Advanced Technologies for Bleaching of Eucalyptus Pulps.

Biobleaching

María E. Eugenio y J. Carlos VillarLaboratorios de Celulosa y Papel

CIFOR-INIA

Wood DegradationSoft rot fungi

Brown rot fungi

White rot fungi

. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

70-80 % LIGNIN(15-20 % of theTOTAL LIGNIN

OF THE CELL WALL)

20-25 % LIGNIN(80 % of the

TOTAL LIGNINOF THE

CELL WALL)

Secondary wall

Primary wall

S1

S2

Lumen

S3

Middle lamella

. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

Use of Enzymes in the Pulp and Paper industry

PulpWaste water

Papermaking

Bleaching

Beating

Deinking

Recycled fibers

Pulp

Beating Bleaching

Trees

Wood chips

Cellulases asBeating aid

Enzymes indeinking

Cellulases forenhance dewatering

Amylases forreducing starch viscosity

in coating

Bleaching

Xylanases LacasasGenetic manipulation (ARBORGEN,USA)

Mechanical pulps

Microorganisms for waste water cleaning and slime control

. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

Chemical pulps bleaching

Lipases as pitch control

Bleaching

Brightness

Stability(no color

reversion)

Without decreasing pulp and paper

properties

SELECTIVITY

Cost

AOX (environmental

concerns)

. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

Bleaching process concerns

ECF (Elementary Chlorine Free)

TCF (Totally Chlorine Free)

Chlorine Dioxide

Hypochlorite

Oxygen

Ozone

Hydrogen Peroxide

High pollution by chlorolignins No effluents recovery

. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

To degrade hemicellulose: Hemicellulases Xylanases

1. Promote the elimination of lignin

2. Remove reprecipited xylanes layer

3. Remove region with high content of hexenuronic acid

PeroxidasesLignin Peroxidase LiP

Manganese Peroxidase MnP

Phenoloxidases or Laccases

To degrade lignin:

Biobleaching Enzymes (efficient and very specific catalysts)

Xylanases

Lacasas

. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

Remove reprecipited xylanes layer (open pores for bleaching chemicals to enter the fibers)

XylanaseBleaching chemicals Bleaching chemicals

Xylane

Xylanases Biobleaching

1. Promote lignin elimination (LCC)

Xylanase

Lignin

. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

Advantages

Disadvantages

Brightness increase

Less chemical consumption (10-20%)

Lower contamination

Easy production

Cellulose degradation (low cellulase activity)

Less yield (higher cost)

Lower strength properties

. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

LACCASES (p-diphenyl oxygen reductase)

Laccases are copper-containing

enzymes:

Contain four coppers

Three coppers comprise a catalytic site

that reduces O2 to H2O

The fourth copper, a Cu++, carries out

one-electron oxidation of organic substrates

Laccases Biobleaching. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

-O3S

N

SN

SO-3

N

SN

OH

N

NN

2,2'-azinobis-3-etilbenzothiazoline sulphonate (ABTS)

1-hydroxibenzotriazol (HBT)

O2 laccase

H2O [laccase]OX

[mediator]OX

mediator

lignin

ligninoxidyzed

LMS

Uses low molecular weight molecules as oxidants (mediators). Laccase oxidises the mediator and this molecule recovers its reduced form oxidizing lignin

The mediator has a small size and is able to diffuse inside the fibers to oxidise lignin efficiently. The efficiency of this system depends on the redox potential of the laccase and the reactivity and stability of the oxidized mediator.

Laccase with highest potencial redox were found in white-rot fungi

. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

Advantages

Disadvantages

Brightness increase

Less chemical consumption

Lower contamination

Good delignification

Mediators must be used (higher cost)

Toxic mediators

. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

RESULTS

LE

P

Orig

inal

pul

pN

o la

c-N

O m

edia

tor

Lac-

acet

osiri

ngon

eLa

c-H

BT

Orig

inal

pul

pN

o la

c-N

O m

edia

tor

Lac-

acet

osiri

ngon

eLa

c-H

BT

Orig

inal

pul

pN

o la

c-N

O m

edia

tor

Lac-

acet

osiri

ngon

eLa

c-H

BT

0

2

4

6

8

10

12

14

16

kapp

a nu

mbe

r

40ºC, pH 3. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

LE

P

Orig

inal

pul

pN

o la

c-N

O m

edia

tor

Lac-

acet

osiri

ngon

eLa

c-H

BT

Orig

inal

pul

pN

o la

c-N

O m

edia

dor

Lac-

acet

osiri

ngon

aLa

c-H

BT

Orig

inal

pul

pN

o la

c-N

O m

edia

tor

Lac-

acet

osiri

ngon

eLa

c-H

BT

10

15

20

25

30

35

40

45

50

55

Brig

htne

ss (%

ISO

)

40ºC, pH 3

Future overview in Biobleaching processes

• Develop new enzymes:more cheapermore efficient endure high pHs and temperatures (Industrial bleaching conditions)with low cellulose activity (increased selectivity)

Optimize the process economyCost vs Saving

. Wood components and their biological degradation

. Biotechnology in pulp and paper industry

. Biobleaching

. Laboratory assays

.Future overview

• Looking for new mediators:more efficient more cheaper environmentally friendly