Development of hydrolysis route for cellulosic ethanol

from sugarcane biomass

Henrique M. Baudel

Catalytic Processes LaboratoriesBiomass Conversion Group

UFPE

Catalytic Processes LaboratoriesBiomass Conversion Group

UFPE

Catalytic Processes LaboratoriesBiomass Conversion Group

UFPE

- MCT, CNPq, CAPES, FINEP, FACEPE (Brazil)STINT (Sweden), EULA-ALFA (European community), MES (Cuba)

- Cesar Abreu, Mario T. Kato, A.M.Souto-Maior (UFPE)- Guido Zacchi, Gunnar Lidén, Bärbel Hahn-Hagerdal, Mats Galbe

Marie Linde; P. Sassner; C. Roslander (Lund University, Sweden)- Silvia Nebra (NIPE/UNICAMP; FINEP-BIOETANOL)- Claudio Z.Zaror, Oscar Parra (Univ. de Concepción, Chile)- Carlos Martín (UMCC, Cuba)- George J.M. Rocha, Adilson Gonçalves (EEL/USP) - Aldo J.P. Dillon; M.Camassola (UCS); Alexandra Salgueiro (UNICAP)- C. E. Vaz Rossel (CTBE), Luiz P. Ramos (UFPR), E.M.P. Bon (UFRJ)- CTC colleagues and associates - Students: J. Augusto Tomé, Isaías B. Soares, M.R. Tavares (UFPE)

Khalil Bensalem, Benjamin Bois (Univ. Lyon, France)J. Sendelius, Cristhian Carrasco (Lund University, Sweden)

- Benjamin Knudsen, E.M. Bordin, Frank Haagensen (Novozymes)- Carlos F. Chagas (Bioenzima); Antenor Dvorak (REGMED)

ACKNOWLEDGEMENTS

• Why to produce Ethanol from Cane Biomass ?

• Fuel or Chemical Ethanol ?

• Holocellulosic or Cellulosic Ethanol ?

• Chemical or Enzymatic Processes ?

Frequently Asked Questions (FAQ)

• Urged Profitable Eco-Friendly Depletion of Surplus Biomass

• Cellulosic Ethanol Claimed by the Market

Ethanol from Surplus Cane Biomass = Opportunity

- no major environmental issues

- more product (ethanol) using the same feedstock (sugarcane)

- complimentary with current plant activities

- getting best using (as much as possible) AMAP conventional technologies

- simpler process configuration

- easy and fast to implement (turn key)

- self-sufficiency on energy

- profitable, low investment

Why to produce Ethanol from Cane Biomass ?

Possibilities

No competitionwith food!

Bagasse or Straw?

Preliminary Issues

• Bagasse more suitable to burn ?

• Straw less recalcitrant to hydrolysis ?

• Bagasse available in-house

• Straw to be collected and transported ?

• Bagasse naturally comminuted

• Straw to be milled ?

BagasseCellulosicChemical

Straw??????

BagasseEnzymatic

CellulosicStraw

Holocellulosic

Thermo-ChemicalThermo-Biochemical??????

Fuel or Chemical Ethanol ?

1985 2000 2005 2015

BOTH!

Holocellulosic or Cellulosic Ethanol ?

Chemical or EnzymaticProcesses ?

Once made feasible, enzymatic will be unrivalled in the

medium-long term!

?

Cellulosic Ethanol from Sugarcane Biomass

Enzymatic Hydrolysis of Bagasse

FeedstockProduction

SugarProduction

EthanolProduction

Preparation Saccharification Fermentationand

PurificationPretreatment Hydrolysis

Residue Processing

Industrial R&D approach

Pretreatment

Hydrolysis

FermentationResidue

Processing

per ton cane

per hectare

per ton dry biomass

Litres of Ethanol

Feedstock EconomicAssessment

Separate Hydrolysis and Fermentation (SHF)- Simpler equipments and configurations = lower capital costs - Use of existing fermentation equipments- Processable solid LC residue = eco-efficiency- Easy yeast recovery

A Practical and Pragmatic Approach

Molasses boosting / Mixing with dilute hydrolysates- No concentration required = energy savings / lower degradation- Moderate cellulose conversions = cheaper enzyme cocktails- Simpler fermentation

Integration with existing 1 st Generation Ethanol plants- Capital cost, energy efficiency, emissions, transportation costs

Combustion of the residual cellulignin / mixing wit h bagasse- Use of existing boilers / steam generators - Deliver of additional bagasse for ethanol production- No recovery systems or conditioning required

Burning

C6Fermentation

Pretreatment

Enzymatic Hydrolysis

Separation

Slurry

Separation

Yeast Recovery and

Distillation

CellulosicEthanol

LC Solid

Hydrolysate

Treatment and Disposal

Slurry

Surplus Yeast

Stillage

Prehydrolysate

LC Pulp

Heat / Power

Process Development Concept

cane juice / molasses

Surplus Biomass

Biomass

Enzymes

Burning

C6Fermentation

Pretreatment

Enzymatic Hydrolysis

Separation

Slurry

Separation

Yeast Recovery and

Distillation

CellulosicEthanol

LC Solid

Hydrolysate

Treatment and Disposal

Slurry

Surplus Yeast

Stillage

Prehydrolysate

LC Pulp

Heat / Power

Process Development Concept

cane juice / molasses

Surplus Biomass

Biomass

Enzymes

Attractive in the short-term.Competitive in the medium-term.

Best for the long-term ?

Pretreatment

• Washed or unwashed incoming biomass?

• Single-step or two steps?

• Mill or Diffuser ?

• Do minor differences among feedstocks result in significantdifferences performance?

Over 1200 pretreatment runs performed at Lab/Bench, PDU and Industrial scales during 2002-08!

LAB / Bench Scale

Acidic and Alkaline Pretreatments(without explosion):- Dilute Acid, (C)LHW- Lime / Soda ; (C)WAO, WPO

PARR Batch Stirred 1-L Reactor

Acidic and Alkaline Pretreatments(with/without explosion):- (C)WEX, Dilute acid,(C)LHW - (L)AFEX, Lime / Soda ; WPO

POP Batch 1.5 L-Reactor

Pretreatment

PDU Scale

Steam Explosion. Process Development Unit (PDU) Lund University, Sweden.

Pretreatment

PDU Scale

HB-21 polyvalent batch rotary 23-L reactor. REGMED, Brazil

Pretreatment

- Dual-Chamber (1L and 20 L)- Electrically Heated- Gas Inlet (O2, CO2, NH3)- Rapid Discharge Valve- Adaptable to Cyclone / Flash Tank

Acidic and Alkaline Pretreatments - Dilute Acid, (C)LHW, (C) WEX, (C)STEX- Lime / Soda ; (C)WAO, WPO, AFEX

Industrial Scale

Polyvalent Steam Treatment Unit. CTC associate mills . Brazil.

Pretreatment

2000 L batch reactorFeeding system (O 2, catalysts, NH 3)Controllable biomass loadingControllable heating profileControllable pressure profileControllable discharge valveSteam flow meter

Cyclone / flash tank

Unwashed bagasse. 200ºC, 5 min, no catalyst. 24-h enzymatic hydrolysis, 2% WIS, pH 4.8, 15 FPU/g .

Xylan

Glucan

Lignin

Others

Fiber reactivity

Similar bagasse compositions result in different PT p erformances.

38 394343

8286

7475

0

20

40

60

80

100

A B C D E F

(The use of catalysts on STEX tends to reduce such differences)

Pretreatment

Bagasse originated from diffusers tends to be less reca lcitrant than the ones proceeding from mill/crushers, notably with un catalysed

STEX (Steam Explosion) processes and rigid cane variet ies.

Soft cane varieties are well processed in simpler equi pments, under milder operational conditions.

Pretreatment

Soft

Rigid

70

80

90

100C

NC C

NC C

NC C

NC C

NC C

NC C

NC C

NC C

NC

M MD D M MD D M MD D

180ºC 190ºC 200ºC

Hol

ocel

ulos

e re

mov

al

(normalized)

C: CatalysedNC: Uncatalysed

M: MillD: DiffuserMD: Mixed

Pre-washed bagasse tend to pretreat better, notably wi th uncatalysed STEX (Steam Explosion) processes.

Fiber reactivity may be influenced, although not ex clusively related to hemicellulose removal.

Pre-washed

Unwashed

Pretreatment

40

55

70

85

100

180ºC 190ºC 200ºC 180ºC 190ºC 200ºC

Uncatalysed Catalysed

HC RemovalFiber Reactivity

(normalized)

40

55

70

85

100

180ºC 190ºC 200ºC 180ºC 190ºC 200ºC

Uncatalysed Catalysed

0

10

20

30

40

50

60

70

80

90

100

0,4 0,5 0,6 0,7 0,8 0,9 1,0

(xylan+lignin) / glucanglucan / (xylan + lignin)

Glu

can

reco

very

Pretreatment

Global efficiency tends to be more favoured by hemicel lulose removal than by delignification

Delignification of ST bagasse does NOT necessarily improve process efficiency

Higher LigninRemoval

Delignification

Higher XylanRemoval

Desacetylation

Two-step pretreatment tends to render more reactive fib ers for uncatalysed STEX (Steam Explosion) processes.

0

20

40

60

80

100

180ºC 190ºC 200ºC 180ºC 190ºC 200ºC

Catalysed Uncatalysed

Unwashed bagasse

(normalized)

Fib

er r

eact

ivity

Pretreatment

Single step

Two steps

(The use of catalysts on STEX tends to reduce such differences)

HC ratio (EHHC/HHHC) defines pretreatment severity lev els for optimal HC removal from a given biomass

Small differences among PT bagasses result in signifi cantly different fiber reactivity levels and cellulose conversions

Washed uncatalysed ST bagasse. 180-200ºC , 5-10 min . 8-10%Hemicelluloses; 58-62%Cellulose; 25-28% Lignin . 24-h enzymatic hydrolysis; 2% WIS; 15 FPU/g.

EHHC/HHHC

Crystallinity

Converted cellulose

crystallization

EHHC: Easy to Hydrolyse Hemicelluloses

HHHC: Hard to Hydrolyse Hemicelluloses

0

20

40

60

80

100

PCS1 PCS2 PCS3 PCS1 PCS2 PCS3

Pore Size Crystallinity

Uncatalysed

Catalysed

Fib

er r

eact

ivity

PSC: Physico-Chemical SeverityPSC = f (T, t, P, H 2O, additives)

How to address the influence of the lignin removal o n fiber reactivity ?

How do catalysts alter LCC structure while removing HC and/or lignin ?

Is delignification really necessary ?

How do HC and lignin behave after fragmentation and re moval ?

??????

Still to Investigate

" The challenges we face are real.They are serious and they are many.

They will not be meteasily...... or in a short span of time

But know this: - TheyWILL be met!"

Barack Houssein Obama