Lewatit® Ion Exchange Resins
Tailor-made solutions for
biodiesel production
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Biodiesel production with Lewatit® ion exchange resins
Lewatit®
iex resins
Pure Biodiesel
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Biodiesel purification with Lewatit® K 2567
•
Lewatit K 2567 has specifically been developed for biodiesel purification and is used to remove
glycerine, soaps, salts and to a certain extent, monoglycerides.
•
It can replace the conventional water-wash, eliminate costly water stripping to dry the biodiesel
and thereby reduce operating and investment costs.
Biodiesel
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Advantages of using Lewatit® K2567
•
Biodiesel purified with Lewatit K 2567 fulfills the stringent specification requirements
of the European and American fuel industries.
•
Lewatit K 2567 is a macroporous cation exchange resin with monodisperse bead
sizing, to optimize break-through and pressure drop performance in packed beds.
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•
One liter of K 2567 will purify 11-14 tons biodiesel / year
•
It can be reused many times, thus minimizing resin disposal costs.
•
Resin lifetimes up to 7 years have been obtained.
•
Therefore only relatively small beds are necessary for cycle times of 7–10 days
•
It can be retrofitted into existing plants.
•
All biodiesel qualities irrespective of the triglyceride source can be treated.
•
It is currently used in plants ranging widely in size, from 10,000  350,000 to/a.
•
It is the most cost-effective ion exchange resin based purification system in the market.
•
Lewatit K 2567 has been used for biodiesel production in Europe since 1997.
Biodiesel quality standards ASTM
5
Property
ASTM
Flash point
93
Lim its
100 min.
Units
°C
Water sediment
2709
0.05 max.
vol. %
Carbon residue
4530
0.050 max.
w t. %
Kin. viscosity 40°C
445
1.9 - 6.0
Sulfur
5453
0.05 max.
Cetane
613
40 min.
Cloud point
2500
by customer
Copper corrosion
130
No 3 max.
Acid number
664
0.08 max.
Sulfated ash
874
0.020 m ax.
w t. %
Free glycerine
6584
0.020 m ax.
w t. %
Total glycerine
6584
0.240 max.
w t. %
mm²/sec.
w t. %
°C
mg KOH/g
Biodiesel quality standards Europe: EN 14214 *
Property
Limits
Flash point
> 101
Water content
Units
°C
ISO CD 3679e
500
mg/kg
EN ISO 12937
Alkali metals
5 max.
mg/kg
pr EN 14108
Viscosity 40°C
3.5 - 5.0
mm²/sec.
EN ISO 3104
Sulfur
10 max.
mg/kg
Cetane
51 min.
Methanol content
0.2 max.
Copper corrosion
Class1
Acid number
0.5 max.
mg KOH/g
pr EN 14104
Sulfated ash
0.02 m ax.
% (m /m )
ISO 3987
Free glycerine
0.02 m ax.
%(m /m )
pr EN 14105
Total glycerine
0.25 max.
w t. %
pr EN 14105
EN ISO 5165
%(m/m)
pr EN 141101
EN ISO 2160
* As specified for BD from rape seed oil (not all specs. listed)
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Test method
Raw oil sources
Oil types
Palm
Rape seed
Soyabean
Sunflower
Canola
Coconut
Jatropha
Used cooking
Animal fats
High viscosity
Poor combustion
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Conversion
Biodiesel
Low viscosity
Good combustion
Raw oils chemical composition
O
Triglycerides
O
> 95%
O
O
Fatty-Acids:
OH
0.1- 5%
Others:
< 1%
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Micelles, phospholipids, proteins, mineral salts
Triglyceride transesterification
Purified Triglycerides
O
O
> 95%
O
NaOCH3*
CH3OH
O
Top Layer
Biodiesel phase
OCH3
Glycerine phase
OH
HO
Bottom Layer
OH
* The catalyst Na-methoxide is also a drying agent and should be used instead of NaOH to suppress the
formation of soap.
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Transesterification byproduct soap
O
Free fatty acid (FFA)
< 5%
OH
+
NaOCH3
O
Soap
ONa
+
Methanol
CH3OH
The FFA content of the triglycerides should be maintained
below 0.5% to minimize soap formation and maximize BD selectivity,
i.e. FFA´s should be esterified to Me-esters before transesterification.
FFA´s can be esterified with H2SO4 or Lewatit K 2621 as catalysts.
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Free fatty acids removal with Lewatit® K 2621
K 2621
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Design for an 8,000 to/a esterification unit
for
Reduction of free fatty acids (FFA´s) from triglycerides
with
Lewatit K 2621
Feed
Triglycerides with FFA´s
Resin volume:
3.0 m3
Diameter:
1.0 m
Bed depth:
4.0 m
Throughput
1 m3/h (upflow)
Temperature:
90 °C
MeOH conc:
20 – 50 wt%
FFA content influent
1 – 5 wt%
FFA content outlet
< 0.2%
Classical biodiesel production process
Low-acid
triglycerides
MeOH
MeONa
HCl
Antioxidant
Water
Water strip
Methyl ester phase
Water strip
Esterification
Water
wash
Transesterification
Separation
Glycerine phase
Glycerine purification
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MeOH Strip
Raw oils with
free fatty acids
MeOH +
Gly. + salts
Water +
Glycerine +
Salts
Glycerine +
Salts
Pure
methyl esters
(Biodiesel)
Purification with Lewatit® K 2567
Low-acid
triglycerides
MeOH
MeONa
Methyl ester phase
Separation
Glycerine phase
Lewatit
MDS 1368
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MeOH Strip
Glycerine purification
MeOH +
glycerine
Glyc. adsorption desorption
Esterification
Transesterification
Raw oils with
free fatty acids
Antioxidant
HCl
Lewatit K 2567
Glycerine +
Salts
Pure
methyl esters
(biodiesel)
Lewatit® K 2567 vs water wash
Purification with Lewatit® K 2567
Purification with water wash
Water
Glyc. adsorption desorption
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Water strip
Water +
glycerine +
salts
Water strip
Water
wash
One column of resin
completely replaces
the water washing
system!!
Lewatit® K 2567 vs water wash
Purification with water wash
Many biodiesel plants already use NaOCH3 for
transesterification, i.e. the streams are already
very dry.
Water efficiently removes impurities but needs to
be stripped down down to <500 ppm in the
purified biodiesel.
In classical biodiesel plants, dry streams are
wetted and redried at subtantial cost.
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Purification with Lewatit K 2567
With K 2567, dry biodiesel streams remain
dry.
Only methanol is required as a washing
agent to regenerate the resin. The washing
effluent is recycled to the transesterification.
Mechanism of glycerine adsorption
Dry Lewatit K 2567 is hygrosopic
and strongly hydrogen-bonds to
alcohols and water.
HO
HO
Glycerine is a polar tri-alcohol and
is very efficiently removed from
low polarity biodiesel esters.
OH
Glycerine
HO
O
K 2567
S O
O
Hydrogen bonding
HO
HO
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HO
Na+
HO
OH
Solvation with glycerine
MeOH-washed, dry resin
HO
OH
Glycerine-solvated resin
OH
HO
SO3- Na+
K 2567
SO3- Na+
OH
K 2567
OH
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Mechanism of salts and soaps adsorption
Glycerine layer
Ionic impurities + soaps
dissolve in the glycerine
layer
Mg++
Cl-
K+
-O2C
SO3-Na+
K2567
-O2C
Na+
SO42-
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Ca++
Impurities adsorption in glycerine
Transesterification
phase separation
Capture of ionic impurities on
glycerine phase of K 2567
Biodiesel phase
+
Biodiesel phase
Small concentrations of
ionic impurities + soaps
clean
K 2567
+
Glycerine phase
Glycerine phase
+
High concentrations of
ionic impurities + soaps
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+
High concentrations of
ionic impurities + soaps
Structure of Lewatit® K 2567
Monodisperse bead sizing, hexagonal closest packing
K 2567 “sponge-structure“
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Application mode of Lewatit® K2567
Alternate loading and washing
Washing with dry MeOH
Biodiesel + glycerine
Lewatit
K 2567
Transesterification
Purified biodiesel
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MeOH + glycerine
Regeneration / cleaning with methanol
Raw oils
MeOH
Methanol
+
glycerine
+
salts & soaps
K 2567
+
glycerine
+
salts & soaps
Transesterification
K 2567
clean
Methanol
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Operating conditions
Preconditioning
Biodiesel from
phase separation
glycerine: 600 – 4000 ppm
soap:
10 – 500 ppm
• Fresh K 2567 is first preconditioned by drying with 3-4 bed volumes MeOH at
2BV/h. The MeOH is then drained and the biodiesel passed into the reactor.
Before the MeOH wash, the biodiesel is also drained.
• After preconditioning, K 2567 is only subjected to alternate MeOH / biodiesel
treatments and never washed with water.
• 100% bed volume water-wet, shrinks to 95% in MeOH, further shrinks to 90%
in biodiesel + glycerine
Lewatit®
K2567
Operating parameters:
Temperature:30°C – 40°C
LHSV:
Bed height:
Freeboard:
Operating capacity:
Regeneration:
Regeneration volume:
Resin life:
1.5 – 2 (BV* biodiesel/hr)
1 – 2 m**
20%
250 g glycerine/liter
MeOH @ 20-35°C
5-10 BV to transesterification
4-5 years (average)
*BV = bed volumes
** Please refer to us for specific design details
Refined biodiesel: glycerine <10 ppm, soap: < 5 ppm
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Plant configuration
• Depending on the the amount of biodiesel produced and manufacturing site infrastructure,
any of the configurations A-C can be used.
• Greatest flexibility is obtained with the classical lead-lag setup, whereby the freshly MeOHregenerated reactor is switched to the lag-position.
A: Single unit
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B: 1x in operation, 1x in standby
C: 2 units in series: lead-lag
Operating data
Adsorption of glycerine & soaps from rape seed biodiesel with Lewatit K 2567
at 2 BV/h and 28°C
800
glycerine inlet
soaps inlet
glycerine outlet
soaps outlet
700
600
ppm
500
400
300
200
100
0
5
25
10
15
20
25
Bed volumes biodiesel from rape seed oil
30
35
Basic design
Capacity
100,000 to/a*
30 mio. gal/a
Annual operation
Throughput
8,000 h
12.5 to/h
15,600 l/h
69 gal./min.
LHSV
2 bed vols/h
Bed volume
7,800 liter K2567
Bed height
2 meter
Pressure drop
Glycerine capacity
0.4 bar
150-250 g/liter resin**
Glycerine conc
800 ppm
Cycle time
156 h
Resin lifetime
5 years
* This basic design can be scaled linearly for plant sizing ranging from 1,000  300,000 to/a.
bed depth should be kept in the range 1.5 meters (1,000 to/a) to 3 meters (300,000 to/a)
**Variable, depending on the influent glycerine concentration.
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Competitive technologies and resin cost of operation
Competitive ion exchange resin-based biodiesel purification processes are also available
involving once-only use of disposable resin without regeneration.
A comparison of the two approaches is summarised in the following tables:
Lewatit K 2567
Competitor resins dry
Resin disposal every 5 years
Resin disposal every 2-4 weeks
Clean, smooth operation
Regular opening of reactor & waste handling
No regular BD loss
Regular BD loss in resin during dispoal
No swelling relative to delivery form
Resin swelling of 100-200%
80-90% utilization of reactor volume
20-30% utilization of reactor volume
Competitor resins dry (one way application)
0.007500 €/l
0.0350 $/gal
Lewatit K 2567 (lifetime 5 years)
0.000043 €/l
0.0002 $/gal
Competitor : Lewatit
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175
cost factor
Glycerine salts-removal with Lewatit® MDS 1368
Design for a 2000 to/a glycerine purification unit
via
Ion Exclusion Chromatography
with
Lewatit MDS 1368-Na 350µ
MDS 1368-Na 350µ
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Feed
Glycerine from BD transesterification
Resin volume:
8.0 m3
Diameter:
1.4 m
Bed depth:
5.0 m
Loading / cycle
1 to. glycerine in 0.8 to water
Salts conc. in raw glycerine:
5-7 wt%
Temperature:
85 °C
LHSV:
0.25 (1.2 m/h)
Effluent conc:
1 to. glycerine in 6 to. water [ø]
Glycerine purification with Lewatit® MDS 1368
Salts [*100 µS/cm]
MDS 1368-Na 350µ
60
60
50
50
40
40
30
30
20
20
10
10
0
0
0,2
0,4
0,6
Filtered bed volume
29
0,8
)%( Glycerine
Separation of salts from transesterification-glycerine
Glycerine polishing with Lewatit® S 2528 / S 4268
MDS 1368-Na 350µ
S 2528
Strongly acidic,
monodisperse
gel-type
cation exchange
resin
Strongly acidic,
heterodisperse
macroporous
cation exchange
resin
S 4268
Raw glycerine from
transesterification
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Intermediate-basic
monodisperse
macroporous
anion exchange
resin
Refined glycerine
Biodiesel and glycerine purification with Lewatit® iex resins
Transesterification
K 2567
Biodiesel phase
Glycerine phase
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MDSS1368
2568
S 2568
Additional information
at
www. lewatit.com
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Legal note
This information and our technical advice - whether verbal, in writing or by way of
trials - are given in good faith but without warranty, and this also applies where
proprietary rights of third parties are involved.
Our advice does not release you from the obligation to verify the information
currently provided (especially that contained in our safety data and technical
information sheets) and to test our products as to their suitability for the intended
processes and uses.
The application, use and processing of our products and the products
manufactured by you on the basis of our technical advice are beyond our control
and, therefore, entirely your own responsibility.
Our products are sold and our advisory service is given in accordance with the
current version of our General Conditions of Sale and Delivery.
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