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