Advanced Technologies for Bleaching of Eucalyptus Pulps. · Genetic Xylanases Lacasas manipulation...
Transcript of Advanced Technologies for Bleaching of Eucalyptus Pulps. · Genetic Xylanases Lacasas manipulation...
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