Renewable Energy Hydrogen

Sustainable and efficient biohydrogen production via electrohydrogenesis

Authors: Cheng, S. Logan, B.E. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Civil and Environmental Engineering]
 
Abstract: Hydrogen gas has tremendous potential as an environmentally acceptable energy carrier for vehicles, but most hydrogen is generated from nonrenewable fossil fuels such as natural gas. Here, the authors show that efficient and sustainable hydrogen production is possible from any type of biodegradable organic matter by electrohydrogenesis. In this process, protons and electrons released by exoelectrogenic bateria in specially designed reactors (based on modifying microbial fuel cells) are catalyzed to form hydrogen gas through the addition of a small voltage to the circuit. By improving the materials and reactor architecture, hydrogen gas was produced at yields of 2.01-3.95 mol/mol (50-99% of the theoretical maximum) at applied voltages of 0.2 to 0.8 V using acetic acid, a typical dead-end product of glucose or cellulose fermentation. At an applied voltage of 0.6 V, the overall energy efficiency of the process was 288% based solely on electricity applied, and 82% when the heat of combusion of acetic acid was included in the energy balance, at a gas production rate of 1.1 m 3 of H 2 per cubic meter of reactor per day. Direct high-yield hydrogen gas production was further demonstrated by using glucose, several volatile acids (acetic, butyric, lactic, propionic, and valeric), and cellulose at maximum stoichiometric yields of 54-91% and overall energy efficiencies of 64-82%. This electrohydrogenic process thus provides a highly efficient route for producting hydrogen gas from renewable and carbon-neutral biomass resources.
Publication Date: 20 Nov 2007
Resource Type: Journal Article
Resource Relation: Journal: Proceedings of the National Academy of Sciences of the United States of America; Journal Volume: 104; Journal Issue: 47; Other Information: doi: www.pnas.org/cgi/doi/10.1073/pnas.0706379104
Country of Publication: United States
Language: English
Keywords relating to this report:
ACETIC ACID
ARCHITECTURE
BIOMASS
CELLULOSE
ELECTRICITY
ELECTRONS
ENERGY BALANCE
ENERGY EFFICIENCY
FERMENTATION
FOSSIL FUELS
FUEL CELLS
GLUCOSE
HYDROGEN
HYDROGEN PRODUCTION
NATURAL GAS
ORGANIC MATTER
PRODUCTION
PROTONS

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