Issues of Scale in Microbial Fuel Cells and

Bioelectrochemical Systems

UNIVERSITY OF GLAMORGAN

Presented by – Giuliano C. Premier

Sustainable Environment Research Centre, University of Glamorgan, Wales, UK

Contributors:

Jungrae Kim, Iain Michie, Arseniy Popov, Hitesh Boghani, Katrin Fradler, Richard Dinsdale, Alan Guwy

World Renewable Energy Forum, WREF2012.

Em-Powering the World with Renewable Energy

12-19th May 2012

Content:

•Brief introduction to BES

•Some wider context for BES

substrates

•A discussion of the scale issue

•Integration – will it help

deployment

Microbial Electrolysis – An example of BES

Biofilm

Electrode

Microorganisms

e-

e-

e-

e-

H2

H+

H+

H+ H+

Membrane

2HCO3-

H2 H2

H2 H2 Anod

e Cathode

Anode: CH3COO- +4H2O → 2HCO3- +9H+ +8e-

Cathode: 8H+ +8e- → 4H2

Whole: CH3COO- +4H2O → 2HCO3- +H+ +4H2

Some of our work in this area:

Kyazze G, Popov A, Dinsdale RM, Esteves S, Hawkes FR, Premier GC, Guwy AJ. In press. Influence of catholyte pH and temperature on hydrogen production

from acetate using a two chamber concentric tubular microbial electrolysis cell. International Journal of Hydrogen Energy.

• Clean water supply and Wastewater treatment are energy issue (Oh et al, 2010): – In UK – about 2-5%

– Mostly done by the activated sludge process

– in US about 1.5% of electricity ~$1.6B pa,

– needs ~0.35kWh/m3 WWT

– In US was about 21 billion kWh (electrical) used in public treatment works.

– Pumping (~21%) and aeration (~30-55%) require most of the energy

– Nutrients also represent GHGs and energy.

Feedstock - Wastewater is Energy

Oh S T, J R Kim, G C Premier, T H Lee, C Kim, W T Sloan. Sustainable wastewater treatment: How

might microbial fuel cells contribute, Biotechnol Adv (2010) dio:10.1016/j.biotechadv.2010.07.008

Sludge digesters – Thames

Water

• UK AD implementation

strategy is to generate 36-72 PJ heat and power by 2020 (3.8-7.5%) of the 20% renewables target. (Shared goals,

DEFRA, 2009).

• Bioelectrochenical systems (BES) - likely comparable with AD

• We estimate that total available biomass resources and methane potential from AD in the UK is 641.67 PJ/y 15.3Mtoe net (57% conversion eff.) (PhD Thesis; Penumathsa, 2010)

Biomass Feedstock: MFCs and BES would compete/share with AD

Many biomass sources Kitchen waste Food processing waste Crop waste Mixed organic feedstock's

Kitchen waste, sewage sludge, animal slurry, etc.

Organic fraction after mechanically separated from entire MSW e.g. MBT systems

What is the hold up? We know 1-2kW/m3 achieved. (Nevin et al (2008)

Will use MFC anode as a model for BES

Some questions arise Purpose of BES energy and materials production mitigation of energy use (aerobic) pollution reduction.

– Which bacteria and reactor configurations? – Which substrates and the practicality of their use? – Embodiment design for scale-up? – Stability? – Routemap to deployment?

A way forward

• Limitation on geometry and relationship to ohmic losses – There is a tension between need for large volume and

need to minimise overpotentials

• Modularization

• Mass transfer – Efficiently getting complex substrate to

– and removing products from microbial populations

• Hydraulic and gas diffusion sealing

• Cost effectiveness – Energy sources

– Product or function value

– CAPEX and OPEX

Issues for Scale-up

IRVV caecell

Current or Current density

Cell

Voltage

Activation

overpotentials

Ohmic

overpotentials

Concentration

overpotentials

Overpotential Losses

• Tubular system – Possible scale-up

potential

– Improved manufacturability

• Membrane electrode assembly (MEA) system – 6.1 W m- 3

– reactor - 200 cm3

• 71% max coulombic efficiency observed

Tubular Bioelectrochemical systems

Kim JR, Premier GC, Hawkes FR, Dinsdale RM, Guwy AJ. 2009. Development of a tubular microbial fuel

cell (MFC) employing a membrane electrode assembly cathode. Journal of Power Sources 187(2):393-

399.

Ion exchange

Membrane

Cathode

Top view

Section

Hydrogel

Anode

Solution

Cathode

Ion exchange

Membrane

Hydrogel

Plastic tube

(anode chamber)

Plastic tube shell

Anode

Solution

A B

Plastic tube (anode chamber)

Plastic tube shell

C

Ion exchange

Membrane

Cathode

Top view

Section

Hydrogel

Anode

Solution

Cathode

Ion exchange

Membrane

Hydrogel

Plastic tube

(anode chamber)

Plastic tube shell

Anode

Solution

A B

Plastic tube (anode chamber)

Plastic tube shell

Ion exchange

Membrane

Cathode

Top view

Section

Hydrogel

Anode

Solution

Cathode

Ion exchange

Membrane

Hydrogel

Plastic tube

(anode chamber)

Plastic tube shell

Anode

Solution

A B

Plastic tube (anode chamber)

Plastic tube shell

C

Kim, J.R., G.C. Premier, F. Hawkes, Jorge Rodríguez, R. Dinsdale, A. Guwy. 2010. Modular tubular microbial fuel cells for energy recovery

during sucrose wastewater treatment at low organic loading rate. Bioresource Technology. 101: 1190-1198.

Kim, J.R., N. Beecroft, J. Varcoe, R.M. Dinsdale, A.J. Guwy, A. Thumser, R. CT Slade, C. Avignone-Rossa, G.C. Premier. 2011. Spatio-

temporal development of the bacterial community in tubular longitudinal microbial fuel cells, Applied Microbiology and Biotechnology. DOI:

10.1007/s00253-011-3181-y.

Tem

pera

ture

(oC

)

30

20

40

Time (Days)

0 20 40 60 80

Voltage (

V)

0.0

0.1

0.2

0.3

0.4

A1

A2

B1

B2

0.04

0.08

0.16

0.21-0.24

0.41-0.42

A1

B1

A2

B2

Effluent

Effluent

A1

B1

A2

B2

Effluent

Effluent

Voltage generation from each

module at OLRs (0.04 – 0.42 g

COD/l/d) and ambient temperature

variation during operation

c.f.

AD high OLRs of 10-20gCOD/l/d (Speece, 1996)

May be suitable for polishing to approx

20mg/l BOD

Sewage ~200-300mg/l COD (Logan, 2008)

Agro-Indust WW ~1.5-8.0g/l COD (Angenent and Wrenn, 2008)

For ME to compete with current WWT

H2 = 10 l/l/d which would need a

minimum OLR of 6.5gCOD/l/d (Logan et al,

2008)

Loading rate, performance and scalability

• Continuous operation, with: – effluent polishing from other bioprocesses

– Power generation and

• Systems repeatability was unknown (not much done)

• Spatial distribution of metabolic processes – Compared 2 modules each in 2 reactor

– On sucrose, OLRs between 0.04 and 0.42 g COD/l/d.

– First modules removed most sCOD

– Mainly VFAs reaching the 2nd modules

– CE in second modules 3-4 times higher

– Peak power was 1.75 W h/g COD in 2nd modules

• Modular tubular design – Reproducibly

– suggested scalable

– Good prospects for polishing in WWT

Continuous operation for power and sCOD

removal

Kim JR, Premier GC, Hawkes FR, Rodriguez J, Dinsdale RM, Guwy AJ. 2010a. Modular tubular microbial fuel

cells for energy recovery during sucrose wastewater treatment at low organic loading rate. Bioresource

Technology 101(4):1190-1198.

Current (mA)

0 2 4 6 8 10

Pow

er

(mW

)

0.0

0.5

1.0

1.5a

0.00 0.02 0.04 0.06 0.08 0.10

0.000

0.002

0.004

0.006

0.41-0.42

0.16

0.08

0.04

0.21-0.24

Current (mA)

0 2 4 6 8 10

Pow

er

(mW

)

0.0

0.5

1.0

1.5

0.08

0.16

0.21-0.24

0.41-0.420.00 0.02 0.04 0.06 0.08 0.10

0.000

0.002

0.004

0.006

0.04 b

A1

B1

A2

B2

Effluent

Effluent

A1

B1

A2

B2

Effluent

Effluent

(a) Helical monolith micro-porous conductive carbon (MMCC)

(provided from UCL), and (b) Layered carbon veil Spoked

former electrode (LVSF), showing spokes on ABS plastic

former. Also (c) showing former.

Kim, J.R., H. Boghani, N. Amini, I. K. Aguey-Zinsou, Michie, R. M. Dinsdale, A. J. Guwy, X. Guo, G. C. Premier. 2012. Porous anodes with helical flow

pathways in bioelectrochemical systems: The effects of fluid dynamics and operating regimes. Journal of Power Sources. In press

• Increased conductivity by novel carbon material and heat

treatment

• High surface/volume ratio for bacterial attachement

Anode Structure using Novel Carbon

Monolith c.f. Veil on Former

c

Monolithic carbon foam

electrode

•Increasing flowrate

•Not much mixing

•Shear does exist and

Carbon fiber veil and former

•Increasing flowrate

•Better mixing with velocity

mW

Flowrate

3D arrow plots showing fluid particle velocities (with arrows showing velocity field direction and their tone indicates magnitude); zoomed in on helical flow path MMCC (a) – (c); and LVSF (a) – (c). Inlet velocities and flow rates:

(a, d) Vin = 1.67e-9 m3 s-1 [0.1 mL min-1], (b, e) 3.33e-8 m3 s-1 [2 mL min-1], (c, f) 1.25e-7 m3 s-1 [7.5 mL min-1].

Scaling up the tubular MFC

• Twice doubling its scale to 1 Lt • Power recovery and COD removal

efficiency were shown to depend on: • organic loading rate. • electrical connectivity.

• Lower loading rates affect power • Self monitoring by voltage is

plausible but storage effects would complicate the issue.

• Power recovery and organic removal could be maximized by extending the number of modules

• Could simultaneously control effluent quality and power, facilitating scale-up.

Current (A)

0.000 0.005 0.010 0.015 0.020 0.025 0.030

Pow

er

(mW

)

0

1

2

3

4

5

6

Mode A

Mode B

a

Kim, J.R., J. Rodríguez, F.R. Hawkes, R.M. Dinsdale, A.J. Guwy, G.C. Premier. 2011. Increasing power recovery

and organic removal efficiency using extended longitudinal tubular microbial fuel cell (MFC) reactors. Energy and

Environmental Sciences. Energy & Environmental Science. 4(2): 459 – 465.

0

2

4

6

8

0 2 4 6 8 10

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

Notional current (A)Notional time

(days)

No

tio

na

l p

ow

er

( W

)

Control system followingpeak power as it alters

with time

0 100 200 300 400 5000

0.05

0.1

0.15

0.2

Time (hours)

Charg

e Y

ield

(C

)

Controlled MFC (LC-MFC)

Charge

Filtered

0 100 200 300 400 5000

0.2

0.4

Time (hours)

Charg

e Y

ield

(C

)

Un-controlled MFC (SL-MFC)

0 100 200 300 400 5000

500

1000

1500

2000

2500

Time (hours)

Cum

ula

tive C

harg

e (

C)

0 100 200 300 400 5000

100

200

300

Time (hours)

Cum

ula

tive C

harg

e (

C)

Charge

5% Lower ohmic tolerance

5% Higher ohmic tolerance

20% Lower ohmic tolerance

Charge

Filtered Charge

20% Higher Ohmic Tolerance

Charge with const. 200 ohm load

(a)(b)

(c)

(d)

Control as a means to

improve performance

•MPPT is beneficial to BES

•The control strategy applied selection

pressures favouring electrogenic

behaviour

0 100 200 300 400 5000

0.05

0.1

0.15

0.2

Un-controlled MFC (SL-MFC)

Time (hours)

Cell

Pote

ntial (V

)

0 100 200 300 400 5000

0.05

0.1

0.15

0.2

Time (hours)

Cell

pote

ntial (V

)

Controlled MFC (LC-MFC)

0 100 200 300 400 5000

1

2x 10

-4

Time (hours)

Pow

er

(W)

0 100 200 300 400 500 6000

1

2

3x 10

-4

Time (hours)

Pow

er

(W)

(a) (b)

(c) (d)

Premier GC, Kim JR, Michie I, Dinsdale R, Guwy A. 2011. Automatic control of load increases power and efficiency in a microbial

fuel cell. Journal of Power Sources 196:2013-2019.

Integration of Microbial Fuel Cell with

two-stage H2 - AD reactor using wheat-

feed

• MFCs as a type of BES can inform anodic subsystem.

• BES and other anaerobic biological processes could make

a contribution to renewable energy.

• Apart from O2 and H+ reduction for H2 production there are

other several other reduction reactions which may be

viable

• The technologies are reasonably versatile and efficient and

cover a spectrum of plausible products and technological

integration.

Closing remarks

Acknowledgements

Thanks you gcpremier@glam.ac.uk