U.S. patent application number 11/427921 was filed with the patent office on 2008-01-03 for method for processing high hemicellulose pulp in viscose manufacture.
Invention is credited to Mengkui Luo, John A. Westland.
Application Number | 20080001325 11/427921 |
Document ID | / |
Family ID | 38659349 |
Filed Date | 2008-01-03 |
United States Patent
Application |
20080001325 |
Kind Code |
A1 |
Luo; Mengkui ; et
al. |
January 3, 2008 |
Method for Processing High Hemicellulose Pulp in Viscose
Manufacture
Abstract
Pulp with a high hemicellulose level is blended with a
dissolving grade pulp and converted to viscose. Blending can be
performed during steeping or after steeping. Spinning of the
viscose containing the blend, into filaments yields fibers with
strength properties that are at least equal to those of the
dissolving pulp alone.
Inventors: |
Luo; Mengkui; (Auburn,
WA) ; Westland; John A.; (Auburn, WA) |
Correspondence
Address: |
WEYERHAEUSER COMPANY;INTELLECTUAL PROPERTY DEPT., CH 1J27
P.O. BOX 9777
FEDERAL WAY
WA
98063
US
|
Family ID: |
38659349 |
Appl. No.: |
11/427921 |
Filed: |
June 30, 2006 |
Current U.S.
Class: |
264/188 |
Current CPC
Class: |
D21C 11/0007 20130101;
C08B 1/08 20130101; D01F 2/06 20130101; D21C 3/02 20130101; C08B
9/00 20130101 |
Class at
Publication: |
264/188 |
International
Class: |
D01F 2/06 20060101
D01F002/06 |
Claims
1. A method comprising the steps of providing a non dissolving
grade pulp with a hemicellulose level of at least 10%; providing a
dissolving grade pulp with a hemicellulose level less than 4%;
blending said non dissolving grade pulp with said dissolving grade
pulp; processing said blended pulp into viscose; processing said
viscose into fiber.
2. The method of claim 1 wherein the hemicellulose level of the non
dissolving grade pulp is at least 12%.
3. The method of claim 1 wherein the S.sub.18 of the non dissolving
grade pulp is at least 13%.
4. The method of claim 1 wherein the S.sub.18 of the non dissolving
grade pulp is at least 15%.
5. The method of claim 1 wherein the S.sub.10 of the non dissolving
grade pulp is at least 14%.
6. The method of claim 1 wherein the S.sub.10 of the non dissolving
grade pulp is at least 16%.
7. The method of claim 1 wherein the D.P. of the non dissolving
grade pulp is at least 700 but 1200 or less.
8. The method of claim 1 wherein the D.P. of the non dissolving
grade pulp is at least 800 but less than about 1100.
9. The method of claim 1 wherein the D.P. of the non dissolving
grade pulp is at least 900 but less than about 1000.
10. The method of claim 1 wherein the non dissolving grade pulp
with high hemicellulose is blended with the dissolving grade pulp
in a sheet steeping process.
11. The method of claim 1 wherein the non dissolving grade pulp
with a high hemicellulose level is blended with the dissolving
grade pulp in a slurry steeping process.
12. The method of claim 1 wherein the non dissolving grade pulp is
blended with the dissolving grade pulp at a 50% by weight level or
less.
13. The method of claim 1 wherein the non dissolving grade pulp is
blended with the dissolving grade pulp at a 35% by weight level or
less.
14. The method of claim 1 wherein the non dissolving grade pulp is
blended with the dissolving grade pulp at a 20% by weight level or
less.
15. The method of claim 1 wherein the non dissolving grade pulp is
blended with the dissolving grade pulp at a 10% by weight level or
less.
Description
FIELD
[0001] The present application relates to a method for using high
hemicellulose pulps in viscose manufacture and the resulting fibers
therefrom.
DESCRIPTION
[0002] Pulp used for rayon manufacture has a high alpha cellulose
content generally in the range of 88 to 98 percent where alpha
cellulose represents the insoluble fraction of pulp that is not
dissolved when pulp is treated with 1.7.5% sodium hydroxide. Such
pulps are termed dissolving pulps. To achieve this degree of
purity, manufacturers must remove a substantial amount of the
hemicellulose by, for example, steam prehydrolysis prior to cooking
a Kraft pulp, or by cold caustic extraction in the bleaching
process, thereby adding substantially to the cost of manufacture. A
high percent of pentosans and other hemicelluloses are
objectionable in rayon grade pulps due to problems they cause in
filtration, spinning, fiber properties and also because they are an
indication that the morphological structure of the pulp has not
been altered sufficiently to obtain the desired reactivity.
[0003] Briefly, the viscose process is as follows. Steeping, or
mercerization, requires 18% sodium hydroxide and is carried out
either in sheet steeping in hydraulic presses with perforated steel
plates in batches of cellulose sheets vertically inserted, or as
slurry steeping where a slurry of fibers in approximately 18
percent caustic is prepared. The former operation is batchwise and
the excess caustic is removed by draining the caustic and then
pressing the alkali cellulose to a fixed press weight ratio. The
slurry steeping operation is continuous or batch and is followed by
pressing of the slurry by, for example, perforated roll presses or
vacuum filters with press rolls. At this point the alkali cellulose
contains about 30 percent cellulose and 15 percent sodium
hydroxide. It is then shredded, either batchwise in cooled sigma
blade shredders, or continuously in disc shredders to alkali
cellulose crumb. The alkali cellulose crumb is then aged in a
controlled manner at 15-40.degree. C. for a fixed time depending on
the end product use to reduce the degree of polymerization in the
range of 400 to 600. Xanthation is then conducted in chums or
barettes whereby carbon disulfide is charged into the vessel.
Approximately three hours are required at 20-35.degree. C. to give
a degree of substitution of the xanthate group of about 0.4-0.5.
The xanthate crumb is then dissolved in caustic to give viscose
which contains cellulose in the form of cellulose xanthate,
Dissolution is performed in vessels equipped with paddle stirrers.
The viscose is ripened, filtered and deaerated prior to
regeneration. Cellulose is regenerated by extrusion of the viscose
into coagulation baths, one or two in series, containing sulfuric
acid and such salts as sodium sulfate, bisulfate, and bisulfite,
magnesium sulfate, ammonium sulfate and zinc sulfate. The
composition of the baths varies with the effects desired. A typical
bath contains about 130 g/l H.sub.2SO.sub.4, 280 g/l
Na.sub.2SO.sub.4, 15 g/l Zn SO.sub.4 and 60 g/l glucose. If two
baths are used in series the second one is acidic to complete the
regeneration, whereas the first can be either acidic or a mainly
salt bath. The temperature of the coagulation baths is kept at
around 50.degree. C., spinning speed is around 100 m/min and the
bath travel is normally around 25 cm or longer. The spinneret holes
vary in diameter from 0.05 to 0.30 mm. The number of filaments per
thread varies from 10 to 1,000 and in the case of rayon staple
fiber, up to 50,000. The emerging yarn is stretched by godet wheels
at different speed differentials and subsequently wound on a
rotating bobbin or collected as a as a centrifugal cake in a
rotating bucket or fed to a cutter. The bobbins, cakes or cut
staple fibers are then washed, desulfurized, bleached, and
finishing treatment applied.
[0004] Cellophane manufacture follows the same pattern as textile
yarns up to the stage of coagulation, with small changes in the
caustic handling system. The viscose is extruded through a slit
into one or two coagulation baths the first of which may only
contain salts. The cellophane web passes through finishing baths,
one of which contains glycerol or other plasticizers and finally
into a dryer section and then further modified in the converting
industry such as laminating, printing and combination with plastic
films, metal foils, paper or board.
[0005] It has now been shown that an experimental non dissolving
grade pulp with high hemicellulose levels, (hereinafter called pulp
with high hemicellulose levels), and consequently lower cost, can
be used in the viscose process to achieve fiber properties which
are comparable to those of dissolving pulps. In the process, the
high hemicellulose pulp is blended with a dissolving grade pulp in
either the sheet steeping process or the slurry process.
[0006] The term hemicellulose refers to a heterogeneous group of
low molecular weight carbohydrate polymers that are associated with
cellulose in wood. Hemicelluloses are amorphous, branched polymers,
in contrast to cellulose which is a linear polymer. The principal,
simple sugars that combine to form hemicelluloses are D-glucose,
D-xylose, D-mannose, L-arabinose, D-galactose, D-glucuronic acid
and D-galacturonic acid. As used herein, hemicellulose refers to
the weight percent of xylan and mannan in oven dry pulp. In one
embodiment a high hemicelluose pulp contains at least about 12
percent by weight hemicellulose, In another embodiment the pulp
contains at least about 10 percent by weight hemicellulose. The
term high hemicellulose means at least 10 percent by weight
hemicellulose, in pulp based on oven dry weight of pulp. Oven dry
weight means the pulp was dried at 105.degree. C. for at least one
hour.
[0007] In one embodiment a high hemicellulose pulp is blended with
a dissolving pulp in the sheet steeping process. The two different
pulps can be placed in sheet form in separate compartments in the
steeping press or they can be placed in separate steeping presses.
In either case, after steeping and pressing the sheets to a fixed
press weight ratio, (PWR), the pulp is shredded to yield alkali
cellulose crumb. The alkali cellulose crumb from the separate
steeping presses can be mixed to yield a blended alkali cellulose
crumb. Blending can be accomplished either after shredding the
alkali cellulose sheets and then aging or after aging the alkali
cellulose from each of the two different pulps to a given D.P. of
the cellulose. D.P. refers to the degree of polymerization and
represents the number of D-glucose monomers in a cellulose
molecule. In one embodiment the pulp with high hemicellulose levels
is blended with the dissolving grade pulp at a 50 percent level, or
less, by total dry weight of pulp; in another embodiment pulp with
high hemicellulose levels is blended with the dissolving grade pulp
at a level of 35 percent, or less, by total dry weight of pulp; in
another embodiment the pulp with high hemicellulose levels is
blended with the dissolving grade pulp at a 20 percent level, or
less, by total dry weight of pulp; in yet another embodiment the
pulp with high hemicellulose levels is blended with the dissolving
pulp at a level of 10 percent, or less, by total dry weight of
pulp. Typical properties of two pulps with high hemicellulose
levels are presented in Table 1; Table 2, 2A, 3 and 3A represent
pulp and viscose processing properties of various pulp blends.
TABLE-US-00001 TABLE 1 Typical Pulp Properties for High
Hemicelluose Pulps Pulp EF EK .alpha.-Cellulose ~85 87 ~85 86
R.sub.10, % 85 82 R.sub.18, % 88 87 S.sub.18, % 12 13 Viscosity,
mPa * S 25 45 25 35 Copper Number 0.6 0.6 Cr, mg/kg <0.03
<0.03 Cu, mg/kg 0.3 0.3 Fe, mg/kg 3 3 Mn, mg/kg 20 10 K, mg/kg
<0.2 <0.2 SiO.sub.2, mg/kg 40 40 100 LWAFL, mm 2.1 1.2
TABLE-US-00002 TABLE 2 Pulp and Alkali Cellulose Properties Using
Sheet Steeping 85% Beech 65% Beech Saiccor Beech 85% PHK 65% PHK
Sulfite Sulfite 85% Saiccor Pulp sulfite sulfite EK PHK 15% EK 35%
EK 15% EK 35% EK 15% EK Pulp Parameter D.P. (CED) 901 1171 907 855
867 853 1151 1101 912 R 18 (%) 93.99 92.55 84.73 94.57 93.9 91.97
91.66 90.6 93.97 R 10 (%) 90.06 88.28 83.19 91.82 92.09 88.91 87.29
86.44 89.5 S.sub.18, % 6.01 7.45 15.23 5.43 6.1 8.03 8.34 9.4 6.03
S.sub.10, % 9.94 11.72 16.81 8.18 11.09 11.09 12.71 13.56 10.5
Hemicellulose, % ~2.3 3.59 12.5 3.19 4.9* 6.5* 4.9* 6.7* ~3.9*
Pulp, (g) 345 284 293 293 295 292 288 281 296 A.C, (g) 1142 840 923
832 830 850 869 865 971 PWR 3.31 2.98 3.18 2.84 2.81 2.91 3.02 3.08
3.28 A.C. (%) 29.58 31.39 27.67 33.87 33.73 31.96 30.51 29.56 28.6
Alkali (%) 15.4 15.06 15.36 15.88 14.81 15.10 14.66 14.70 15.15
Aging Time, Hr. 27 38 26.at 28.degree. C. 28 at 28.degree. C. 30 at
28.degree. C. 27 at 28.degree. C. 32.5 at 32.5 at 28.degree. C. 29
at 28.degree. C. at 28.degree. C. at 28.degree. C. and 20 at and 23
at 28.degree. C. and 24 at 23.degree. C. 25.degree. C. 20.degree.
C. D.P. (CED) 592/348 573/337 594/349 585/344 628/368 540/319
585/344 564/332 591/347 Beech Sulfite, from Lenzing; PHK from
Buckeye *calculated value
TABLE-US-00003 TABLE 2A Viscose and Fiber Properties Using Sheet
Steeping 85% Beech 65% Beech Saiccor Beech 85% PHK, 65% PHK,
Sulfite Sulfite 85% Saiccor Pulp Sulfite Sulfite EK PHK 15% EK 35%
EK 15% EK 35% EK 15% EK Viscose Preparation Filter Plugging No Yes
Yes No No No No No No Cellulose (%) 8.2 8.35 7.81 8.5 8.29 7.82
8.16 8.18 8.26 Alkali (%) 5.95 6.0 6.07 6.21 6.2 6.03 6.03 6.05
5.92 D.S. Viscose 0.50 0.47 0.52 0.52 0.52 0.54 0.53 0.51 0.50 Ball
Fall, 1/8'' (s) 54 53 82 73 58 28 60 46 40 KW 6431 23857 19702 749
1042 1216 2982 3729 5375 KR 5235 19465 13503 539 824 1277 2315 3236
4943 Counts/g viscose (.times.100) >4 .mu.m 455 772 793 91 77
124 420 496 623 >10 .mu.m 138 213 157 11 9 15 53 82 187 >20
.mu.m 7 23 25 1 1 1 4 5 17 Counts/g cellulose (.times.100) >4
.mu.m 5554 9250 10158 1069 934 1583 5150 6058 7538 >10 .mu.m
1689 2548 2013 131 111 192 652 1003 2260 >20 .mu.m 82 278 317 16
12 11 45 62 202 Spinning: max draw ratio 1.4 1.5 1.6 1.5 1.5 1.5
1.5 1.5 1.5 1.5 1.5 Fiber Properties Tensile strength (cN/tex) 20.5
19.2 20.96 20.99 20.6 20.8 21.0 20.5 20.3 Elongation (%) 10.05 13.2
12.05 11.25 12.3 12.59 11.1 11.52 11.6 Modulus (cN/tex) 1035 954
1050 1048 1038 1016 1069 1037 1054 Beech Sulfite, from Lenzing; PHK
from Buckeye. Ball fall, KW, KR and viscose and cellulose counts
were determined on unfiltered viscose after 20 hr.
TABLE-US-00004 TABLE 3 Pulp And Alkali Cellulose Properties Using
Sheet Steeping 85% PHK 85% Beech Sulfite Pulp 15% EF 15% EF 100% EF
Pulp Parameter D.P. (CED) 860 1009 822 R 18 (%) 93.97 89.75 86.22 R
10 (%) 92.03 86.53 83.99 S.sub.18, % 6.03 10.25 13.78 S.sub.10 7.97
13.47 16.01 % Hemicellulose 4.59* 4.93* ~12.5 A.C. Pulp, (g) 291
288 295 A.C, (g) 826 850 833 Press factor 2.84 2.95 2.82 A.C. (%)
34.26 30.95 30.82 Alkali (%) 15.49 15.30 15.52 Aging time, Hr. 29
at 28.degree. C. and 32.5 at 28.degree. C. 25.5 at 26.5 at
20.degree. C. 28.degree. C. D.P. (CED) 562/331 456/272 553/326
*Calculated value
TABLE-US-00005 TABLE 3A Viscose and Fiber Properties Using Sheet
Steeping 85% Beech 85% PHK Sulfite Pulp 15% EF 15% EF 100% EF
Viscose Preparation Filter Plugging No No No Cellulose (%) 8.26
8.35 8.18 Alkali (%) 5.98 5.99 5.84 D.S. Viscose 0.49 0.53 0.51
Unfiltered viscose after 20 hr. Ball Fall, 3.18 mm (s) 28 16.6 19.9
KW 463 2887 6095 KR 489 3756 7371 Counts/g viscose (.times.100)
>4 .mu.m 37 334 370 >10 .mu.m 7 62 74 >20 .mu.m 1 6 20
Counts/g cellulose (.times.100) >4 .mu.m 444 4000 4524 >10
.mu.m 90 744 903 >20 .mu.m 11 71 241 Spinning:max draw ratio 1.5
-- 1.6 Fiber Properties Not spinnable Tensile strength (cN/tex)
21.4 -- 20.1 Elongation (%) 11.2 -- 10.2 Modulus (cN/tex) 1065 --
1104
[0008] Fiber properties of viscose preparations made from blends of
pulp are at least equal to those of the dissolving pulp, Table 2A
and 3A. In one embodiment the tensile strength of the fibers
prepared from a viscose containing high hemicellulose pulp are at
least equal to those prepared from a dissolving grade pulp. In
another embodiment the tensile strength of the fibers prepared from
a viscose containing blends of the pulp with high hemicellulose
levels and a dissolving grade pulp are at least equal to those
prepared from a dissolving grade pulp alone. Elongation and modulus
of fibers prepared only from the pulps with high hemicellulose,
designated as EK and EF, are at least equal to the dissolving grade
pulps. In one embodiment the elongation of the fibers prepared from
a viscose containing pulp with high hemicellulose levels are at
least equal to those prepared from a dissolving grade pulp alone.
In another embodiment the modulus of the fibers prepared from a
viscose containing pulp with high hemicellulose levels and a
dissolving grade pulp are at least equal to those prepared from a
dissolving grade pulp alone.
[0009] The chemical composition of the viscose fibers is given in
Table 4.
TABLE-US-00006 TABLE 4 Hemicellulose Levels of Viscose Fibers % % %
% % % Total Pulp Arabinose Galactose Glucose Xylose Mannose Total %
Hemicellulose Beech Sulfite <0.1 <0.1 94.63 0.84 0.01 95.47
0.85 65% PHK/ <0.1 <0.1 95.07 0.95 0.95 96.97 1.90 35% EK 65%
Beech <0.1 <0.1 94.72 1.05 0.90 96.68 1.96 Sulfite/35% EK 85%
PHK/ <0.1 <0.1 94.08 1.02 -.69 95.79 1.71 15% EF 85% PHK/
<0.1 <0.1 94.87 0.76 0.78 96.41 1.54 15% EK 85% Beech Sulfite
<0.1 <0.1 94.71 0.96 0.41 96.08 1.37 15% EK PHK <0.1
<0.1 95.59 0.76 0.68 97.03 1.44 EK <0.1 <0.1 91.59 1.06
2.36 95.01 3.42 Total Hemicellulose represents the sum of xylan and
mannan
[0010] In another embodiment the pulps are blended in a slurry
process. In this case the pulp with high hemicellulose levels and
the dissolving grade pulps can be added separately in sheet form to
the alkaline medium and then mixed thoroughly to obtain a
homogeneous fibrous slurry. Alternatively, each pulp can be added
to separate steeping vessels, in sheet form, followed by
disintegration in the steeping vessel, steeping the pulp, pressing
the alkali cellulose (AC) after removal of the alkaline medium, and
subsequently shredding the alkali cellulose for conversion to an
alkali cellulose crumb. At this point the shredded alkali cellulose
crumb can either be blended subsequent to shredding and aged as a
uniform alkali cellulose blend or can be aged separately to a given
D.P. and then blended. Alkali cellulose and viscose properties are
shown in Table 5.
TABLE-US-00007 TABLE 5 Alkali Cellulose and Viscose Properties
Using Slurry Steeping Sample 50% EF/ 50% EF/ 25% EF/ 25% EF/
sulfite PHK sulfite PHK 100% EF Time to P.W.R., sec. 15 15 15 15 15
Aging Time, hrs 6.5 5.25 6.5 5.25 6.3 Final AC viscosity, cp 10.5
10.5 10.6 10.3 11.5 70% Vacuum Recovery, 41 42 47 52 50 min.
Filterability, .times. 0.001 94 269 46 200 419 Salt Index 4.5 4.5
4.5 4.5 3.5 Clarity, cm 12.7 20.1 13.5 16.5 7.7 Haze, .times. 1000
92 59 86 75 115 Mixer Ball Fall 45 77 40 57 123 Viscosity, sec.
19-Hour Ball Fall 30 58 37 44 85 Viscosity, sec.
[0011] In one embodiment in the slurry process, the pulp with high
hemicellulose levels is blended with the dissolving grade pulp at a
50 percent level, or less, by total dry weight of pulp; in another
embodiment the pulp with high hemicellulose levels is blended with
the dissolving grade pulp at a level of 35 percent, or less, by
total dry weight of pulp; in another embodiment the pulp with high
hemicellulose levels is blended with the dissolving grade pulp at a
20 percent level, or less, by total dry weight of pulp; in yet
another embodiment the pulp with high hemicellulose levels is
blended with the dissolving grade pulp at a level of 10 percent, or
less, by total dry weight of pulp.
[0012] The dissolving pulps used for blending with the non
dissolving grade pulp with high hemicellulose pulps can be either
Kraft, sulfite, or cotton linters. Kraft and sulfite pulps can be
made from southern or northern softwoods. Commercially available
pulp used in this work included the following, a sulfite pulp from
Saiccor with an S.sub.18 of 6.01%, an S.sub.10 of 9.94% and a
hemicellulose level of 2.3%; a Beech sulfite pulp from Lenzing with
an S.sub.18 of 7.45%, an S.sub.10 of 11.72% and a hemicellulose
level of 3.59%; a prehydrolyzed kraft pulp from Buckeye with an
S.sub.18 of 5.43%, an S.sub.10 of 8.18% and a hemicellulose level
of 3.19%; an experimental modified Kraft pulp made from sawdust
with an S.sub.18 of 15.23%, an SO.sub.10 of 16.81% and a
hemicellulose level of .about.12.5%, designated as EK; and an
experimental modified Kraft pulp for viscose made from southern
pine chips with an S.sub.18 of 13.78% an S.sub.10 of 16.01% and a
hemicellulose level of -12.5 designated as EF pulp. Analytical
properties of all pulps used are shown in Tables 2 and 3.
[0013] S.sub.18 as defined herein is 100-% R.sub.18 where R.sub.18
refers to the residual amount of undissolved material left after
attempting to dissolve the pulp in an 18% caustic solution and is
expressed as a percent. S.sub.10 as defined herein is 100-%
R.sub.10 where R.sub.10 refers to the residual amount of
undissolved material left after attempting to dissolve the pulp in
10% caustic solution and is expressed as a percent. 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.
R.sub.10 value and the R.sub.18 values were determined by TAPPI
235. The percent hemicellulose was determined by the method
described in this application and represents the sum of the percent
mannan and xylan in the pulp or fiber.
[0014] The modified Kraft pulp with high hemicellulose, designated
as EF, can be made in a commercial continuous extended
delignification process in the laboratory utilizing a specially
built reactor vessel with associated auxiliary equipment, including
circulating pumps, accumulators, and direct heat exchangers, etc.
Reactor temperatures can be controlled by indirect heating and
continuous circulation of cooking liquor. In the process, the
reactor vessel is charged with a standard quantity of equivalent
moisture free wood. An optional atmospheric pre-steaming step may
be carried out prior to cooking. A quantity of cooking liquor,
ranging from about 50% to 80% of the total, is then charged to the
digester along with dilution water to achieve the target liquor to
wood ratio. The reactor is then brought to impregnation temperature
and pressure and allowed to remain for the target time. Following
the impregnation period, an additional portion of the total cooking
liquor is added to the reactor vessel, ranging from about 5% to 15%
of the total. The reactor is then brought to cooking temperature
and allowed to remain there for the target time period to simulate
the co-current portion of the cook.
[0015] Following the co-current portion of the cook, the remainder
of the cooking liquor can be added to the reactor vessel at a fixed
rate. The rate is dependent on the target time period and
proportion of cooking liquor used for this step of the cook. The
reactor can be controlled at a target cooking temperature and
allowed to remain there during the simulation of the
counter-current portion of the cook. Spent cooking liquor can then
be withdrawn from the reactor into an external collection container
at the same fixed rate. At the end of the cook, the reactor vessel
is slowly depressurized and allowed to cool below the flash point.
The reactor vessel is then opened and the cooked wood chips
collected, drained of liquor, washed, screened and made ready for
testing. Typical conditions which can be used to make a modified
Kraft pulp from southern pine chips that have high hemicellulose
levels and designated as EK pulp in this application are given in
Table 6.
TABLE-US-00008 TABLE 6 Pulping Process Parameters for Low Specific
Gravity Wood Wood Chip S.G. 0.410 Pre-Steam @ 110.degree. C.,
minutes 5 Impregnation: Time, minutes 35 % Effective Alkali,
initial 8.5 % EA, second @ 5 minutes 1.6 % sulfidity 29 Liquor
ratio 4 Temperature - degrees C. 110 Residual, G/L EA 9.63
Residual, % EA 3.85 pH 12.77 H-factor 2 Pressure Relief Time,
Minutes 3 Co-Current: % Effective Alkali 4.2 % sulfidity 29 Liquor
addition time, minutes 1 Temperature - degrees C. 154 Time to,
minutes 9 Time at, minutes 5 Temperature - degrees C. 170 Time to,
minutes 51 Time at, minutes 3 Residual, G/L EA 9.42 Residual, % EA
3.77 pH 12.92 H-factor 649 Counter-Current: % effective alkali 8 %
sulfidity 29.2 Temperature - degrees C. 171 Time to, minutes 54
Time at, minutes 0 Temperature - degrees C. 171 Time to, minutes 0
Time at, minutes 162 EA, G/L - strength 16.0 Displacement rate,
CC/M 93 Displacement volume, liters 20.00 Residual, G/L EA 9.95
Residual, % EA 3.98 pH 12.74 H-factor 3877 Total Time, minutes 319
% Effective Alkali - Total Cook 22.3 Accepts, % on O.D. Wood 41.01
Rejects, % on O.D. Wood 0.03 Total Yield, % on O.D. Wood 41.04
Kappa Number, 10 minutes 16.80
Bleaching Process
[0016] The brownstock pulp was processed through an ODE.sub.PD
stage using the following chemical addition levels:
Oxygen Stage
Sodium hydroxide was added at a rate of 32 kg/T and peroxide at
13.6 kg/T. Caustic strength of 12% was used and the top tray of the
reactor was about 130.degree. C.
D Stage
Chlorine Dioxide was added at 10-11.4 kg/T.
E.sub.P Stage
Caustic was added at a rate of about 27.3 kg/T. Hydrogen peroxide
was added at a rate equivalent to 18.2 kg/T.
D Stage
Chloride dioxide was added at a rate of 12.3 kg/T.
[0017] Pulp treated in this manner has a hemicellulose, (xylan and
mannan), content of 11.92%.
[0018] In another example, low specific gravity wood having a
specific gravity of 0.410 was pulped using the Kraft process and
subsequently bleached and treated with varying amounts of oxygen to
reduce its viscosity. Components in the pulps made using low
specific gravity wood chips are 7.2% xylans and 5.5% mannans for a
total hemicellulose level of 12.7% by weight hemicellulose.
[0019] Table 7 shows typical properties of pulp from cooking a low
specific gravity wood.
TABLE-US-00009 TABLE 7 Chips Specific Gravity 0.410 Kappa of
Brownstock 24.4 Yield, % 43.2 Brownstock pulp viscosity (cP)
Falling Ball 414 Brownstock pulp WAFL (mm) 2.70 Brownstock pulp
Coarseness 18.3 (mg/100 m) O.sub.2 pulp viscosity cP 55 (50 g/kg
NaOH) 7.6 kappa O.sub.2 pulp viscosity cP 80 (30 g/kg NaOH) 6.0
kappa Bleached pulp coarseness 32.4 (mg/100 m) Bleached pulp
fibers/g .times. 10.sup.6 4.8 Bleached pulp viscosity (cP) 31.8
Bleached pulp intrinsic viscosity 4.1 Bleached pulp Cu (ppm) 0.6
Bleached pulp Fe (ppm) 12 Bleached pulp Mn (ppm) 1.5 Bleached pulp
Cr (ppm) <0.4 Bleached pulp Si (ppm) 41
[0020] Pulping conditions used for typical wood chip having a
specific gravity of 0.495 are shown in Table 8.
TABLE-US-00010 TABLE 8 Pulping Process Parameters for Non-Low
Specific Gravity Wood Wood Chip S.G. 0.495 Pre-Steam @ 110 C.,
minutes 5 Impregnation: Time, minutes 35 % Effective Alkali,
initial 8.5 % EA, second @ 5 minutes 1.6 % sulfidity 30.5 Liquor
ratio 4 Temperature - degrees C. 110 Residual, G/L EA 9.17
Residual, % EA 3.67 pH 13.24 H-factor 2 Pressure Relief Time,
Minutes 2 Co-Current: % Effective Alkali 4.2 % sulfidity 30.5
Liquor addition time, minutes 1 Temperature - degrees C. 157 Time
to, minutes 14 Time at, minutes 0 Temperature - degrees C. 170 Time
to, minutes 54 Time at, minutes 0 Residual, G/L EA 8.31 Residual, %
EA 3.32 pH 13.07 H-factor 680 Counter-Current: % effective alkali 8
% sulfidity 30.0 Temperature - degrees C. 171 Time to, minutes 54
Time at, minutes 0 Temperature - degrees C. 171 Time to, minutes 0
Time at, minutes 162 EA, G/L - strength 20.4 Displacement rate,
CC/M 73 Displacement volume, liters 15.87 Residual, G/L EA 9.72
Residual, % EA 3.89 pH 13.18 H-factor 3975 Total Time, minutes 319
% Effective Alkali - Total Cook 22.3 Accepts, % on O.D. Wood 44.23
Rejects, % on O.D. Wood 0.13 Total Yield, % on O.D. Wood 44.36
Kappa Number, 10 minutes 17.75
[0021] Table 9 shows typical properties of pulp of three different
cooks using a conventional wood chips made from a non-low specific
gravity wood. Components in the pulps made using non-low specific
gravity wood chips were 5.7% xylans; and 5.9% mannans.
TABLE-US-00011 TABLE 9 Inwoods Inwoods chips chips Inwoods chips
Cook A Cook B Cook C Chips Specific Gravity 0.495 0.495 0.495 Kappa
of Brownstock 26.9 20.8 17.8 Yield, % 46.6 46.1 44.4 Brownstock
pulp viscosity (cP) 633 358 243 Falling Ball Brownstock pulp WAFL
(mm) 4.13 4.14 4.19 Brownstock pulp Coarseness 26.1 24.4 24.3
(mg/100 m) O.sub.2 pulp viscosity cP 96 43 41 (50 g/kg NaOH) 6.4
kappa 6.9 kappa 4.7 kappa O.sub.2 pulp viscosity cP 180 88 70 (30
g/kg NaOH) 8.3 kappa 5.5 kappa 6.2 kappa Bleached pulp coarseness
24.9 27.5 (mg/100 m) Bleached pulp fibers/g .times. 10.sup.6 3.8
2.8 Bleached pulp viscosity (cP) 28.5 24.2 Bleached pulp intrinsic
viscosity 4.3 4 Bleached pulp Cu (ppm) <0.6 <0.7 Bleached
pulp Fe (ppm) 11.5 16.0 Bleached pulp Mn (ppm) 5 6 Bleached pulp Cr
(ppm) <0.4 0.3 Bleached pulp Si (ppm) .ltoreq.1 32
Example of Pulping Conditions--Modified Kraft Pulp, EK
[0022] Brownstock sawdust pulp was produced in an industrial scale
M&D digester. The digester was operated at a temperature of
about 182.degree. C., and average residence time in the digester
was about 60 minutes. White liquor was used as the cooking liquor
in the digester. The white liquor had a total titratable alkali
(TTA) of 115.2 grams per liter as Na.sub.2O, an active alkali (AA)
of 99.2 grams per liter as Na.sub.2O, an effective alkali (EA) of
81.6 grams per liter as Na.sub.2O. Sulfidity of the white liquor
was 28% of TTA. Specific gravity of the white liquor was 1.15.
[0023] Northern Softwood sawdust unbleached alkaline kraft pulp
(main wood species were Douglas fir, Spruce and Lodgepole pine),
produced under the stated conditions, with a kappa number of 21.0
(TAPPI Standard T236 cm-85 and a viscosity of 110 cp (TAPPI T230)
(D.P. of 1264), and a hemicellulose content of 14.1%.+-.1.5%.
[0024] Brownstock was processed through five stage D.sub.0
E.sub.P1D.sub.1E.sub.P2D.sub.2 bleaching with a Papricycle stage
intermediate D.sub.0 and E.sub.P1.
[0025] D.sub.0 Stage
[0026] A chlorine dioxide level of 6.8-9.5 kg/ADMT at 68.degree. C.
was used.
[0027] Papricycle Stage
[0028] This stage was run at a target pH of 12.0 at 74.degree. C.
using 9.1 kg/ADMT.
[0029] E.sub.P1 Stage
[0030] This stage is key to reducing viscosity. Peroxide was added
at 22.7 kg/ADMT. Caustic was added at 22.7 kg/ADMT at 84.degree. C.
and a pH of 11.2.
[0031] D.sub.1 Stage
[0032] ClO.sub.2 was added at 12.5 kg/ADMT.
[0033] E.sub.P2 Stage
[0034] Peroxide was added at 50 kg/ADMT and caustic at 29.5-31.8
kg/ADMT.
[0035] D.sub.2 Stage
[0036] Chlorine dioxide was added at a level of 5 kg/ADMT.
Pulp Preparation for Use in Sheet Steeping
[0037] Pulp sheets, blended in the ratios shown in Tables 2, 2A, 3,
and 3A were prepared with the modified Kraft pulps designated as EF
pulp, prepared from southern pine chips and the modified Kraft pulp
designated as EK pulp, prepared from northern softwood sawdust as
follows. The appropriate amounts of dissolving pulp and high
hemicellulose pulp, based on oven dry weight, and the ratios
indicated in Tables 2, 2A, 3 and 3A were dispersed in water at a 3%
consistency with a Lightning mixer. The resulting fibrous slurry
was dewatered through a 30.5 cm.times.30.5 cm. screen, the
dewatered mat pressed twice in a TAPPI press, and steam dried to
make a 750 g/m.sup.2, 0.55 g/cm.sup.3 sheet. As an example, an 85%
PHK 15% EK means that the pulp sheet contained 85% by total oven
dry weight. PHK pulp and 15% by total oven dry weight of the non
dissolving grade pulp with high hemicellulose.
Pulp Preparation for Use in Slurry Steeping
[0038] A fibrous mixture of a dissolving pulp and the non
dissolving grade pulp with the high hemicellulose, designated as EF
pulp, prepared from southern pine chips and a fibrous mixture of a
dissolving grade pulp and the pulp with the high hemicellulose
levels, designated as EK pulp, were prepared from northern softwood
sawdust follows. The appropriate amounts of dissolving pulp and
high hemicellulose pulp, based on oven dry weight, and the ratios
indicted in Table 5 were dispersed in water at a 3% consistency
with a Lightning mixer. The resulting fibrous slurry was dewatered,
centrifuged, fluffed with a pin mill and air dried. The resulting
fluffed pulp fibers were used for slurry steeping.
[0039] Sheet Steeping
[0040] Steeping was conducted in a steeping press using 12-14
sheets of the blended pulp, shown in Tables 2, and 3 and 18%
caustic at ambient temperature for 40 minutes. The sheets were
pressed out in a Blashke press to a press weight ratio (PWR) in 60
seconds at a pressure of 30 bar. Press weight ratio (PWR) is
defined as the final weight of the alkali cellulose divided by the
initial oven dry weight of cellulose. Oven dry weight is the weight
of a sample after drying at 105.degree. C. for at least one
hour.
[0041] Shredding/Aging
[0042] The alkali cellulose sheets were shredded through a
laboratory refiner and the shredded alkali cellulose crumb was aged
at 28.degree. C. to reach a target D.P. (CED, cupriethylenediamine
solution) of 580. D.P. was determined by SCAN-CM-15:88. In the
test, commercial cupriethylenediamene (cuene) solution, 1 mol/l was
used at a concentration of 0.2% in a 50/50 mixture cuene (1
mol/l)/water at 25.degree. C. The formula for the D.P. were as
follows, D.P.<950:.eta.=0.42.times.D.P. and D.P.>950:
.eta.=2.28.times.D.P..sup.0.76. Alkali and cellulose in AC were
determined as follows. Five g of AC and 25 ml. of 1N
H.sub.2SO.sub.4 were mixed in a flask and diluted with water after
15 minutes. After an additional 5 minutes the mixture was titrated
with 1 N NaOH using methyl orange as indicator. The percent alkali
was calculated as
( 25 - c ) .times. 4 W ##EQU00001##
where c is the concentration of NaOH, and W is the sample weight.
Cellulose in AC was determined by thoroughly washing the
precipitated cellulose of the AC analysis on a fritted funnel and
drying the cellulose at 105.degree. C. The percent cellulose was
calculated as
w .times. 100 W ##EQU00002##
where w is the weight of the dried sample and W is the weight of
the AC.
[0043] Xanthation/Dissolution/Filtration
[0044] The AC (alkali cellulose) crumb was dry xanthated in a
rotating bottle. AC crumb was introduced into the bottle and the
bottle evacuated. CS.sub.2, 28 weight percent on dry cellulose was
introduced into the bottle, and xanthation allowed to proceed for
1.5 hr. at 28.degree. C.
[0045] Dissolution of the cellulose xanthate was conducted by
mixing the xanthate crumb with caustic containing 0.1%
hemicellulose for 2 hours at 2-12.degree. C. to make an 8.5%
cellulose, 6% caustic 28% CS) viscose solution. The viscose
solution for spinning was filtered using Southwest Screens and
Filters (Belgium) with three filter screens with openings of 20,
10, and 5 .mu.m respectively. For filterability, a 400 ml tube is
filled with viscose and a pressure of 2 bar is applied over a
surface area of 4 cm using a filter paper with an air permeability
of 15+/-2 l/min. In the test, the quantity of viscose filtered in
the first 20 minutes is measured in grams (a), and then in the next
20 to 60 minutes the viscose is measured in grams (b). Based on
these values, the filterability is calculated as
KW=100000.times.(2-b/a)/(a+b). KR is the viscosity corrected
filterability according to the following equation,
KR=F.times.KW/.eta..sup.0.4 where .eta.is the ball fall time of a
3.18 mm ball in seconds and F is the filter surface area of 4
cm.sup.2. A good filterability range for KW and KR is 500 and less.
The viscose was ripened at 20 to 25.degree. C. to the 8.degree. H
range. H is the Hottenroth degree or number and represents the
number of milliliters of 10% ammonium chloride that is necessary to
add to a diluted viscose to induce incipient coagulation under
standard conditions. In the test, 20 g of viscose was diluted with
30 ml water and titrated with 10% ammonium chloride solution to
coagulation. The Degree of Substitution (D.S.) of the xanthate
group was determined on viscose immediately after completion of
mixing. Ball fall viscosity, filtration value and particle count
were determined after 20 hours of ripening. Ball fall viscosity is
the time required in seconds for a 3.18 mm steel ball to fall 20 cm
in viscose in a 20 cm. diameter cylinder at 20.degree. C. Particle
count was determined with PAMAS particle counter. The D.S. (degree
of substitution) of the xanthate group was determined as follows.
One gram of viscose is dissolved in 100 ml cold water and then,
under cooling, CO.sub.2 is fed into the solution to the point where
hydrogen sulfide is not detected with lead acetate (2) paper in the
CO.sub.2 stream. The solution is then titrated with 0.02%
Iodine--solution using starch as indicator. The gamma value is
calculated as (a.times.32.4)/W.times.b, where a is the volume of
0.02 percent iodine--solution, b is the cellulose in viscose and W
is the sample weight. The alkali and cellulose in viscose were
determined as follows. Two to three grams of viscose were
accurately weighed and dissolved in 100 ml. water. Twenty ml. of
0.5 N H.sub.2SO.sub.4 was added and the mixture shaken. The mixture
was titrated after 30 minutes with 0.5 N NaOH using methyl red as
indicator and the alkali content calculated as follows
% alkali = ( 20 - a ) .times. 2 W ##EQU00003##
where a is the volume of 0.5 N NaOH consumed and W is the weight of
the viscose sample. The cellulose content in viscose was determined
by accurately weighing 3 grams of viscose onto a slide and the
viscose pressed to a thin film with a second slide. The two slides
are separated and each slide dried for 15 min. at 50.degree. C.,
then immersed in a bath containing 10% H.sub.2SO.sub.4. The films
are then washed thoroughly and dried at 105.degree. C. and the
cellulose content in the viscose calculated.
[0046] Spinning
[0047] The viscose was spun through a 40 hole spinnerette with 70
.mu.m holes into a coagulation bath of 80 g/l sulfuric acid, 240
g/l sodium sulfate and 30 g/l zinc sulfate at 48.degree. C. A
decomposition bath containing 50 g/l sulfuric acid and 20 g/l
sodium sulfate was used. The single fiber titer was 2.8 dtex.
Washing was conducted on the first mating roll at ambient
temperature and on mating rolls two and three at 60.degree. C. The
filaments were finished with Stocko MW 5866. Two rolls were dried
at once at a temperature of 100.degree. C. to 70.degree. C.
Shrinkage was 1.5%, draw ratio 1.2 and a spinning speed of 40
m/min.
[0048] Slurry Steeping
[0049] In cases where Saiccor pulp was blended with EF pulp, each
pulp was first dispersed in water, the two fibrous mixtures then
blended into a single mixture, stirred, dewatered, and made into
sheets. The resulting sheets were air dried and then a fixed weight
of pulp introduced into the slurry steeping vessel containing 17.8
percent sodium hydroxide, stirred to disintegrate the sheets, and
steeped for 30 minutes at 45.degree. C. In the case where PHK pulp
was used, the pulp was first cut into 1.25.times.1.25 cm. squares
and then disintegrated together with the EF pulp, in sheet form, in
the slurry medium. The resulting slurry was then processed as
previously described. In both cases, the resulting slurry was
drained to recover the alkali cellulose and then pressed to a PWR
of 2.95. The pressed alkali cellulose was then shredded in a high
speed shredder to yield alkali cellulose crumb. The AC crumb was
aged at 46.5.degree. C. and viscosity determined by TAPPI T25.
Xanthation was conducted with 28% by weight carbon disulfide on dry
weight of cellulose basis for 60 minutes at 31.degree. C. The
resulting xanthate crumb was dissolved in caustic to make a
9.0/5.5/28 composition viscose. The resulting viscose solution was
ripened at 18.degree. C. and filterability determined on the
ripened viscose using a filter pack containing one piece of muslin
cloth, one piece of Whatman 54 filter paper and two pieces of
canton flannel. The muslin and flannel were obtained from Celanese
Corp. of America. In the method the volume of filtrate is recorded
every ten minutes and a graph of time vs. time/volume is plotted to
obtain a slope.
Sugar Analysis
[0050] 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).
Summary of Method
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.
Sampling, Sample Handling and Preservation
Wet samples are air-dried or oven-dried at 25.+-.5.degree. C.
Equipment Required
Autoclave, Market Forge, Model # STM-E, Serial # C-1808
[0051] 100.times.10 mL Polyvials, septa, caps, Dionex Cat #
55058
Gyrotory Water-Bath Shaker, Model G76 or some equivalent.
Balance capable of weighing to .+-.0.01 mg, such as Mettler HL52
Analytical Balance.
Intermediate Thomas-Wiley Laboratory Mill, 40 mesh screen.
NAC 1506 vacuum oven or equivalent.
0.45-.mu. GHP filters, Gelman type A/E, (4.7-cm glass fiber filter
discs, without organic binder)
Heavy-walled test tubes with pouring lip, 2.5.times.20 cm.
Comply SteriGage Steam Chemical Integrator
GP 50 Dionex metal-free gradient pump with four solvent inlets
Dionex ED 40 pulsed amperometric detector with gold working
electrode and solid state reference electrode
Dionex autosampler AS 50 with a thermal compartment containing the
columns, the ED 40 cell and the injector loop
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
CarboPac PA1 (Dionex P/N 035391) ion-exchange column, 4
mm.times.250 mm
CarboPac PA1 guard column (Dionex P/N 043096), 4 mm.times.50 mm
Millipore solvent filtration apparatus with Type HA 0.45u filters
or equivalent
Reagents Required
All references to H.sub.2O is Millipore H.sub.2O
[0052] 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. JT 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, [127-09-3].
Standards
Internal Standards
Fucose is used for the kraft and dissolving pulp samples.
2-Deoxy-D-glucose is used for the wood pulp samples.
[0053] 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. 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.
Kraft Pulp Stock Standard Solution
Kraft Pulp Sugar Standard Concentrations
TABLE-US-00012 [0054] 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
Kraft Pulp Working Solution
[0055] 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.
Pulp Sugar Standard Concentrations for Kraft Pulps
TABLE-US-00013 [0056] Fucose mL/200 mL mL/200 mL mL/200 mL mL/200
mL mL/200 mL Sugar mg/mL 0.70 ug/mL 1.40 ug/mL 2.10 ug/mL 2.80
ug/mL 3.50 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
Dissolving Pulp Stock Standard Solution
Dissolving Pulp Sugar Standard Concentrations
TABLE-US-00014 [0057] Sugar Manufacturer Purity g/100 mL Glucose
Sigma 99% 6.40 Xylose Sigma 99% 0.120 Mannose Sigma 99% 0.080
Dissolving Pulp Working Solution
[0058] 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.
Pulp Sugar Standard Concentrations for Dissolving Pulps
TABLE-US-00015 [0059] Fucose mL/200 mL mL/200 mL mL/200 mL mL/200
mL mL/200 mL Sugar mg/mL 0.70 ug/mL 1.40 ug/mL 2.10 ug/mL 2.80
ug/mL 3.50 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
Wood Pulp Stock Standard Solution
Wood Pulp Sugar Standard Concentrations
TABLE-US-00016 [0060] Sugar Manufacturer Purity g/200 mL Fucose
Sigma 99% 12.00 Rhamnose Sigma 99% 0.0701
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.
Wood Pulp Working Solution
[0061] Use the Kraft Pulp Stock solution and the fucose and
rhamnose stock solutions. Make working standards as in the
following table.
Pulp Sugar Standard Concentrations for Kraft Pulps
TABLE-US-00017 [0062] 2-Deoxy-D-glucose mL/200 mL mL/200 mL mL/200
mL mL/200 mL mL/200 mL Sugar mg/mL 0.70 ug/mL 1.40 ug/mL 2.10 ug/mL
2.80 ug/mL 3.50 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
Procedure
Sample Preparation
[0063] Grind 0.2.+-.05 g sample with Wiley Mill 40 Mesh screen
size. Transfer 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 Brinkman 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:
Heat: High
Control Thermostat: 7.degree. C.
[0064] Safety thermostat: 25.degree. C.
Speed: Off
Shaker: Off
[0065] 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.
Tightly cover samples and standard flasks with aluminum foil to be
sure that the foil does not come off in the autoclave.
[0066] 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.). 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. For Kraft and Dissolving pulp samples:
Filter an aliquot of the sample through GHP 0.45.mu. filter into a
16-mL amber vial.
[0067] For Wood pulp samples: 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.
Chromatography Procedure
Solvent preparation
Solvent A is distilled and deionized water (1.8 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.
[0068] 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. (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.
0.400 M NaOH*(1000 mL H.sub.2O/19.1 M NaOH)=20.8 mL NaOH
[0069] Round 20.8 mL down for convenience:
19.1 M*(20.0 mL x mL)=0.400 M NaOH
[0070] x mL=956 mL 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.
The post-column addition solvent is 300 mM NaOH. This is added
post-column 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.
[0071] (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.
0.300 M NaOH*(1000 ml H2O/19.1 M NaOH)=15.7 mL NaOH
[0072] Round 15.7 mL down:
19.1M*(15.0 mL/x mL)=0.300 M NaOH
[0073] x mL=956 mL
(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.)
Set up the AS 50 schedule.
[0074] 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. Run the five standards at the beginning of
the run in the following order:
STANDARD A1 DATE
STANDARD B1 DATE
STANDARD C1 DATE
STANDARD D1 DATE
STANDARD E1 DATE
After the last sample is run, run the mid-level standard again as a
continuing calibration verification
Run the control sample at any sample spot between the beginning and
ending standard runs.
Run the samples.
Calculations
Calculations for Weight Percent of the Pulp Sugars
[0075] Normalized area for sugar = ( Area sugar ) * ( g / mL fucose
) ( Area Fucose ) ##EQU00004## 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 ##EQU00004.2##
Example for arabinose:
Monomer Sugar Weight % = 0.15 g / mL arabinose 70.71 mg arabinose *
20 = 0.043 % ##EQU00005## Polymer Weight % = ( Weight % of Sample
sugar ) * ( 0.88 ) ##EQU00005.2##
Example for arabinan:
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.
[0076] Various embodiments of the invention have been described.
One of ordinary skill will be able to substitute equivalents
without departing from the broad concepts imparted herein. It is
therefore intended that the present disclosure be limited only by
the definition contained in the appended claims.
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