U.S. patent application number 11/967820 was filed with the patent office on 2009-07-02 for enzymatic treatment of pulp for lyocell manufacture.
This patent application is currently assigned to Weyerhaeuser Co.. Invention is credited to Mengkui Luo.
Application Number | 20090165969 11/967820 |
Document ID | / |
Family ID | 40786669 |
Filed Date | 2009-07-02 |
United States Patent
Application |
20090165969 |
Kind Code |
A1 |
Luo; Mengkui |
July 2, 2009 |
Enzymatic treatment of pulp for lyocell manufacture
Abstract
Bleached and unbleached pulps are treated with an enzyme in one
or more stages of the bleaching process to yield a low DP pulp
suitable for lyocell manufacture. This allows higher throughput of
fiber an economy of manufacture.
Inventors: |
Luo; Mengkui; (Auburn,
WA) |
Correspondence
Address: |
WEYERHAEUSER COMPANY;INTELLECTUAL PROPERTY DEPT., CH 1J27
P.O. BOX 9777
FEDERAL WAY
WA
98063
US
|
Assignee: |
Weyerhaeuser Co.
Federal Way
WA
|
Family ID: |
40786669 |
Appl. No.: |
11/967820 |
Filed: |
December 31, 2007 |
Current U.S.
Class: |
162/76 ;
162/70 |
Current CPC
Class: |
D06L 4/40 20170101; D01F
2/00 20130101; D21C 3/04 20130101 |
Class at
Publication: |
162/76 ;
162/70 |
International
Class: |
D21C 3/04 20060101
D21C003/04 |
Claims
1. A method for making a lyocell pulp comprising the steps of
providing an unbleached pulp; wherein said pulp has a IV of from 10
to 5 dl/g; contacting said pulp in a bleaching sequence; wherein
said bleach sequence has at least one stage of an enzyme treatment;
wherein said bleach sequence having at least one enzyme treatment
reduces said pulp by 8 to 2 IV units; and wherein said bleached
pulp is suitable for lyocell manufacture.
2. The method of claim 1 wherein the enzyme treatment is
immediately after the oxygen delignification stage.
3. The method of claim 1 wherein the enzyme treatment is after the
last bleaching stage.
4. The method of claim 1 wherein the enzyme treatment is
immediately after the oxygen delignification stage and after the
last bleaching stage.
5. The method of claim 1 wherein the enzyme is added at 0.045 to
4.5 kg/MT pulp.
6. The method of claim 1 wherein the enzyme is added at 0.136 to
3.27 kg/MT pulp.
7. The method of claim 1 wherein the enzyme is added at 0.227 to
1.3 kg/MT pulp.
8. The method of claim 1 wherein the IV is reduced to 2 to 4 IV
units
9. The method of claim 1 wherein the IV is reduced to 2.5 to 3.5 IV
units.
10. The method of claim 1 wherein the pH is adjusted after the
oxygen delignification stage and before the bleaching stage.
11. The method of claim 10 wherein the pH is adjusted in the range
of a pH of 3 to a pH of 10.
12. The method of claim 1 wherein the pH is adjusted after the last
bleaching stage.
13. The method of claim 12 wherein the pH is adjusted in the range
from a pH of 3 to a pH of 10.
14. The method as in any one of claims 10 or 12 wherein the pH is
adjusted with carbon dioxide.
15. The method as in any one of claims 10 or 12 wherein the pH is
adjusted with a mineral acid.
16. The method as in any one of claims 10 or 12 wherein the pH is
adjusted with an organic acid.
17. The method of claim 1 wherein the enzyme is selected from the
group consisting of xylanases, cellulases, hemicellulases,
peroxidases, mannases, laccases, lipases and combinations thereof.
Description
FIELD
[0001] This application relates to the reduction in the degree of
polymerization (DP) of cellulose with enzymes to provide a pulp
with acceptable metals levels suitable for lyocell manufacture.
BRIEF DESCRIPTION OF THE DRAWING
[0002] FIG. 1 is a 1 K magnification of a lyocell fiber spun from
the low DP pulp in this application.
SPECIFICATION
[0003] In order to obtain a higher throughput in lyocell production
(higher concentration of pulp in the solvent NMMO or higher
throughput per hole per minute) it is necessary to use a lower DP
pulp than currently used. Use of enzymes at various stages of the
bleaching process can yield lower DP pulps which are suitable for
lyocell.
[0004] Enzymes are used in the treatment of cellulosic pulp to
improve the bleaching and to reduce the DP of the pulp. One use of
enzymes is to control the viscosity of the pulp during the bleach
treatment. A low uniform viscosity is needed for dissolving and non
dissolving pulps useful for rayon or lyocell production. Enzymes
may be used to control this viscosity.
[0005] Enzymes that are useful with cellulose include xylanases,
cellulases, hemicellulases, peroxidases, mannases, laccases
(oxidoreductases), lipases and combinations of these enzymes.
[0006] The cellulose pulp must be at the correct pH in order for
the enzymes to work. The usual pH is 3 to 10. An acids such as
sulfuric, nitric or hydrochloric acid, is usually used to adjust to
the appropriate pH but there are problems associated with the use
of these mineral acids. The mineral acids tend to harden the
outside of the cellulose fibers and reduce the void volume within
cellulose pulp fibers thus make it more difficult for the enzymes
to interact with the cellulose pulp fibers. Mineral acids are
applied as a liquid and the dispersion of the acid through the pulp
can be non-uniform.
[0007] Carbon dioxide can be used to adjust the pH of the cellulose
pulp fiber to the correct pH of 2 to 7.5 and does not create the
problems that the use of mineral acids do. The carbon dioxide tends
to maintain the openness of the cellulose pulp fiber or biomass and
allow better interaction of the enzyme with both the outside and
the inside of the cellulose pulp fiber or biomass. The carbon
dioxide is applied as a gas and tends to disperse more uniformly
throughout. Other organic acids such as acetic acid can also be
used.
[0008] Various bleaching sequences can be used to make non
dissolving pulp for lyocell. It is important that during the
bleaching sequence that copper levels and total transition metals
be kept low since this element adversely affects the NMMO which is
used to dissolve the cellulose.
[0009] It has now been found that lyocell pulps with a low DP and
suitable for lyocell production can be produced by the use of
enzymes after oxygen delignification (before bleaching),
intermediate in the bleaching sequence or alternatively at the end
of the bleaching sequence. In one embodiment the bleaching sequence
is OXDE.sub.pD where O is oxygen delignification stage, X is the
enzyme treatment stage, D is the chlorine dioxide stage, E.sub.p is
the caustic extraction stage in the presence of peroxide and D is
the bleaching stage with chlorine dioxide. In another embodiment
the bleaching sequence is ODE.sub.pDX where O is oxygen
delignification, D is bleaching with chlorine dioxide, E.sub.p is
caustic extraction in the presence of peroxide, D is chlorine
dioxide bleaching and X is enzyme treatment. In yet another
embodiment the bleaching sequence is OXDE.sub.pDX where O is oxygen
delignification X is enzyme treatment, D is bleaching with chlorine
dioxide, E.sub.p is caustic extraction in the presence of peroxide,
D is chlorine dioxide bleaching and X is enzyme treatment.
Treatment of an unbleached kraft pulp with an IV of 6.2 and a Kappa
of 28 to 30 using one of these bleach sequences, for example
OXDE.sub.pD, can reduce the pulp to an acceptable D. P. range, and
the pulp has an acceptable copper number and acceptable total
transition metals levels.
[0010] Unbleached pulp with an IV (intrinsic viscosity) from 10 to
5 dl/g can be contacted in a bleaching sequence with at least one
stage of an enzyme treatment and reduce the pulp by 8 to 2 units.
The enzyme treatment can also occur after the bleach sequence or
alternatively the enzyme treatment can be in the bleaching sequence
and after the bleach sequence.
[0011] In one embodiment the pulp is reduced to 2 to 4 IV units; in
another embodiment the pulp is reduced to 2.5 to 3.5 units.
[0012] In one embodiment the enzyme is added at 0.045 to 4.5 kg/MT
pulp. In another embodiment the enzyme is added at 0.136 g to 3.27
kg/MT pulp In yet another embodiment the enzyme is added at 0.227 g
to 1.36 kg/MT pulp.
[0013] The term "degree of polymerization" (abbreviated as DP)
refers to the number of D-glucose monomers in a cellulose molecule.
Thus, the term "average degree of polymerization", or "average DP",
refers to the average number of D-glucose molecules per cellulose
polymer in a population of cellulose polymers. DP and IV were
determined by ASTM 1795-96.
EXAMPLE 1
[0014] Pulp with a Kappa of 28 to 30 from the normal Kraft process
underwent an oxygen stage delignification with H.sub.2O.sub.2 and
sodium extraction at 121.degree. C. (250.degree. F.) to obtain
unbleached pulp with an IV of 6.2 dl/g ( Falling Ball or FB of 86).
This pulp was washed (POW, post oxygen washer) and the POW 3.sup.rd
stage wash had an initial set point of 68.degree. C. and stock exit
pH of about 7 (CO2 adjusted), the pulp with the adjusted pH was
treated with cellulase Biotouch C700 from Ashland Inc. (AB Enzymes)
added at POW standpipe at a dosage of 0.45 kg/MT with a retention
time of about three hours to lower viscosity the viscosity to an
intrinsic viscosity (IV) of 5.5 (FB of 50) for DE.sub.pD bleaching.
This bleached pulp (DE.sub.pD) had an intrinsic viscosity (IV) of
3.2 dl/g when taken from the couch trim (control sample in Table
1). This was the starting material for more treatment (Tables 1 to
5).
[0015] In one embodiment pulp with an IV of 6.2 dl/g is treated
with an enzyme after the oxygen delignification stage followed by a
chlorine dioxide (D), caustic extraction with peroxide (Ep), and
then a chlorine dioxide stage. In another embodiment the pulp with
an IV of 6.2 dl/g is treated with an enzyme after the oxygen
delignification stage followed by a chlorine dioxide (D) stage,
caustic extraction with peroxide (Ep), a chlorine dioxide stage and
another enzyme stage, X, after bleaching.
[0016] The procedure for the preparation of the solution for the
treatment is as follows. Table 1 gives the treatment conditions.
[0017] 1. Makeup DI water to pH 7. [0018] 2. Dilution of the enzyme
(Biotouch C-700) with water of pH of 7 to make a 1% solution.
Dilution of the surfactant, (Tergitol), with water of pH 7 to make
a 1% solution. [0019] 3. Add water with a pH 7 to the never dried
control pulp (40 g. oven dried basis) in sealed zipped plastic
bags. [0020] 4. Add 1% water cellulose solution or/and surfactant
solution onto the never dried (ND) pulp slurry so the final pulp
consistency is 10%. [0021] 5. Set the bag in a 70.degree. C. water
bath and let it sit for a retention time of 1 hour. [0022] 6. After
one hour the treated pulp is washed with deionized water and then
the pulp is air dried for analysis.
TABLE-US-00001 [0022] TABLE 1 Pulp Treatment Conditions 1 kg 4.53
kg 1 kg each of C 700 C 700/MT C 700/MT and 1 kg surfactant/ pulp
pulp MT pulp Sample No. 1 2 3 ND Pulp, g* 40 40 40 Cellulase, g .04
.4 .04 1% Cellulase soln, g 4 40 4 1% surfactant soln., g 4 Water,
g, pH 7 356 320 352 Consistency, % 10 10 10 *Never dried pulp, OD
weight
[0023] The same procedure as used in Table 1was used to treat the
same never dried pulp with 0.23, 0.34, 0.45 and 2.27 kg/ton of
C-700 to obtain samples 4, 5, 6 and 7, respectively.
[0024] This same procedure with 1 kg/MT of Biotouch C-700 was used
to treat 600 gram (OD) pulp (never dried) to make "trial" pulp. The
treated pulp and control pulp had the properties listed in Table
2.
TABLE-US-00002 TABLE 2 Analytical Properties Of Cellulase Treated
Peach .RTM. Cellulase, Sample kg/MT pulp DP Cu No. IV, dl/g Control
608 0.6 3.2 4 0.23 570 0.9 3.0 5 0.34 561 1 2.95 6 0.45 551 1.1 2.9
1 0.9 532 1.3 2.8 Trial 0.9 523 1.3 2.75 7 2.27 513 1.4 2.7 3* 0.9
513 1.4 2.7 2 4.54 456 2.2 2.4 *With 0.9 kg surfactant/MT pulp
(Tergitol)
[0025] The data indicates that cellulase treatment after bleaching
can reduce viscosity; for example, at 0.9 kg/MT pulp the IV levels
were reduced from 3.2 to 2.7 dl/g. High levels of enzyme have an
adverse effect on copper number and increase it to unacceptable
levels.
[0026] Cellulase treated Peach.RTM. had a low viscosity and still
sugar content as starting control implying minimal yield loss The
R.sub.10 and R.sub.18 are decreased.
TABLE-US-00003 TABLE 3 Sugar and R.sub.10, R.sub.18 In Cellulase
Treated Peach .RTM. Sample Arabinan, % Galactan, % Glucan, % Xylan,
% Mannan, % R.sub.10, % R.sub.18, % Control' 0.45 0.24 82.19 7.15
5.01 84.1 87.0 (Peach .RTM.) 1 0.3 0.24 83.24 6.85 5.30 76.6 84.5 2
0.37 0.24 84.53 6.82 5.30 73.8 84.1 3 0.41 0.26 82.86 7.42 5.71
76.4 84.6 4 0.32 0.20 82.30 7.42 5.25 5 0.31 0.19 87.86 7.18 5.15 6
0.31 0.20 83.00 7.29 5.21 7 0.30 0.19 82.69 7.154 5.18 Trial 0.31
0.19 84.14 7.13 4.99
[0027] R.sub.10 refers to the residual undissolved material that is
left after attempting to dissolve the pulp in a 10% caustic
solution. R.sub.18 refers to the residual amount of undissolved
material left after attempting to dissolve the pulp in an 18%
caustic solution. Generally, in a 10% caustic solution,
hemicellulose and chemically degraded short chain cellulose are
dissolved and removed in solution. In contrast, generally only
hemicellulose is dissolved and removed in an 18% caustic
solution.Thus, the difference between the R.sub.10 value and the
R.sub.18 value represents the amount of chemically degraded short
chained cellulose that is present in the pulp sample. Providing a
pulp having a relatively broad molecular weight distribution of at
least equal to or greater than about 2.8 is desirable from the
standpoint of being able to provide customers with pulp which may
not require blending with pulps of other molecular weight
distribution to arrive at the desired composition. Sugar analysis
was determined by the method described below.
TABLE-US-00004 TABLE 4 Metals (ppm) In Cellulase Treated Peach
.RTM. Control Sample 4 5 6 1 Trial 7 2 (Peach .RTM.) 3 Ca 60 50 60
50 60 50 30 60 40 Cu 0.2 0.2 0.3 0.4 0.2 0.2 0.3 0.3 0.2 Fe 4 4 2 5
2 3 3 3 3 Mg 20 10 20 10 10 10 <10 20 10 Mn 2.7 2.8 2.8 2.5 2.4
2.6 1.8 3.4 2.2 Na 290 320 280 280 300 290 250 1300 250
[0028] The data indicate that Cellulase treated pulps still have
acceptable transition metals (eg. copper, manganese and iron) and
other metals content (metals such as calcium, sodium and magnesium)
for lyocell manufacture. Metal levels were determined by EPA 3050
and EPA 200.8M.
[0029] Both the control Peach(D and cellulose treated pulp (trial)
were dissolved in lyocell solvent (NMMO (N-methylmolptioline
N-oxide) in a lab kneading machine at different concentrations and
the viscosity, Pas, at different shear rates (zero shear, 1 and 10
l/s were measured at different dissolution times (2, 4, and 6
hours) at different temperatures. The results are presented in
Table 5.
TABLE-US-00005 TABLE 5 Rheology of Low DP pulp Compared with Peach
.RTM. Solution In NMMO Viscosity Dope Kneading Visc. 80.degree. C.
(Pas) 100.degree. C. (Pas) conc. time shear rate, 1/s shear rate
1/s Pulp (%) (hr) 0 1 10 0 1 10 Control 8 2 403 286 140 157 126 67
4 173 152 105 77 48 37 6 72 71 65 27 26 25 Trial 8 2 168 137 84 78
62 42 4 160 135 84 58 53 39 6 84 79 64 29 27 24 Trial 10 2 503 363
195 148 133 95 4 434 338 192 165 141 95 6 211 201 152 67 64 56
Trial 12 2.5 1343 928 607 420 195 4.5 1169 837 379 320 201 6.5 670
550 199 179 144
[0030] The low DP pulp (trial) had lower viscosity at all shear
rates compared with Peach.RTM. (control). This indicates that
higher throughput (higher concentration at the same viscosity or
higher throughput per hole per minute) for meltblowing is possible
with lower DP pulp due to lower solution viscosity.
[0031] Cellulase treatment can lower pulp viscosity. The treated
pulp has acceptable copper number and metal content for the lyocell
process. Certain surfactants also help cellulase treatment. Treated
pulp can have similar hemicellulose as a control (Peach.RTM.) pulp
implying minimal yield loss. The lower DP pulp has lower solution
viscosity in NMMO, thus it is possible to use lower DP pulp at
higher throughput (higher concentration or higher thoughtput per
hole per minute during lyocell production) to improve economics for
lyocell production.
EXAMPLE 2
[0032] Weyerhaeuser Port Wentworth never dried pulp with bleaching
sequence of DEDED with a intrinsic viscosity of 7.1 or FB viscosity
of 140 was treated with 0.91 kg/MT or 0.9 lb/MT of Biotouch C-700
with the same condition listed in Table 1 and the treated pulp had
intrinsic viscosity of 5.9 or FB of 72.
EXAMPLE 3
[0033] Kamloops never dried pulp with a bleaching sequence of DEDED
with a intrinsic viscosity of 3.7 or FB viscosity of 22 was treated
with 0.91 kg MT of Biotouch C-700 at the same condition as listed
in Table 1 and the treated pulp had intrinsic viscosity (IV) of 3.4
dl/g or FB of 19 and a copper number of 0.9.
EXAMPLE 4
[0034] Weyerhaeuser Flint River Peach.RTM. (never dried) with an IV
of 3.2 (OXDEpD) was treated with another Ep stage (2.0% NaOH, 3%
H.sub.2O.sub.2, at 10% consistency, at 88.degree. C. for 90
minutes). The treated sample has an IV viscosity of 2.6 and a
copper number of 0.8. Part of the same sample from above treatment
was dried and then treated with Biotouch C-700 again (same
condition as sample 1 in Table 1) to obtain a sample with an IV of
2.5 and copper number of 0.8. Part of the same sample above from
the Ep stage was not dried and then treated with C-700 (same
condition as sample 1 in Table 1) again to obtain another samples
having IV of 2.5 and copper number of 0.8.
[0035] Never dried pulp after DEpD bleaching with different DP
levels were treated with 0.5% cellulase (Celluclast from Novozyme,
on pulp) with or without surfactant (0.1% Tergitol on pulp);the
conditions are shown in Table 6.
TABLE-US-00006 TABLE 6 Celluclast Treatment Condition Starting
Treatment Enzyme Tergitol Pulp water Time % % IV, slurry Sample pH
hours (wt) (wt) DP dl/g pH Control 1 897 4.7 5.9 Control 2 782 4.1
5.2 8* 3.44 1.5 0.5 850 4.5 5.3 9** 3.44 1.5 0.5 728 3.8 5 10* 3.44
1.5 0.5 0.1% 831 4.4 5.2 11** 3.44 1.5 0.5 0.1% 704 3.7 4.7 *from
control 1; **from control 2
[0036] The analytical properties of the pulp are given in Table
7.
TABLE-US-00007 TABLE 7 Analytical Properties Of Cellulase Treated
Pulp Mannan, Sample Alpha Hemi Cu No. R.sub.10 R.sub.18 Xylan, % %
8 85 15 0.6 84.7 87.2 6.22 4.86 9 84.8 15.2 0.8 84.1 87 6.21 5.09
10 84.6 15.4 0.7 84.1 86.9 6.45 4.91 11 84.1 15.9 0.8 83.6 86.7
6.43 5.04 alpha cellulose was measured by TAPPI method 203
EXAMPLE 6
[0037] In a representative example, Peach.RTM., a never dried
bleached kraft southern pine pulp, available from Weyerhaeuser,
Federal Way, Wash., was treated with cellulase (1% Ashland Biotouch
700) on air dry pulp weight with the same condition as sample 1 in
Table 1) to yield a pulp having an average degree of polymerization
of about 500 (IV of 2.63), a hemicellulose content of 12.0% by
weight hemicellulose in pulp (6.8% and 5.3% by weight xylan and
mannan, respectively) and an R.sub.10 and R.sub.18, of about 76.6
and 84.5, respectively. The pulp was dissolved in NMMO (N-methyl
morpholine N-oxide)/water mixture as follows. A 250 mL three necked
flask was charged with, for example, 66.4 g of 97% NMMO, 24.7 g of
50% NMMO, 10.4 g pulp, 0.1 g of propyl gallate. The flask was
immersed in an oil bath at 105.degree. C., a stirrer inserted and
stirring continued for about 1 hr. A readily flowable dope resulted
that was suitable for spinning. The cellulose concentration in the
dope was about 12% by weight. The dope was extruded from a melt
blowing die that had 3 nozzles having an orifice diameter of 457
microns at a rate of 1.0 gram/hole/minute. The orifices had a
length/diameter ratio of 5. The nozzle was maintained at a
temperature of 95.degree. C. The dope was extruded into an air gap
30 cm long before coagulation in water and collected on a screen as
either continuous or discontinuous filaments depending on dope
rheology and meltblown conditions. Air, at a temperature of
95.degree. C. and a pressure of about 10 psi, was supplied to the
head. Air pressures of from 8 to 30 psi were used to achieve
varying fibers diameters shown in Table 8.
[0038] FIG. 1 shows a longitudinal section of the fiber and
indicates the fiber spun from a low DP pulp has a smooth
surface.
TABLE-US-00008 TABLE 8 Lyocell Fiber Properties Control Meltblown
lyocell 1 2 3 97% NMMO g 66.4 66.4 66.4 50% NMMO g 24.7 24.7 24.7
Propyl Gallate g 0.2 0.2 0.2 Pulp DP 532 532 532 Pulp g 10.5 10.5
10.5 Cellulose % 10.33 10.33 10.33 Air Pressure (psi) 5 10.00 20.00
Diameter (micron) 20.0 15.2 9.1 Birefringence 0.018 0.025 0.030
Xylan, % 5.0 5.2 5.1 Mannan, % 4.4 4.3 4.2
Sugar Analysis
[0039] This method is applicable for the preparation and analysis
of pulp and wood samples for the determination of the amounts of
the following pulp sugars: fucose, arabinose, galactose, rhamnose,
glucose, xylose and mannose using high performance anion exchange
chromatography and pulsed amperometric detection (HPAEC/PAD).
[0040] Summary of Method
[0041] Polymers of pulp sugars are converted to monomers by
hydrolysis using sulfuric acid. Samples are ground, weighed,
hydrolyzed, diluted to 200-mL final volume, filtered, diluted again
(1.0 mL+8.0 mL H.sub.2O) in preparation for analysis by
HPAEC/PAD.
[0042] Sampling, Sample Handling and Preservation
[0043] Wet samples are air-dried or oven-dried at 25.+-.5.degree.
C.
[0044] Equipment Required [0045] Autoclave, Market Forge, Model #
STM-E, Serial # C-1808 [0046] 100.times.10 mL Polyvials, septa,
caps, Dionex Cat #55058 [0047] Gyrotory Water-Bath Shaker, Model
G76 or some equivalent. [0048] Balance capable of weighing to
.+-.0.01 mg, such as Mettler HL52 Analytical Balance. [0049]
Intermediate Thomas-Wiley Laboratory Mill, 40 mesh screen. [0050]
NAC 1506 vacuum oven or equivalent. [0051] 0.45-.mu. GHP filters,
Gelman type A/E, (4.7-cm glass fiber filter discs, without organic
binder) [0052] Heavy-walled test tubes with pouring lip,
2.5.times.20 cm. [0053] Comply SteriGage Steam Chemical Integrator
[0054] GP 50 Dionex metal-free gradient pump with four solvent
inlets [0055] Dionex ED 40 pulsed amperometric detector with gold
working electrode and solid state reference electrode [0056] Dionex
autosampler AS 50 with a thermal compartment containing the
columns, the ED 40 cell and the injector loop [0057] Dionex PC10
Pneumatic Solvent Addition apparatus with 1-L plastic bottle 3 2-L
Dionex polyethylene solvent bottles with solvent outlet and helium
gas inlet caps [0058] CarboPac PA1 (Dionex P/N 035391) ion-exchange
column, 4 mm.times.250 mm [0059] CarboPac PA1 guard column (Dionex
P/N 043096), 4 mm.times.50 mm [0060] Millipore solvent filtration
apparatus with Type HA 0.45u filters or equivalent
[0061] Reagents Required
[0062] All references to H.sub.2O is Millipore H.sub.2O
[0063] 72% Sulfuric Acid Solution (H2SO4)--Transfer 183 mL of water
into a 2-L Erlenmeyer flask. Pack the flask in ice in a Rubbermaid
tub in a hood and allow the flask to cool. Slowly and cautiously
pour, with swirling, 470 mL of 96.6% H.sub.2SO.sub.4 into the
flask. Allow solution to cool. Carefully transfer into the bottle
holding 5-mL dispenser. Set dispenser for 1 mL.
[0064] J T Baker 50% sodium hydroxide solution, Cat. No. Baker
3727-01, [1310-73-2]Dionex sodium acetate, anhydrous (82.0.+-.0.5
grams/1 L H.sub.20), Cat. No. 59326, [127-09-31.
[0065] Standards
[0066] Internal Standards
[0067] Fucose is used for the kraft and dissolving pulp samples.
2-Deoxy-D-glucose is used for the wood pulp samples.
[0068] Fucose, internal standard. 12.00.+-.0.005 g of Fucose, Sigma
Cat. No. F 2252, [2438-80-4], is dissolved in 200.0 mL H.sub.2O
giving a concentration of 60.00.+-.0.005 mg/mL. This standard is
stored in the refrigerator.
[0069] 2-Deoxy-D-glucose, internal standard. 12.00.+-.0.005 g of
2-Deoxy-D-glucose, Fluka Cat. No. 32948 g [101-77-9] is dissolved
in 200.0 mL H.sub.2O giving a concentration of 60.00.+-.0.005
mg/mL. This standard is stored in the refrigerator.
[0070] Kraft Pulp Stock Standard Solution
TABLE-US-00009 KRAFT PULP SUGAR STANDARD CONCENTRATIONS Sugar
Manufacturer Purity g/200 mL Arabinose Sigma 99% 0.070 Galactose
Sigma 99% 0.060 Glucose Sigma 99% 4.800 Xylose Sigma 99% 0.640
Mannose Sigma 99% 0.560
[0071] Kraft Pulp Working Solution
[0072] Weigh each sugar separately to 4 significant digits and
transfer to the same 200-mL volumetric flask. Dissolve sugars in a
small amount of water. Take to volume with water, mix well, and
transfer contents to two clean, 4-oz. amber bottles. Label and
store in the refrigerator. Make working standards as in the
following table.
TABLE-US-00010 PULP SUGAR STANDARD CONCENTRATIONS FOR KRAFT PULPS
mL/200 mL mL/200 mL mL/200 mL mL/200 mL mL/200 mL Fucose 0.70 1.40
2.10 2.80 3.50 Sugar mg/mL ug/mL ug/mL ug/mL ug/mL ug/mL Fucose
60.00 300.00 300.00 300.00 300.00 300.00 Arabinose 0.36 1.2 2.5 3.8
5.00 6.508 Galactose 0.30 1.1 2.2 3.30 4.40 5.555 Glucose 24.0 84
168.0 252.0 336.0 420.7 Xylose 3.20 11 22.0 33.80 45.00 56.05
Mannose 2.80 9.80 19.0 29.0 39.0 49.07
[0073] Dissolving Pulp Stock Standard Solution
TABLE-US-00011 DISSOLVING PULP SUGAR STANDARD CONCENTRATIONS Sugar
Manufacturer Purity g/100 mL Glucose Sigma 99% 6.40 Xylose Sigma
99% 0.120 Mannose Sigma 99% 0.080
[0074] Dissolving Pulp Working Solution
[0075] Weigh each sugar separately to 4 significant digits and
transfer to the same 200-mL volumetric flask. Dissolve sugars in a
small amount of water. Take to volume with water, mix well, and
transfer contents to two clean, 4-oz. amber bottles. Label and
store in the refrigerator. Make working standards as in the
following table.
TABLE-US-00012 PULP SUGAR STANDARD CONCENTRATIONS FOR DISSOLVING
PULPS mL/200 mL mL/200 mL mL/200 mL mL/200 mL mL/200 mL Fucose 0.70
1.40 2.10 2.80 3.50 Sugar mg/mL ug/mL ug/mL ug/mL ug/mL ug/mL
Fucose 60.00 300.00 300.00 300.00 300.00 300.00 Glucose 64.64
226.24 452.48 678.72 904.96 1131.20 Xylose 1.266 4.43 8.86 13.29
17.72 22.16 Mannose 0.8070 2.82 5.65 8.47 11.30 14.12
[0076] Wood Pulp Stock Standard Solution
TABLE-US-00013 WOOD PULP SUGAR STANDARD CONCENTRATIONS Sugar
Manufacturer Purity g/200 mL Fucose Sigma 99% 12.00 Rhamnose Sigma
99% 0.0701
[0077] Dispense 1 mL of the fucose solution into a 200-mL flask and
bring to final volume. Final concentration will be 0.3 mg/mL.
[0078] Wood Pulp Working Solution
[0079] Use the Kraft Pulp Stock solution and the fucose and
rhamnose stock solutions. Make working standards as in the
following table.
TABLE-US-00014 PULP SUGAR STANDARD CONCENTRATIONS FOR KRAFT PULPS
2-Deoxy- mL/200 mL mL/200 mL mL/200 mL mL/200 mL mL/200 mL
D-glucose 0.70 1.40 2.10 2.80 3.50 Sugar mg/mL ug/mL ug/mL ug/mL
ug/mL ug/mL 2-DG 60.00 300.00 300.00 300.00 300.00 300.00 Fucose
0.300 1.05 2.10 3.15 4.20 6.50 Arabinose 0.36 1.2 2.5 3.8 5.00
6.508 Galactose 0.30 1.1 2.2 3.30 4.40 5.555 Rhamnose 0.3500 1.225
2.450 3.675 4.900 6.125 Glucose 24.00 84 168.0 252.0 336.0 420.7
Xylose 3.20 11 22.0 33.80 45.00 56.05 Mannose 2.80 9.80 19.0 29.0
39.0 49.07
[0080] Procedure
[0081] Sample Preparation
[0082] Grind 0.2.+-.05 g sample with Wiley Mill 40 Mesh screen
size. Transfer .about.200 mg of sample into 40-mL Teflon container
and cap. Dry overnight in the vacuum oven at 50.degree. C. Add 1.0
mL 72% H.sub.2SO.sub.4 to test tube with the Brinklman. dispenser.
Stir and crush with the rounded end of a glass or Teflon stirring
rod for one minute. Turn on heat for Gyrotory Water-Bath Shaker.
The settings are as follows: [0083] Heat: High [0084] Control
Thermostat: 7.degree. C. [0085] Safety thermostat: 25.degree. C.
[0086] Speed: Off [0087] Shaker: Off
[0088] Place the test tube rack in gyrotory water-bath shaker. Stir
each sample 3 times, once between 20-40 min, again between 40-60
min, and again between 60-80 min. Remove the sample after 90 min.
Dispense 1.00 mL of internal standard (Fucose) into Kraft
samples.
[0089] Tightly cover samples and standard flasks with aluminum foil
to be sure that the foil does not come off in the autoclave.
[0090] Place a Comply SteriGage Steam Chemical Integrator on the
rack in the autoclave. Autoclave for 60 minutes at a pressure of
14-16 psi (95-105 kPa) and temperature >260.degree. F.
(127.degree. C.).
[0091] Remove the samples from the autoclave. Cool the samples.
Transfer samples to the 200-mL volumetric flasks. Add
2-deoxy-D-glucose to wood samples. Bring the flask to final volume
with water.
[0092] For Kraft and Dissolving pulp samples:
[0093] Filter an aliquot of the sample through GHP 0.45 .mu. filter
into a 16-mL amber vial.
[0094] For Wood pulp samples:
[0095] Allow particulates to settle. Draw off approximately 10 mL
of sample from the top, trying not to disturb particles and filter
the aliquot of the sample through GHP 0.45 .mu. filter into a 16-mL
amber vial. Transfer the label from the volumetric flask to the
vial. Add 1.00 mL aliquot of the filtered sample with to 8.0 mL of
water in the Dionex vial. Samples are run on the Dionex AS/500
system. See Chromatography procedure below.
[0096] Chromatography Procedure
[0097] Solvent Preparation
[0098] Solvent A is distilled and deionized water (18 meg-ohm),
sparged with helium while stirring for a minimum of 20 minutes,
before installing under a blanket of helium, which is to be
maintained regardless of whether the system is on or off. Solvent B
is 400 mM NaOH. Fill Solvent B bottle to mark with water and sparge
with helium while stirring for 20 minutes. Add appropriate amount
of 50% NaOH.
[0099] (50.0 g NaOH/100 g solution)*(1 mol NaOH/40.0 g NaOH)*(1.53
g solution/1 mL solution)*(1000 mL solution/1 L solution)=19.1 M
NaOH in the container of 50/50 w/w NaOH. [0100] 0.400 M NaOH*(1000
mL H.sub.2O/19.1 NaOH)=20.8 mL NaOH [0101] Round 20.8 mL down for
convenience: [0102] 19.1 M*(20.0 mL.times.mL)=0.400 M NaOH [0103] x
mL=956 mL
[0104] Solvent D is 200 mM sodium acetate. Using 18 meg-ohm water,
add approximately 450 mL deionized water to the Dionex sodium
acetate container. Replace the top and shake until the contents are
completely dissolved. Transfer the sodium acetate solution to a 1-L
volumetric flask. Rinse the 500-mL sodium acetate container with
approximately 100 mL water, transferring the rinse water into the
volumetric flask. Repeat rinse twice. After the rinse, fill the
contents of the volumetric flask to the 1-L mark with water.
Thoroughly mix the eluent solution. Measure 360.+-.10 mL into a 2-L
graduated cylinder. Bring to 1800.+-.10 mL. Filter this into a
2000-mL sidearm flask using the Millipore filtration apparatus with
a 0.45 pm, Type HA membrane. Add this to the solvent D bottle and
sparge with helium while stirring for 20 minutes.
[0105] The post column addition solvent is 300 mM NaOH. This is
added postcolumn to enable the detection of sugars as anions at pH
>12.3. Transfer 15.+-.0.5 mL of 50% NaOH to a graduated cylinder
and bring to 960.+-.10 mL in water.
[0106] (50.0 g NaOH/100 g Solution)*(1 mol NaOH/40.0 g NaOH)*(1.53
g Solution/1 mL Solution) (1000 mL Solution/1 L solution)=19.1 M
NaOH in the container of 50/50 w/w NaOH. [0107] 0300 M NaOH*(1000
ml H2O/19.1 M NaOH)=15.7 mL NaOH [0108] Round 15.7 mL down: [0109]
19.1M*(15.0 mL/x mL)=0.300 M NaOH [0110] x mL=956 mL [0111] (Round
956 mL to 960 mL. As the pH value in the area of 0.300 M NaOH is
steady, an exact 956 mL of water is not necessary.) [0112] Set up
the AS 50 schedule. [0113] Injection volume is 5 uL for all
samples, injection type is "Full", cut volume is 10 uL, syringe
speed is 3, all samples and standards are of Sample Type "Sample".
Weight and Int. Std. values are all set equal to 1. [0114] Run the
five standards at the beginning of the run. [0115] After the last
sample is run, run the mid-level standard again as a continuing
calibration verification [0116] Run the control sample at any
sample spot between the beginning and ending standard runs. [0117]
Run the samples.
[0118] Calculations [0119] Calculations for Weight Percent of the
Pulp Sugars
[0119] Normalized area for sugar = ( Area sugar ) * ( g / mL fucose
) ( Area Fucose ) ##EQU00001## IS Corrected sugar amount ( g / mL =
( ( Normalized area for sugar ) - ( intercept ) ) ( slope ) Monomer
Sugar Weight % = IS - Corrected sugar amt ( g / mL ) Sample wt . (
mg ) * 20 ##EQU00001.2##
[0120] Example for arabinose:
Monomer Sugar Weight % = 0.15 g / mL arabinose 70.71 mg arabinose *
20 = 0.043 % ##EQU00002## Polymer Weight % = ( Weight % of Sample
sugar ) * ( 0.88 ) ##EQU00002.2##
[0121] Example for arabinan:
[0122] Polymer Sugar Weight %=(0.043 wt %)*(0.88)=0.038 Weight
Note: Xylose and arabinose amounts are corrected by 88% and fucose,
galactose, rhamnose, glucose, and mannose are corrected by 90%.
Report results as percent sugars on an oven-dried basis.
* * * * *