Characterization of lignocellulosic materials during …web.abo.fi/fak/tkf/spk/costfp0901/Turku_2013/Orlandi.pdfCharacterization of lignocellulosic materials during the biorefinery

Characterization of lignocellulosic materials during the biorefinery

process of Arundo donax for “Fine” chemicals production

Marco Orlandi, Zoia Luca, Anika Salanti.

University of Milano-Bicocca Department of Earth and Environmental Sciences

Biorefinery is a process to obtain biofuel, power, heat, value-added chemicals

based on cyclic, renewable, biodegradable feedstock (biomass).

We studied Arundo Donax as Feedstock for the isolation of High-Value

Biomaterials: a simple process has been applied to obtain Cellulose nanocrystal

and Lignin, followed by GPC.

ARUNDO DONAX (Giant Cane)

BIOREFINERY

Annual renewability Large annual biomass stock Widespread availability Ability to grow in different soil types and climatic conditions (550 mln tons/year)

%

Lignin 28

Hemicellulose 29

Cellulose 36

Ashes 4

ARUNDO DONAX (composition)

β-O-4 β-β β-5 5-5’-O-4

lignocellulose pretreatment to fractionate the recalcitrant lignocellulose structure; enzymatic hydrolysis of the isolated cellulose moiety, by which cellulases hydrolyze reactive intermediates to fermentable sugars; and fermentation, which produces cellulosic ethanol or other bio-based chemicals

SCHEME OF BIOREFINERY PLANT

BIOREFINERY PROCESS

Arundo Donax Blender

Alkaline extraction NaOH 4 % , 100 ⁰ C , 1-2 h

Buchner Filtration

Bleaching Acetic Acid / NaClO2

Acid Hydrolysis 64% H2SO4 , 50 ⁰ C, 1 h

Centrifugation, sonication and dialysis

Acidification With HCl to pH 1

Coagulation overnight and centrifugation

Lignin fraction Cellulose nanocrystals

Precipitation with EtOH

Hemicellulose fraction

ANALYTICAL PROBLEMS

•Qualitative analysis of different fractions •complete solubilization of the materials under investigation and a homogeneous derivatization reaction •Qualitatative analysis of LCC Present in different fractions

LIGNIN-CARBOHYDRATE COMPLEXES (LCCs)

In herbaceous plants, lignin and hemicellulose

are connected through a phenolic bridge.

Ferulic and p-coumaric acids are esterified to

hemicelluloses and lignin, respectively.

In wood, LCCs mainly consist of ester and

ether linkages connecting sugar hydroxyls of

hemicellulose to the a-carbanol of

phenylpropane subunits in lignin.

O

OH

OLignin

O

O

O[Xyl Xyl Xyl]

OH

OH

OCH3

OH

OCH3

O

OH

OLignin

O

OH

OCH3

O

[Xyl Xyl Xyl]

CH3CH3

OH

O

OR

O

OCH3

Lignin

O

O[Arabinoxylan]

OLignin

OOO

O

CH3

CH3

[Xyl Xyl Xyl]

OCH3

Crestini C.; Argyropoulos D.S. Structural Analysis of Wheat Straw Lignin by Quantitative 31P

and 2D NMR Spectroscopy. The Occurrence of Ester Bonds and β-O-4 Substructures. J.

Agric. Food Chem. 1997, 45, 1212-1219

The complex structure and the tridimensional lignin network that binds

lignocellulosic components together makes it practically impossible to

dissolve lignocellulosic materials in their native form in conventional solvents

IONIC LIQUIDS (ILs)

1-allyl-3-methylimidazolium chloride - [amim]Cl

N+

N

CH3

CH2

Cl-

t0 20 min 50 min 2 h

The aromatic electronrich cationic moiety creates strong interactions for

polymers which undergoes π-π stacking (lignin)

The chloride anion is the most efficient in disrupting the extensive inter-

and intramolecular H-bonding interactions present in wood (cellulose)

allowing the IL to diffuse into the interior of the material

Fluorescence images of a stem of switchgrass treated with ionic liquid. The organized cell wall structure has been completely broken down.

BENZOYLATION AND ACETYLATION OF MILLED NATIVE SUBSTRATES IN IONIC LIQUID FOR GPC-UV ANALYSES

ACETYLATION vs BENZOYLATION

GPC-UV (280 nm) GPC-UV (240 nm)

• ACETYLATED FREE LIGNIN: RESPONSE (aromatic rings)

• ACETYLATED LCCs: RESPONSE (aromatic rings)

• ACETYLATED FREE POLYSACCHARIDES: NO RESPONSE (none aromatic rings)

• BENZOYLATED FREE LIGNIN: RESPONSE (more aromatic rings)

• BENZOYLATED LCCs: RESPONSE (more aromatic rings)

• BENZOYLATED FREE POLYSACCHARIDES: RESPONSE (aromatic rings)

[amim]Cl

90°C, 18 h

CH3

Cl

O

O

Cl

Aliphatic and aromatic hydroxyls from cellulose, hemicellulose and lignin R = CH3CO, PhCO

OH

OH

OH

OH

OHOH

OH

OH

OH

OH

LIGNO

CELLULOSE

OR

OR

OR

OR

ORRO

RO

RO

RO

RO

LIGNO

CELLULOSE

BENZOYLATION AND ACETYLATION OF MILLED NATIVE SUBSTRATES IN IONIC LIQUID FOR GPC-UV ANALYSES

10

20

30

40

50

60

70

80

90

100

%T

1000 1500 2000 2500 3000 3500 4000

Wav enumbers (cm-1)

AD AD L BZ AD Ac

ARUNDO DONAX CHARACTERIZATION BY GPC

5 7 9 11 13 15 17 19

Time (min)

AD Ac

AD Bz

High MW (cellulose)

High MW (LCCs)

Low MW (Free hemi)

Low MW (aromatic)

A. Salanti, L. Zoia, E-L Tolppa, and M.Orlandi Biomacromolecules (2012), 13, 445-454

ARUNDO DONAX CHARACTERIZATION: CNCs ISOLATION



Buchner Filtration






Lignin fraction CNCs



-10

0

10

20

30

40

50

60

70

80

90

100

110

%T

1000 1500 2000 2500 3000 3500 4000

Wav enumbers (cm-1)

Cellulose AD after NaOH AD after NaClO2



5 7 9 11 13 15 17 19

Time (min)

Cellulose

AD Bz

AD benzoylated vs AD after NaClO2 benzoylated (cellulose)


Weight (g)

Starting AD 10

After NaOH 4,5

After NaClO2 4

CNCs 0,8

200 ml of a stable suspension 0,4 % w/v of CNCs has been obtained


SEM and TEM characterizations are on going.

CNCs have great potential as reinforcing agents in nanocomposites due to their size and the possibility of chemically modifying their surface.

AFM Analyses

ARUNDO DONAX CHARACTERIZATION: LIGNIN RECOVERY



Buchner Filtration










10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

%T

1000 1500 2000 2500 3000 3500 4000

Wav enumbers (cm-1)

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

%T

1000 1500 2000 2500 3000 3500 4000

Wav enumbers (cm-1)

AD acidolysis lignin AD Alkaline extraction 1 h AD alkaline extraction 2 h

5 7 9 11 13 15 17 19

Time (min)

AD Ac

Lignin

Hemicellulose



5 7 9 11 13 15 17 19

Time (min)

AD Ac

1 h

2 h

Lignin

5 7 9 11 13 15 17 19

Titolo asse

Lignin Ac

Lignin Bz


Lignin fraction 1 h

Lignin fraction 2 h

5 7 9 11 13 15 17 19

Time (min)

Lignin Ac

Lignin Bz

In herbaceous plants, lignin and hemicellulose

are connected through a phenolic bridge.

Ferulic and p-coumaric acids are esterified to

hemicelluloses and lignin, respectively.

OH

O

OR

O

OCH3

Lignin

O

O[Arabinoxylan]

OLignin

OOO

O

CH3

CH3

[Xyl Xyl Xyl]

OCH3




Buchner Filtration









ARUNDO DONAX CHARACTERIZATION: HEMICELLULOSE RECOVERY

ARUNDO DONAX CHARACTERIZATION: HEMI RECOVERY

After lignin precipitation (2 h sample) : 10 Fold dilution with EtOH and centrifugation (1 g)

45

50

55

60

65

70

75

80

85

90

95

%T

1000 1500 2000 2500 3000 3500 4000

Wav enumbers (cm-1)

AD hemicellulose AD hemi fraction

ARUNDO DONAX CHARACTERIZATION: HEMI RECOVERY

After lignin precipitation: 1- 10 Fold EtOH and centrifugation

5 7 9 11 13 15 17 19

Time (min)

Hemi Ac

Hemi Bz

Recovery of LCCs and hemicellulose

CONCLUSION REMARKS

With the simple process used, it was possible to recovery from 10 g of blended Arundo donax: 0,8 g of CNCs (from around 3 g of cellulose); 1 g of hemicellulose (from around 3 g of hemicellulose); 2,5 g of lignin (from 2 g of lignin in the starting AD); By GPC it was possible to follow the process: The use of Ionic liquid permits the complete solubilization of the materials

under investigation and a homogeneous derivatization reaction; Homogeneous derivatization reaction gives high solubility of all the samples in

THF (chromatographic solvent); Different derivatizations permit to obtain information about the connection

between the different lignocellulosic fraction; NaOH treatment solubilized almost all the hemicellulose and lignin. The connections between hemi and lignin were partially broken during the

process.

Documents

Characterization of lignocellulosic materials during …web.abo.fi/fak/tkf/spk/costfp0901/Turku_2013/Orlandi.pdfCharacterization of lignocellulosic materials during the biorefinery