[330d] Fractionation and Recovery of. Characterization for Biorefinery Processes

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1 [330d] Fractionation and Recovery of Lignin and Xylan from Alkali Liquors Characterization for Biorefinery Processes 330 Separation Processes in Biorefineries Ryan Stoklosa and David Hodge Chemical Engineering & Materials Science Michigan StateUniversity 13 AIChE Annual Meeting November 5, 13

2 Integration and Separations in the Forest Biorefinery Wood Chips Regenerated Alkali Soda Pulping Delignified Wood Sulfur free black liquor Enzyme Hydrolysis, Fermentation Chemical Recovery Smelt Gasification Sulfur free SynGas Fuel Synthesis Example 1 Fuel Biochemically Derived Biofuels Thermochemically Derived Biofuels

3 Integration and Separations in the Forest Biorefinery Wood Chips Regenerated Alkali Tall Oil for Green Diesel Kraft Pulping Chemical Recovery Example 2 Delignified Wood Black liquor Lignin Precipitation Spent Black Liquor Recovery Boiler Papermaking Paper Lignin i Fuels, Chemicals, and Materials Heat and Power

4 Scope of Work 1. Lignin and xylan extraction by soda pulping (and dliquid id hot water pretreatment) and integration with cellulosic ethanol processes 2. Correlating alkali lignin properties to their phase partitioning behavior

5 Biomass: Soda Pulping Conditions Sugar maple (Acer saccharum) Silver birch (Betula a pendula) Hybrid poplar (Populus nigra x maximowiczii cv. NM6) Digester: M/K Systems 10 L reactor Liquid Loading: 4 L/dry kg NaOH Loading: 18% (per dry kg wood) Temp (C C) Heat Up H Factor = 1135 Cook Time (min)

6 Biomass Composition Changes with Soda Pulping Similar xylan removal for all extractions Less effective lignin removal for birch More alkali consumption Silver Birch Sugar maple Hybrid Poplar Untreated Soda Pulping Untreated Soda Pulping Untreated Soda Pulping

7 Soda Pulping Kinetics Increasing extraction of material during initial heat up and cooking Maximum xylan recoverable at end of heat up Represents only 10 % of total xylan possible Wood mg/g Dry 50 Maple Birch Poplar Heat Up Cook Soluble Xylan Time (Min.) mg/g Dry Wood Maple Birch Poplar Soluble Lignin Heat Up Heat Up Cook Cook Time (Min.)

8 Conce entration in Liqu uor (g/l) Liquid Hot Water Pretreatment of Hybrid Poplar O Acetyl Substitutions on Polymers Polymeric Arabinan Polymeric Xylan 40 Polymeric Glucan 35 Free Acetate Free Arabinose 30 Free Xylose Free Glucose Digester Heat up Digester Heat up Pretreatment Pretreatment at at 170 C 160 C Time (minutes) Soluble Polym mers s Percent of Untreated Biom mass (%) Untreated Poplar LHWP poplar L:W = 4, 170 C for 1.5 hour Comparable xylan solubilization (~50%) without delignification Substantial xylan recovery as soluble oligomers Mas Not Quantified Extractives Ash Acetyl Ara Xyl/Man/Gal Glucan Lignin (Klason)

9 Enzymatic Conversion of Pretreated Woody Biomass Liquid Hot Water Pretreatment ld (%) Glucose Yie ld (%) Soda Pulping Pretreatment Pretreated Poplar Untreated Poplar Untreated Maple 60 Pretreated Maple 50 Untreated Birch 30 mg/g cellulose 40 Pretreated Birch CTec2/HTec2 30 Pretreated Poplar Hydrolysis Time (Hours) Glucose Yie Hydrolysis Time (Hours) All pretreatments/delignifications result in significant improvement in enzymatic yields of glucose Size reduction required after pretreatment Glucose Yiel ld (%)

10 Soda Pulping of Hybrid Poplar at Differing Levels of Delignification 170 C 1 hour 150 C 3 hour 150 C 0.5 hour

11 Impact of Pulping Conditions on Poplar Enzymatic Hydrolysis y Yields Glucos se Yield (%) Pulping Conditions: 150 C, 30 minutes 78% biomass/pulp yield 51% of lignin removed Time (hours) H Factor = 166 Pulping Conditions: 150 C, 3 hour 67% biomass/pulp yield 62% of lignin removed Pulping Conditions: 170 C, 1 hour 54% biomass/pulp yield 85% of lignin removed H Factor = 579 H Factor = 1430 Comparable glucose yields Minor dff differences due to drying/hornification? Xylose yield differences due to high xylan contents?

12 cose Yield (% ) Glu Impact of Size Reduction or Refining on Soda Pulped Biomass Poplar 100 Maple 100 Birch Wiley milled (pretreated) Gluc cose Yield (% ) Waring blender 40 "refining" (pretreated)" 30 Wiley milled (Untreated) Time (Hours) Time (Hours) Glu ucose Yield (% ) mg/g cellulose CTec2/HTec Time (Hours) Minimal difference between conditions tested Potential to optimally couple pretreatment and size reduction or refining to minimize: Pretreatment cost (temperature, time, chemical input) Energy requirements for size reduction/ refining

13 Glucose Yie eld (%) mg/g 5 mg/g Impact of Enzyme Loading on Hydrolysis Yields LHW Poplar Time (Hours) Glucose Yie eld (%) Soda Birch mg/g 10 mg/g 5 mg/g Time (Hours) High yields possible at low enzyme loadings for delignified pulps

14 Scope of Work 1. Lignin and xylan extraction by soda pulping (and dliquid id hot water pretreatment) and integration with cellulosic ethanol processes 2. Correlating alkali lignin properties to their phase partitioning behavior

15 Approaches Solubility Based Lignin Fractionation/Recovery Acidification + Filtration or Settling e.g. CO 2, H 2 SO 4, acetic acid Solvent Extraction or Fractionation Ultrafiltration ti Acid precipitated d hardwood dlignin Properties impacting solubility Surface charge: from soda pulping black liquor Ionizable groups: Aliphatic OH (pka > 12) electrostatic double layer (ζ potential) Phenolic OH (pka 10.5) COOH (pka 4 5)

16 Recovery of Alkali Lignins: Lignoboost Process Bäckhammar, Sweden 30 tons lignin/day CO 2 /H 2 SO 4 acidification of alkaline pulping liquors Developed by Innventia AB (Stockholm, SE) Commercialization/scale up by Metso (Finland) Domtar, Plymouth NC mill Potentially 73 ton lignin/day BRDI DOE/USDA

17 Recovery of Alkali Lignins: Sequential Liquid Lignin Recovery & Purification (SLRP) DOE Phase II SBIR grant, $1.15M (11) NSF CBET (12) Collaboration with Mark Thies, Chemical Engineering, Clemson University

18 Lignin Fractionation by CO 2 acidification Generation of liquid lignin or Hydrated lignin phase 1% Collaboration with Mark Thies, Chemical Engineering, Clemson University 100% F7 F6 Mass of Lignin n Recovered 18 80% 60% 40% % 0% F5 F4 Very low yield of high ph recovered fractions F3 F2 F1 Unfraction nated ph at Separation

19 Quantitative 1 H NMR of Acetylated Lignins 1 H NMR to quantify MeO, ArOH, Aliphatic H Normalized to a per MeO basis = 1 mol monomer β-aryl l ether Phenylcoumaran Benzodioxane Dibenzodioxocin i (β-o-4) (β-5 + α-o-4) (β-o-4 + α-o-5) (5-5 + β-o-4 + α-o-4) Possible for softwood lignins eg resin acids e.g. resin acids, sterols, fatty acids

20 Polysaccharides and Extractives Polysaccharide and extractives (resin acids, sterols, fatty acids) contaminate early precipitating fractions Stoklosa et al. (13). Green Chem /C3GC41182F

21 Lignin Aromatic and Aliphatic Hydroxyl Strong correlation lti bt between aromatic hd hydroxyl content and alkaline solubility pkaof AOH ArOH 10.5 Correlation with other properties? β-aryl ether Phenylcoumaran (β-o-4) (β-5 + α-o-4) O Stoklosa et al. (13). Green Chem /C3GC41182F 21

22 Lignin Molecular Weight System A: Column: Wt Waters Styragel HR Acetylation of lignin THF mobile phase System B: no lignin derivatization DMF M LiBr mobile phase Calibration with polystyrene Clear trend of decreasing MW with decreasing ph of precipitation Stoklosa et al. (13). Green Chem /C3GC41182F Es stimated Weigh ht Average MW (Da)

23 Alkyl Aryl Ether Content Clear trend of decreasing β O 4 content with decreasing ph of separation Quantitative 13 C NMR (In Review). Green Chem. Stoklosa et al. (13). Green Chem /C3GC41182F δ (ppm)

24 Correlating Lignin Structural Features to Phase Partitioning Behavior Multiple structural features are strongly correlated to each other and solubility as a function of ph Recovery ph Recovery ph Recovery ph 1 ArOH Content β O 4 content MW Stoklosa et al. (13). Green Chem /C3GC41182F

25 Conclusions Soda pulping of hardwoods Xylan extraction and degradation during heat up and cook Substantially less xylan recovery than from wood flour (10 %) Pulp is highly hl digestible upon dl delignification Substantial delignification not necessary to reach high enzymatichydrolysis yields Lignin properties Fractionation by CO 2 acidification by differences in MW, ArOH content Multiple property correlations

26 Research Group: Acknowledgements Funding: Dr. Tongjun Liu Ryan Stoklosa DOT, NE Sungrant Muyang Questions??? Li Zhenglun Li Initiative Dan Williams Jacob Crowe NSF CBET # NSF DUE #07570 Collaborators: Mark Thies Chris Saffron Ulrika Rova Curt Lindström