Alternative anodic reactions in water splitting. Final report

Technical Report · Mon Oct 01 04:00:00 EDT 1984

DOI:https://doi.org/10.2172/6067620· OSTI ID:6067620

Murphy, O J; Bockris, J O'M

An anodic depolarization path to hydrogen production through water electrolysis has been examined, using lignite, grass and household wastes. Iron was removed from lignite by extensive washing. The degree of dissolution of lignite in 5 M H/sub 2/So/sub 4/ at 100/sup 0/C is ca. 0.1 wt %. Washed lignite dissolves less than unwashed material. Cyclic voltammograms showed peaks arising from dissolved organics. Increase of temperature produced more peaks. In alkaline solution, peaks disappeared. Oxidation currents were three times greater if the lignite particles were in contact with the electrode compared with their absence from solution. Platinum anodes oxidized lignite better than PbO/sub 2/. Redox systems, added to the electrolyte, helped compound formation. Grass and household wastes gave similar results but lower oxidation currents. Compounds present in solution prior to electrolysis dissolve off the internal surfaces of lignite particles. Increased oxidation currents, caused when lignite particles came in contact with the anode, arose, not because of enhanced electrochemical reactions, but from enhanced lignite dissolution following erosion. The organic compounds eventually form CO/sub 2/; the presence of heavy oils lasts for 10 hr. Current densities up to 750 mA cm/sup -2/ at ca. 1 V should be obtainable. The hydrocarbons are formed via a Kolbe mechanism from carboxylic acids. Speculative economic considerations show that the final cost of hydrogen produced, using lignite as an anode depolarizer, is considerably cheaper than that from natural gas: $0.40 per GJ, or less, compared to $5 per GJ.

• Research Organization: Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6067620
• Report Number(s): BNL-35458; ON: DE85004159
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
080101* -- Hydrogen-- Production-- Electrolysis
ANODES
BIOMASS
BROWN COAL
CARBONACEOUS MATERIALS
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
COAL
DATA
DEPOLARIZATION
DISPERSIONS
ELECTRODES
ELECTROLYSIS
ENERGY SOURCES
EXPERIMENTAL DATA
FOSSIL FUELS
FUELS
HYDROCARBONS
HYDROGEN PRODUCTION
INFORMATION
LIGNITE
LYSIS
MATERIALS
MIXTURES
NUMERICAL DATA
ORGANIC COMPOUNDS
RENEWABLE ENERGY SOURCES
SLURRIES
SUSPENSIONS