Characterizing Sweetgum from Biomass to Bioethanol Poulomi Sannigrahi and Arthur J. Ragauskas School of Chemistry and Biochemistry Georgia Institute of Technology, Atlanta, GA .

INTRODUCTION BIOMASS FEEDSTOCK RESULTS 60.0 to glucose conversion The conversion of lignocellulosics into bioethanol remains a Sulf. Acid  Widely prevalent hardwood 50.0 yields for low enzyme dose experiments. technically demanding process due to the complicated cell wall Organosolv (SA) 20 U cellulase; 40 U beta-glucosidase /g species in South-Eastern US Oxone structure of lignocellulosics and their recalcitrant properties. The 40.0 AFEX cellulose in 50 mM, pH 4.8 acetate buffer. 1.1 ClO2 efficient processing of lignocellulosics into biofuels is contingent  Used for lumber, veneer, e conversion (%) 22ClO22.2 ClO2 Incubated at 45 °C and 150 rpm. ss 30.0 Organosolv on the characterization of the chemical constituents of plant plywood and (ClO2) carbohydrates and and their changes in structure  Bark-free Sweetgum chips 20.0 Organosolv (SA); 1.1ClO2 and throughout the process. This research program is directed at obtained from chipping mill in 10.0 Organosolv (ClO2) were selected developing the fundamental knowledge needed to (1) describe Dewey Rose, GA. for further investigation Cellulose to gluco 0.0 the changes in biomass constituents during the overall conversion  Chips stored at < -5 °C 0 1020304050607080 As % o.d. weight of untreated sweetgum of plant polysaccharides into bioethanol and (2) optimize the Time (hours) Pretreatment Klason Acid soluble Organosolv Lignin in Total  Composite sample being used for lignin lignin lignin effluent overall process. New pretreatment strategies are also being all analyses Untreated 25.90 2.60 - - 28.50 developed. Organosolv 4.06 0.04 13.45 8.35 25.90 Distribution map of Sweetgum (SA) RESEARCH OBJECTIVES Organosolv 6.27 0.19 12.53 5.85 24.84 (ClO )  Chemical characterization of the incoming feedstock Carbohydrates 2 60.0 1.1 ClO 16.07 0.06 - 9.28 25.41  Impact of pretreatment technologies on chemical PRETREATMENT STRATEGIES 2

structure and reactivity of biomass resources towards Untreated  Dilute acid (Sulfuric and Formic) 50.0 OH Organosolv (SA) results in highest lignin removal from wood – 84% O OS-SA HO enzymatic hydrolysis OH 180.0 204 °C; 10 min; pH:2 OH OS-SA effluent OH Inorganic elements  Determination of reactive and unreactive components of  Ammonia Fiber Explosion 40.0 OS-ClO2 160.0 ted wood OS-ClO2 effluent g/Kg) 140.0

aa Ba pretreated biomass towards enzymatic hydrolysis 1.1 ClO2 mm Fe Wood : Ammon ia= 1131:1.3; 90 °C10iC, 10 min. 120.0 Na 30.0 1.1 ClO2 effluent Si  Analysis of chemical constituents impacting fermentation Cl + Br + I  Organosolv 100.0 O OH 80.0 of enzyme hydrolyzed biomass to bioethanol ° 20.0 Content ( 60% , 1.2% H2SO4, 180 C, 60 OH OH % o.d. untre o.d. % OH CH OH 60.0 HO 2 CH OH O OH O OH min 2 OH OH O OH 40.0 PROCESS OVERVIEW HO 10.0 OH OH  New** Oxidative + high temperature OH 20.0 OH OH 0.0 BIOMASS treatment 0.0 Step 1:Oxidative treatment (75 °C; 3 Glucose Xylose Mannose Arabinose Galactose Reactor used for pretreatments 1200.0 Pretreatment hours--oxidizes lignin, generates in-situ Untreated Sweetgum Lignin Lignin CelluloseLignin Hemicellulose 1000.0 Ca C=O K acidity ) Phenolic -OCH3 R-COCH3 Mg S 6 800.0 Pretreated wood Effluent OH Mn Oxone (KHSO ); Chlorine dioxide CH2 OH 1 5 4 OH O O 2 Step 2:High temperature (204 °C; 10 min) 1 O 160 140 120 100 80 60 40 20 PPM 600.0 Fermentation OH O Enzyme hydrolysis 3 CH OH Potentially patentable pretreatment OH 2 C2,3,5 400.0  New **Organosolv with ClO as catalyst Cellulose Organosolv treated Sweetgum

2 Content (mg/Kg) Solid residue Aqueous phase Ethanol Cellulose: Solid-state CP/MAS 13C NMR 200.0 C1 C4 Fermentation C6 0.0 150 100 60 0 PPM Research FY 2007-08 Milestone Overview Degree of Crystallinity: 53.3% Solid-state CP/MAS 13C NMR spectra of extractive free sweetgum

Quarter Cellulose Cellulose Para- Cellulose Accessible fibril Inaccessible CONCLUSIONS I surface fibril surface 1 Secure and characterize sample of hardwood feedstock alpha Ialpha+beta crystalline Ibeta On the basis of cellulose to glucose conversion, 12/2007 to 02/2008 for lignin, cellulose, hemicellulose, extractives and ash 9.6 % 1.4% 33.7% 5.2% 22.3% 17.8% Organosolv (sulfuric acid), Organosolv (ClO2) and 1.1 ClO2 -- Determine cellulose crystallinity, hemicellulose sugars, pretreatments were selected for detailed investigation lignin, extractives and trace elemental content in starting Milled wood lignin: Quantitative 13C NMR Main effects of pretreatments biomass resource Decrease in ash content -- Perform pretreatments on hardwood feedstock Decrease in acid soluble and insoluble lignin 2 Characterize chemical changes in hardwood feedstock  In the organosolv pretreatments, up to 50 % lignin recovered 03/2008 to 05/2008 after pretreatments β-5 as Ethanol Organosolv Lignin which has potential commercial -- Determine cellulose, hemicellulose, lignin, extractives value and trace elemental content β- β Increase in proportion of glucose in carbohydrates --Preliminary enzyme hydrolysis experiments on α-CO/ β-O-4 Low furan (fermentation inhibitors) content in pretreatment liquids pretreated feedstock 4-O-5 --Characterize dissolved biomass components in pretreatment effluent β-1/α-OH Funding from Chevron is gratefully acknowledged