Presentation of Cesar A. M. Abreu for the "Workshop Virtual Sugarcane Biorefinery" Apresentação de Cesar A. M. Abreu realizada no "Workshop Virtual Sugarcane Biorefinery " Date / Data : Aug 13 - 14th 2009/ 13 e 14 de agosto de 2009 Place / Local: ABTLus, Campinas, Brazil Event Website / Website do evento: http://www.bioetanol.org.br/workshop4

1. CONVERSÃO DA BIOMASSA
Cesar A. M. Abreu
UNIVERSIDADE FEDERAL DE PERNAMBUCO
DEPARTAMENTO DE ENGENHARIA QUÍMICA
LABORATÓRIO DE PROCESSOS CATALÍTICOS
RECIFE, PERNAMBUCO

2. CONVERSÃO DA BIOMASSA
CONVERSÃO DA BIOMASSA COM VALORIZAÇÃO
Conversão da biomassa
Processos de conversão
Natureza química
Fracionamento
Funcionalização ou degradação
Intermediários
Produtos finais

3. CONVERSÃO DA BIOMASSA
BIOMASSA LIGNOCELULÓSICA
Principais componentes: celulose, hemicelulose, lignina
Outros componentes: cinzas, fenois , acidos graxos, ….
Celulose: polissacarídeo de D-glucose, unidades associadas
via β-1,4-glucosidic ligações.
Hemicelulose: polissacarídeo de xilose, arabinose, manose,
promovendo interações entre a celulose e a lignina
Lignina: polímero baseado em fenilpropano, estruturado em
grupos guaiacil, siringil and p-hidroxifenylpropano

4. CONVERSÃO DA BIOMASSA
CONVERSÃO DA BIOMASSA (CANA-DE-AÇÚCAR)
1 EXTRAÇÃO SACAROSE QUÍMICO GLUCOSE,FRUTOSE
(MELAÇO) BIOQUÍMICO AÇÚCAR INVERTIDO
CELULOSE
BIOMASSA PRÉ-TRAT.
HEMICELULOSE
L-CEL FRACIONAMENTO
LIGNINA
(BAGAÇO)
2 HIDRÓLISE CELULOSE ÁCIDO DILUÍDO GLUCOSE
HEMICELULOSE ÁCIDO CATALÍTICO HMF, DMF
ENZIMÁTICO XILOSE, ARABINOSE,
FURFURAL,

5. CONVERSÃO DA BIOMASSA
CONVERSÃO DA BIOMASSA (CANA-DE-AÇÚCAR)
3 OXIDAÇÃO LIGNINA QUÍMICO ALDEÍDOS
AROMÁTICOS
CATALÍTICO
ÁCIDOS DERIVADOS
4 HIDROGENA SACAROSE QUÍMICO POLIÓIS
ÇÃO
GLUCOSE CATALÍTICO ÁCIDOS DERIVADOS
HIDROGENÓ FRUTOSE ÉSTERES
LISE
XILOSE
OXIDAÇÃO
(MELAÇO,
HIDROLISADOS)
ESTERIFICA
ÇÃO

6. CONVERSÃO DA BIOMASSA
CONVERSÃO DO BAGAÇO DE CANA-DE-AÇÚCAR
BAGAÇO
DE
CANA-DE-AÇÚCAR
CELULOSE HEMICELULOSE LIGNINA
ACETATO SORBITOL / FURFURAL XILITOL RESINAS PLÁSTICOS VANILINA
DE MANITOL FENÓLICAS
CELULOSE

7. The acid hydrolysis process
Dilute acid hydrolysis,
Low acid consumption
Maximum monosaccharide yields reached at high
temperatures and short residence times,
Fast reaction rates
Yields circa of 50-60% of the theoretical value
Concentrated acid hydrolysis,
Processed decomposing and dissolving the polysaccharides
Occurs with water deficiency
Production of oligosaccharides

8. The acid hydrolysis process
Limitations,
Severe conditions (e.g. higher temperature, low pH)
Formations of degradation by-products
Furans and organic acids
Monomeric hexoses and pentoses transformed into HMF and
furfural,
Further degradation into organic acids (e.g. levulinic, humic
acids) and condensation reactions
Dissolved lignin result in the formation of inhibiting phenolic
compounds
Corrosion of the equipment

9. The acid hydrolysis process
Production process of saccharidic mixtures to further
processing,
Degradation of corn starch or sugarcane hemicellulose in acid
media
Quantification of the oligomeric decompositions
Selection of saccharidic mixtures to further catalytic
treatements
Kinetics of starch and pentosane depolymerization
Consecutive evolutions of the oligomeric components
Identification by the degree of polymerizations (DP6, DP5,
DP4, DP3, DP2, DP1 = glucose, xylose,..).

10. The acid hydrolysis process
Starch and sugar cane bagasse hydrolysis,
Native corn starch solutions were hydrolyzed at
temperatures ranging 343 K to 373 K, producing
glucose with yield circa 70%
Sugar cane bagasse was hydrolised at 393 K,
producing xylose, with approximate yield of 60%
Abreu, C. A. M. et al. (1995) Biomass and Bioenergy Vol
9, No. 6, 487-492

11. The acid hydrolysis process
Mechanism Kinetics
S+ 
AcH 1
→ SH + Ac - dC S  k' 
= −k ' C S 1 − ((C S O − C G )
dt  k 
SH + H 2 O 1'
→ DPn + G
DPn + AcH 2 → DPn H + Ac − 1/2
dC G   
= k ' K AcH 1 − ' (C So − C G ) (C So − C G )
k
DP H + H O 2
'
n → DP
2 +G
n −1
dt   k 
----------------------------
DP + AcH n
2 → DP H + Ac -
1
DP1 H + H 2 O n  
'
→ G + G
dC OL
= k (C S − C G )1 − ' (C So − C G )
k
dt  k 
AcH ⇔ Ac - + H +

12. CONVERSION OF CARBOHYDRATES
Processing of raw materials rich in saccharides (sugarcane, starch,
molasse, bagasse,…),
Products with industrial application as polyols and organic
acids
Carbohydrate hydrogenations (saccharides → monosaccharides → polyols)
Carbohydrate oxidations (saccharides → monosaccharides + acids → acids)
Heterogeneous processes with supported catalysts based on
nickel, chromium, ruthenium to hydrogenate glucose,
fructose and sucrose to sorbitol and mannitol

13. Hydrogenation of carbohydrates
Heterogeneous mechanism

14. 1st Brazilian Workshop on Green Chemistry
Hydrogenation of carbohydrates
Heterogeneous mechanism

15. Hydrogenation of carbohydrates
Saccharide hydrogenation process,
Polyol production in a batch three-phase reactor
Glucose conversions of 85% with a selectivity in sorbitol of
99.05% at 413K, under 24 bar, after 3 hours of reaction with
a nickel catalyst (14.75 % weight)/activated carbon
Saccharose conversions of 52% after 3 hours of reaction
Production of glucose and fructose and sorbitol and mannitol
L. C. A. Maranhão, F. G. Sales, J. A. F. R. Pereira, C. A. M. Abreu (2004) React. Kinet. Catal. Lett.
81, 169-175

16. Hydrogenolysis of carbohydrates
Saccharide hydrogenolysis process,
More drastic temperature and hydrogen pressure conditions
Splitting of carbon-carbon and carbon-oxygen carbohydrate
bonds
Polyols obtained from hydrogenations can be hydrogenolysed
Products: other polyols, glycols and alcohols
Catalysts: noble metals

17. Continuous production of fine
polyols
Scale-up of carbohydrate hydrogenations,
Fine polyols from biomass resources are traditionally
produced in discontinuous processes
Apparatus of great volume in relation to the small quantity of
the obtained products
Scale-up from discontinuous operations to continuous one
Development of the saccharide hydrogenation process into a
continuous operation
Continuous polyol production

18. Continuous production of fine
polyols
Continuous hydrogenation in a three-phase reactor,
Trickle-bed reactor under moderate operation conditions
(1.22 MPa, 413 K)
Glucose conversions of 44% with a polyol selectivity of
99.31%
Yield of 24% in sorbitol and mannitol for the saccharose
hydrogenation
Possibility to develop a process (pressures up to 2.54MPa, low
liquid flow rates) to obtain high conversions
Maranhão, L. A., Abreu, C. A. M. (2005) Industrial and Engineering Chemistry Research. v. 44, p.
9642-9645

19. Continuous production of fine
polyols
0,5
dC G ′
dC G η G k G C G
Dax − uL − =0
0,4 dz 2
dz 1 + K G CG
0,3 glucose
C (mol L-1)
sorbitol
model
0,2
f e φ G [coth (3φ G f e ) − ( f e 3φ G )]
ηG =
0,1
( )
1 + φ G ShLG [coth (3φ G f e ) − ( f e 3φ G )]
0,0
0,0 0,1 0,2 0,3 0,4 0,5 0,6
Axial position (m)
Hydrogenation of glucose at 1.22MPa and 413K in trickle-bed
reactor

20. Continuous production of fine
polyols
0,3
d 2 C Sac dC Sac
Dax − uL ′
− η Sac k Sac C Sac = 0
dz 2 dz
0,2
C (mol L-1)
saccharose
d 2 C Mo dC Mo  ′
k Mo C Mo 
0,1
monosaccharides
Dax −u + η Mo  k Sac C Sac −
 ′ =0

polyols
model dz 2 dz  1 + K Mo C Mo 
0,0
0,0 0,1 0,2 0,3 0,4 0,5 0,6 d 2 C Po dC Po ′
k Mo C Mo
Dax −u + η Po =0
Axial position (m)
dz 2
dz 1 + K Mo C Mo
Hydrogenation of saccharose at 1.22MPa and 413K in trickle-
bed reactor.

21. Continuous production of fine
polyols
An up grade of the discontinuous to the continuous process for saccharide
hydrogenation may be compared in the following terms:
Discontinuous process (slurry reactor) Continuous process (trickle-bed
reactor)
Ni/C catalyst; 413 K, 2.44 MPa Ni/C catalyst; 413 K, 1.22 MPa
Operation time = 3 hours Operation time = 3 hours
Concentration of the saccharide feed = Concentration of the saccharide feed =
100.00 g/L 100.00 g/L
Production = 42.50 g in polyol Acumulated production = 749.35 g in
polyol

22. LIGNIN FROM BIOMASS
Biomass conversion into aldehydes and acids,
Lignin degradation: break up into fragments producing
aromatic aldehydes
Polifenate ions, precursors of the aromatic aldehyde
formations
Aldehyde conversion into organic acids

23. LIGNIN PROCESSING FROM
SUGARCANE BAGASSE
Lignin oxidation,
Wet air oxidation process (WAO) as an alternative technology
Valorization of lignocellulosic materials
Production of a mixture of aromatic aldehydes of industrial
interest
Catalytic wet air oxidation (CWAO) process using air and
catalysts
Treatment of effluents and by-product of the biomass industry

24. Catalytic wet oxidation of lignin
H 2COH
CH
CO
H2 COH
OCH3
1 H2COH HC
HC 3 O CH
H3CO
O CH
OCH3 4
2 H2 COH
OCH3
HC O
H3CO OCH3
O CHO
(a)
H 2COH HO O
H2COH H O
HC C
H C OH C
O 2 Pd γ − Al2 O
CH
//  3 →  HO C H  2 /γ−Al2
Pd/ O3 →
O
 + AcH Pd / γ−Al O3 →
 2 / 2
O
 2 + AcH
2
2 R1 R2
2 R1 R2
OH
OH
H3CO OCH3
O R1 R2
OH
[ Lignin ] [ Aldehydes ] [ Acids ]
(b)
Basic structure of lignin and degradation/oxidation
mechanism. (a) basic unit of the Fagus silvatic lignin. (b)
degradation/oxidation reaction steps. R1= H, OCH3 ;
R2 = OCH3 .

25. Catalytic wet oxidation of lignin
CWAO of lignin from sugar-cane bagasse was evaluated to
produce aromatic aldehydes
Lignin (L) is depolymerized with the productions of
aldehydes, acids and other products of low molecular
weights
The aromatic aldehydes vanillin (V), syringaldehyde (S) and
p-hydroxibenzaldehyde (P) were submitted to subsequent
oxidations
Other products (R), such as organic acids can degrade into
carbon dioxide
Reaction scheme of the catalytic wet oxidation of lignin

26. Process operations
Operations in a slurry reactor,
Palladium catalyst, 373-413 K, 2-10 bar/ PO2
Lignin as a by-product from sugarcane bagasse by the DFH
(Dedine Fast Hydrolysis)
Yields of the aromatic aldehydes associated with lignin
consumption and their oxidations to acids
Aromatic aldehyde yields approximately ten to twenty times
higher then with the noncatalytic oxidation process
Sales, F. G. , Maranhão, L. A. , Lima Filho, N. M. , Abreu, C. A. M.( 2006). Industrial & Engineering
Chemistry Research. v. 45, p. 6627-6631

27. Processo continuo de produção de aldeídos
aromáticos
Scale-up of process,
From batch to continuous operations
Aromatic aldehyde productions operated in a continuous
fluidized-bed reactor
Lignin as a by-product from sugarcane bagasse
Yields of the aromatic aldehydes associated with the lignin
consumption and their oxidations to acids

28. Processo continuo de produção de aldeídos
aromáticos
Three-phase fluidized-bed reactor

29. Processo continuo de produção de aldeídos
aromáticos
Escalonamento,
Batch operation: 56.24x10-2g of vanillin and
50.01x10-2g of syringaldehyde from a 0.50L-lignin
solution (60.00g/L), 2 h of reaction at 5.00 bar and 393
K
Continuous operation: 65.10x10-1g of vanillin and
114.84x10-1g of syringaldehyde, with a feed
concentration of lignin of 30.00 g/L, 2 h of reaction, at
5.00 bar and 393 K, liquid-phase flow rate of 5.00 L/h
F. G. Sales, L. C.A. Maranhão, N. M. Lima Filho, C. A.M. Abreu (2007) Chemical
Engineering Science 62, 5386 – 5391

30. Conclusions
Recent technology developments done in the scope of the biorefinery
concept have emerged as alternatives, making production of chemicals
from ligno-cellulosic feedstocks become a reality.
Biomass conversions employ hydrolysis and pretreatments of hemicellulose
and lignin, and acid or enzymatic hydrolysis of cellulose to break the
polymeric structures to their saccharides and lignin components.
In the presence of homogeneous or heterogeneous catalysts the oligomeric
mixtures selected may be processed in order to produce valuable
chemicals.
Through catalytic hydrogenation, hydrogenolysis or oxidation these
mixtures can be converted to polyols, glycols, monoalcohols, aldehydes and
organic acids.