bio fuels, chemicals and materials a walk on the green side of...

Bio Fuels, Chemicals and MaterialsA Walk on the Green Side of

Sustainability

Art J. RagauskasSchool of Chemistry and Biochemistry

Georgia Institute of Technology

Top Global Challenges

• ENERGY• WATER• FOOD• CHEM 2312• ENVIRONMENT • TERRORISM & WAR

GT Chem 2312 Students

Global Challenges Energy/Sustainability

Research Opportunities: New Industrial EconomyDavid Morris - early 1980s • Coined the term "carbohydrate economy"• Envisaged that by shifting society's engine toward renewable, environmentally

benign materials from agro/forestry-based materials

- Agricultural Risk Protection Act of 2000 Title III: Biomass R&D Act of 2000, established the Biomass Research & Development Board.

Defining a Biobased Economy

An economy based on renewable raw materials to produce products and energy in a sustainable manner

Biofuels – Biomaterial FutureBiomass Resources

OO

O OAcO

O

HOOAc

O

HOO

OO

AcOOH

O-XylanO

O

HOOAc

OO

AcOOAc

O

O

HO

HO

OHO

OHO

HO OH

HO

O

O

HO

OH

O

O

O

H3CO

OH

OH

OH

OO

HOOH

OO

HOOH

OH

OH

O

HOOH

OO

HOOH

O

OH

OH

O

OH

OH

OCH3HO

OCH3

O

HO

HO

H3COO

HO

HO OCH3

O

HOOCH3

OHO OH

OOH3CO

HO

HO

O

OH

OH

OCH3

OCH3

OH

OH

OOCH3

OO

OCH3

O

OCH3

HO

HO

OCH3

O

O

OCH3

HOO

HO

HO

OCH3

Lignin

PolymerDerived from

Coniferyl, Coumaryl,Sinapyl, Alcohol

Major Global Biopolymers Hemi

Cellulose

Short chainbranched,substitutedpolymer of sugarsDP: ~ 70 - 200

Cellulose

Polymer of β-(1,4)-glucan

DP: ~300 – 15,000

Content: ~ 35 – 50%

Cont

ent:

~ 20

-30

%Content: ~ 15 –

30%

Lignin

PolymerDerived from

Coniferyl, Coumaryl,Sinapyl, Alcohol

Major Global Biopolymers Hemi

Cellulose

Short chainbranched,substitutedpolymer of sugarsDP: ~ 70 - 200

Cellulose

Polymer of β-(1,4)-glucan

DP: ~300 – 15,000

Content: ~ 35 – 50%

Cont

ent:

~ 20

-30

%Content: ~ 15 –

30%

Lower Cost Higher AvailabilityNo Competition with Food Demand

BioResource % ∼ Lignin Hemicellulose CelluloseSoftwood 27 28 39Hardwood 25 30 40Corn Stover 18 22 38Wheat Straw 23 21 38Fine Paper - 20 80Switch Grass 18 20 31

Biofuels – Biomaterials FutureIntegrated Biorefinery

The Path Forward for Biofuels and Biomaterials. Ragauskas, A.J.; Williams, C.K.; Davison, B.H.; Britovsek, G.; Cairney, J.; Eckert, C.A.; Frederick, W.J., Jr.; Hallett, J.P.; Leak, D.J.;

Liotta, C. L.; Mielenz, J.R.; Murphy, R.; Templer, R.; Tschaplinski, T. Science (2006), 311(5760), 484-489

The biorefinery is facility that integrates biomass conversion processes and equipment to produce fuels, power, and chemicals from biomass. It fully

utilizes all components of biomass to make a range of foods, fuels, chemicals, feeds, materials, heat and power in proportions

that maximizes sustainable economic sustainability.

Biofuels – Biomass Research Research Challenges and Opportunities

Biomass Productivity/Processability: Plant Science

Biomaterials- Biomass Characterization- New Separations- New Biopolymers- New Chemical Conversions- Biocomposites

Biofuels- Biomass Depolymerization- Fermentation C5/C6- New Catalyst Chemistry

- Decarboxylation/decarbonylation- Dehydration/reductive

BioPower: Gasification – Fischer/Troph

Biofuels: Novel Oxidative Chemistry in Ionic Liquids

OH

OH

OCH3HO

OCH3

O

HO

HO

H3COO

HO

HO OCH3

O

HOOCH3

OHO OH

OOH3CO

HO

HO

O

OH

OH

OCH3

OCH3

OH

OH

OOCH3

OO

OCH3

O

OCH3

HO

HO

OCH3

O

O

OCH3

HOO

HO

HO

OCH3

C8 – C22

Need New Green Chemistry Catalytic Oxidative System Preferably in Ionic Liquid

• Inert solvent • Tailor solubility of lignin• Almost no vapor pressure• Facilitate isolation of oxidized fragments

OH

HO

O OCH3

O

OCH3

O

HO

O OCH3

O

OCH3

Oxid.

C810 – C900

Biofuels: Novel Oxidative Chemistry Ionic Liquids

Solvent TEMPO (R) Conversion/Selectivity (%) Yield (%)1. EtOAc as solvent H 36/97 312. CHCl3 H 38/99 363. I2 replace HBr H 6/99 --

4. [bmin]PF6 H 98/99 90Yield Grand

But non-recyclable! NN

PF6

H2O2

2 H2O

2 HBr

Br2

Nitrosonium Ion

NOH

RCH2OHH R

NO

H R

2

H

H

NO

H R

NOH

H R

+

+ RCHO

PhCH2OH PhCHO40 °C/2 h

Model Compound StudiesModel Compound Studies

Initial Effort with TEMPO


OH O

40 oC, 2 h

Solvent TEMPO (R) % Conversion - % Selectivity % Yield1. [bmin]PF6 H 98/99 90

2. [bmin]PF6 NH-Ac 98/98 92Extracted - Reused3. [bmin]PF6 NH-Ac 98/98 90Repeated Three Additional Times6. [bmin]PF6 NH-Ac 98/96 91

First example of TEMPO ‘locked’ in an ionic liquid, can not be extracted with Et2O, n-Hexane

Easy and viable alternative to TEMPO-polymer agents

H2O2, HBr

NO

H R


NNPF6

OH

R40 oC

H2O2, HBrNO

HN

O

Strengths• Acetamido TEMPO/HBr completely recyclable• High yield for electron poor, slightly electron rich

benzylic alcohols• No over oxidation

Concerns• Need an expensive oxidant• Limited range of benzylic alcohols• HBr

Benzylic alcohols Conditions Products % Yield

CHO

MeO

CHOCH2OH

CHONC

92

83

81

93

72

91

83

_

87

CH2OH

CHO

CH2OH

CH2OH

CH2OH

CHO

Cl

CH2OH

NC CH2OH

Br CH2OH Br CHO

Cl

CHO

O2N

CH2OH

O2N

CHO

MeO CHO

2 eq. H2O2, 2 h

2 eq. H2O2, 3 h

2 eq. H2O2, 3 h

3 eq. H2O2, 4 h

5 eq. H2O2, 4 h

3 eq. H2O2, 4 h

4 eq. H2O2, 4 h

2 eq. H2O2, 2 h

2 eq. H2O2, 2 h

TEMPO-catalyzed oxidation of benzylic alcohols to aldehydes with the H2O2/HBr/ionic liquid [bmim]PF6 system.Tetrahedron Letters (2005), 46(19), 3323-3326.


NO NHO

NNMe Bu

[bmin] [mmim] [bmpy]

NNMe Me

NBu Me

OH

R ILs

Literature• Efficient, Copper-Catalyzed, Aerobic Oxidation of Primary Alcohols by I. E. Markóet al. Angew. Chem. Int. Ed. 43, 1588 (2004).• TEMPO/Copper Catalyzed Oxidation of Primary Alcohols to Aldehydes Using Oxygen as Stoichiometric Oxidant by D. GeiBlmeir et al. Montashefte fur Chemie136, 1591 (2005)

N N

DMAP

0.05 equiv. Cu(II), 0.10 equiv. DMAP

0.05 equiv. acetamido-TEMPO ILs, O2 (1 atm), RT, 5 h

Run Copper salt Ionic Liquid Conversion (%) Yield (%)

147

44

52

87

4345

32

2

3

4 81

CuCl2 [bmim]PF6

[bmim]BF4

[mmim]OSO3Me

[bmpy]PF6

CuCl2

CuCl2CuCl2

CH2OHMeO CHOMeO


66

99

87

91

59

4

7

5

e No DMAP wasadded. f No acetamido-TEMPO was added. g No copper salt was added.

81

91 886 CuBr2

Cu(OAc)2

Cu(ClO4)2

[bmpy]PF6CuCl2

[bmpy]PF6

[bmpy]PF6

[bmpy]PF6

48e [bmpy]PF6

09f Cu(ClO4)2 [bmpy]PF6

010g

Cu(ClO4)2

[bmpy]PF6

- - --

Exp. Copper salt Ionic Liquid Conversion (%) Yield (%)

NNMe Bu

[bmin] [mmim] [ bmpy]

NNMe Me

NBu Me

N N

DMAP

0.05 equiv. Cu(II), 0.10 equiv DMAP

0.05 equiv. acetamido-TEMPO ILs, O2 (1 atm), RT, 5 h

CH2OHMeO CHOMeO


Entry Alcohols Time (h) Product Convn/yield (%)

1

2

3

5

6

7

8

CHO

MeO

CHOCH2OH

CHOO2N

4

99/92

98/90

100/90

99/91

99/84

CH2OH

CH2OH

Br CH2OH Br CHO

Cl

CH2OH

O2N CH2OH

Cl

CHO

MeO CHO

MeO

MeO

CH2OH MeO

MeO

CHO

CH2OH CHO

5

5

5

5

5

5

5

5

98/92

100/81

96/89

0.05 equiv. Cu(ClO4)2, 0.10 equiv DMAP

0.05 equiv. acetamido-TEMPO [bmpy]PF6, O2 (1 atm), RT, 5 h

ArCH2OH ArCHO


11

OH

Ph

Ph CHO

OH

Ph Ph CHOOH

OH

( )6 OHCHO

( )6

24d

O

O

13

14

15

16

d The reaction was carried out at 40 °C.

5

24d

24 RT 40 C

24 RT 40 C

94/61

100/54

-

-

100/89

OH CHO 100/7712

MeO CH2OH MeO CHO

Ph CHO17 4

97/75

12/-

5

Ph OH24 48/26

NCHO

NCH2OH

S CH2OH S CHO9

10

5

5

99/88

97/79

0.05 equiv. Cu(ClO4)2, 0.10 equiv DMAP

0.05 equiv. acetamido-TEMPO [bmpy]PF6, O2 (1 atm), RT, 5 h

RCH2OH RCHO

Entry Alcohols Time (h) Product Convn/yield (%)


Strength• Acetamido-TEMPO ‘locked’ in ionic

liquid(s) and easily recycled and reused for five runs without significant loss of catalytic activity

• A mild and efficient aerobic oxidation of primary alcohols in [bmpy]PF6• High selectivity to aldehydes and no over-oxidized product observed• Good tolerance toward heteroatom (S and N) containing compounds• Electron rich benzylic alcohols oxidized

Concerns• Will not oxidize secondary alcohols

Copper(II)-Catalyzed Aerobic Oxidation of Primary Alcohols to Aldehydes in Ionic Liquid[bmpy]PF6 Organic Letters (2005), 7(17), 3689-3692.

CH2OH

OMe

CHO

OMe0.05 equiv. Cu(ClO4)2, 0.1 equiv. DMAP

0.05 equiv. acetamido-TEMPO [bmpy]PF6, O2, RT

1 5 99 912 5 96 913 5 94 924 8 93 855 8 87 81

run time (h) conversion (%) yield (%)


ILs, O2

CHOCH2OH

R R

O

O

V

2

Vanadium Oxyacetylacetonate: VO(acac)2

O


Entry Ionic Liquid Additive Convn/sel % Yield

1

62/>99

28/>99

31/>9952/>.99

37/>99

59/>99

2420

43

17

49

234

7

5

51

64/>99 586

[bmim]BF4

[bmim]PF6

[hmim]OTf[bmpy]PF6

[bmim]PF6

[bm2im]BF4

[bmpyr]NTf2

51/>998 [bmim]PF6

90/459 [bmim]PF6

98/>9910 [bmim]PF6

-DMAP

DABCO

Et3NEt3NEt3NEt3N

Et3N

Et3N

Pyridine

DBU40

91

N

N

DABCO

N

N

DBU (1,8-diazabicyclo[5.4.0]undec-7-ene)

N N

DMAP

NNMe Bu

[hmim] [bmim] [bm2im] [mmim] [ bmpy]

NNMe Me

NBu MeNNHex Bu

NNMe Bu

Me

0.05 equiv. VO(acac)2

ILs, O2, 80 °C, 6hCHO

OMe

CH2OH

OMe

Biofuels: Novel Oxidative ChemistryIonic Liquids

0.05 equiv. VO(acac)2,

0.10 equiv. DABCO[bmin]PF6, O2, 80-100 °C

RCH2OH RCHOEntry Alcohols Time (h) Product Convn./yield (%)

1

2

3

5

6

7

8

9

CHO

MeO

CHOCH2OH

CHOO2N

4

99/96

98/90

100/95

98/91

22/

CH2OH

CH2OH

Cl

CH2OH

O2N CH2OH

Cl

CHO

MeO CHO

OH

Ph CHO

Ph Ph CHOOH

MeO

MeO

CH2OH MeO

MeO

CHO

6

6

12

12

9

24*

6

O

11

12

13

14

12

12

98/86

14/

100/87

-

-

100/87

10

94/82

6*

Ph OH

NCHO

NCH2OH

S CH2OH S CHO

MeO

HO

CH2OH MeO

HO

CHO

6*

1294/9035/29

6*

12

99/91

OH O

Ph24* <5/PhOH O

6* 96/85-

96/94

0.05 equiv. VO(acac)2,

0.10 equiv. DABCO[bmim]PF6, O2, 80 °C

Recycling of VO(acac)2 aerobic catalytic system for 4-methoxybenzyl alcohol into aldehyde

CH2OH

OMe

CHO

OMe

1 6 98 912 6 93 873 9 97 92

Run Time (h) % Conversion % Yield

Strengths:• Aerobic catalytic• Tolerant for hetereo-atoms• Electron rich/poor benzylic hydroxyl groups• Oxidizes 1o and 2o benzylic hydroxyl groups• First oxovanadium oxidation system in ILConcerns• noneSubmitted Tetrahedron Lett.

Novel Oxidative Green Chemistry

• Better to prevent waste than treat it• Raw materials should be renewable• Catalytic reagents are superior to stoichiometric reagents


Entry Ligand Additive Conversion (%)c Yield (%)d

1

21

90

5345

56

76

414530

84

234

7

5

Optimization of Aerobic Oxidation of 4-Methoxybenzyl Alcohol with Acetamido-TEMPO in DMSO.a,b

66

85 706

DMAP

TMDPTMDP

TMDP

nonenonenonenone

Bipy

Phen

TMDP

K2CO3

KOH

968 Et3N

1009 TMDP DABCO10010e

TMDP

DABCOTMDP9911 Et3N

-

pyridine

-

909692

aReaction condition, 0.06 mol equiv. acetamido-TEMPO, 0.04 mol equiv. Cu(ClO4)2·6H2O, 0.04 mol equiv. %. e Reaction was run for 2h. f Water (0.1 mL) was added. g No acetamido-TEMPO was added. h No TMDP was added.

_

12e, f DABCO

-

TMDP100TMDP

013e,g

14e,h DABCOTMDP

0DABCO

9194

Question: Can Aerobic Acetamido-TEMPO oxidation occur in other solvents?

Entry R Cycle #

% Conversion % Yield

1 4-MeOPh 100/90 94/89 88/82

0.04 equiv. Cu(ClO4)2, 0.04 equiv. TMDP

0.06 equiv. acetamido-TEMPO, O2 0.1 equiv. DABCO, DMSO, RT

RCH2OH RCHO

2 Ph 100/85 93/92 90/89

3 3-ClPh 99/93 95/85 92/90

4 4-MePh 100/92 96/91 89/83

5 trans-PhCH=CH 99/93 93/84 90/87

Recycling of the Catalytic System for Aerobic Oxidationof Benzylic andAllylic Alcohols

6 Ph 98/88 90/85 81/78

1 2 3

N NN N

N NN

N

2,2'-bipyridine Bipy

1,10-phenanthrolinePhen DABCO

trimethylenedipyridine TMDP

0.04 equiv. Cu(ClO4)2, 0.04 equiv. L

0.06 eqival. acetamido-TEMPO0.1 equiv. additive, DMSO, RT, O2R2

R1

OH

R2

R1

O


Entry Alcohols Product Time (h) % Conversion % Yield

Aerobic CatalyticOxidation of Alcohols in DMSO with Cu2+/Acetamido-TEMPO

1

2

3

5

6

7

CHO

MeO

CHOCH2OH

4 CH2OH

CH2OH

Cl

CH2OH

Cl

CHO

MeO CHO

Ph CHO

Ph Ph CHOOH

( )6 OHCHO

( )6

CH2OH CHO

2 100 98

2 98 90

2 99 93

2 100 92

24 19 11

2 100 92

9

2 99 93

OH CHO

8

2 100 85

Ph OH24 (40 oC) 71 40

24 (40 oC) 58 33

10

11

NCHO

NCH2OH 2 98 71

S CH2OH S CHO2 99 92

N

N

DABCO

N N

trimethylenedipyridine TMDP


0.06 eqival. acetamido-TEMPO 0.1 equiv. DABCO, DMSO, RT, O2R2

R1

OH

R2

R1

O

For Compounds 1 – 7Turn-over Frequency (TOF) of 12.5/h were achieved, which for a RT reaction is very good


Entry Alcohols Product Time (h) % Conversion % Yield

Aerobic CatalyticOxidation of Alcohols in DMSO with Cu2+/Acetamido-TEMPO

OH

OH

O

O

13

14

15

24 35 27

-

-

MeO CH2OH MeO CHO

18

1.57 -

OH O 24 (40 oC) 87 74

PhOH Ph

O

24 (40 oC) 98 90

16

24 (RT/40 oC)

24 (RT/40 oC)

12

24 (40 oC)

OH O

PhOH Ph

OOH O

-

-

97 75

95 84

- -

Ph Ph CHOOH 98 85

Ph CHOPh OH 4 -1.517

N

N

DABCO

Cu(II)-Catalyzed Selective Aerobic Oxidation of Alcohols under Mild Conditions. Journal of Organic Chemistry ACS ASAP. 4,4'-trimethylenedipyridine (TMDP)

N N


0.06 equiv. acetamido-TEMPO 0.1 equiv. DABCO, DMSO, RT, O2R2

R1

OH

R2

R1

O

Conclusions

• Acetamido-TEMPO is‘locked’ in DMSO

• No over oxidation• Amendable to hetero

atoms• Recyclable

Novel Oxidative Green Chemistry Solvent Re-use at ‘End-of-Life’

PiperyleneSulfone (PS)

S

O O

+ SO2CH2OH

OMe

CHO

OMe 1 mol% CuBr, 2 mol% DMAP

2 mol% acetamido-TEMPO O2 (1atm), PS, RT, 3 h

1 100 96 33.32 95 88 31.73 85 82 28.3

run conversion (%) yield (%) TOF (h-1)

CHO Cl

CHOS CHO

CHO

98% 92% 91% 94%

Piperylene Sulfone: A “Labile” and Recyclable DMSO SubstituteD. Vinci, M. Donaldson, J.P. Hallett, E.A. John, P. Pollet, C. A. Thomas, P.G. Jessop, Charles L. Liotta. C.A. Eckert

Additional collaborative studies ongoing ….

*Concerted cheletropic reaction of trans-1,3-pentadiene (trans-piperylene) & SO2

*


Laccase

Novel Oxidative Green ChemistryLaccase: Overview

Laccase

Laccase

•• Oxidoreductase enzyme•• Reduces OReduces O2 to H 2O2

concomitantly oxid izesconcomitantly oxid izes• MW varies 65,000-140,000.• Carbohydrate content ~10-45 (% wt).

• Catalysis occurs due to 4 copper atoms/ active site

• Active sites near surface

Active sites on surface

E.I. Solomon et al

Cu1+

HisN

Cu1+

SCys

Cu1+

NHis

1+Cu

Type II

Type III

Type I

HO

H

Fully Reduced

Cu2+

OH

SCys

Cu2+

Cu2+

HisN O NHis

2+Cu

H

Fully Oxidized

O2 Laccase employed as a novel green oxidation agent for:• Phenols• Allylic, benzylic alcohols• Carbohydrates

Potential for Novel Laccase Initiated Cascade Chemistry

OH

OH

R

Laccase

O2 - H2O

X

Para

or

OrthoQuinone

O

O

RX

O

O

R

X

Novel Oxidative Green ChemistryLaccase Initiated Cascade Chemistry

OH

OH

MeOO

MeO

O

O

O

MeO

1 2 3 4

Laccase, O2

50 oC, 24 hrs

The Effect of Laccase Dose on the Formation of Compound 3

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25

Reaction time (hr)

Yiel

d (%

)

500 U/ 1g subatrate1000 U/ 1g substrate2000 U/ 1g substrate4000 U/ 1g substrate

The Effect of Laccase Dose on the Formation of Compound 4

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25Reaction time (hr)

Yiel

d (%

)

500 U/ 1g subatrate1000 U/ 1g substrate2000 U/ 1g substrate4000 U/ 1g substrate

O

MeO

O


OH

OH

MeOO

MeO

O

O

O

MeO

1 2 3 4

Laccase, O2

50 oC, 24 hrs

The Effect of Temperature on the Formation of Compound 3

0102030405060708090

0 5 10 15 20 25

Reaction time (hr)

Yiel

d (%

)

25 °C 50 °C 70 °C

The Effect of Temperature on the Formation of Compound 4

0102030405060708090

100

0 5 10 15 20 25

Reaction time (hr)

Yiel

d (%

)

25 °C 50 °C 70 °C

O

MeO

O

O

O

MeO

NR > 100 oC


OH

OH

MeOO

MeO

O

O

O

MeO

1 2 3 4

Laccase, O2

50 oC, 24 hrs

OH

OH

MeO

O

O

MeO

Laccase+

Diels-Alder

O

MeO

O

Diels-Alder

O

MeO

O

[O]

O

MeO

O

Compound 3

[O]

O

MeO

O

[O]

O

MeO

O

Compound 3

O

MeO

O

[O]

Compound 4

O

MeO

O

[O]

O

MeO

O

[O]

Compound 4

[Ox]

[Ox]


OH

OH

R1

R2

R3

R4

R5

O

O

R1

R2

R3

R4

R5

R1

R2

R3

R4

R5

O

O

O

O

R1

p-hydroquinone diene products (% yield)b

1a: R1 = OMe 2a: R2 = R5 = H, R3 = R4 = Me 3a (10 %) 4a (60 %)

1a 2b: R2 = R4 = H, R3 = R5 = Me 3b (9 %) 4b (55 %)

1a 2c: R3 = R4 = H, R2 = R5= Me 3c (46 %) no product formed

1a 2d: R2 = R5 = H, R3 = R4 = OMe no product formed 4c (12 %)

1a 2e: R3 = R4 = R5 = H, R2 = OMe no product formed 4d (79 %), R2 = H

1a 2f:

1b: R1 = Me 2a 3d (20 %) 4e (22 %)

1b 2c 3e (19 %) no product formed

1b 2d no product formed 4f (4.28 %)c

1b 2e no product formed 4g (40 %), R2 =H

1c: R1 = Br 2a no product formed 4h (21 %)

1b

1c

2f

2f

3f (64 %)

3g (49 %)

3h (51 %)

1 2 3 4

New green chemistry 1-pot synthesis of 1,4-naphthoquinones and related structures in water!


New green chemistry synthesis of 1,4-, 1,2-naphthoquinones and related structures employing a nonhazardous oxidizing agent, laccase, and a environmentally benign solvent, water.

HO

OHLaccase - O2

R

O

O R

O

O

O

O

O

O

H3CO

34%

77%

57%

Biofuel - Bioethanol

BiofuelResearch Challenges

Biofuel

Enzymatic Hydrolysis of Cellulosics

Biofuels: Enzymatic Hydrolysis of CellulosicsBackground Native

Cellulose Iα and Iβ

Chains are parallel; Differences due to orientation of Cellulose sheets

I – IV PolymorphsAmorphousParacrystalline

Cellulose II:

anti-parrellel Question: What role, if any, does cellulose ultra structure have on enzymatic hydrolysis?

Cellulose: Iα is more abundant in lower plants/bacteriaIβ is more abundant in higher plants

Analysis of Cellulose Crystallinity: X-ray, NMR, FT-IR

O

OO

CH2OH

OHO

OH

HOOH

CH2OH1

2

3

45

6

4

1

C-1

C-4

C-2, 3, 5

C-6

Assignments Chemical shift (ppm)

Cellulose I(α) 89.5 Cellulose I(α+β) 88.8 Para-crystalline cellulose 88.3 Cellulose I (β) 87.8 Accessible fibril surface 84.3 Inaccessible fibril surfaces and hemicellulose 83.7

Accessible fibril surface 83.3

Biofuels: Enzymatic Hydrolysis of Cellulosics

Cellulase from Trichoderma reesei

0 5 10 15 20 253

4

5

6

7

8

Rel

ativ

e in

tens

ity, %

Hydrolysis time, hr

ΙβCellulose: Iβ

0

20

40

60

80

100

0 10 20 30 40 50

Hydrolysis Time, h

Glu

cose

yie

ld, %

Pulpavicel

Cellulose: Iα

0 5 10 15 20 252.5

3.0

3.5

4.0

4.5

5.0

Rel

ativ

e in

tens

ity, %

Hydrolysis time, hr

ΙαCellulose: Iα


• Cellulolytic filamentous fungus

cellobiohyrolasesendoglucanasesβ-glucosidases

NREL

0

20

40

60

80

100

0 10 20 30 40 50

Hydrolysis Time, h

Post

-hyd

roly

sis p

erce

ntag

e, %

avicelpulp

0 5 10 15 20 25

33

34

35

36

37

Rel

ativ

e in

tens

ity, %

Hydrolysis time, hr

Para-crystalline

0 5 10 15 20 25

46

48

50

Rel

ativ

e in

tens

ity, %

Hydrolysis time, hr

Amorphous

• First study quantifying changein paracrystalline phase

• First to quantify to changes in ultrastruture of kraft cellulose aftercellulase treatment

• Compliments recent study byHayashi on cellulase changes onIα/Iβ

CP/MAS 13C NMR analysis of cellulase treated bleached softwood kraft pulp. Carb. Res. (2006), 341(5), 591-597.


DARPA: Anaerobic Fermentation of Cellulosics

36.8

43.9

52.3

30

35

40

45

50

55

CrI,

%

Starting cellulosediet

F1 F3

Cellulose Fermentation

Samples F1 and F3 were fermented with different populations of Bacteroides and Prevotella for 8 weeks

Cellulosic NMR Studies• Provide a diagnostic analysis of reactive and resistance cellulose ultrastructuretowards enzymatic hydrolysis• Provides fundamental information for rational design of pretreatments to enhance cellulose reactivity

0

15

30

45

60

75

Ia I(a+β) Para-crystalline Iβ

Starting cellu. diet

F1-Wk8 residual

F3-Wk8 residual

Rel

ativ

e pr

opor

tion,

%

NanoligninNanocellulose

Nanohemicellulose

Structures – Materials - Composites

Defining the Opportunities, Challenges, and Research Needs for NanoBiomaterials Derived from Lignocellulosics

Nanocellulosem

10 nm

1 nm

μmmm

OO

HOOH

OO

HOOH

OH

OH

O

HOOH

OO

HOOH

O-Cellulose

OH

OH

O

OO

HOOH

OO

HOOH

OH

OH

O

HOOH

OO

HOOH

O-Cellulose

OH

OH

O

Surface AreaFully Exfoliated Clay ∼ Cellulose Whiskers > Fumed Silica > Graphite >> Paper Fiber > E-glass Fibers

TensileCarbon Fibers > Cellulose Whiskers > > S-Glass > Aramid

Nanocellulose

1. Mechanical Milling40 mesh

2. H+, 45 oC

Pine Cellulosic Fiber

2.7 x 0.07 mm

1. Mechanical Milling2. Pre-swell NaOH – DMSO3. Acidic Ultrasonification(s) 0

50100150200250300350400450500

0 2 4 6 8 10

Time (hour)

Siz

e (n

m)

020406080

100120140160180200

0 1 2 3 4

Size

(nm

)

100 nm100 nm0.7050 – 100 nm Nanocellulose Balls -

Cellulose II

0.65300 – 500 nm Nanocellulose Balls -Cellulose II

0.61Original Fibers – Cellulose 1

Crystallinity indexSample



0.61Original Fibers – Cellulose 1

Crystallinity indexSample

Cellulose Whiskers100-250 nm length5-15 nm width.

Nanocellulose - Composites

0200400600800

100012001400

TEA

Latex nanoball whisker acacia

Cellulose Whiskers

Cellulose 80 nm Nanoball

Acacia Fibers (0.66 mm)

PolystyrenePLA

Acrylic Latex

Acrylic Films + 5% Nanoballs + 5% Whiskers

0

500

1000

1500

2000

2500

3000

3500

4000

0 1 2 5 10 20

% Cellulose

Tens

ile E

nerg

y A

bsor

ptio

n

Cellulose WhsikersAcacia Fibers

Same benefits observed for Tensile and Strain Properties

Investigation into Nanocellulosics versus Acacia Reinforced Acrylic Films - Accepted in Composites Part B (Biocomposites)

Nanocellulose - Composites• Cellulose Whiskers

– Composites• Biodegradable, Conventional

Polymers• Crosslinked Whiskers for

Film/Barrier Properties– Oxidized

• Hydrophilic Materials– Surface Functionalized

Whiskers• Cellulose Balls

– Drug delivery– Templating– Oxidized/Sulfonated

• Viscosity modifiers

• Self Assembly on Paper – ‘Lotus Effect’ hydrophobic

coatings

Exploring The Fundamental Chemistry of Bio-Renewable Polymers

2003 – Current

Research Vision

Leader in SustainablePolysaccharide/Lignin

Chemistry

Polysaccharide/Lignin Modification

New Materials

Oligo - Polysaccharide Synthesis

New Biological Tools

Polysaccharide/Lignin Depolymerization

New Resources forBiofuels and Biopolymer

Thank You!

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