What is methanol or methyl alcohol?
You’ve probably read headlines about people getting poisoned by drinking methanol, or that methanol is the green alternative to fossil fuels in the future. But “What is methanol?” is a topic that has been covered in so many different headlines. Methanol, also known as methyl alcohol, wood alcohol, or methyl alcohol, is a chemical compound with the formula CH₃OH. It is the simplest type of alcohol and is a colorless, volatile, flammable, and toxic liquid. Methanol is used in various industries and has many applications.
Methanol, or methyl alcohol, is one of the oldest known chemical compounds. It was first isolated by chemists in the 17th century by distilling wood. For this reason, methanol is also known as “wood alcohol.” In this early method, wood was heated and the resulting vapors were distilled to extract methanol.
In the early 20th century, with the advancement of chemistry and technology, new methods for producing methanol were developed. One of these methods was the synthesis gas process, which involved converting natural gas or coal into synthesis gas (a mixture of carbon monoxide and hydrogen) and then converting it into methanol. This method was developed industrially in the 1920s by chemical companies in Germany and the United States, and methanol production began on an industrial and large-scale basis.
Over time and with scientific advances, methanol production methods improved and new applications for this substance were discovered. In the 1970s and 1980s, methanol was proposed as an alternative fuel for cars and as a fuel additive (such as MTBE). These applications became attractive due to methanol’s properties as a cleaner fuel and the ability to be produced from renewable resources.
Methanol production
Methanol production is carried out industrially in two main ways: production from natural gas and production from coal. These processes involve the production of synthesis gas (a mixture of carbon monoxide and hydrogen) and then its conversion into methanol.
Production from natural gas
This method is the most common method of producing methanol. The steps for producing methanol using this method are explained below.
Conversion of natural gas into synthesis gas
- Methane vaporization: Natural gas (mainly methane) is converted into synthesis gas (carbon monoxide and hydrogen) at high temperature in the presence of water vapor and a nickel catalyst.
- Water-gas conversion: Carbon monoxide and water are converted into carbon dioxide and hydrogen.
Conversion of synthesis gas into methanol
The synthesis gas produced in the previous step is converted into methanol in the presence of a catalyst (usually copper, zinc, and alumina) under appropriate pressure and temperature.
Production from coal
This method is used in areas where natural gas resources are limited. The steps for producing methanol from coal are as follows.
Conversion of coal into synthesis gas
Coal is converted into synthesis gas (carbon monoxide and hydrogen) in the presence of oxygen and water vapor at high temperatures.
Conversion of synthesis gas into methanol
- Similar to the production method from natural gas, the synthesis gas produced is converted into methanol in the presence of a suitable catalyst.
Production of methanol from renewable sources
In recent years, more attention has been paid to the production of methanol from renewable and biological sources. These methods include producing methanol from carbon dioxide and hydrogen from renewable sources, and producing biomethanol from biomass and organic waste. These approaches can help reduce greenhouse gas emissions and create a more sustainable supply chain for methanol.
Dangers of Methanol
Methanol, or methyl alcohol, is a highly toxic alcohol and is often confused with ethanol, the alcohol found in alcoholic beverages. Methanol is sometimes used in illegal alcoholic beverages instead of ethanol because it is cheaper. This can be very dangerous and can lead to severe poisoning, serious health damage, and even death.
Methanol is a highly toxic substance and can enter the body through inhalation, ingestion, and skin contact. Consuming even small amounts of methanol can cause serious complications. Methanol is converted in the body to formaldehyde and formic acid, which can cause severe tissue damage and gastrointestinal, neurological, and eye symptoms.
Symptoms of methanol poisoning include nausea, vomiting, dizziness, blurred vision, and in more severe cases, blindness and death. Treatment for methanol poisoning includes administering drugs that block the production of toxic byproducts, controlling acidosis, and, if necessary, dialysis.
Treatment of methanol poisoning
Methanol poisoning is a medical emergency and must be treated promptly. The main steps in treatment are:
- Prescribe drugs that block the production of toxic methanol derivatives: such as fompizole.
- Control acidosis: using sodium bicarbonate or other appropriate treatments.
- Maintenance treatments: Including general medical care and support of vital body functions.
- Dialysis: If needed to remove methanol and its toxic derivatives from the body.
If treatment is started in a timely manner, it can prevent the progression of poisoning and the occurrence of dangerous complications and death.
Specifications
Molecular formula C1H4O1
Molar mass 32.04 g mol−1
Appearance Colorless liquid
Density 0.7918 g cm−3
Boiling point 65 °C (149 °F; 338 K)
log P -0.69
Vapour pressure 13.02 kPa (at 20 °C)
Acidity (pKa) 15.5[2]
Viscosity 5.9×10−4 Pa s (at 20 °C)
Dipole moment 1.69 D
