Ha
The Gene and Linda Voiland School of Chemical Engineering and Bioengineering
Washington State University
INTRODUCTION
XRD: Commercial MoO2 No Pretreatment
10
8
6
H2 yield
Intensity
Energy consumption continues to skyrocket worldwide. Biodiesel is
a renewable fuel source that has become more popular due to its
high energy output, making it a good candidate as potential
feedstock in solid oxide fuel cells. Petroleum based fuels become
scarcer daily, and biodiesel provides renewable energy. This fuel is
created from the reaction of alcohol with vegetable oils and can
therefore be made from a diverse number of sources from waste
frying oil to algae.
4
2
0
24
34
44
2 Theta
54
64
Particle Size Distribution
Commercial molybdenum dioxide was used for all tests. Catalytic
partial oxidation was carried out in a fixed bed tubular (quartz)
reactor. Typically, 0.5 grams of sample were used for each run. Tests
were performed with the O2/C ratio = 0.5, WHSV = 1 h 1, at 8500 C
and atmospheric pressure unless otherwise noted. All syngas
information was taken from a gas chromatograph. XRD information
was gathered as part of the characterization process. A Horiba LA950V2 machine provided particle size distribution information. SEM
and EDX images were taken to better understand how the catalyst
changed after testing. The BET surface area was measured using a
Micromeritics ChemiSorb 2720.
Intensity
0
1000
2000
3000
Diameter (µm)
4000
RESULTS AND DISCUSSION
Effect of WHSV
H2 yield
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
The
WHSV
was
increased every 2 hours
in increments of 1.0
beginning with WHSV =
1
h 1.
The
best
conversion occurs at
WHSV = 1 h 1.
H2 yield
CO yield
Conversion
0
2
4
6
Time (h)
8
10
24
34
44
2 Theta
54
64
100%
80%
60%
H2 yield
40%
CO yield
20%
Conversion
0
CHARACTERIZATION OF THE CATALYST
2
4
6
8
10
The O2/C ratio was
increased every 2 hours
in increments of .1
beginning
with
O2/C=0.5. The best
conversion occurs at
O2/C=0.5.
Time (h)
100%
Reaction temperature
was lowered every 2
hours in increments of
500 C, beginning at
8500 C. The most
effective temperature
was 8500 C .
H2 yield
H2 yield
80%
CO yield
60%
Conversion
40%
20%
0%
4
6
Time (h)
More efficient technology for energy production is important. The
prospect of solid oxide fuel cells using biodiesel and molybdenum
dioxide shows great promise and must be studied further. Though
alone molybdenum dioxide is stable for 19 hours, more can be
done to increase the length of stability and productivity of the
catalyst. The addition of components such as nickel may improve
performance. Further study is in progress to see how nickel will
alter catalyst performance.
This work was supported by the National Science Foundation’s REU
program under grant number EEC-0754370.
Effect of Temperature Change
2
Maximum hydrogen yield and conversion were achieved at 8500 C
and atmospheric pressure with WHSV = 1 h 1, and O2/C=0.5. Long
term tests with similar conditions allowed the catalyst to continue
producing stable results with 50 percent hydrogen yield after 19
hours. EDX images showed little coking, so the decline of the
catalyst cannot be attributed to coking problems. XRD of the spent
sample shows evidence of sintering, which lead to the lowering of
the already low surface area, eventually causing the decline of the
catalyst.
ACKNOWLEDGEMENTS
BET surface area = 3.9 m2/g
0
CONCLUSIONS
FUTURE WORK
Effect of O2/C Change
0%
SEM images of commercial MoO2
XRD: MoO2 Sample after long term test
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
SEM images and XRD of commercial MoO2 after long term test
H2 yield
METHODS
25
20
15
10
5
0
Percentage
Researchers have found molybdenum dioxide displays excellent
behavior as catalytic material for the oxidative reforming of both
isooctane [1] and dodecane [2]. Isooctane yielded 78% H2 100%
carbon conversion while dodecane had 99.21% H2 yield. High
conversion and yield percentages with isooctane and dodecane
make molybdenum a good candidate as an effective catalyst for
biodiesel.
Few papers have been published on the topic of catalytic partial
oxidation with molybdenum dioxide. Further research must be
done to fully understand its potential for use in solid oxide fuel
cells. This cutting edge area of research continues to be important
as energy consumption increases worldwide. Combining two
promising components, biodiesel and molybdenum dioxide, may
prove useful for solid oxide fuel cells.
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
After finding ideal
WHSV, O2/C ratio, and
temperatures for the
reaction, a long term
test was performed at
8500
C
and
H2 yield
atmospheric pressure
CO yield
Conversion
with WHSV = 1 h 1,
and O2/C=0.5. The
0 2 4 6 8 1012141618202224 catalyst was stable for
Time (h)
19 hours.
Long Term Test
8
10
REFERENCES
[1]. O. Marin Flores and S. Ha, Appl. Cata. A Gen. 352 (2009), p.
124- 132.
[2]. O. Marin Flores, T. Turba, J. Breit, M. Grant Norton, and S. Ha,
Appl. Cata. A Gen. 381 (2010), p. 18-25.