Lignin as a Renewable Aromatic Resource

Lignin as a renewable aromatic resource

for the chemical industry

Mini-symposium organised by Wageningen UR Lignin Platform, 6 December 2011, Wageningen

Richard J.A. Gosselink

Contents

PhD program

Lignin valorization

Results

Conclusions and recommendations

PhD program

Lignin valorization for wood adhesives and aromatic chemicals

Universal method for molar mass determination of lignin

Fractionation, analysis and PCA modeling

Lignin activation

Lignin depolymerization

Promotor: Prof. J.P.M. Sanders (WUR-VPP)

Co-promotors: Prof. G. Gellerstedt, Dr. J.E.G. van Dam

Dr. E. de Jong, Dr. E.L. Scott

Lignin valorization

Biobased aromatic feedstock

Abundantly available at relatively low costs

Energy source

Versatile raw material for many applications

Additional revenues for Pulp&Paper industry and 2nd Generation Biorefinery industry

A competitive industry can be developed

Lignin production needs to go hand in hand with application development

Lignin valorization

Lignin availability (dry ton/y)

Pulp & Paper industry

50 M ton lignin extracted, 2% commercial lignins

1 M ton lignosulfonates, 0.1 M ton kraft lignins, 5-10 kton sulfur-free lignins

Efficient processing and extraction in 2020 2-4 M ton extra kraft lignin

Biomass conversion (Biorefinery)

Not commercially available yet, several R&D/pilot initiatives

Organosolv lignins (eg. Lignol, CIMV, Dechema)

Steam explosion (eg. Abengoa, ENEA)

Hydrolysis lignins (eg. Inbicon, Chemtex)

Large quantities expected in EU in 2020 (4-5 M ton)1; in 2030 (12 M ton)1

1EU directive

10% biofuels in 2020, 25% in 2030

Lignin production versus utilisation

Universal method for molar mass lignin

In EUROLIGNIN 2 size exclusion methods recommended organic SEC after acetylation

alkaline SEC

Alkaline SEC method Alkaline solvent (0.5M NaOH)

Directly applicable for wide range of lignins

Disadvantage: no commercial column available

Alkaline SEC method improved for highly dispersed lignins

2 gels used with different pore sizes

Universal method for molar mass lignin

2 gels enables the analysis of highly dispersed lignins Low dispersed lignins give same results

Lignin Overlay one gel and two gels

Alcell

SampleName: Alcell

SampleName: Alcell

2259 -

21.0

33

2054 -

9.5

17

AU

0.00

0.20

0.40

0.60

0.80

1.00

Minutes

1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00

Sarkanda grass F5

SampleName: S5 (=I4)

SampleName: S5 (=I4)

5758 -

20.0

70

124939 -

4.7

27

6006 -

8.7

04

AU

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

Minutes

1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00

Steam explosion

SampleName: Steam Explosion

SampleName: Steam Explosion

3159

- 2

0.68

6

1263

80 - 4

.814

3248

- 9

.171

AU

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

Minutes

1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00

Curan 100

SampleName: Curan 100

SampleName: Curan 100

3420 -

20.6

04

3289 -

9.1

61

74 -

14.0

33

AU

0.00

0.20

0.40

0.60

0.80

Minutes

1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00

EAL

SampleName: EAL

SampleName: EAL

621605 -

14.9

70

6493 -

19.9

47

124801 -

4.7

20

6700 -

8.6

20

76 -

14.0

93

AU

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

Minutes

1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00

EMAL

SampleName: EMAL

SampleName: EMAL

3776

- 2

0.50

2

1269

35 - 4

.864

4718

- 8

.888

75 - 1

4.07

8

AU

0.00

0.05

0.10

0.15

0.20

0.25

Minutes

1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00

R.J.A. Gosselink et al. (2010)

Holzforschung 64:193-200

Alkaline SEC with 2 columns (gels)


Lignin characterization is important for selection of suitable application

Fractionation of lignin can be used to tailor the properties of a lignin fraction

By Principle Component Analysis lignins can be clustered and selected for an application

Analyses: Carbohydrates and ash (lignin impurities)

Molar mass

Degree of condensation

Functional groups (phenolic OH, free ortho)


Fractionation performed by organic solvents leading to fractions with increasing molar mass

High molar mass - low

Indulin AT

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

* F1 F2 F3 F4 F5

Mw

(D

alto

n)

Organic SEC

Alkaline SEC

Curan 100

0

10000

20000

30000

40000

50000

60000

* F1 F2 F3 F4 F5

Mw

(D

alto

n) * Unfractionated lignin

Sarkanda grass soda lignin

0

5000

10000

15000

20000

25000

30000

35000

* F1 F2 F3 F4 F5

Mw

(D

alto

n)

Hardwood soda lignin

0

10000

20000

30000

40000

50000

60000

70000

* F1 F2 F3 F4 F5M

w (

Da

lto

n)


PCA modeling results in different clusters of lignins or their fractions

Each clusters has its own poperties and application potential

Biplot (axes PC1 and PC2: 80.15 %)

Indulin ATCuran 100

Sarkanda grass soda

Hardwood soda

Organosolv

P1000

Sarkanda grass soda F1Sarkanda grass soda F2

Sarkanda grass soda F3

Sarkanda grass soda F4Sarkanda grass soda F5

log_(1/carb)

log_(1/ash)

log_molar_massFree_ortho

log(1/condensation)

log(phenolicOH)

-3

-2

-1

0

1

2

3

-3 -2 -1 0 1 2 3

-- axis PC1 (57.61 %) -->

-- a

xis

PC

2 (

22

.54

%)

-->

R.J.A. Gosselink et al. (2010)

Holzforschung 64:193-200

Lignin as wood adhesive

Lignin is a natural glue

Binders are used in panel & boards

1 M tonnes phenol formaldehyde (PF) resins globally

Why lignin?

Substitution of expensive phenol part

Reduction in emission of carcinogenic formaldehyde

Partial substitution of PF resin by modified lignin

Lignin structure resembles PF structure

Development of emission-free renewable binders

Lignin-furan resins (ECOBINDERS)

Ocobinders

Ocobinders

Lignin valorization

Bakelite (PF resin) Lignin

Activation needed

PF resin can be substituted up to 50% by lignin

Ocobinders

Ocobinders

Lignin activation

Sodium periodate oxidises lignin moieties

Lignin treated under mild conditions

Lignin quinones have the ability to react with furfuryl alcohol (furan derivatives) via a Diels-Alder reaction

Ocobinders

Ocobinders

Proposed mechanism

Lignin activation

Ocobinders

Ocobinders

0

0.2

0.4

0.6

0.8

1

1.2

900100011001200130014001500160017001800

Wavenumber (cm-1)

Ab

so

rba

nce

15

98

16

58

17

01

15

12

14

58

14

21

13

26

12

63

12

18

11

24

10

87

10

29

91

4

13

59

0

0.2

0.4

0.6

0.8

1

1.2

900100011001200130014001500160017001800

Wavenumber (cm-1

)

Ab

so

rba

nce

Untreated

1% periodate

10% periodate

50% periodate

17

14

16

62 15

95

15

12

14

65

14

52

14

20

13

67

12

69

12

13

11

36

11

26

10

80

10

26

55C during 10 min at pH 5

1658 cm-1 corresponds to quinoid structures

Soda lignin

Kraft lignin

Lignin based wood adhesive

Ocobinders

Ocobinders

Furan resin with 10% lignin

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Str

ength

(N

/mm

2)

0

25

50

75

100

Fura

n re

sin

(no

ligni

n)

Gra

ss/s

traw

Gra

ss/s

traw 1

0% o

xid.

Gra

ss/s

traw 5

0% o

xid.

SKL

SKL

10%

oxid.

Gra

ss

Gra

ss 1

0% o

xid.

Wood f

ailu

re (

%)

0.0

0.5

1.0

1.5

2.0

2.5

37% DM 47% DM Grass/straw Grass/straw 10%

oxid.

Grass/straw 50%

oxid.

SKL SKL 10% oxid. Grass Grass 10% oxid.

Str

en

gth

(N

/mm

2)

0

25

50

75

100

37%

DM

47%

DM

Gra

ss/straw

Gra

ss/straw

10%

oxid.

Gra

ss/straw

50%

oxid.

SKL

SKL

10%

oxid.

Gra

ss

Gra

ss 1

0% o

xid.

Wo

od

fa

ilu

re (

%)

10% lignin in PF resin

30% lignin in PF resin

PF resin

PF resin with 10 and 30% lignin

R.J.A. Gosselink et al.

(2011) Holzforschung

65:155-162

Further developments wood adhesives

Currently 30% P replacement by soda lignin in commercial PF resins (Lora, 2008)

Ultimate goal 100% P replacement

Near 100% Ecofriendly boards (isocyanates)

Lignin + tannin + glyoxal (non-toxic, non-volatile) (Pizzi, 2009; Mansouri, 2011)

Binderless boards (Van Dam, 2006)


Production of value added AROMATIC chemicals

Replacement of petrochemical based phenol or derivatives

Replacement of fossil based polymers (polycarbonate, polyurethanes, polyesters..) and phenol based resins (PF)

Lignin conversion to phenol can decrease the production costs of cellulose ethanol substantially


Lignin needs to be defunctionalised and char formation needs to be depressed

Lignin depolymerization under supercritical

conditions

Process development under high P and T (100 bar, 300C)

ScCO2 with co-solvents

Non-toxic, industrial experience, easy downstream processing

Phenolic oil separated from residual lignin/char by expansion

Labscale process development

Lignin in acetone/water 8:2 (v/v) + scCO2 Formic acid as hydrogen donor

Mixed hardwoods organosolv lignin (Alcell)

Wheat straw organosolv lignin (ECN)

Supercritical depolymerization of lignin

Gas

Lignin oil

Char

Lignin

Reactor

Lignin depolymerization under supercritical

conditions

Mono-phenolics 3-12% in phenolic oil 20-30%

Char 40-55%; gases 6-12%: CO, CH4, C2H4, MeOH; water 15%

Formic acid favours formation of monomers

Straw and hardwood lignin comparable conversion, but different phenolic mixture

R.J.A. Gosselink et al.

(2011) Biores.

Technol. accepted

Conclusions and recommendations (1)

Today there is an increased demand for green alternatives to materials and products made from fossil resources.

Plant biomass offers this alternative. However to realise this, biomass needs to be used in an optimal way including the

rest-stream lignin.

My research focused on the utilisation of lignin for value-added applications such as wood adhesive and production of aromatic

chemicals as building blocks for polymers.

By measuring the lignin properties, its suitable application can be predicted.

Lignin fractionation lead to fractions with different properties and application potential

Conclusions and recommendations (2)

Lignin needs to be activated to reach the desired glue strength. Furthermore novel glues fully based on biomass and

without using formaldehyde were studied and show good

potential.

Production of aromatic building blocks from lignin is an important future development as a large part of our daily

consumer products can be made from these. The results of

this research showed that promising opportunities are

identified.

Supercritical depolymerization of lignin should be further optimised focusing on lowering the formation of char

More info: [email protected]

Documents

Lignin as a Renewable Aromatic Resource