Transcript Pre-treatment Technologies Jean-Luc Wertz and Prof. Michel Paquot Lignofuels 2011 - 29 September 2011

Pre-treatment Technologies
Jean-Luc Wertz and Prof. Michel Paquot
Lignofuels 2011 - 29 September 2011
PLAN
1. Introduction
2. Physical pre-treatments
3. Chemical pre-treatments (e.g. organosolv)
4. Physicochemical pre-treatments (e.g. steam explosion;
AFEX)
5. Biological pre-treatments
6. Economic analysis (OPEX, CAPEX)
7. Performance summary
Average composition of lignocellulosic
biomass
Cellulose: molecular structure
• Glucose units linked by β 1-4 glycosidic bonds
• One reducing end and one non-reducing end
• Linear straight polysaccharide
Hemicelluloses
• High structural diversity
• Monomers: pentoses and hexoses
• Branched polysaccharides
• Example: xyloglucans as shown below
Lignin
• Monomers : 3 different monolignols (H,
hydroxyphenyl; G, guaïacyl; S, syringyl)
H
G
S
Lignin
Cross-linked polymers of monolignols
Schematic of the role of pre-treatment
Source: P. Kumar et al., 2009
Liquid hot water (LHW)
Biomass pretreatment with water at high temperature and pressure
Inbicon’s hydrothermal pre-treatment pilot plant
Weak and strong acid hydrolysis
1 Weak acid:
-High-temperature (>160°C), continuous-flow process for low solids
loadings
-Low-temperature (<160°C) batch process for high solids loadings
2. Strong acid:
Powerful agents for cellulose hydrolysis and no enzymes are needed
after the concentrated acid process
Alkaline hydrolysis
Well known in the pulp and paper industry as kraft pulping
Extraction of lignin from Kraft pulp mill
black liquor by the LignoBoost process
Source: Metso, LignoBoost
Schematic of the MixAlco® process
(Terrabon, Inc.)
Source: Holtzapple et al., Terrabon
Organosolv processes
Solvolytic cleavage of an alpha-aryl ether linkage by nucleophilic
substitution; R=H or CH3; B=OH, OCH3
Some important organosolv processes
Process
Name
Solvent / Additive
Asam
Water + sodium carbonate + hydroxide + sulfide
+ methanol / Anthraquinone
Organocell
Water + sodium hydroxide + methanol
Alcell (APR) Water+ low aliphatic alcohol
Milox
Water + formic acid + hydrogen peroxide (forming
peroxyformic acid)
Acetosolv
Water + acetic acid/Hydrochloric acid
Acetocell
Water + acetic acid
Formacell
Water + acetic acid + formic acid
Formosolv
Water + formic acid + hydrochloric acid
Lignol’s process based on
water/ethanol pre-treatment
Source: Lignol
lignocellulosic materials
Formic Ac./Acetic Ac./Water
heating
filtration
CIMV process: formic
acid / acetic acid / H2O
black liquors
pulp
Formic Ac./Acetic Ac./Water
rinsing
black liquors
Water
pulp
water precipitation
washing
centrifugation
pulp
lignins
Water
Acidified water
Source: C. Vanderghem et al.,
ULg-GxABT
washing
lignins
Water solubles
CIMV process using acetic acid/formic acid/water
Source: C. Vanderghem et al., ULg-GxABT
Contour Plot of Pulp Yield vs Temperature; Time
1,0
,
0,5
Temperature
Pulp
Yield
< 60
60 – 70
70 – 80
80 – 90
> 90
Hold Values
FA /A A/W 1
0,0
-0,5
-1,0
-1,0
-0,5
0,0
Time
0,5
1,0
Time: 1h (-1), 2h (0), 3h(1). Temperature: 80°C (-1), 90°C (0), 107°C (1)
CIMV process using acetic acid/formic acid/water
Source: C. Vanderghem et al., ULg-GxABT
Contour Plot of % Of delignification vs FA/AA/W; Temperature
1,0
% Of
delignification
< 20
20
– 40
40
– 60
60
– 80
> 80
FA/AA/W
0,5
Hold Values
Time 1
0,0
-0,5
-1,0
-1,0
-0,5
0,0
Temperature
0,5
1,0
Temperature: 80°C (-1), 90°C (0), 107°C (1).
FA/AA/W: 20/60/20 (-1) 30/50/20(0); 40/40/20 (1)
CIMV process using acetic acid/formic acid/water
Source: C. Vanderghem et al., ULg-GxABT
Contour Plot of Furfural (ppm) vs Temperature; Time
1,0
Furfural
(ppm)
< 0
0 – 10
10 – 20
20 – 30
30 – 40
40 – 50
> 50
Temperature
0,5
0,0
Hold Values
FA /A A/W 1
-0,5
-1,0
-1,0
-0,5
0,0
Time
0,5
1,0
Time: 1h (-1), 2h (0), 3h(1). Temperature: 80°C (-1), 90°C (0), 107°C (1)
CIMV process using acetic acid/formic acid/water
Source: C. Vanderghem et al., ULg-GxABT
Contour Plot of Enzymatic digestibility (%) vs FA/AA/W; Temperature
1,0
Enzymatic
digestibility
(%)
< 30
30 – 40
40 – 50
50 – 60
60 – 70
> 70
FA/AA/W
0,5
0,0
Hold Values
Time 1
-0,5
-1,0
-1,0
-0,5
0,0
Temperature
0,5
1,0
Temperature: 80°C (-1), 90°C (0), 107°C (1).
FA/AA/W: 20/60/20 (-1) 30/50/20(0); 40/40/20 (1)
Oxidative delignification
1. Hydrogen peroxide treatment
2. Ozone treatment
3. Wet oxidation: treatment with oxygen or air in combination with water at
high temperature and pressure
Room temperature ionic liquids
Main cations and anions in ionic liquids
Room temperature ionic liquids
Different types of interaction present in imidazolinium-based
ionic liquids
Room temperature ionic liquids
Proposed mechanism for cellulose dissolution in EmimAc
Room temperature ionic liquids
Hydrolysis of cellulose in a mixture of cellulases and an ionic liquid (HEMA)
+
Steam explosion
Schematic of the steam explosion process. 1, sample charging valve; 2,
steam supply valve; 3, discharge valve; 4, condensate drain valve
ULg-Gembloux Agro-Bio Tech steam
explosion pilot plant (Source: N. Jacquet et al.)
ULg-Gembloux Agro-Bio Tech steam
explosion pilot plant (Source: N. Jacquet et al.)
Ulg-GxABT steam explosion pilot plant (Source: N. Jacquet et al.)
Ammonia pre-treatments
1. Ammonia fiber explosion (AFEX™): biomass is
exposed to liquid ammonia at high temperature
and pressure and then pressure is reduced
2. Ammonia recycle percolation (ARP): aqueous
ammonia passes through biomass at high
temperature, after which ammonia is recovered
What is AFEX™?
Recovered
Ammonia
Ammonia
Recovery
Recovery
Ammonia
vapor
Heat
Biomass
Reactor
Reactor
Expansion
Explosion
Treated
Biomass
Ammonia Fiber Expansion Process
– Moist biomass is contacted with ammonia
– Temperature and pressure are increased
– Contents soak for specified time at temperature and ammonia load
– Pressure is released
– Ammonia is recovered and reused
AFEX™ is a trademark of MBI
Biomass Conversion for Different
Feedstocks Before and After AFEX
Glucan conversion for various AFEX treated Feed stocks
Switchgrass
Corn stover
Sugarcane
Bagasse
Rice straw
Miscanthus
DDGS
Glucan conversion after
enzymatic hydrolysis
UT=No Pretreatment
AFEX=Ammonia Pretreatment
Excellent Biomass Conversion After AFEX Pretreatment
Carbon dioxide explosion
High pressure carbon dioxide, and particularly
supercritical carbon dioxide is injected into the reactor
and then liberated by an explosive decompression
Mechanical/alkaline pre-treatment
Continuous mechanical pre-treatment with the aid of an
alkali
Biological pre-treatments
White-rot fungi are the most efficient in causing lignin degradation
Source: L. Goodeve, 2003
Source: R.A. Blanchette, 2006
Performance summary
Pretreatment
Decrystallization of cellulose
Removal of hemicelluloses
Removal of lignin
Inhibitor formation
Liquid hot water1)
XX
XX
Weak acid1)
XX
XX
Alkaline
X
XX
Organosolv
X3
XX
X
XX
Wet oxidation
XX
Steam explosion* 1)
XX
Ammonia fiber
explosion (AFEX)
XX
X
CO2 explosion
XX
XX
XX
Mechanical/alkaline
X
XX
Biological
XX
XX
XX: Major effect; X: Minor effect;; *: increases crystallinity; 1) alters lignin structure
Inhibitors: furfural from hemicelluloses and hydroxymethylfurfural from cellulose and hemicelluloses
Performance summary
1. All pretreatments partially or totally remove
hemicelluloses
2. Wet oxidation, AFEX and CO2 explosion reduce
cellulose crystallinity
3. Alkaline, organosolv, wet oxidation,
mechanical/alkaline and biological partially or totally
remove lignin
4. High amounts of fermentation inhibitors are formed
with liquid hot water, weak acid and steam explosion
ECONOMIC ANALYSIS: OPEX (Minimum Ethanol Selling Price), CAPEX
Pretreatment
OPEX
($/gal EtOH)
CAPEX
($/gal annual
capacity)
Liquid hot water
1.65
4.57
Weak acid
1.35
3.72
Alkaline
1.60
3.35
Ammonia fiber explosion (AFEX)
1.40
3.72
Ammonia recycle percolation (ARP)
1.65
4.56
Ideal
1.00
2.51
Organosolv
Wet oxidation
Steam explosion
NB Enzyme cost: EUR 3/kg of
produced cellobiose
Source: Eggeman et al., 2005
Thank you for your attention