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ADVANCED POWER SYSTEMS
INTERNATIONAL INC.
558 Lime Rock Road
Lakeville, CT 06039
tel 860-435-2525
fax 860-435-2424
Technical Bulletin #4-B
January 4, 2006
By
Ruma Ghosh and Fabian Garces
University of Connecticut- Dept. of Chemistry - U
3060
55 North Eagleville Rd - Storrs, CT 06269-3060
SEE this Study in PDF
OBJECTIVE
Investigation was carried to measure the
effect of the Fitch Fuel Catalyst C on the growth
of bacteria in contaminated bio-diesel blend
(B20).
EXPERIMENTAL METHODS
Pseudomonas Oleovorans (ATCC 29347) was the
bacterial inoculums used for infecting the 1.5 L of
bio-diesel blend for ~ 3 months. The flow of the
bio-diesel blend was maintained at 500 mL per
minute through a circulating system. The system
had provisions for product draw off. The quality
of the bio-diesel was monitored using UV-Visible
spectroscopy.
The same inoculated Bio diesel was
observed in standing flasks with and without the
presence of an element of Fitch Fuel Catalyst C.
CONTROL EXPERIMENTS
An identical circulating systems
for testing uninfected bio-diesel blend served as
control.
FUEL PREPARATION
Circulating System
The 1.5 liters of bio-diesel blend was
prepared in a 2.5 L glass jar (which served as the
reactor). The bio-diesel blend used in the
experiment was a mixture of 80% (v/v) DF-2
(commercially available diesel) and 20% (v/v) Soy
Gold AL-25842 (B -100 supplied by Southwest
Research Laboratory). The bacteria infected
bio-diesel was subjected to forced circulation
through an In-Line system.
Flask System
Culture flasks labeled 1 and 2 containing 50
mL of BHB (Bushnell Haas Broth) + 5% (v/v) blended
bio-diesel (B20) with 1 mL of Pseudomonas
Oleovorans (ATCC 29347) inoculum were
prepared. Flask 1 is the blank (no catalyst) while
flask 2 containing a catalyst C element cut into
half. Only the characteristic surface or thin
slice of the top part of the catalyst element was
used in the culture flask. The flasks were
inspected visually for any differences in
turbidity or appearance or disappearances of the
blended bio-diesel layer. The BHB salts medium is
a typical aqueous inorganic salt medium. The
floating bio-diesel blend layer can be
distinguished by a distinct yellow-orange color.
The gradual disappearance of the bio-diesel blend
layer is indicative of the decomposition of the
bio-diesel blend components by the bacterial
inoculum.
RESULTS
The contaminated bio-diesel in the In-Line
circulation system that included the In-Line
Catalyst, showed marked differences as evident in
the absorbance of UV-Visible spectroscopy. A fresh
bio-diesel blend was used as the blank for this
analysis. The appearance of a peak in the
UV-Visible spectrum from the inoculated bio-diesel
blend shows that the bacteria produce measurable
differences in the composition of the bio-diesel
blend compared to the uninfected bio-diesel blank.
In addition differences in visual color were also
evident (Figure 1). Suspended particulate matter
was evident in the infected bio-diesel blend.
These particulates settled at the bottom of the
glass jar. The same particulates were not evident
after exposure to the In-Line Catalyst.
The UV-Visible spectrums results
show a peak at around 400 nm and 428 nm in the
visible wavelength range. The peaks are more
obvious in the untreated inoculated bio-diesel
blend than in the same inoculated bio-diesel blend
that went through the In-Line catalyst system.
Gradual decrease in the peak
heights over time in infected bio-diesel blend
subjected to the influence of Fitch Fuel Catalyst
In-Line system
The peaks that appear in the
UV-Visible spectra, from the infected bio-diesel
blend when compared to the uninfected bio-diesel
blend are due to changes in the chemical
composition of the bio-diesel blend from bacterial
action. When the inoculated bio-diesel blend is
exposed to the Inline Catalyst through the
circulating system, we see the extra peaks that
show in the UV-Visible spectra, decrease with time
and reach a saturation level. Control experiments
were run with uninfected bio-diesel blends through
the online catalyst system. There was no
appearance of the extra peaks in the UV-Vis
spectrum in the control.
The culture flasks that remained
for the 4-5 months under still conditions exhibit
obvious differences in appearance as shown in
Figures 3, 4, 5a and b. Culture flask 1 is
inoculated bio-diesel blend without catalyst and
culture flask 2 is inoculated bio-diesel blend
with the a catalyst element present.
Figures 3, 4 and 5 show that the
culture flasks without the catalyst have gone
through severe decomposition of the bio-diesel
blend layer, as the separate floating layer is
practically absent. Flask 1 in Figure 3 and 5b,
showed only a patch of the bio-diesel blend left
on the top layer and much of the bio-diesel layer
is lost / disintegrated as is evident from the
particulate matter that has settled at the bottom.
When flask 1 was shaken the remainder of the
bio-diesel layer got encapsulated by the aqueous
phase and formed oily minuscule droplets (Figure
4). Such observation was absent in flask 2 which
had an element of the catalyst C present.
DISCUSSION
A similar study was also done on
pure diesel DF-2. (See APSI - Technical Bulletin
#4). The most remarkable difference between the
effect of the bacteria on pure diesel (DF-2) and
on B20 bio-diesel is that in the DF-2, the
turbidity in the infected fuel is evident while in
the B20 the appearance of particulates is more
evident. bio-diesel is an oxygenated fuel or
blending component made from vegetable oils, waste
cooking oil, or animal fats by reaction of the
triglyceride fats with methanol to form methyl
esters via transesterification. From past
literature when methyl soyate is used as
bio-diesel blend component, microbial growth from
Bacillus species was inhibited compared to
bacterial growth in pure diesel. Therefore,
evidence suggests that the bacterial action in a
bio-diesel blend is far different from pure diesel
(DF-2). The breakdown of the bio-diesel blend
components by the Pseudomonas species in
this study, as seen from the culture flasks
experiments, shows that bio-diesel by itself is
more susceptible to bacterial spoilage. The
appearance of turbidity in the aqueous phase in
the culture flask 2 shows the presence of
bacterial growth, but at the same time the
bio-diesel blend layer is not destroyed as evident
from the top layer color. The catalyst slows down
the bio-diesel spoilage. The appearance of the
extra peaks in the UV-Vis spectra ( Figure 2) may
be a result of the changed chemical composition ,
the waste metabolites or the fragments of the
bacterial cell.
Acknowledgements:
Dr. Al Berlin Director Research
Advanced Power Systems International, Inc.
Dr. Steven Suib, Board of
Trustees Distinguished Professor, Dept of
Chemistry - University of Connecticut
Funding Support:
Advanced Power Systems
International, Inc. Lakeville, CT USA
US Army TACOM / TARDEC Warren
Michigan, USA Contract W56HZV
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