Evaluation of energy-conversion efficiencies in microbial fuel cells (MFCs) utilizing fermentable and non-fermentable substrates

2008 ◽  
Vol 42 (6-7) ◽  
pp. 1501-1510 ◽  
Author(s):  
Hyung-Sool Lee ◽  
Prathap Parameswaran ◽  
Andrew Kato-Marcus ◽  
César I. Torres ◽  
Bruce E. Rittmann
Keyword(s):  
Fuel Cells ◽  
Energy Conversion ◽  
Microbial Fuel Cells ◽  
Conversion Efficiencies

The Thermodynamic Evaluation and Optimization of Fuel Cell Systems

2006 ◽  
Vol 3 (2) ◽  
pp. 155-164 ◽  
Author(s):  
N. Woudstra ◽  
T. P. van der Stelt ◽  
K. Hemmes
Keyword(s):  
Heat Transfer ◽  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Energy Conversion ◽  
System Optimization ◽  
Fuel Conversion ◽  
Cell Systems ◽  
Electrochemical Conversion ◽  
Conversion Efficiencies

Energy conversion today is subject to high thermodynamic losses. About 50% to 90% of the exergy of primary fuels is lost during conversion into power or heat. The fast increasing world energy demand makes a further increase of conversion efficiencies inevitable. The substantial thermodynamic losses (exergy losses of 20% to 30%) of thermal fuel conversion will limit future improvements of power plant efficiencies. Electrochemical conversion of fuel enables fuel conversion with minimum losses. Various fuel cell systems have been investigated at the Delft University of Technology during the past 20 years. It appeared that exergy analyses can be very helpful in understanding the extent and causes of thermodynamic losses in fuel cell systems. More than 50% of the losses in high temperature fuel cell (molten carbonate fuel cell and solid oxide fuel cell) systems can be caused by heat transfer. Therefore system optimization must focus on reducing the need for heat transfer as well as improving the conditions for the unavoidable heat transfer. Various options for reducing the need for heat transfer are discussed in this paper. High temperature fuel cells, eventually integrated into gas turbine processes, can replace the combustion process in future power plants. High temperature fuel cells will be necessary to obtain conversion efficiencies up to 80% in the case of large scale electricity production in the future. The introduction of fuel cells is considered to be a first step in the integration of electrochemical conversion in future energy conversion systems.

Microbial fuel cells for wastewater treatment

2006 ◽  
Vol 54 (8) ◽  
pp. 9-15 ◽  
Author(s):  
P. Aelterman ◽  
K. Rabaey ◽  
P. Clauwaert ◽  
W. Verstraete
Keyword(s):  
Wastewater Treatment ◽  
Fuel Cells ◽  
Potential Energy ◽  
Microbial Fuel Cells ◽  
Energy Recovery ◽  
Oxygen Demand ◽  
Wastewater Effluent ◽  
Hospital Wastewater ◽  
Potato Processing ◽  
Conversion Efficiencies

Microbial fuel cells (MFCs) are emerging as promising technology for the treatment of wastewaters. The potential energy conversion efficiencies are examined. The rates of energy recovery (W/m3 reactor) are reviewed and evaluated. Some recent data relating to potato-processing wastewaters and a hospital wastewater effluent are reported. Finally, a set of process configurations in which MFCs could be useful to treat wastewaters is schematized. Overall, the MFC technology still faces major challenges, particularly in terms of chemical oxygen demand (COD) removal efficiency.

Modeling of a Methane Fuelled Direct Carbon Fuel Cell System

2005 ◽  
Author(s):  
N. Woudstra ◽  
T. P. van der Stelt ◽  
K. Hemmes
Keyword(s):  
Heat Transfer ◽  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Energy Conversion ◽  
Fuel Conversion ◽  
Cell Systems ◽  
Electrochemical Conversion ◽  
Direct Carbon Fuel Cell ◽  
Conversion Efficiencies

Energy conversion today is subject to high thermodynamic losses. About 50 to 90 % of the exergy of primary fuels is lost during conversion into power or heat. The fast increasing world energy demand makes a further increase of conversion efficiencies inevitable. The substantial thermodynamic losses (exergy losses of 20 to 30 %) of thermal fuel conversion will limit future improvements of power plant efficiencies. Electrochemical conversion of fuel enables fuel conversion with minimum losses. Various fuel cell systems have been investigated at the Delft University of Technology during the past twenty years. It appeared that exergy analyses can be very helpful in understanding the extent and causes of thermodynamic losses in fuel cell systems. More than 50 % of the losses in high temperature fuel cell (MCFC and SOFC) systems can be caused by heat transfer. Therefore system optimisation must focus on reducing the need for heat transfer as well as improving the conditions for the unavoidable heat transfer. Various options for reducing the need for heat transfer are discussed in this paper. High temperature fuel cells, eventually integrated into gas turbine processes, can replace the combustion process in future power plants. High temperature fuel cells will be necessary to obtain conversion efficiencies up to 80 % in case of large scale electricity production in the future. The introduction of fuel cells is considered to be a first step in the integration of electrochemical conversion in future energy conversion systems.

Continuous microbial fuel cells convert carbohydratesto electricity

2005 ◽  
Vol 52 (1-2) ◽  
pp. 515-523 ◽  
Author(s):  
K. Rabaey ◽  
W. Ossieur ◽  
M. Verhaege ◽  
W. Verstraete
Keyword(s):  
Fuel Cells ◽  
Plant Extract ◽  
Microbial Fuel Cells ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Continuous Mode ◽  
Practical Applications ◽  
Batch Systems ◽  
Power Outputs ◽  
Conversion Efficiencies

Microbial fuel cells which are operated in continuous mode are more suitable for practical applications than fed batch ones. Three influent types containing carbohydrates were tested, i.e. a glucose medium, a plant extract and artificial wastewater. The anode reactor compartment yielding the best results was a packed bed reactor containing graphite granules. While in non-mediated batch systems power outputs up to 479 W m−3 of anode compartment could be attained; in continuous mode the power outputs were limited to 49 W m−3. Cyclic voltammetry was performed to determine the potential of the in-situ synthesized bacterial redox mediators. Addition of mediators with a potential similar to the bacterial potential did not significantly alter the MFC power output, indicating a limited influence of soluble mediators for continuous microbial fuel cells. Maximum coulombic and energy conversion efficiencies were, for the continuous microbial fuel cell operating on plant extract at a loading rate of 1 kg COD m−3 of anode compartment per day, 50.3% and 26.0% respectively.

scholarly journals Waste to energy conversion utilizing nanostructured Algal‐based microbial fuel cells

2021 ◽  
Author(s):  
Rehab H. Mahmoud ◽  
Farag A. Samhan ◽  
Mohamed K. Ibrahim ◽  
Gamila H. Ali ◽  
Rabeay Y. A. Hassan
Keyword(s):  
Fuel Cells ◽  
Energy Conversion ◽  
Microbial Fuel Cells ◽  
Waste To Energy
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