1 Wood to Wheel: Process Improvement for the Production of Substituted Fuels from Renewable Biomass POKE Symposium , Ösel Venkata Prabhakar Soudham
2 The Problem: Our Society STOPS Without Liquid Fuels!
3 Busslink - Stockholm Biofuels production Ethanol (C 2 H 5 OH) Butanol (C 4 H 9 OH) First generation Ethanol fermentation: Glucose (C 6 H 12 O 6 ) Fermentation organisms Bio-alcohols Starch (C 6 H 10 O 5 ) n Enzymes Glucose Fermentation organisms Bio-alcohols "...large increases in biofuels production is the main reason behind the steep rise in global food prices" -World Bank policy research paper July 2008
4 Source: Lignocellulosic materials Agricultural residues Municipal solid wastes Abundant Inexpensive Sustainable Forest residues Second generation feedstock Cellulosic fuels can achieve much greater energy and GHG benefits
5 Chemical Composition of Lignocellulose (10-35 %) (20-35 %) (20-50 %)
6 First & Second Generation Biofuels Corn Weighs more than Corn Stover
7 Monomer Sugars? Source:
8 Sugars extraction from biomass Biomass Splitting of cellulose to glucose Hydrolysis Pretreatment goals: Opening crystalline structure of Lignocellulose Hydrolysis of hemicelluloses Enhance the enzymatic hydrolysis Severity factor: Log R o =t*e (T-Tr)/14.75 t: time (min), T: reaction temperature, Tr: reference temperature (100 C)
9 Toxic Compounds from Pretreatment (Source: Alriksson B., 2006) Sugars are inhibitory to the celluase enzymes
10 Bioconversion of lignocelluloses to biofules Biomass Pretreatmen t Solid liquid separation Enzyme production Hydrolysis Hexose fermentation Pentose fermentation Product recovery Biofuels
12 Critical Areas of Research Evaluation of lignocellulose recalcitrance: Screening of transgenic Aspens Application of different solvents for the biomass pre-treatment - Existing: H 2 SO 4, SO 2, and CH 3 COOH etc.. - Green solvents: Ionic Liquids (IL s): 1-allyl-3-methylimidazolium formate [Amim](HCO2) 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU), monoethanol amine (MEA), SO 2 / CO 2 Investigation of strategies to lighten the toxicity of lignocellulose hydrolysates using 1. Fenton's reagent: Fe(+2) and H 2 O 2 2. Reducing agents: Sodium sulphite (Na 2 SO 3 ), Sodium dithionite (Na 2 S 2 O 4 ), Dithiothreitol (DTT: C 4 H 10 O 2 S 2 ) 3. Alkali: NaOH, Ca(OH) 2, NH 4 (OH)
13 Screening of Transgenic Aspens plants (14 constructs, 3 lines each) Selected on basis of growth characteristics (height, width) and lignin content. Investigation of factors that govern the recalcitrance of lignocelluloses up on their conversion to valuable products
14 Strategy for screening Acid pretreatment targeting hemicellulose Steam pretreatment Detailed analysis of liquid fractions Harvesting, cutting, lyophilization, milling, sieving No pretreatment IL pretreatment Separation of liquid and solid fraction Wash of solid fraction Enzymatic hydrolysis Rapid analysis of glucose in liquid fraction pretreatment targeting Lignin Analysis of wood composition Steam pretreatment Protocols were developed for an optimal investigation Detailed analysis of solid fractions A battery of pretreatment techniques that together give more information than is obtained with only one pretretment technique.
15 Steam pretreatment with acid catalyst Total reducing sugars (g/l) No pretreatment Total reducing sugars (g/l) 4,0 3,5 3,0 3,07 2,92 2,79 2,81 2,5 2,0 T-Test P Critical = ,5 1,0 0,5 Line X 0,52 Line Y 0,76 Line Z 0,96 0,0 Line 1 X Line 2 Y Line 3 Z Wild 4type 9,0 8,0 7,0 6,0 7,57 28 % 6,93 6,64 17 % 12 % 5,91 5,0 4,0 T-Test P Critical = ,0 2,0 1,0 Line X <0,01 Line Y <0,01 Line Z <0,01 0,0 LMP Line X LMP Line Y LMP Line Z Wild T89-27 type
16 Evaluation of different solvents for the pretreatment of lignocelluloses 1. A comparision study of SO 2 and H 2 SO 4 pretreatments of chipped Norwegian spruce performed at biorefinery demo plant (Örnsköldsvik, SWEDEN) 2. Fractionation of forestry wood using CH 3 COOH 3. Pre-treatment of different lignocelluloses (e.g. Birch, Pine, Spruce, Sugar cane bagasse, and Reed canary grass) using IL solvents: [Amim](HCO2), DBU-MEA-SO 2, and DBU-MEA-CO 2
18 AS 121C AS NBT Glucose (mmol/l) Lignin removal (%) Lignin removal and recovery 100 AC - 50% AC - 70% AC - 90% Pulp after delignification AS-121C AS-NBT DAPH/AS-121C DAPH/AS-NBT Enzymatic hydrolysis of transgenic aspens after AS delignification Solids from ASD Milled Aspen wood Recovered lignin 0 24 h 70 h Hydrolysis Time
19 Wood chips Microcrystalline cellulose Agriculture residues 3. Pre-treatment of Lignocelluloses using various Ionic Liquid Solvents Biorefinery demo plant < (Örnsköldsvik, SWEDEN) Solvation of cellulosic material in ionic liquid.
20 Glucose concentration (g/l) Cellulose dissolution in various IL-solvents DBU SO2 MEAS 1-allyl-3-methylimidazolium formate ([Amim](HCO2) Microcrystalline cellulose Control DBU SO2 MEA DBU CO2 MEA [Amim](HCO2) DBU CO2 MEAS Hydrolysis time (h)
21 Untreated DW 45 C (48 h) IL 45 C (48 h) IL 80 C (2 h) IL 100 C (2 h) IL 120 C (2 h) DW 45 C (48 h) IL 45 C (48 h) Untreated DW 45 C (48 h) IL 45 C (48 h) IL 80 C (2 h) IL 100 C (2 h) IL 120 C (2 h) DW 45 C (48 h) IL 45 C (48 h) Released sugars (mg/g DS) Enzymatic Hydrolysis of Norway Spruce wood & Sugar Cane Bagasse after treatment with [Amim](HCO2) IL Glucose Xylose Mannose Total N. Spruce TCP. Spruce N. Bagasse TCP. Bagasse Material, temperature and time of IL and DW pretreatment Monomer sugars obtained after enzymatic hydrolysis (72 h at 45 ºC) of native (N) and thermo chemically pretreated (TCP) spruce and sugarcane bagasse. The cellulosic substrates were treatment with [AMIM]Fo ionic liquid (IL) or deionized water (DW).
23 1. Detoxificaion with Fenton s reagent i.e H2O2 and FeSO4 - A widely used technology in waste water treatment - Considered as environmentally friendly
24 Inhibitors profile Concentrations of inhibitors present in detoxified spruce hydrolysates compare to the non-detoxified hydrolysate.
25 Glucose (g/l) Ethanol (g/l) Enzymatic hydrolysis and fermentation of spruce hydrolysates detoxified with H2O2 and FeSO A Non-detoxified Untreated 150/2.5 Conc-X 150/5.0 Conc-Y 150/7.5 Conc-Z H2O2/FeSO4 Concentration (mm) 7 6,5 6 5,5 5 4,5 4 3,5 3 2,5 2 1,5 1 0,5 0 B Non-detoxified Untreated 150/2.5 Conc-X 150/5.0 Conc-Y 150/7.5 Conc-Z H2O2/FeSO4 Concentration (mm) A: Glucose produced from 72 h enzymatic hydrolysis of Avicel in H2O2/FeSO4 detoxified and non-detoxified spruce liquid hydrolysates, B: Ethanol produced from 48 h fermentation of chemically detoxified and non-detoxified spruce liquid hydrolysates.
26 Inhibitors effect on Fermentation Ethanol production from spruce hydrolysates, non-detoxified ( ), detoxified with 150 mm H 2 O 2 and 2.5 mm FeSO 4. 7H 2 O ( ) and detoxified with 150 mm H 2 O 2 and 2.5 mm FeSO 4. 7H 2 O but the degraded furfural and HMF were recompensed to the levels equal to original concentrations ( ).
27 % increase in glucose production after 120 h enzymatic hydrolysis compare to the unconditioned references 2. Detoxification with reducing agents DTT Sodium sulfite Sodium Sodium DTT Sodium sulfite Sodium dithionite dithionite dithionite PL-1 LH-1 LH-2 PL-2 Citrate buffer LH-1: Liquid hydrolysate of slurry from Norway spruce imprignated with sulfur dioxide LH-2: Liquid hdrolysate from first step of a two-step dilute sulfuric acid hydrolysis of Norway spruce
28 Glucose Concentration (g/l) Fermentation of spruce hydrolysates after detoxification with reducing agents B A Glucose consumption profile during the thanol production Time (h) Non Detoxificed Detoxificed with sodium dithionite Detoxificed with sodium sulfite Ref. Glucose medium
29 Abs (nm) Glucose (g/l) Conditioning with Alkali Glucose production from 72 h enzymatic hydrolysis of Alkaline conditioned and unconditioned spruce slurry hydrolysates. 5 0 Un-treated Reference Ca(OH)2-treated Solvent "X" NaOH-treated Solvent "Y" NH4OH-treated Solvent "Z" GPC analyses of the Alkaline conditioned and unconditioned spruce liquid hydrolysates. 1,4 1,2 1 0,8 0,6 0,4 0,2 0-0,2 No Un-treated Treatment Solvent Ca(OH)2-treated "X" Solvent NaOH-treated "Y" Solvent NH4OH-treated "Z"
30 Biomass Processing Conclusions Pretreatment SSCF SSCF-ICD Chemical detoxification IL-Mediated dissolution SSCF Cellulose hydrolysis Hexose fermentation (Or) Pentose fermentation SSCF: Simultanious Saccharification & Co-Fermentation SSCF-ICD: Simultanious Saccharification & Co-Fermentation with an Integrated Chemical Detoxification
31 Acknowledgements Prof. Jyri-Pekka Mikkola Prof. Christer Larsson Dr. Tomas Brandberg Dr. Björn Alriksson (SP Processum AB) Prof. Leif Jönsson Kempe Foundations ( Knut and Alice Wallenberg Foundation Bio4Energy ( Academy of Finland SEKAB E-Technology AB Gruop members