Methanol Fuel Cells and Portable Electronics
Methanol has a wide variety of uses. Its main use is as an industrial solvent for inks, resins, adhesives and dyes -- you'll find it in products like household cleaners, insecticides and paint thinners and removers. It's also used as an antifreezing agent for both car radiators and gasoline, and even as an alternative to gas for cars. While it can be man-made, methanol is also naturally emitted by volcanic processes, plants, microbes, insects and decomposing biological waste like sewage.
There are several different types of fuel cell technologies. At their most basic, fuel cells are devices that convert the chemical energy of a fuel -- such as hydrogen, gasoline or methanol -- and air into electricity. Fuel cells work like batteries, but unlike batteries they don't need to be recharged and they last far longer. The only byproducts of a methanol fuel cell's reaction are electricity, water and a small amount of carbon dioxide [source: Sistek].
The type of fuel cell some hope will eventually replace the internal combustion car engine is the Proton Exchange Membrane Fuel Cell (PEMFC), which uses hydrogen for power; however, Toshiba and other technology companies are looking into a slightly different form, one more suitable for MP3 players and other mobile devices -- Direct Methanol Fuel Cells (DMFC). In liquid form, methanol (CH3OH) reacts with water (H2O) to create CO2, hydrogen ions and electrons. The hydrogen ions travel through a thin plastic film polymer and react with oxygen, creating electricity.
Toshiba originally began developing their DMFC as a small cartridge that contains a "passive" supply of methanol in a highly concentrated form. There are actually two different prototypes they've announced in the past -- one meant for flash memory-based MP3 players and another for players with hard disk drives. The first, a 100-milliwatt version, is about the size of a pack of gum; it doesn't have to be too large because flash memory-based MP3 players are smaller and require less power. It still packs a punch, though, since it's designed to provide about 35 hours on a single charge. On the other hand, the 300-milliwatt version meant for hard-disk MP3 devices is a little bigger -- it's about the size of a pack of playing cards -- and can power an MP3 player for 60 hours on one charge.
It's unclear whether or not users would refill an empty methanol fuel cell or if they would use disposable cartridges. And although these models haven't left the laboratory, Toshiba appears to be carefully honing its products: The company introduced a prototype of a small headphone and MP3 player combination that can run for about 10 hours using a methanol fuel cell. Despite fears associated with methanol -- inhalation or ingestion of the substance can cause blurred vision and lead to blindness, while contact with the skin can cause mild dermatitis, or inflammation of the skin -- reports assure that DMFC technology is designed to be perfectly safe [source: Digital World Tokyo].
For lots more information on fuel cell technology and eccentric MP3 players, see the next page.
Related HowStuffWorks Articles
More Great Links
- Environmental Protection Agency. "Methanol." Technology Transfer Network Air Toxics Web Site. Nov. 6, 2007 (Aug. 4, 2008) http://www.epa.gov/ttn/atw/hlthef/methanol.html
- Fuel Cell Test and Evaluation Center. "Direct methanol fuel cells (DMFC)." 2008. (Aug. 4, 2008) http://www.fctec.com/fctec_types_dmfc.asp
- Lytle, J. Mark. "Toshiba's future vision sees methanol fuel cells on our heads." Digital World Tokyo. Feb. 20, 2007. (Aug. 4, 2008) http://www.digitalworldtokyo.com/index.php/digital_tokyo/articles/ toshibas_future_vision_sees_methanol_fuel_cells_on_our_heads/
- Sherwood, James. "Toshiba to mass-produce mobile-friendly fuel cells in 2009." Register Hardware. May 12, 2008. (Aug. 4, 2008) http://www.reghardware.co.uk/2008/05/12/toshiba_mass_prodice_dmfc/
- Singer, Michael. "A fuel cell to gas up your MP3 player." CNET News. Sept. 16, 2005. (Aug. 4, 2007) http://news.cnet.com/A-fuel-cell-to-gas-up-your-MP3-player/2100-1041_3-5869515.html
- Sistek, Hanna. "At MTI Micro, pushing fuel cells for portables." CNET News. April 7, 2008. (Aug. 13, 2008) http://news.cnet.com/At-MTI-Micro,-pushing-fuel-cells-for-portables/2100-13840_3-6236716.html