Cellulose Conversion to Hydrogen and ElectricityCellulose Conversion to Hydrogen and Electricity

Jay ReganAssistant Professor

Department of Civil & Environmental EngineeringPenn State University

Jay ReganAssistant Professor

Department of Civil & Environmental EngineeringPenn State University

de Groot (2003). In: Bio-Methane & Bio-Hydrogen.

Biomass to Secondary Energy Carriers

microbial fuel cells

1) Fermentative production of H2 from sugars

• Full oxidation of glucose to H2:

C6H12O6 + 6 H2O 12 H2 + 6 CO2

• Known pathways:

C6H12O6 + 2 H2O 4 H2 + 2 C2H4O2 + 2 CO2

C6H12O6 2 H2 + C4H8O2 + 2 CO2

• Typical yield < 2 mol H2/mol glucose

Cellulosic biomass is more recalcitrant to biological treatment

(DOE, 2006)

Cellulose Cellobiose Glucose

Hydrolysis of Cellulose

Inoculum H2 Yield Reference(mol/mol hexose)

Clostridium cellulolyticum 1.66 (6.7 g/L initial) Desvaux et al (2000)

0.33 (29.1 g/L)

Heat-shocked sludge 0.36 (12.5 g/L) Lay et al (2001)

0.08 (50 g/L)

Heat-shocked soil 0.005 (4.0 g/L) Logan et al (2002)

Activated sludge 0.07 (5.0 g/L) Liu et al (2003)

Cellulose-derived hydrogen:

• Clostridium speciesacetobutylicum, cellulolyticum, cellobioparum, celerecrescens, populeti, phytofermentans

• SubstratesCellobiose (disaccharide)MN301 cellulose (mixture of amorphous and crystalline ) Avicel (microcrystalline)

• AnalysesBiogas, Hydrogen, CO2, Biomass protein, Substrates,

Fermentation products

Characterization of Cellulolytic, H2-Producing Clostridia

Gas production from cellobiose

0

5

10

15

20

25

30

0 1 2 3 4 5 6 7 8 9 10

day

H2(

mL)

C.acetobutylicumC.cellulolyticumC.cellobioparumC.celerecrescensC.populetiC.phytofermentans

H2 yield comparison

Ren, Ward, Logan, and Regan (2007) J. Applied Microbiol.

0.0

0.5

1.0

1.5

2.0

2.5

MN301 Avicel Cellobiose

Hyd

roge

n Y

ield

(mol

hyd

roge

n m

ol-1

Hex

ose)

Clostridium species: acetobutylicum, cellulolyticum, cellobioparumcelerecrescens, populeti, phytofermentans

H2 production rates

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

MN301 Avicel Cellobiose

Hyd

roge

n pr

oduc

tion

rate

s(m

l hyd

roge

n m

g-1 p

rote

in d

ay-1

)

Ren, Ward, Logan, and Regan (2007) J. Applied Microbiol.

Clostridium species: acetobutylicum, cellulolyticum, cellobioparumcelerecrescens, populeti, phytofermentans

CathodeAnode

PEM

Fuel (cellulose)

CO2

Fe(CN)63-

Fe(CN)64-

H+

e- e-

2) Microbial fuel cells for production of electricity from biodegradable organic matter

Electricity production by the binary culture on cellulose

Co-culture can be used to make electricity from cellulose

• Clostridium cellulolyticum– Converts cellulose to H2 and

volatile acids – Can not produce electricity

• Geobacter sulfurreducens– Produces electricity from

acetate and H2– Can not degrade cellulose

Ren, Ward,and Regan (2007) ES&T

Hours0 200 400 600 800 1000 1200 1400 1600 1800

Pow

er D

ensi

ty (m

W/m

2 )

0

20

40

60

80

100

120

140

160G.sulfurreducens C.cellulolyticum

B

2g/LCMC1g/LCellobiose

8mM Acetate 12.3 mM Acetate

1g/LCMC

Neither pure culture produced electricity on cellulose

Co-culture achieved comparable power on CMC as Geobacter on acetate

0

20

40

60

80

100

120

140

160

180

0.00 0.02 0.04 0.06 0.08 0.10Current density (mA/cm2)

Pow

er d

ensi

ty (m

W/m

2 )

Geobacter on acetate (154 mW/m2)

Co-culture on CMC (143 mW/m2)

Co-culture on MN301+ NaCl (67.9 mW/m2)

Co-culture on MN301 (59.2 mW/m2)

H0 200 400 600 800 1600 1800

Pow

er D

ensi

ty (m

W/m

2 )

0

10

20

30

40

50

60

2g/L CMC

1g/L CMC 1g/L MN301

Hours0 200 400 600 800 1600 1800

Pow

er D

ensi

ty (m

W/m

2 )

0

10

20

30

40

50

60

2g/L CMC

1g/L CMC 1g/L MN301

Max. Power: Enhanced MFC: 53.8mW/m2

Sludge only MFC: 40.8mW/m2

Electricity from cellulose: undefined mixed culture

Ren, Ward,and Regan (2007), ES&T

• Inoculum is wastewater (bacteria naturally present in the environment)

• C. cellulolyticum enhanced power production:

Electricity from cellulose and chitin in a sediment MFC

SeawaterCathode

AnodeMarine Sediment

Chitin 80 Chitin 20

Carbon cloth filled with Chitin 80

CelluloseTime (hr)

0 50 100 150 200 250 300

Pow

er D

ensi

ty (m

W/m

2 )

020406080

100120

Rep 1Rep 2Rep 3

Time (hr)

0 50 100 150 200 250 300

Pow

er D

ensi

ty (m

W/m

2 )

0

20

40

60

80

100

Chitin80 Chitin20 Control

Cellulose

Chitin

Rezai, Richard, Brennan and Logan, ES&T (2007)

Microbial identification by fluorescent in situhybridization (FISH)

Suspended sample of coculturefrom CMC-fed MFCGeobacter (yellow/red) - Clostridium (green)

Geobacter (SRB385)

Clostridium (SYTO 9)

Summary

• C. cellulolyticum and C. populeti showed the highest hydrogen production rates and yields from solid cellulose

• H2 yields (~1.6 mol/mol) comparable to typical values with glucose, but rates were only 50-70% that of cellobiose

• Cellulose conversion to electricity is possible in microbial fuel cells through pairing of cellulolytic and anode-reducing phenotypes

Co-PIs:Bruce Logan (Civil and Environmental Engineering)Mark Guiltinan (Horticulture)

Students/Post-docs/Research Associates:Zhiyong Ren, Thomas Ward, Sang-Eun Oh, Shaoan Cheng, David Jones

Funding:USDA/DOE 2003 Biomass Research and Development Initiative