Activities in UW Forest Resources and Lignocellulosic Biorefineries

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1 Activities in UW Forest Resources and Lignocellulosic Biorefineries Rick Gustafson, Renata Bura, Bill McKean, Sharon Doty, Brian Marquardt, Rob Synovec, Joyce Cooper 3 May 2010

2 U.S. Renewable Fuel Standard Schedule Billions gallons/year

3 Obama / Biden Proposal 60 Billion Gallons/year of Advanced Biofuels by Billion Gallons from Corn 40 Billion Gallons from Cellulosic 5 Billion Gallons from Other

4 40 billion gallons/year cellulosic fuel 400 Biorefineries 1 million tons/year biomass (or more) 100 million gallons/year $0.25/lb product $500 million capital 100 Kraft pulp mills 1 million tons/year biomass 350,000 tons/year $0.40/lb product $500 million capital

5 Biofuels will be a commodity business Efficient process High process yields Efficient use of resources raw materials and energy Little down time Help from high value co-products Could have big environmental impact

6 UW biofuels research agenda Overarching approach Fractionate biomass to recover greatest value Biomass Substrates Products Biological conversion Fractionation Chemical conversion Pre-pretreatment

7 UW biofuels research agenda Develop conversion processes that are feedstock flexible Develop conversion processes that produce high value co-products Develop robust sensors for biorefineries Perform life cycle assessments (LCA) on biofuel systems

8 Conversion processes that are feedstock flexible Rapid assessment and optimization of bioconversion processes Conventional Micro Experimental Flask scale (125ml) 96 wells (0.3 ml/well) Analytical Absorbance Wavenumbers (cm-1) HPLC, GC, wet chemistry Raman, IR, dielectric spectroscopy

9 High value co-products Biopolymer separation and concentration Recover hemicellulose at high concentration Concentrate to ~ 20% solid content Separate lignin and extractives from hemicellulose Membrane Separation Non-volatile Components Lower energy 2/3 1/2 that of evaporation Remove inhibitors as well as water Potential for fouling High capital cost

10 High value co-products Permeate Flux (L/hr/m 2 ) Trial 1 (5%) Trial 2 (12%) Trial 3 (20%) Filtration Time (hr) Biopolymer separation and concentration 100 Trial 1 (5%) Trial 2 (12%) Trial 3 (20%) Percentage to the Feed (%) Arabinose Galactose Glucose Xylose

11 V-Sep membranes Oscillating membrane reduces boundary layer formation High permeate flux on difficult process streams V-Sep

12 Co-production of ethanol and xylitol High value co-products Novel, naturally occurring, robust yeast from genus Rhodotorula selected from poplar trees (Prof. S. L. Doty) Named PTD-3 Rapidly and effectively utilizes both 5C and 6C sugars Tolerant of (and capable of metabolizing) high concentrations of fermentation inhibitors (furfurals, acetic acid, 5-HMF)

13 High value co-products Co-production of ethanol and xylitol Experimental Yields: Ethanol: 93%; Xylitol: 66% Glucose, xylose concentration (g/l) Glucose Ethanol Yeast Xylose Xylitol Xylitol, ethanol concentration (g/l) Time (hours)

14 High value co-products Co-production of ethanol and xylitol PTD3 can tolerate high concentrations of acetic acid, up to 16 g/l High levels of acetic acid increase the ethanol yield but decrease the xylitol yield Similar results were obtained for furfural Acetic acid Concentration Ethanol (%) Xylitol (%) 16g/L g/L g/L

15 High value co-products Integration with pulp and paper mills fermentation of spent pulping liquor Evaporator 5 th Stage To 1 st Stage 1 Stream 1 Red Liquor 504 GPM Temp = 149F ph = Stream 3 NH4OH for ph adjustment Temp = 106F Stream GPM Temp = 106F ph = 2.6 Heat Exchanger Tin= 149F Tout=106F 2 7 Fermenter 5 batch tanks gallon total capacity ph 5.75 for 1 st 24 hrs ph 6.0 for last 6 hrs 0.47g etoh/g sugar Stream 7 to storage tanks CO2 and VOC vent Stream 4 NH4OH for ph adjustment Temp = 106F Stream 5 Nutrient Addition Temp = 106F Corn steep liquor Diammonium phosphate Stream 6 Fermenting Inoculum Temp = 106F Z. mobilis

16 High value co-products Integration with pulp and paper mills fermentation of spent pulping liquor 20 year projection (pre-tax) Ethanol selling price of $1.50/gal Ethanol production of 7.1 MM gal/yr Desired rate of return at 20% Net Present Value = $17.3 MM Break Even Ethanol Price: $1.06/gal

17 High value co-products Integration with pulp and paper mills fermentation of spent pulping liquor 28 Concentration (g/l) C sugars ethanol yeast Time (hours)

18 Robust Sensors Current sensor for analyzing carbohydrates in biorefineries What the instrument sees on the graveyard shift

19 Robust Sensors Spectroscopic analyzers

20 Robust Sensors Spectroscopic analyzers Signal Intensity Wavenumbers / cm -1 Scores on PC 2 (0.20%) Signal Intensity Glucose Xylose Wavenumbers / cm Lignosulfonate Scores on PC 1 (99.73%)

21 Life Cycle Assessment Corn Ethanol Will Not Cut Greenhouse Gas Emissions California regulators may rule that the biofuel is no better--and might be worse--than petroleum for solving climate change Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change

22 Life Cycle Assessment Is a protocol standardized by ISO to quantify the life cycle impacts of energy and materials use and waste by an industrial system, It extends from cradle to grave Goal & Scope Definition Inventory Analysis Impact Assessment Interpretation Manufacturing & Processing Use and Maintenance Extraction of Raw Materials Retirement and Disposal

23 Life Cycle Assessment Feedstock Handling (A100) Each waste stream utilize different feedstock handling equipment to remove contaminants prior to ethanol processing. Pretreatment (A200) MSW & MWP use acid hydrolysis, 4% sulfuric acid, in hydrapulper with hot water (60 o C), for 6 hrs YW uses steam explosion pretreatment, high temperature (215 o C), high pressure for short residence time (5 min), 3% SO2 concentration Hydrolysis/Fermentation (A300) Enzymatic hydrolysis, utilizes special cellulase to breakdown cellulose to glucose, Z. Mobilis bacteria for fermentation, able to ferment hexose and pentose. Ethanol Recovery (A500) Distillation and drying above azeotrope to reach dehydrated ethanol for use in combustion engines Waste Water Treatment (A600) Recycles water back into processing Chemical & Ethanol Storage (A700) Power Plant (A800) Combustion of waste products to produce heat and power for facility. System utilities (A900) Cooling water, air, process water Feedstock handling equipment Experimental Data

24 Life Cycle Assessment

25 Thank You Questions?