Biotech Updates

“Biocoal” and Direct Carbon Fuel Cell Tech- Alternative for Electricity Generation

February 15, 2008
http://pubs.acs.org/cgi-bin/abstract.cgi/iecred/2007/46/i03/abs/ie061202s.html
http://dodfuelcell.cecer.army.mil/library_items/DCFC_Report.pdf
http://biopact.com/2008/02/closer-look-at-direct-carbon-fuel-cells.html

Fuel cells are essentially “batteries” which generate electricity as a result of chemical reactions of the raw materials that occur at the positive electrode (cathode) and at the negative electrode (anode). It is considered one of the “green technologies” for electrical power generation. The conventional industrial fuel cells utilize gaseous raw materials (hydrogen at the cathode, and oxygen at the anode) to drive the electricity generating reaction (hydrogen + oxygen = water). The hydrogen source can be from the thermochemical processing of biomass. Recently, however, a new type of fuel cell technology (called “Direct Carbon Fuel Cell Technology”), utilizes solid carbon at the cathode, instead of hydrogen. Solid carbon (“char”, “charcoal”, or “biocoal”) is the residue from the oxygen-free thermochemical processing of the biomass (also called “pyrolysis”). In the new process, the carbon is dissolved in molten salt and provides the raw material at the cathode. Oxygen is provided as the raw material at the anode, and the electricity generating reaction is: carbon+oxygen= carbon dioxide. The main advantage of the new fuel cell technology is said to be its higher energy efficiency of about 80%, compared to only 30% to 60% in conventional fuel cells. Other advantages include: (1) the versatility in the use of any abundant carbonaceous material, and (2) no costly catalyst needed..