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

U.S. Renewable Fuel Standard Schedule

Billions gallons/year

Obama / Biden Proposal

60 Billion Gallons/year of Advanced Biofuels by 2030

15 Billion Gallons from Corn

40 Billion Gallons from Cellulosic

5 Billion Gallons from Other

40 billion gallons/year cellulosic fuel

400 Biorefineries

1 million tons/year biomass (or more)

100 million gallons/year $0.25/lb product

100 Kraft pulp mills

1 million tons/year biomass

350,000 tons/year$0.40/lb product

$500 million capital

$500 million capital

Biofuels will be a commodity business

Efficient processHigh process yields

Efficient use of resources – raw materials and energy

Little down time

Help from high value co-products

Could have big environmental impact

UW biofuels research agendaOverarching approach –Fractionate biomass to recover greatest value

Fractionation

Biomass Substrates Products

Pre-pretreatment

Biologicalconversion

Chemicalconversion

UW biofuels research agenda

Develop conversion processes that are feedstock flexibleDevelop conversion processes that produce high value co-productsDevelop robust sensors for biorefineriesPerform life cycle assessments (LCA) on biofuelsystems

Conversion processes that are feedstock flexible

Rapid assessment and optimization of bioconversion processesConventional Micro

Experimental

Flask scale (125ml) 96 wells (0.3 ml/well)

Analytical

HPLC, GC, wet chemistryRaman, IR, dielectric

spectroscopy

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High value co-products

Biopolymer separation and concentration

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

Recover hemicellulose at high concentrationConcentrate to ~ 20% solid contentSeparate lignin and extractives from hemicellulose

High value co-products

Biopolymer separation and concentration

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eate

Flu

x (L

/hr/

m2 )

Trial 1 (5%)

Trial 2 (12%)

Trial 3 (20%)

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Arabinose Glucose Xylose

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ge to

the

Feed

(%)

Trial 1 (5%) Trial 2 (12%) Trial 3 (20%)

Galactose

V-Sep

V-Sep membranes• Oscillating

membrane reduces boundary layer formation

• High permeate flux on difficult process streams

High value co-products

Co-production of ethanol and xylitolNovel, 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)

High value co-products

Co-production of ethanol and xylitol

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32 Glucose Ethanol Yeast

Time (hours)

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cose

, xyl

ose

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entra

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(g/L

)

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32 Xylose Xylitol

Xylitol, ethanol concentration (g/L)

Experimental Yields: Ethanol: 93%; Xylitol: 66%

High value co-products

Co-production of ethanol and xylitol

Acetic acidConcentration Ethanol (%) Xylitol (%)

16g/L 99.4 37.2

10g/L 87.8 41.6

5g/L 80.7 48.9

PTD3 can tolerate high concentrations of acetic acid, up to 16 g/LHigh levels of acetic acid increase the ethanol yield but decrease the xylitol yieldSimilar results were obtained for furfural

High value co-products

Integration with pulp and paper mills – fermentation of spent pulping liquor

Evaporator 5th Stage

Stream 1•Red Liquor•504 GPM•Temp = 149F•pH = 2.6

1

Heat ExchangerTin= 149FTout=106F

Fermenter•5 batch tanks

•1250000 gallon total capacity•pH 5.75 for 1st 24 hrs•pH 6.0 for last 6 hrs•0.47g etOH/g sugar

2Stream 2•504 GPM•Temp = 106F•pH = 2.6

To 1st Stage

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4

5

Stream 3•NH4OH for pH adjustment•Temp = 106F

Stream 4•NH4OH for pH adjustment•Temp = 106F

Stream 5•Nutrient Addition•Temp = 106F•Corn steep liquor•Diammonium phosphate

6Stream 6•Fermenting Inoculum•Temp = 106F•Z. mobilis

7Stream 7• to storage tanks

CO2 and VOC vent

High value co-products

20 year projection (pre-tax)Ethanol selling price of $1.50/galEthanol production of 7.1 MM gal/yrDesired rate of return at 20%

Net Present Value = $17.3 MM

Break Even Ethanol Price: $1.06/gal

Integration with pulp and paper mills – fermentation of spent pulping liquor

High value co-products

Integration with pulp and paper mills – fermentation of spent pulping liquor

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Con

cent

ratio

n (g

/L)

Time (hours)

6C sugars ethanol yeast

Robust Sensors

Current sensor for analyzing carbohydrates in biorefineries

What the instrument sees on the graveyard shift

Robust Sensors

Spectroscopic analyzers

Robust Sensors

Spectroscopic analyzers

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Scores on PC 1 (99.73%)

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Lignosulfonate

Glucose

Xylose800 1000 1200 1400 1600 1800

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Life Cycle Assessment

Corn Ethanol Will Not Cut Greenhouse Gas EmissionsCalifornia 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

Life Cycle Assessment

Is a protocol standardized by ISO 14040.

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

Extraction of Raw Materials

Use and Maintenance

Retirement and

Disposal

Life Cycle AssessmentFeedstock 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 (60oC), for 6 hrsYW uses steam explosion pretreatment, high temperature (215oC), 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

Life Cycle Assessment

Thank You

Questions?