-
he Dallas Group of America Inc.,a recognized leader in
oleo-chem-ical purification technology, is
arguably the only U.S. company activelymarketing a commercial
product for theadsorptive purification of biodiesel. Thecompany’s
synthetic magnesium silicateadsorbent, sold under the
trademarkedname Magnesol, is an “adsorbent filteraid” that ensures
biodiesel quality byremoving contaminants within methylesters.
Subsequently, the removal of con-taminants enables biodiesel
producers toguarantee that the fuel they produce meetsASTM D-6751
specifications and otherindustry standards.
The Dallas Group broke into theNorth American biodiesel market
withMagnesol only recently, but according toone producer, the
adsorbent could be “acure-all for most process upsets and impu-rity
problems” that occur during biodieselproduction. Multiple customers
nation-wide in the edible oils industry are alreadyusing the
product. Bryan Bertram, direc-tor of industrial sales with The
DallasGroup, believes the U.S. biodiesel market
represents one of the next big opportuni-ties for the product
line. In an interviewwith Biodiesel Magazine, Bertram, alongwith
Chris Abrams, business developmentmanager, and Brian Cooke, product
devel-opment specialist, discussed the compa-ny’s ongoing efforts
with Magnesol.Bertram said the product increases theoxidative
stability of biodiesel and is usedin conjunction with—orin place
of—the water-wash treatment in thebiodiesel productionprocess.
After the glycerinseparation process,methyl esters
containcontaminant materialsthat are detrimental to the quality of
thefuel and must be eliminated from theproduct. Reduction of the
water-solublecontaminants, traditionally, is accom-plished by
water-washing the biodiesel.However, according to Bertram, the era
ofthe biodiesel water-wash may be graduallyending. “The water-wash
method doesnothing to remove the water-insoluble
impurities,” he told Biodiesel Magazine.“And due to the
resulting effluent water, itgives cause for environmental
concerns.”
With Magnesol, the water-wash stepcan be eliminated, and so can
the liquidseparation and drying of biodiesel. “It canalso replace
other methods of removingchlorophyll, metals, and color
frombiodiesel,” Bertram said. “If the processor
is utilizing a costly distil-lation step on the tail endto
remove metals orother contaminants, theycould forgo that stepalso.
In addition,Magnesol has a highaffinity for methanol andwater, so
it will remove
the last bits from methl esters..”Purification with Magnesol
also
increases the oxidative stability ofbiodiesel, Bertram said,
which is becomingincreasingly important, due to thedemands being
placed on fuel producersby the auto manufacturing industry
andgovernment.
Magnesol, which can be used in either
What is perhaps mostattractive aboutMagnesol, is that itworks
simply and relatively inexpensively.
PROCESS
By Tom Bryan
T
With a solid track record in oleo-chemical purification, The
Dallas Group has
entered the biodiesel industry with a synthetic magnesium
silicate adsorbent that
has changed the way some producers clean up their methyl
esters.
gAdsorbing It All
March 2005 BIODIESEL MAGAZINE 40
-
PROCESS
batch or continuous processes, removesresidual methanol,
providing a cost sav-ings in the stripping step. Magnesol isable to
remove sulfur, which is especial-ly important in light of impending
U.S.EPA regulations that will limit sulfur indiesel fuel to 15
parts per million.Furthermore, the product significantlyreduces a
plant’s need for heated andconditioned water. The
traditionallyemployed water-wash method necessi-tates either the
purchase of centrifugesor the gravity-separation of the waterfrom
biodiesel.
“After transesterification, you havemethyl esters that need
purification,”Bertram said, explaining how waterwashing is
typically used to remove con-taminants from methyl esters.
Abrams said The Dallas Groupbelieves the water-wash method has
sev-eral limitations, including decreasedyields due to methyl ester
loss in efflu-ent; high soap levels that cause emulsifi-cation;
high effluent treatment and dis-posal costs; and the time and cost
ofdrying methyl esters. High soap levels inparticular may lead to
poor separation,contribute to yield losses and requiremultiple
washes to achieve specification,Abrams said. In some cases, 24
hours arerequired to effect a single separation.
Additionally, it is not uncommonfor producers to end up with a
methylester/water emulsion. “Without a water-wash, there are no
such emulsionsformed,” Abrams said. “The disposal,and even
permitting of, wastewater isdifficult to impossible, depending
onplant location. Magnesol greatly reducesdependency on water and
resultantwastewater disposal issues.”
What is perhaps most attractiveabout Magnesol, is that it works
simplyand relatively inexpensively.
Cooke shared information aboutMagnesol at the 2005 National
BiodieselConference & Expo in Ft. Lauderdale,Fla., in early
February. His presenta-tion—essentially a detailed explanationof
how biodiesel can be purified byusing the company’s trademarked
adsor-bent—covered the basic biodieselprocess, the technology of
filtration(passive and active), the results of a pilot
Catalyst(NaOH)
+ Methanol
VegetableOils, used
cooking oil,animal fats
TransesterificationContaminated
Methyl Esters
Glycerin
MethanolRemoval
WaterWashing
MethylEsters &Residual
Water
DirtyEffluent
Drying MethylEsters
Biodiesel Production with aWater-wash Treatment
Catalyst(NaOH)
+ Methanol
VegetableOils, used
cooking oil,animal fats
TransesterificationContaminated
Methyl Esters
Glycerin
MethanolRemoval
AdsorbentPurification
FilterCake
MethylEsters
Biodiesel Production with Adsorbent Purification
Animal Feed Fuel Value (Biomass)Compost
41 BIODIESEL MAGAZINE March 2005
-
PROCESS
plant trial that involved the product, and abrief look at
replacing the water-wash stepwith the company’s magnesium
silicatetreatment.
Cooke explained that Magnesol couldbe used by biodiesel
producers as a “totalreplacement” of the water wash step, or
a“polishing step” used to round out thewater wash treatment.
In a standard biodiesel productionprocess, Magnesol—a fine white
pow-der—is mixed with unwashed biodiesel ina mixing tank (for five
to 10 minutes) afterglycerin separation and after
methanolremoval.
According to Cooke, magnesium sili-cate has a strong affinity
for polar com-pounds, thereby actively filtering outexcess
methanol, free glycerin, mono anddi-glycerides and metal
contaminants, inaddition to free fatty acids and soap.These
materials are then removed fromthe process through filtration.
Note:Glycerin is a polar molecule, and therebysusceptible to the
adsorptive abilities ofmagnesium silicate. That’s why Magnesolis
added to the process after the glycerinseparation step.
Explaining the difference between“passive filtration” and
“active filtration,”Cooke said Magnesol has “charged sites”on its
surface (areas that attract the aforementioned unwanted polar
compounds).
“Adsorptive sites may have eitheracidic or basic
characteristics,” he said,before explaining the testing methodsused
to measure the number—andstrength—of adsorptive sites on a
givenamount of adsorbent matter such asMagnesol.
Cooke said testing has shown thatsynthetic magnesium silicate
has highnumbers of acidic and basic adsorptivesites, as opposed to
passive filter-aid-typematerials like diatomaceous earth, which“did
not have any active filtration sites.”
With the use of Magnesol, Cookesaid, the producer is left with a
potentiallyvaluable “filter cake” rather than dirtyeffluent.
Clients of The Dallas Group arecurrently exploring a variety of
marketsfor this filter cake, and the companybelieves the byproduct
has potential valueas an animal feed supplement, a form ofbiomass
fuel, fertilizer or compost.
The BECON study The Dallas Group has over 30 years
experience in the purification of variouschemicals, including
esters and the result-ing byproducts of those processes. Inaddition
to its own in-house work onbiodiesel (with outside lab
confirmation),the Biomass Energy Conversion Facility(BECON) at Iowa
State University per-formed trials comparing the
traditionalwater-wash method to biodiesel purifica-tion with
Magnesol. Results from thisstudy were discussed by Cooke in
hispresentation and also by Dr. Jon VanGerpen during a special
technology ses-sion at the National Biodiesel Conference.Van
Gerpen, a respected authority on thesubject of biodiesel, directed
the pilotstudy at the BECON facility. He has sincetaken a position
at the University of Idahoas department head of Biological
andAgricultural Engineering.
In that study, methyl esters were pro-duced in 40-gallon batches
from bothdegummed soybean oil and yellow grease
Filter
FinishedProduct
TankMixTank
Magnesol ® Unwashed biodiesel(after separation and after
methanol removal)
Biodiesel Purification Process
Benefits of treatment with
MAGNESOL ®
✔No water-effluent stream
✔No emulsification
✔Improved oxidative stability (OSI)
✔Minimal yield loss
✔Minimal capital expenditure
✔Allows for continuous operation
✔Expedites the purification process
✔Adsorbs residual water
March 2005 BIODIESEL MAGAZINE 42
-
43 BIODIESEL MAGAZINE March 2005
PROCESS
feedstocks in BECON’s pilot plant reac-tor. In both cases, the
methanol wasremoved from the methyl esters, but notinitially
water-washed.
First, 20 gallons of the soybeanmethyl esters were water-washed
anddried, while another 20 gallons were treat-ed at 77 degrees
Celsius with 1-percent-by-weight Magnesol. After 20 minutes of
mix-ing (longer than is probably required in acommercial plant
setting, Cooke said), thepurified methyl ester was filtered.
Theresulting biodiesel from both methodspassed all specifications
of ASTM D-6751. According to the study’s authors,Van Gerpen and
Kirk Menges, theMagnesol-treated biodiesel contained alower soap
and sodium content than thewater-washed and dried
sample.Furthermore, the Magnesol-treatedbiodiesel showed a
significant improve-ment in oxidative stability when comparedto
both the original methyl esters and thewater-washed and dried
sample.
In a second trial, 20 gallons of theyellow grease methyl esters
were water-washed and dried and 20 gallons weretreated with at 77
degrees Celsius with 2-percent-by-weight Magnesol. After 20minutes
of mixing, the purified methylester was filtered. Like the first
test withsoy methyl esters, the Magnesol-treatedsample of yellow
grease-derived methylesters passed all ASTM specificationswhile the
waterwashed and dried sampledid not. The Magnesol-treated
biodieselcontained a lower soap and sodium con-tent than the
water-washed and dried sam-ple. Again, the Magnesol-treated
biodieselshowed a significant improvement inoxidative stability
when compared to boththe original methyl esters and the
water-washed and dried sample.
During his presentation, Cooke con-cluded that the benefits of
treating methylesters with Magensol are multi-fold. Hereiterated
Bertram’s claims about theproduct: With Magnesol, there is no
watereffluent, no emulsification, improvedoxidative stability,
minimal yield loss andminimal capital expenditure, all throughan
application that “expedites the purifica-tion process and allows
for continuous
operation.”Fielding questions from attendees,
Cooke said the cost of using Magnesol isin the range of 1 cent
to 10 cents per gal-lon of finished biodiesel, depending onthe
starting contaminant level. However,he reminded attendees that the
filter cakecould potentially be used as an animalfeed. “It has a
certain nutritional value,” hesaid.
According to Bertram, the capitalcosts of transitioning a
biodiesel facility toMagnesol are relatively low. That’s
becauseonly a low-tech filtering system is required.In addition to
potentially eliminating thedrying step and the requirement for
awastewater treatment system, the use ofMagnesol could replace a
centrifuge, yield-ing additional savings of capital, time
andmaintenance costs.
There are less obvious savings, too,
Bertram said. “Magnesol actually offersthe biodiesel producer a
lot of latitude inrunning their process,” he said. “It
adsorbsglycerin, free glycerin, metals, soaps,chlorophyll, residual
free fatty acids, odors,color, methanol and water. Since
Magnesoladsorbs such a wide range of impurities, itcompensates for
upstream upsets in theprocess, offering clean and more
stablebiodiesel.”
For more information about Magnesol visitwww.dallasgrp.com.
Tom Bryan is editorial director of BiodieselMagazine. Reach him
by e-mail [email protected] or by phone at
(701)746-8385.
MAGNESOL®
• Guarantee biodiesel quality(ASTM D6751)
• Reduce or eliminate water wash • Eliminate emulsions •
Expedite purification process • Reduce energy requirements •
Increase process yield • Improve storage stability (OSI)
PHONE 812-283-6675 Ext. 5 EMAIL [email protected] WEB
www.dallasgrp.com
PURIFICATIONOF BIODIESELAND OTHER HIGH-PURITY ESTERS
This article was printed in the 2005 March issue ofBiodiesel
Magazine.
0605I203