csir enzyme applications in pulp and paper rav - tappsa · enzyme applications in pulp and paper:...

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.


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


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


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


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


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


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


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


(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


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


- (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


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


y yOH

HO

OHOHOH

Hydrophilic

OHOH

OH

Electron micrographsElectron micrographsUntreated TreatedUntreated Treated


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


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


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


gy q

Fibrillation

Endo-Beta 1,4 Xylanase4/29/2009

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


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


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


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


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


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?)


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


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


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


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


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


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


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.


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