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Enzyme Applications in Pulp and Paper: An Introduction to Applications
Dr. Richard VendittiAssociate Professor - Director of Graduate ProgramsDepartment of Wood and Paper Science Biltmore Hall Room 1204Raleigh NC 27695-8005Tel (919) 515-6185 Fax (919) 515-6302Tel. (919) 515-6185 Fax. (919) 515-6302Email: [email protected]
Endo-Beta 1,4 XylanaseSlides courtesy of Phil Hoekstra.
EnzymesEnzymes
• Are proteins that catalyze chemicalAre proteins that catalyze chemical reactions
• Biological cells need enzymes to• Biological cells need enzymes to perform needed functionsTh t ti l l th t• The starting molecules that enzymes process are called substrates and th t d t d tthese are converted to products
Endo-Beta 1,4 Xylanase
Cellulase enzyme which acts on cellulose substrate to make product of glucose.
Endo-Beta 1,4 Xylanase
EnzymesEnzymes
• Are extremely selective for specificAre extremely selective for specific substrates
• Activity affected by inhibitors, pH, y y , p ,temperature, concentration of substrate
• Commercial enzyme products are typically y p yp ymixtures of different enzymes, the enzymes often complement the activity of
hone another
Endo-Beta 1,4 Xylanase
Types of Enzymes in Pulp and P d R i S bPaper and Respective Substrates
• Amylase --- starchAmylase starch• Cellulase --- cellulose fibers
P t t i• Protease --- proteins• Hemicellulases(Xylanase) ---hemicellulose• Lipase --- glycerol backbone, pitch• Esterase --- esters stickiesEsterase esters, stickies• Pectinase --- pectins
Endo-Beta 1,4 Xylanase
Enzyme Applicationsi P l d Pin Pulp and Paper
• Treat starches for paper applicationsp p pp• Enhanced bleaching• Treatment for pitch
E h d d i ki• Enhanced deinking • Treatment for stickies in paper recycling• Removal of fines• Removal of fines• Reduce refining energy• Cleans white water systemsC ea s te ate syste s• Improve softness in tissue• Clean outs
Endo-Beta 1,4 Xylanase
Starch Conversion for Surface C iCoatings
• Amylases are used to cleave starch molecules to reduce the viscosity y
• Used for surface sizing and for starch in coatingscoatings
• Not used for dry strength agent additive
Endo-Beta 1,4 Xylanase
BleachingBleaching
• Hemicellulases (xylanases) are used toHemicellulases (xylanases) are used to cleave hemicelluloses in fiber, making the bleaching process more effectivebleaching process more effective
• May be able to reduce bleaching chemicals by up to 30%chemicals by up to 30%
• Can improve brightness
Endo-Beta 1,4 Xylanase
Pitch treatmentPitch treatment
• Lipases used to control pitch in pulpingLipases used to control pitch in pulping processes
• Converts tri glycerides to fatty acids which• Converts tri-glycerides to fatty acids which are more stable in water, won’t deposit as muchmuch
Endo-Beta 1,4 Xylanase
CH2 –--------- CH –---------CH2 Triglycerides
Ester-BondsO OO
C=O C=OC=OC=O
(CH2)15 CH3
C=OC=O
(CH2)15 CH3 (CH2)15 CH3
glycerolFatty acids
│OH OH
Fatty acidsCH2 –--------- CH –---------CH2
OH│C=O│
OH OH
Endo-Beta 1,4 Xylanase
(CH2)15 CH3
DeinkingDeinking
• Paper recycling inks and stickies attach to fibersPaper recycling inks and stickies attach to fibers at the surface of the fibers, stuck to microfibrils
• Cellulase and hemicellulase enzymes hydrolyze y y ythese microfibrils, releasing the adhesives
• Enzyme assisted DI reported to remove 30-60% y pmore toners
• Enzyme assisted DI reported to improve brightness by 4-5 points
Endo-Beta 1,4 Xylanase
Enzymes as stickies treatmentEnzymes as stickies treatment
• Esterases used to break ester bonds inEsterases used to break ester bonds in polymers used in toners and adhesives
• Improved paper cleanliness• Improved paper cleanliness• Less deposits, less clean up on PM• Can be used as substitute for talc or
solvent based dispersants
Endo-Beta 1,4 Xylanase
- (CH2 – CH - CH2 – CH - CH2 – CH )n -
PVAcEster-Bonds
O OO
C=O C=OC=OC=O
CH3
C=OC=O
CH3 CH3
PVAlcoholAcetic acid
- (CH2 – CH )- CH2 – CH - CH2 – CH )n -│OH OH
Acetic acid
OH│C=O│
OH OH
Endo-Beta 1,4 Xylanase
CH3
polyvinyl acetate -(-CH2CH-)n-
HydrophobicSurface( CH2CH )n
OCOCH3without Esterasewithout Esterase
Agglomerates of PVAc
with Esterase
gg
polyvinyl alcohol + acetic acid
OH
OHHO
OHOH
OHHO
OH
OHHO
OHOH
OH OH
OHHO
OH
-(-CH2CH-)n-OH + CH3COOH
Polyvinyl alcohol
OH
OHHO
OHOH
OHHO
OHOH
OH
OHHO
OHOH
OH
OHHO
OHOH
OHHO
OH
OHHO
OH
OHOH
OH
OH
OH
OHOH
OH
OHOH
OHOH
OH
OH
Endo-Beta 1,4 Xylanase
y yOH
HO
OHOHOH
Hydrophilic
OHOH
OH
Optimyze Plus 735 trial dataOptimyze Plus 735 trial data
stickies transfer on reel samplesduring Optimyze Plus 735 evaluation
160 1 2
100
120
140
160
0.8
1
1.2
e (lb
/t)
count
PPM
BLX dosage
60
80
100
stic
kies
0.4
0.6
X 13
064
dosa
ge
0
20
40
2/12 3/4 3/24 4/13 5/3 5/230
0.2
BLX
Endo-Beta 1,4 Xylanase
2/12 3/4 3/24 4/13 5/3 5/23
Caustic replacement: t l d i ki f i t d i kineutral deinking for newsprint deinking
• Caustic is used in pulping recycled fibersCaustic is used in pulping recycled fibers to swell fibers, improving paper making potentialp
• Cellulase enzymes can be used in conjunction with or as a substitute for the jcaustic to swell fibers
• Neutral deinking has some advantages g gincluding less COD in the white water, lower costs
Endo-Beta 1,4 Xylanase
Decrease energy in refiningDecrease energy in refining
• Cellulase enzymes cause partialCellulase enzymes cause partial depolymerization of cellulose and swelling of fibers, more flexible fibers
• Reduction of fines• Improves efficiency of refining, canImproves efficiency of refining, can
decrease energy consumption or obtain improved strength at higher freenessp g g
• Often better runnability or less dryer energy required
Endo-Beta 1,4 Xylanase
gy q
Fiber ModificationFiber Modification
• Enzymes can assist this de-laminationEnzymes can assist this de lamination process
• Conditions fiber for refining• Conditions fiber for refining• Reduces refining energy• Changes the refining curve• Old rules do not applypp y• Laboratory Testing
Endo-Beta 1,4 Xylanase
Case HistoryCase History
• MILL: QuebecQ• FIBER: Recycled/Softwood Kraft• GRADE: Napkin• GOAL: Increase tensile strength to
middle of specification, reduce kraft fiber usagekraft fiber usage
• METHODS: Treated MOW stock at the pulper with 0.5 to 1.0 kg/tonne BZM 2545, about 3 hours of contact time
Endo-Beta 1,4 Xylanase
Machine Trial of Buzyme 2545i N ki din Napkin grade
40
45
270
275
25
30
35
e (%
)
265
engt
h
15
20
Kraf
t Usa
g
255
260
Tens
ile S
tre
SWK UsageTensile
5
10
250
0
Pre-trial Trial245
Endo-Beta 1,4 Xylanase
Machine Trial of Buzyme 2545i N ki din Napkin grade
25
250
300
15
20
(%)
200
250
ngth
10Kraf
t Usa
ge
100
150
Tens
ile S
tren
SWK UsageTensile
550
0
Pre-trial Trial0
Endo-Beta 1,4 Xylanase
Refining energy reduced
Results: Machine Trial of Buzyme 2545in Napkin grade
• Reduced kraft from 40% to 0% of furnishReduced kraft from 40% to 0% of furnish• Increased tensile to a “comfortable” range
R fi i d d 14%• Refining energy reduced 14% • Drainage is better, but cannot take
advantage of it, due to drive limitations
Endo-Beta 1,4 Xylanase
Hydrolysis of finesHydrolysis of fines
• Fines build up in water loop in PM andFines build up in water loop in PM and cause drainage, formation and paper properties problemsproperties problems
• Cellulase enzymes hydrolyze these fines, making them soluble improving PM opsmaking them soluble, improving PM ops
• Can run PM faster (up to 10% faster in ?)some cases?)
Endo-Beta 1,4 Xylanase
Softness in tissueSoftness in tissue
• Cellulase enzymes improve softness byCellulase enzymes improve softness by hydrolyzing cellulose in fibers, creating weak spots in fibers making fibers flexibleweak spots in fibers, making fibers flexible
• Softness increases of up to 25%P&G h l t t d t d• P&G has several patents, some donated to NCSU
Endo-Beta 1,4 Xylanase
Case HistoryCase History
• MILL: Quebec• FIBER: 95% SWD/5% Recycled Fibery• GRADE: Premium Bath• GOAL: Reduce refining energy, increase
softness and bulk maintainsoftness and bulk, maintain tensile
• METHODS: Treated stock at the pulper with0.5 to 1.0 kg/tonne BZM 2545, about 3 hours of contact time
Endo-Beta 1,4 Xylanase
Bulk vs. TensileBuzyme 2535 vs. Glyoxylated Polyacrylamidey y y y y
11
10
Average Bulk to Tensile Increase of 3.5%
9
B/B
W
8
712 14 16 18 20 22
GMT/BW
Endo-Beta 1,4 Xylanase
GMT/BW
Buzyme 2535 Gloxylated PAM
Linear (Buzyme 2535) Linear (Gloxylated PAM)
ResultsResults
• Shut down refinersShut down refiners• Maintained tensile• Bulk/basis weight increased by avg of 3 5%Bulk/basis weight increased by avg. of 3.5%• Able to reduce BWT due to increase in tensile• Machine speed increase of 100 FPM due to• Machine speed increase of 100 FPM, due to
better drainage
Endo-Beta 1,4 Xylanase
ROI for Fiber ModificationROI for Fiber Modification• Reduction in refiner energy• Less fines generation
– Better drainage– Softer feel– Less dustingg– Cleaner white water
• Reduction in starch or CMCReduction in starch or CMC• Fiber substitution
C ld MOW l i iEndo-Beta 1,4 Xylanase
– Could use more MOW, less virgin
Improved biodegradability of pulp illmill waste water
• Cellulases and Hemicellulases used to degrade cellulose and other high molecular weight polymersCOD/BOD i f d i• COD/BOD ratio of domestic sewage 2:1
• COD/BOD ratio of paper mill waste• COD/BOD ratio of paper mill waste water up to 5:1
• Hydrolysis of cellulose fines by yd o ys s o ce u ose es byenzymes to lower molecular weight sugars that are more biodegradable
Endo-Beta 1,4 Xylanase
Clean Ups / Boil OutsClean Ups / Boil Outs
• Amylase to treat starch deposits in cleanAmylase to treat starch deposits in clean ups of starch preparation/application equipmentequipment
• Protease used as biodispersants or enzyme boil outs cleave proteinenzyme boil-outs, cleave protein molecules in deposits and solubilize depositsdeposits
Endo-Beta 1,4 Xylanase
SummarySummary• Enzymes are green chemicals that can y g
improve operations in pulp and paper• Wide variety of enzymes, must be
applied with understanding of how theyapplied with understanding of how they work
• Several widely accepted applications, t h bl hi lstarch, bleaching, clean ups
• Future: high valued functionalized fibers, improved pulping, specialized paper p o ed pu p g, spec a ed papeproperties, conversion of wastes to fermentable sugars.
Endo-Beta 1,4 Xylanase