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Additional recommended knowledge
Methyl alcohol, wood spirits, and Methanol
Methanol has been considered as a fuel, mainly in combination with gasoline. Lately it has received less attention than ethanol, possibly because of pressure from the ethanol lobby. Today it's generally produced using methane (the chief constituent of natural gas) as a raw material, but it can also be produced by pyrolysis of many organic materials or by Fischer Tropsch from synthetic gas. Production of methanol from synthesis gas using Biomass-To-Liquid can offer methanol production from biomass at efficiencies up to 75%. This has a potential to offer methanol fuel at a low cost and with great benefits to the environment. These production methods are however not suitable for small scale production, so it's not advisable to try to produce methanol from renewable resources like wood on a small (personal use) scale. Both methanol and ethanol burn at lower temperatures than gasoline, and both are less volatile, making engine starting in cold weather difficult.
When using methanol as a fuel in spark ignition engines it can offer an increased thermal efficiency and increased power output compared with gasoline due to its high octane rating and high heat of vaporisation. It's low energy content of 19.7 MJ/kg and stoichiometric air fuel ratio of 6.42:1 do however mean that fuel consumption (on volume or mass basis) will be high. This also makes the charge rather wet and combined with the formation of acidic products during combustion wear of valves, valveseats and cylinder can be high. Certain additives can be added to the oil in order to neutralize these acids. Methanol is also corrosive on the fuel system, although this problem isn't any worse than for ethanol. In fact the opposite may be true.
Methanol is a toxic product; extensive exposure to it could lead to permanent health damage, including blindness. US maximum allowed exposure in air (40 h/week) are 1900 mg/m³ for ethanol, 900 mg/m³ for gasoline, and 260 mg/m³ for methanol. It is however less volatile than gasoline and this decreases evaporative emissions but increases the risk of a fuel tank fire. Both in the atmosphere and in the liver, methanol is oxidized into two potent toxins: formaldehyde (used as a preservative for dead organic matter in laboratories), and formic acid (the poison found in ant stings). Catalytic converters will however break down most of these two toxins in a manner similar to hydrocarbon, nitrogen oxide, or carbon monoxide molecules which they normally dispose of when the catalytic converter reaches operating temperature. A modern catalyst can become operational as fast as 30 seconds after engine start. Air injection into the exhaust can allow for oxidation of hydrocarbons (as well as alcohols) even when the air fuel mixture is rich, as after a cold start. In addition, this oxidation heats up the catalyst faster. Compared to gasoline, methanol is much more reactive when in contact with a catalyst. The use of methanol, just like ethanol, will also significantly reduce the emissions of toxins such as benzene and 1,3 butadiene.
Use in racing
Beginning in 1965, pure methanol was used in United States Auto Club competition for its series, which then included the Indianapolis 500.
A seven-car crash on the second lap of the 1964 Indianapolis 500 resulted in USAC's decision to mandate methanol. Eddie Sachs and Dave MacDonald died in the crash when their gasoline-fueled cars exploded. The gasoline-triggered fire created a dangerous cloud of thick black smoke, which completely blocked the view of the track for oncoming cars. Johnny Rutherford, one of the other drivers involved, drove a methanol-fueled car which also leaked following the crash. While this car burned from the impact of the first fireball, it formed a much lesser inferno than the gasoline cars, and one that burned invisibly. That testimony, and pressure from Indianapolis Star writer George Moore, led to the switch to alcohol fuel in 1965.
Methanol is currently used by the Champ Car circuit and many short track organizations, especially midget and sprint cars. Pure methanol was used by the IRL until the 2006 season.
Methanol fuel is also used extensively in drag racing, primarily in the Top Alcohol category.
Formula One racing continues to use gasoline as its fuel, but in pre war grand prix racing methanol was often used in the fuel.
Methanol fuel programs in the U.S. and other nations
The State of California ran an experimental program from 1980 to 1990 which allowed anyone to convert a gasoline vehicle to 85% methanol with 15% additives of choice. Over 500 vehicles were converted to high compression and dedicated use of the 85/15 methanol and ethanol, with great results. Detroit was not willing to produce any methanol or ethanol vehicles without government subsidy.
In 1982 the big three were each given $5,000,000 for design and contracts for 5,000 vehicles to be bought by the State. That was the beginning of the low compression "FLEX-FUEL" vehicles which we can still buy today.
In 2005 California's Governor, Arnold Schwarzenegger terminated the use of methanol (after 25 years and 200,000,000 miles of success, to join the expanding use of ethanol driven by producers of corn. Ethanol is currently (2007) priced at 3 to 4 dollars per gallon while methanol made from natural gas remains at 1 dollar per gallon.
A drive to add a significant percentage of methanol to gasoline got very close to implementation in Brazil, following a pilot test set up by a group of scientists involving adding blending gasoline with methanol between 1989 and 1992. The larger-scale pilot experiment that was to be conducted in São Paulo was vetoed at the last minute by the city's mayor, out of concern for the health of gas station workers (who are mostly illiterate and could not be expected to follow safety precautions). As of 2006, the idea has not resurfaced.
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Methanol_fuel". A list of authors is available in Wikipedia.|