Methanol fuel

From Wikipedia, the free encyclopedia

1 Methyl Alcohol, wood spirits, and Methanol
2 Toxicity
3 In practice
4 See also
5 External links

[edit] Methyl Alcohol, wood spirits, and Methanol

Methanol has been considered as a fuel, mainly in combination with gasoline. It has received less attention than ethanol, however, because it has a number of problems of its own. Its main advantage is that it can be easily manufactured from methane (the chief constituent of natural gas) as well as by pyrolysis of many organic materials. A problem with pyrolysis is that it is only economically feasible on an industrial scale, so it is 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, reducing the risk of explosion or flash fire. Methanol has about the same acute toxicity as gasoline, so similar precautions should be taken when handling it. It is much less carcinogenic than gasoline, and less harmful to the environment if spilled.

Methanol was discovered through pyrolysis of wood. Current technology can convert the synthesis gas generated by pyrolysis of biomass to create additional production of methanol.

[edit] Toxicity

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 also quite volatile and therefore has a risk of fire and explosion. Besides the fire and explosion risk, volatility means evaporative emissions. 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 would usually break down these two toxins in a manner similar to the sulfur, nitrogen, or carbon monoxide molecules which they normally dispose of if it were not for the fact that catalytic converters operate below the required temperature until the vehicle has gone 5 to 10 miles (10 to 15 km).

It is possible to overcome this environmental issue in two ways. Firstly, there is the very expensive option of adding more catalyst to the converter's aluminium honeycomb. But the catalysts themselves just happen to be the metals platinum, palladium, and rhodium - all of which are very rare and expensive to purchase. As an example, palladium costs about $200 per ounce, the equivalent of $3,200 per pound or £4,000 (€5,500) per kilogram. Also, platinum costs even more: $1,200 per ounce, $19,000 per pound, or $41,000 (£22,700 or €32,000 per kilogram.) And rhodium is the most expensive by a long way: $6,000 per ounce - that's $100,000 per pound, or $225,000 (£125,000 or €175,000) per kilo as of July 2006, 6 times as expensive as platinum. That is why catalytic converters contain so little catalyst: the catalysts themselves are too expensive to be used generously enough to be as effective as they were meant to be.

Alternatively, an electric heater (for home conversion, a glow plug from an old diesel engine) would serve to preheat the converter a bit more rapidly than an engine by itself would by idling for 5 or 10 minutes. The catalytic converter would still be operating below the required temperature for some time, but less than in an unmodified vehicle, thus cutting pollution levels significantly. Note that hybrid vehicles will be easier to modify this way because they already have battery systems that can supply sufficient power to heat the catalyst sufficiently, whereas conventional cars may need electrical modifications to enable this.

An additional problem of methanol is that its energy content is only 45% that of gasoline (75% of ethanol) by volume. (gasoline = 30 megajoules/litre, ethanol = 22-23 megajoules/litre, methanol = 16 megajoules/litre.)

[edit] In practice

Nevertheless, 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.

Since 1965, pure methanol was used in United States Auto Club competition for its series, and today used by many short track organisations, especially midget and sprint cars, Champ Car, and until 2005, Indy cars, primarily for safety reasons.

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 McDonald died in the crash when their gasoline-fueled cars exploded. Johnny Rutherford was also involved, in a methanol-fueled car which also leaked following the crash, and while this car burned from the impact of the first fireball, it formed a much lesser inferno than the gasoline cars. That testimony and pressure from the Indianapolis Star writer George Moore, led to the 1965 alcohol fuel mandate.

Currently, the Indy Racing League uses pure methanol (M100). In 2006, the IRL will switch to a 10% ethanol / 90% methanol (M90 or E10) mix, before switching to an all-ethanol mix (E100) in 2007.

Methanol fuel is also used extensively in drag racing, primarily in the Top Alcohol category.