Technologies de prétraitement

Jean-Luc Wertz and Prof. Michel Paquot

VALEBIO 23 mars 2012

PLAN1 Transformation de la biomasse en énergie et produ its

1.1 La bioraffinerie

1.2 Voie biochimique

1.3 Voie thermochimique

2 Prétraitements

2.1 Prétraitements physiques

2.2 Prétraitements chimiques (p. ex. organosolv)

2.3 Prétraitements physico-chimiques (p. ex. steam explosion)

2.4 Prétraitements biologiques

2.5 Résumé

Définition Bioraffinage

Le bioraffinage est le processus durablede transformation de la biomasse en:1. bioénergie (biocarburants, électricité, chaleur) 2. produits biobasés (alimentation, produits chimiques, matériaux)

Raffineries de 1ère et 2ème génération

• Première génération: raffinage à partir de biomasse alimentaire (canne à sucre,, grains de maïs, huile végétale…)

• Deuxième génération: raffinage à partir de biomasse non alimentaire (résidus agricoles et forestiers, déchets municipaux…)

Crude oil refining

Crude oil

Fuels(Energy)

Building blocks(Petrochemistry)

Specialties(e. g. lubricants)

Biomass refining

Biomass

Biofuels(Bioenergy)

Building blocks(Agro-bio chemistry)

Specialties(e. g. biolubricants)

Procédés de transformation

• Plateforme biochimique- Hydrolyse acide (dilué ou concentré)- Hydrolyse enzymatique

• Plateforme thermochimique- Combustion- Gazéification- Pyrolyse & traitement hydrothermique

Dilute acid hydrolysis

Concentrated acid hydrolysis

Enzymatic hydrolysis

Plateforme biochimique Défis

- Prétraitement de la biomasse- Coût et efficacité des enzymes- Fermentation des sucres C5 and C6 - Valorisation de la lignine

Thermochemical conversion: primary routes

Gazéification + Fischer-Tropsch

Conversion de la biomasse en gaz de synthèse ou syngas (H2 + CO) suivie de la conversion du syngas par synthèse Fischer-Tropsch en carburants liquides (BtL)

Synthèse Fischer-Tropsch

Pyrolyse + conversion catalytique

Conversion de la biomasse en bio-huiles, eux-mêmes convertis en carburants liquides

Schematic of the role of pretreatment

Source: P. Kumar et al., 2009

Liquid hot water (LHW)Pretreatment with liquid water at high temperature and pressure

Source: N. Mosier et al., 2005

Liquid hot water

Performance: Strong removal of hemicelluloses but formation of inhibitor

Inbicon’s hydrothermal pretreatment pilot plant Source: Inbicon

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 l oadings

Performance: Strong removal of hemicelluloses but formation of inhibitors

2. Strong acid:

Powerful agents for cellulose hydrolysis (no enzymes are needed after the strong acid process)

Performance: High monomeric sugar yield but toxic and corrosive

Alkaline hydrolysis

Well known in the pulp and paper industry as kraft pulping (or sulfate process) where wood chips are treated with a mixture of NaOH and Na2S

Performance: Weak removal of hemicelluloses, strong removal of lignin

Extraction of lignin from Kraft pulp mill black liquor by the LignoBoost process

Source: Metso, LignoBoost

� Precipitation of lignin from black liquor by lowering the pH with CO2

� Dewatering by filtration� Redispersion of lignin� Dewatering by filtration of the new slurry� Washing to produce lignin cakes

Organosolv processesSolvolytic cleavage of an alpha-aryl ether linkage by nucleophilic substitution; R=H or CH3; B=OH, OCH3

Performance: Weak removal of hemicelluloses, strong removal of lignin

Some important organosolv processes

ProcessName

Solvent / Additive

Asam Water + sodium carbonate + hydroxide + sulfide+ methanol / Anthraquinone

Organocell Water + sodium hydroxide + methanol

Alcell (APR) Water+ low aliphatic alcohol (e.g. ethanol)

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

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

Performance: Decrystalisation of cellulose, weak removal of hemicelluloses, strong removal of lignin

Room temperature ionic liquidsMain cations and anions in ionic liquids

Performance: Partial to complete dissolution of biomass with easy recovery of cellulose upon anti-solvent addition

Room temperature ionic liquidsDifferent types of interaction present in imidazolinium-based ionic liquids

Source: H. Olivier-Bourbigou, 2010

Room temperature ionic liquidsProposed mechanism for cellulose dissolution in EmimAc (1-ethyl-

3-methyl imidazolium acetate)

Source: J. ZHANG et al., 2010

Source: S. Bose et al., 2010

Room temperature ionic liquidsHydrolysis of cellulose in a mixture of cellulases and tris-(2-hydroxyethyl)

methyl ammonium methylsufate (HEMA)

+

Steam explosionSchematic of the steam explosion process. 1, sample charging valve; 2, steam supply valve; 3, discharge valve; 4, condensate drain valve

Performance: Strong removal of hemicelluloses but formation of inhibitors

Principle:Treatment of biomass with high-pressure saturated steam, followed by a rapid reduction of steam pressure to obtain an explosive decompression

Source: T. Jheo, 1998

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

Performance: Strong decrystallisation of cellulose, weak removal of hemicelluloses

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

Reactor Explosion

AmmoniaRecoveryRecovered

AmmoniaAmmonia

vapor

Reactor Expansion

Ammonia Recovery

BiomassTreated

Biomass

Heat

What is AFEX™?

AFEX™ is a trademark of MBI

Source: MBI

Glucan conversion for various AFEX treated Feed sto cks

SwitchgrassSugarcaneBagasse

DDGS

Rice straw

Corn stover

Miscanthus

UT=No PretreatmentAFEX=Ammonia Pretreatment

Biomass Conversion for Different Feedstocks Before and After AFEX

Glucan conversion afterenzymatic hydrolysis

Excellent Biomass Conversion After AFEX Pretreatment

Source: MBI

Carbon dioxide explosion

High pressure carbon dioxide, and particularly supercritical carbon dioxide is injected into the reactor and then liberated by an explosive decompression

Performance: Strong decrystalisation of cellulose, strong removal of hemicelluloses

Mechanical/alkaline pre-treatment

Continuous mechanical pre-treatment with the aid of an alkali

Performance: Weak removal of hemicelluloses, strong removal of lignin

Biological pre-treatmentsWhite-rot fungi are the most efficient in causing lignin degradation

Source: L. Goodeve, 2003

Source: R.A. Blanchette, 2006

Performance: strong removal of hemicelluloses and lignin

XX: Major effect; X: Minor effect;; *: increases crystallinity; 1) alters lignin structureInhibitors: furfural from hemicelluloses and hydroxymethylfurfural from cellulose and hemicelluloses

Pretreatment Decrystallization of cellulose Removal o f hemicelluloses Removal of lignin Inhibitor formati on

Liquid hot water 1) XX XX

Weak acid 1) XX XX

Alkaline X XX

Organosolv X XX

Wet oxidation XX X XX

Steam explosion* 1) XX XX

Ammonia fiber explosion (AFEX)

XX X

CO2 explosion XX XX

Mechanical/alkaline X XX

Biological XX XX

Performance summary

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

Thank you for your attention