Methanol

Methanol or methyl alcohol, wood alcohol, wood naphtha or wood spirits, is a chemical with the formula CH₃OH. Methanol acquired the name “wood alcohol” because it was once produced chiefly as a by-product of the destructive distillation of wood. Modern methanol is produced in a catalytic industrial process directly from carbon monoxide, carbon dioxide, and hydrogen. It smells slightly sweeter than Ethanol. Methanol is produced naturally in the anaerobic metabolism of many varieties of bacteria, and is ubiquitous in small amounts in the environment.

As a result, there is a small fraction of methanol vapour in the atmosphere. Over the course of several days, atmospheric methanol is oxidized with the help of sunlight to carbon dioxide and water. Methanol burns in oxygen (including open air), forming carbon dioxide and water:

2 CH₃OH + 3 O₂ → 2 CO₂ + 4 H₂O

Methanol ingested in large quantities is metabolized to formic acid or formate salts, which is poisonous to the central nervous system, and may cause blindness, coma, and death. Because of these toxic properties, methanol is frequently used as a denaturant additive for ethanol manufactured for industrial uses.

Applications of Methanol

• Methanol is a common laboratory solvent.
• The largest use of methanol by far is in making other chemicals. About 40% of methanol is converted to formaldehyde, and from there into products as diverse as plastics, plywood, paints, explosives, and permanent press textiles.
• Methanol is used to produce a gasoline additive methyl tert-butyl ether (MTBE).
• In addition to direct use as a fuel, methanol (or less commonly, ethanol) is used as a component in the transesterification of triglycerides to yield a form of biodiesel.
• Methanol derived Dimethyl ether (DME) has replaced chlorofluorocarbons as an aerosol spray propellant. Dimethyl ether (DME) also can be blended with liquified petroleum gas (LPG) for home heating and cooking, and can be used as a diesel replacement for transportation fuel.
• Methanol is used on a limited basis to fuel internal combustion engines. It is not widely used as a fuel because , using high concentrations of methanol (and other alcohols, such as ethanol) in fuel is the corrosivity to some metals, particularly to aluminium. Methanol, although a weak acid, attacks the oxide coating that normally protects the aluminum from corrosion
• Methanol is a traditional denaturant for ethanol, the product being known as “denatured alcohol” or “methylated spirit”. This was commonly used during the Prohibition to discourage consumption of bootlegged liquor, and ended up causing several deaths.
• As an antifreeze in pipelines and windshield washer fluid.In some wastewater treatment plants, a small amount of methanol is added to wastewater to provide a carbon food source for the denitrifying bacteria, which convert nitrates to nitrogen to reduce the nitrification of sensitive aquifers.
• Methanol is also a widely used fuel in camping and boating stoves. Methanol burns well in an unpressurized burner, so alcohol stoves are often very simple, sometimes little more than a cup to hold fuel. This lack of complexity makes them a favorite of hikers who spend extended time in the wilderness.
• Methanol is mixed with water and injected into high performance diesel and gasoline engines for an increase of power and a decrease in exhaust gas temperature in a process known as water methanol injection.