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Yu (Ivy) Huang, Ph.D.Membrane Technology & Research, Inc.

1360 Willow Road, Suite 103Menlo Park, California

&

Leland M. Vane, Ph.D.Office of Research and Development

U.S. Environmental Protection AgencyCincinnati, Ohio

AICHESan Francisco, California

November 2006

BioSep™: A New Ethanol Recovery Technology for Small Scale Rural

Production of Ethanol from Biomass

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Ethanol production is growing globally

Brazil > 50% sugar cane crop 40% non-diesel fuel

USA currently, 15% corn crop 2% non-diesel fuel> 1/3 oil displacement by 2025

EU 6% biofuel by 201020 - 30% replacement of oil by 2030

China Launched a program to use ethanol as a fuel

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How much ethanol can we produce?

Oil consumption: 873 MM gal/day, 58% import Ethanol production: 12 MM gal/day

Current:

Oil consumption from import: 870 MM gal/day The President’s goal: replace 75% import from Mideast − 100 MM gal/day

Forecast for 2025:

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5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

1970 1980 1990 2000 2010 2020 2030

Total annual ethanol production

(MM gal/y)

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FERMENTATION DISTILLATIONCOLUMN

MOLSIEVE Ethanol

Water

Biomaterial

Conventional Bioethanol Process

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Two competing driving forces:Ethanol concentration/purification by distillation/molecular sieve is only economical at > 40-50 MM gal/year

driver for central productionTransport of biomass over long distances is costly and energy inefficient

driver for distributed production in rural areas(with added benefits for rural economies)

Can this problem be solved?The solution is membranes (of course).

Ethanol from Biomass

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MTR BioSep Process

FERMENTATION

PERVAPORATION(ethanol concentration)

DEPHLEGMATION

Ethanol

Water

FERMENTATION DISTILLATION

MOLSIEVE

Ethanol

Water

Biomass

PERVAPORATION(dehydration)

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Applications of BioSep Process

Small biomass waste streams generated in the production of-- beer, wine, and juice-- cane and beet sugar-- potatoes, yams, and other root crops-- cheese, soft drinks, confectionery and packaged foods

Replace molecular sieve in conventional corn to ethanol plant

Replace distillation in conventional corn to ethanol plant

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What is pervaporation?

Liquid feed

Saturated vapor

To vacuum systempermeate

βevap

βmem

)1/()1/(

11

11

xxyy

memevap −−

=⋅= βββ

Pervaporation = Permeation + Evaporation

feed residue

Not limited by thermodynamic vapor-liquid equilibrium (VLE)

Separation factor

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Dehydration of organic solventsPrimarily dehydration of ethanol and iso-propanolFirst commercial plant in the world was put into operation in Brazil in 1984.Commercial application of inorganic membranesNeeds improvements to be competitive with molecular sieves in large scale applications

Removal and recovery of organic solvents from waterCommercially successful applications are hard to find

Pervaporation Applications

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Pervaporation using Ethanol-Permeable and Water-Permeable Membranes

Ethanol removal from 5-10 wt% ethanol/water mixture

Water removal from 90 wt% ethanol/water mixture

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Vapor enters at the bottom

Vapor is partially condensedat the top

Condensate trickles down,creates a counter-current effect

Achieves 4 to 6 theoreticalstages of separation

Fractional condensation (dephlegmation) improves separation

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Significant increase in separation performance ….

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Pervaporation-dephlegmation Dehydration

Filtered biomass feed(10 wt% ethanol)

30-40 wt% ethanol vapor 20 wt%

ethanol vapor

5 wt% ethanol recycle

0.5 wt% ethanol to recycle or waste

90 - 95 wt% ethanol

Dephlegmator

Water-permeable

pervaporationmembrane

Ethanol-permeable

pervaporationmembrane

1

2

3

4

5

99+ wt% ethanol6

MTR BioSep Process

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Ethanol Permeable Membranes

0

5

10

15

0

5

10

15

20

25

30

0 10 20 30 40 50

Total membrane area

(Thousand m2)

Total energy consumption

(million Btu/hr)

EtOH/H2O separation factor, β

Energy consumption for distillation

5 MM gal/year plant, feed ethanol concentration = 10wt%

Solution: zeolite mixed-matrix membrane

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0

10

20

30

0

1

2

3

4

5

0 20 40 60 80 100

Ethanol/waterselectivity, β

mem

Zeolite loading (wt%)

Ethanol/waterseparation factor,

β

Mixed-matrix Membranes

Effects of zeolite loadings

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Ethanol Dehydration Membranes

MTR-2

0

20

40

60

80

100

0 20 40 60 80 100

Permeate water concentration

(wt%)

Feed water concentration (wt%)

MTR-2Celfa

Temperature = 100oC

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Package membranes into spiral-wound modules

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Conclusions

• Pervaporation offers alternative to distillation for ethanol recovery

Higher selectivity membranes will yield energy savingsMembranes scale down better than distillation

• Pervaporation offers alternative to molecular sieves for water removal

Chemical and thermal stable membranes developedSystems commercially available

• Synergies achievable through use of pervaporation for bothethanol recovery and dehydration

Combined with dephlegmation condensation

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Acknowledgments

• U.S. Department of Energy• U.S. Department of Agriculture• Jennifer Ly, Tiem Aldajani, Karl Amo of MTR• Vasudevan Namboodiri, Travis Bowen of EPA

20MTR Confidential

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Liquid Separation Group

Questions?Questions?