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Technologies de prétraitement

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Presentation on theme: "Technologies de prétraitement"— Presentation transcript:

1 Technologies de prétraitement
Jean-Luc Wertz and Prof. Michel Paquot VALEBIO 23 mars 2012

2 PLAN 1 Transformation de la biomasse en énergie et produits
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

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

4 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…)

5 Crude oil refining

6 Biomass refining

7 Procédés de transformation
Plateforme biochimique - Hydrolyse acide (dilué ou concentré) - Hydrolyse enzymatique Plateforme thermochimique - Combustion - Gazéification - Pyrolyse & traitement hydrothermique

8 Dilute acid hydrolysis

9 Concentrated acid hydrolysis

10 Enzymatic hydrolysis

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

12 Thermochemical conversion: primary routes

13 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

14 Pyrolyse + conversion catalytique
Conversion de la biomasse en bio-huiles, eux-mêmes convertis en carburants liquides

15 Schematic of the role of pretreatment
Source: P. Kumar et al., 2009

16 Pretreatment with liquid water at high temperature and pressure
Liquid hot water (LHW) Pretreatment with liquid water at high temperature and pressure Source: N. Mosier et al., 2005

17 Liquid hot water Performance: Strong removal of hemicelluloses but formation of inhibitor Inbicon’s hydrothermal pretreatment pilot plant Source: Inbicon

18 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 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

19 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

20 Extraction of lignin from Kraft pulp mill black liquor by the LignoBoost process
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 Source: Metso, LignoBoost

21 Organosolv processes Solvolytic 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

22 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 (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

23 Lignol’s process based on water/ethanol pre-treatment
Source: Lignol

24 Oxidative delignification
Hydrogen peroxide treatment Ozone treatment 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

25 Room temperature ionic liquids
Main cations and anions in ionic liquids Performance: Partial to complete dissolution of biomass with easy recovery of cellulose upon anti-solvent addition

26 Room temperature ionic liquids
Different types of interaction present in imidazolinium-based ionic liquids Source: H. Olivier-Bourbigou, 2010

27 Room temperature ionic liquids
Proposed mechanism for cellulose dissolution in EmimAc (1-ethyl- 3-methyl imidazolium acetate) Source: J. ZHANG et al., 2010

28 Room temperature ionic liquids
Hydrolysis of cellulose in a mixture of cellulases and tris-(2-hydroxyethyl) methyl ammonium methylsufate (HEMA) + Source: S. Bose et al., 2010

29 Steam explosion Schematic of the steam explosion process. 1, sample charging valve; 2, steam supply valve; 3, discharge valve; 4, condensate drain valve Principle: Treatment of biomass with high-pressure saturated steam, followed by a rapid reduction of steam pressure to obtain an explosive decompression Performance: Strong removal of hemicelluloses but formation of inhibitors Source: T. Jheo, 1998

30 Ammonia pre-treatments
Ammonia fiber explosion (AFEX™): biomass is exposed to liquid ammonia at high temperature and pressure and then pressure is reduced 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

31 What is AFEX™? Reactor Explosion Ammonia Recovery Expansion
Recovered vapor Expansion Ammonia Recovery Biomass Treated Heat 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 Source: MBI AFEX™ is a trademark of MBI

32 Biomass Conversion for Different Feedstocks Before and After AFEX
Glucan conversion for various AFEX treated Feed stocks Switchgrass Sugarcane Bagasse DDGS Rice straw Corn stover Miscanthus Glucan conversion after enzymatic hydrolysis UT=No Pretreatment AFEX=Ammonia Pretreatment Excellent Biomass Conversion After AFEX Pretreatment Source: MBI

33 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

34 Mechanical/alkaline pre-treatment
Continuous mechanical pre-treatment with the aid of an alkali Performance: Weak removal of hemicelluloses, strong removal of lignin

35 Biological pre-treatments
White-rot fungi are the most efficient in causing lignin degradation Source: L. Goodeve, 2003 Performance: strong removal of hemicelluloses and lignin Source: R.A. Blanchette, 2006

36 Performance summary Pretreatment Decrystallization of cellulose Removal of hemicelluloses Removal of lignin Inhibitor formation Liquid hot water1) XX Weak acid1) Alkaline X Organosolv Wet oxidation Steam explosion* 1) Ammonia fiber explosion (AFEX) CO2 explosion Mechanical/alkaline Biological XX: Major effect; X: Minor effect;; *: increases crystallinity; 1) alters lignin structure Inhibitors: furfural from hemicelluloses and hydroxymethylfurfural from cellulose and hemicelluloses

37 Performance summary All pretreatments partially or totally remove hemicelluloses Wet oxidation, AFEX and CO2 explosion reduce cellulose crystallinity Alkaline, organosolv, wet oxidation, mechanical/alkaline and biological partially or totally remove lignin High amounts of fermentation inhibitors are formed with liquid hot water, weak acid and steam explosion

38 Thank you for your attention

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