November 4, 2015

Abhijeet P Borole 1,3, Alex Lewis3, Spyros Pavlostathis2, Xiaofei Zeng2, Costas Tsouris1,2, Shoujie Ren3, Philip Ye3, Pyongchung Kim3, Niki Labbe3

1Oak Ridge National Laboratory 2Georgia Institute of Technology 3University of Tennessee

Improving Hydrogen Efficiency During Thermochemical Conversion of Biomass to Fuels

2 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

Overview

• Hydrogen Requirement in Thermochemical Biofuel Pathway • Microbial Electrolysis Technology (MEC) • Prevent Organic Carbon Loss via Aqueous Phase • Potential to Improve Process Efficiency via Energy

Recovery • Address Separations and Unit Operations to Support MEC • Discuss Potential for Carbon and Separations Efficiency

Improvement in Bio-oil Pathways

3 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

TC Pathway – Role of MEC

Microbial Electrolysis

Biomass

Energy/ Potential

Bio-oil Upgrading

and Hydrotreat

ment Hydrocarbon fuels

Pyrolysis

Hydrogen

Oil phase

Aqueous Phase

Bio-oil

Problem Statement • Deoxygenation of

biomass

• Need for hydrogen to make HC fuels

• Loss of carbon to aqueous phase

Goals • Develop technology for

hydrogen production in biorefinery to facilitate biomass deoxygenation.

• Reforming of aqueous phase organics to hydrogen via microbial electrolysis cell (MEC) technology.

4 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

Microbial Electrolysis • Hydrogen production from pyrolysis-derived

aqueous phase – Address aqueous carbon emulsified with oil

phase – acidic and polar molecules – Causes instability of bio-oil – Corrosivity of bio-oil

• Carbon, Hydrogen and Separations Efficiency for Bio-oil Pathways program (CHASE)

• Microbial electrolysis – Conversion of bio-oil aqueous phase (BOAP)

organics to hydrogen – Anode: Conversion of degradable organics to

electrons, protons and CO2

– Cathode: Proton reduction to hydrogen at applied potential of 0.3-1V.

– Uses electroactive biofilms capable of direct electron transfer

H2

H+ Organic Carbon

CO2 + H2O

Bio

cata

lytic

ano

de

e- e-

CxHyOz → CO2 + H+ + e- H+ + e- → H2

Nutrients

Cell mass

Cat

hode

> 0.3 V

Cathode catalyst

H+

H+

H+

H+

MEC

Biotechnol for Biofuels., Controlling accumulation of fermentation inhibitors in biorefinery process water using Microbial Fuel Cells, Borole, A. P., et.al., 2009, 2, 1, 7. Energy Environ. Sci., Electroactive biofilms: Current status and future research needs Borole, A. P., et al., 2011, 4: 4813-4834.

Pathway: Bio-oil Aqueous Phase (BOAP) → electrons + protons (anode ) → H2 (cathode)

5 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

Integrated Pyrolysis-Microbial Electrolysis

Pyrolysis Oil-water Separation

Bio-oil

Aqueous phase Microbial

Electrolysis

Bio-oil Upgrading

+ -

Liquid Fuels

Renewable Hydrogen

H2

Lewis, A. J., et al. (2015). "Hydrogen production from switchgrass via a hybrid pyrolysis-microbial electrolysis process." Bioresource Technology 195: 231-241.

6 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

• Feedstock: switchgrass • Particle size: less than 2mm • Water content of switchgrass: 7-8 wt%. • Feeding rate: 10kg/hr • Reaction temperature: 500°C • Bio-oil: combined by three condensers • Add water to bio-oil (4:1 ratio) to

separate aqueous fraction.

Pilot auger pyrolysis reactor at UTK Center for Renewable Carbon

Bio-oil production process scheme

Bio-oil produc-

tion

Bio-oil yield (wt%)

Bio-char yield (wt%)

Non-condensable gas yield (wt%)

1st batch 50 29 21

2nd batch 54 29 17

Products from switchgrass pyrolysis

Production of bio-oil from switchgrass

Bio-oil production

Ren, S., X. Ye, Borole, A P., Kim, P; Labbe, N (2015). "Analysis of switchgrass-derived bio-oil and associated aqueous phase generated in a pilot-scale auger pyrolyzer." J. Anal. Appl. Pyrolysis, manuscript in review.

7 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

Bio-oil Aqueous Phase characterization…

Classifications Major compounds Concentration in aqueous phase(g/L) Method

Carboxylic acid Acetic acid 11.96 HPLC Propionic acid 1.89 HPLC Vanillic acid 2.69 HPLC

Sugars Levoglucosan 15.33 HPLC

Furans Furfural 1.01 HPLC HMF 0.54 HPLC 2(5H)-Furanone 1.17 GC

Alcohols 1,3-propanediol 1.84 GC 1-hydroxybutanone 1.35 GC

Aldehydes and ketones

Cyclohexanone 0.07 GC 3-methyl-1,2-cyclopentanedione 0.46 GC

Phenols and alkyl phenols

1,2-benzendiol 1.77 HPLC Phenol 1.8 HPLC 2-methoxyphenol 0.25 GC 2-methyl-4-methyphenol 0.07 GC 2,6-Dimethoxyphenol 0.26 GC 3-ethylphenol 0.56 GC

Sum 43.01 Ren, S., X. Ye, Borole, A P., Kim, P; Labbe, N (2015). "Analysis of switchgrass-derived bio-oil and associated aqueous phase generated in a pilot-scale auger pyrolyzer." J. Anal. Appl. Pyrolysis, manuscript in review.

8 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

Anode Biocatalyst Development

• Growth of electroactive biofilms for conversion of BOAP compounds.

• Goals – Tolerance to phenols and furan aldehydes – Optimize population diversity

• Approach – Use of optimized system (MFC) configuration – Use of previously optimized process

parameters.

US Patent 7,695,834, UT-Battelle, Borole, A. P., USA, 2010. US Patent 8,192,854 B2 UT-Battelle, Borole, A. P., USA, 2012. Energy Environ. Sci., Borole, A. P., et al., 2012, 4: 4813-4834. Bioresour. Technol. Borole, A. P., et al., 2011, 102, 5098. Biochem. Eng. J. Borole, A. P., et al., 2009, 48, 71.

Microbial Diversity In Biofilms

9 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

lev

oglu

cosa

n

ace

tic a

cid

p

ropi

onic

aci

d

1-h

ydro

xybu

tano

ne

HM

F

12-

benz

endi

ol

2

(5H)

-fur

anon

e

van

illic

aci

d

phe

nol

f

urfu

ral

gua

iaco

l

3-e

thyl

phen

ol

5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 Retention Time [min]

0

20000

40000

60000

Inte

nsity

b0-T0 - CH9b0-T1 - CH9b0-T3 - CH9

Conversion of Switchgrass Bio-oil Aqueous Phase to Hydrogen

Conversion of organics in BOAP using evolved bioanode:

0 h 24 h 72 h

Batch experiment, BOAP loading = 0.1 g/L, HPLC-Photodiode array

Successful development of anode biocatalyst for conversion of switchgrass bio-oil aqueous phase, including removal of acetic acid and phenolic acids.

1. Source of inoculum 2. Pure culture vs. consortium

3. Gram-positive vs. Gram-negative Biofilm parameters (Dependent variables)

Process/ Operating parameters

Biological parameters

Electroactive Biofilm Optimization

1. Batch vs. flow system

2. External resistance

3. Redox potential 4. Shear rate /

liquid flow rate 5. pH 6. Substrate

loading 7. Temperature 8. Aerobic vs.

anaerobic 9. Ionic strength

1. Electrode spacing 2. Presence of

membrane and type of membrane

3. Relative anode:cathode surface area

4. Electrode surface area to volume ratio

5. Electrode properties: conductivity, hydrophilicity, porosity, etc.

6. Type of cathode (oxygen diffusion)

1. Biofilm growth rate 2. Specific rate of electron transfer 3. Ability to synthesize redox-active mediators 4. Ability to grow nanowires and perform DET

System design parameters

5. Relative exoelectrogen population 6. Characteristics of EPS layer 7. Extent of substrate mineralization 8. Substrate specificity

Energy Environ. Sci. (Review paper) Electroactive Biofilms: Current Status and Future Research Needs, Borole AP, Reguera G, Ringeisen B, Wang Z, Feng Y, Kim, BH, 2011, 4:4813-4834

MEC optimization is a complex process, requiring system design, process and biological parameter optimization.

11 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

H2 production from BOAP – Batch Run • 0.1 to 0.3 g/l batch BOAP

• 12-24 hour experiment

Demonstrated an yield of hydrogen of ~ 70% from bio-oil aqueous phase.

0123

0 0.1 0.2 0.3 0.4H2 P

rodu

ctiv

ity L

/L/d

Concentration (g/l)

H2 Productivity L/L-anode-day

63a

63b

0%

20%

40%

60%

80%

100%

0.1 g/l 0.2 g/l 0.3 g/l

Anode Coulombic Efficiency (CE)

0%

20%

40%

60%

80%

100%

0.1 g/l 0.2 g/l 0.3 g/l

Cathode Efficiency

0%

20%

40%

60%

80%

100%

0.1 g/l 0.2 g/l 0.3 g/l

Hydrogen Yield from Bio-oil Aqueous Phase

Lewis, A. J., et al. (2015). "Hydrogen production from switchgrass via a hybrid pyrolysis-microbial electrolysis process." Bioresource Technology 195: 231-241.

12 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

H2 production from BOAP – Continuous Run • 2 g/l/d to 10 g/l/d continuous BOAP feed

• 12-24 hour experiment

Demonstrated an yield of hydrogen of ~ 80% from bio-oil aqueous phase.

0%

20%

40%

60%

80%

100%

2 g/l/d 4 g/l/d 10 g/l/d

Anode CE

0%

20%

40%

60%

80%

100%

2 g/l/d 4 g/l/d 10 g/l/d

Cathode Efficiency

0%

20%

40%

60%

80%

100%

2 g/l/d 4 g/l/d 10 g/l/d

H2 Yield

0

2

4

6

0 5 10 15H2 P

rodu

ctiv

ity L

/L/d

Loading rate (g/l/d)

H2 Productivity

Lewis, A. J., et al. (2015). "Hydrogen production from switchgrass via a hybrid pyrolysis-microbial electrolysis process." Bioresource Technology 195: 231-241.

13 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

Novelty of Bioelectrochemical Systems

1. Biological electron transfer and electroactive biofilm development

2. Biocatalysis/Electrocatalysis synergy

3. Diversification potential Substrate

Product / Fuel /

Chemical Organic Carbon/ Reduced

substrate/ Waste

CO2 + H2O

Bio

cata

lytic

ano

de

Cat

hode

BioElectrochemical System (BES)

e- e-

H+

H+

H+

H+

CxHyOz → CO2 + H+ + e- MEC: H+ + e- → H2

Nutrients

Cell mass

Load/Power source

Reduction

DIRECT INDIRECT Redox biofilm matrix OM c-cyt Redox mediator

K. Rabaey, L. T. Angenent, U. Schroder, J. Keller, Bioelectrochemical Systems: From Extracellular Electron Transfer to Biotechnological Application, IWA Publishing, UK, 2010. B. E. Logan, D. Call, S. Cheng, H. V. M. Hamelers, T. Sleutels, A. W. Jeremiasse, R. A. Rozendal, Environ. Sci. Technol. 2008, 42, 8630. Borole AP, Reguera G, Ringeisen B, Wang Z, Feng Y, Kim, BH, 2011, Energy Environ. Sci. (Review paper) Electroactive Biofilms: Current Status and Future Research Needs, 4:4813-4834

Type of Cathode Product BES substrate . MFC Oxygen Electricity MEC Protons Biohydrogen BES Acetate Ethanol/biofuel BES Oxygen→ Hydrogen peroxide BES Carbon dioxide → Electrofuels BES other/sunlight →Photo/biofuels

14 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

MEC Supporting Tasks for Biorefinery Application

Produce bio-oil /characterize, analyze aqueous phase

Microbial electrolysis of pyrolysis aqueous Phase

Membrane separations Biocatalyst recovery and recycle

Microbial electrolysis of furanic and phenolic Substrates

Membrane process modules, supplies

Life cycle analysis Techno-economic Analysis

Electrolysis cell materials

Understanding of biooil composition P

robl

em

Biooil pH, instability GHG

reduction

Solut

ions

Industry partners

Develop oil-water Separation methods

Loss of carbon via aqueous phase

Hydrogen requirement

15 Managed by UT-Battelle for the U.S. Department of Energy Presentation_name

Potential for MECs in Algal Conversion Pathways

Without MECs

With MECs Sustainability, Special Issue: Sustainability in Bioenergy Production, Borole, A. P., 2015, Sustainable and Efficient Pathways for Bioenergy Recovery from Low-value Process Streams via Bioelectrochemical Systems in Biorefineries." 7(9): 11713-11726.

NREL/TP-5100-62368, 2014. Process Design and Economics for the Conversion of Algal Biomass to Biofuels: Algal Biomass Fractionation to Lipid- and Carbohydrate-Derived Fuel Products, R. Davis, et al.

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Future Work

• Achieve performance to enable commercial consideration

• Scale up studies

US Patent 7,695,834, April 2010. Borole, AP. Microbial fuel cell with improved anode.

Acknowledgements BioEnergy Technologies Office (CHASE Program) ORNL LDRD Program Oak Ridge National Laboratory Costas Tsouris, Ramesh Bhave RK Goud UTK Bredesen Center Alex Lewis University of Tennessee Institute of Agriculture Niki Labbe, Philip Ye, P. Kim, S. Ren Georgia Institute of Techology S. Pavlostathis, S. Yiacoumi S. Zeng, L. Park Industry Partners: The FuelCellStore, Inc. OmniTech International Pall Corporation

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Environ Sci Technol Conversion of residual organics in corn stover-derived biorefinery stream to bioenergy via microbial fuel cells. 47(1): 642-648. Borole, A. P., C. Hamilton, et al. (2013).