Methanol is a light and colorless liquid that has an alcoholic odor similar to that of ethanol. Over 200 million tons of methanol is produced globally each year. It is a base or an ingredient in many commodity chemicals such as acetic acid, gasoline additive, formaldehyde, and many more.
So, quick answer:
Whether in liquid or gaseous form, methanol is highly flammable. Gaseous methanol molecules can travel quite a distance. This could potentially spread fires in other places. Methanol containers can explode if they’re not sufficiently insulated or protected. When in contact with a platinum-blank catalyst, methanol can also ignite.
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What is Methanol and What are Its Unique Characteristics?
Methanol, commonly known as methyl alcohol or carbinol, is a chemical species belonging to a methyl group of substances linked to a hydroxyl group. It’s also known as wood alcohol in the past due to its extraction process through destructive wood distillation. At present, methanol is created by hydrogenation of carbon monoxide in industrial facilities.
Normal healthy humans produce small amounts of methanol, about 4.5 parts per million (ppm). It can be found in human tissues and bio-fluids such as blood, saliva, or cerebrospinal fluid. The methanol can be metabolized with the structural acid pectin, which is often found in citrus fruits and several types of vegetables. Anaerobic bacteria and phytoplankton also produce small amounts of methanol.
On a much larger scale, regions in outer space that are known to form stars contain vast amounts of methanol. In fact, astronomers use them as markers for such regions. For example, in 2006, using an array of radio telescopes, astronomers discovered a colossal cloud of methanol in space. That cloud is around 288 billion miles in diameter.
Commercially available methanol is classified into various purity grades, typically classified as ASTM purity grades A and AA. Impurities include water, acetone, and ethanol. To detect these impurities, methods such as UV-vis spectroscopy and Kark-Fischer titration are used.
Hazards Associated with Using Methanol
Aside from being highly flammable, methanol has other properties that make it dangerous if not handled properly.
Prolonged exposure to methanol vapor can cause eye irritation, headaches, drowsiness, and fatigue. A person who accidentally ingests as little as 10 milligrams of methanol can become permanently blind as the optic nerve is destroyed.
Ingesting 30 milligrams of methanol is probably fatal. Swallowing 50,000 ppm can cause death within 1 to 2 hours. The toxicity of ingested methanol is carried out by either of two mechanisms. One, methanol can cause death because it affects the central nervous system. Specifically, it acts as a central nervous system depressant.
Also, methanol is metabolized into formaldehyde in a process catalyzed in the liver. Formaldehyde is used as an embalming agent and is incredibly damaging to the liver, causing hypoxia at a cellular level.
Fortunately, the effects start a few hours after ingestion, so there is time to administer an antidote to prevent permanent physical damage.
Methanol belongs to the “Alcohols and Polyols” reactive group. When mixed with acetyl bromide, methanol reacts violently. Mixing methanol with concentrated hydrogen peroxide, sulfuric acid, anhydrous lead perchlorate, or isocyanates can cause dangerous explosions.
Methanol also reacts to hypochlorous acid in water solution, producing methyl hypochlorite. Methyl hypochlorite decomposes in low temperatures and can explode when exposed to sunlight or heat. The same reaction happens when methanol is mixed with chlorine.
Methanol should be cautiously used with cellulose-based absorbents. There have been plenty of situations when untoward reactions happen when methanol is added to these absorbents.
Finally, according to the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT), exposure to methanol at levels found in fruits and vegetables does not cause adverse results.
In case of contact, inhalation, exposure, and ingestion
Avoid direct exposure as much as possible when handling methanol. At the very least, ANSI-approved rubber gloves and safety goggles must be worn. However, in many facilities, more comprehensive protective equipment is often required such as those that cover the face, eyes, and body.
In case of spills and leaks
If methanol is accidentally spilled, immediately get in touch with the fire department. Get rid of potential sources of combustion such as lighters, matches, radiators, and embers.
Isolate the spill or leaks for at least 150 meters in all directions. Do not contain, stop the spill, or reduce the discharge if you’re not properly trained for it. Avoid touching or walking on the spillage. If possible, provide barriers (dams) far ahead of the methanol spill to contain the liquid. Stay upwind to protect yourself from vapors and potential explosions.
For small spills, add soil or sand on the spot—the material absorbs the ethanol. Later, have a specialist transfer the methanol-soaked material in the right containers.
Methanol must be placed in air-tight, leak-proof, and high-quality containers. Methanol containers should never be left open as the vapors are combustible and toxic. Sealed methanol containers should be sealed and labeled according to state, local, and on-site regulations. Facilities should also train personnel on how to handle and move methanol containers.
Methanol is non-corrosive, thus they can be kept together with most metals. However, note that it can corrode metals such as platinum, magnesium, and lead.
Methanol has a very low flash point. This means very small amounts of ignition material can possibly cause fire. Also, because methanol is water soluble, using water to extinguish methanol-caused fires may not be enough.
To extinguish small or big fires, use dry chemicals, alcohol-resistant foam, or carbon dioxide. Check your fire extinguisher; it should have any of these chemicals. You can still use water, but as mentioned above, it might be inefficient. Adjust the nozzle so that the water flows in pressurized sprays.
If a tank containing methanol catches on fire, fight the fire from a maximum distance as indicated in the firefighting apparatus’s instructions. It is also important to cool down other containers by spraying them constantly with water. If you hear venting sounds, withdraw from the area immediately and evacuate all personnel from the facility.
Call the fire department right away in case a methanol-based fire breaks out.
Due to the hazardous nature of methanol, they need to be disposed of correctly. Licensed and professional waste disposal service providers like ACT Enviro have the right equipment and trained personnel to safely and properly handle such tasks. Calling such waste disposal services is the best and safest option for you in disposing methanol.
Do not dispose of waste methanol or water that is contaminated with methanol directly into sewers or drains. Nor should it be poured into open bodies of water such as ponds or lakes.
Uses & Benefits
For all its hazards, methanol is a widely used chemical.
Methanol is a naturally occurring substance in fruits and vegetables. In natural dietary amounts, methanol is essential in regulating human gene activity. Our digestive system also creates methanol to metabolize the food we eat.
Almost half the methanol the world produces is utilized for energy-related processes and applications. It can be used as a fuel for vehicle or marine vessels. Gasoline formulations that include methanol as an additive result in a more efficient fuel called methyl tertiary butyl ether (MTBE). MTBE is more environmentally friendly fuel than gasoline as it produces fewer emissions. Methanol can be added in biodiesel, which is a clean and renewable fuel based on plants or animal fats.
Race car teams often mix water and methanol. This is then injected into high-performance diesel or gasoline engines for a boost in power and a decrease in intake air pressure.
Solvent for commercial products
Methanol is also used as a solvent to create resins, adhesives, inks and dyes.
Despite its hazardous nature, methanol is also widely used in the pharmaceutical industry. Specifically, it is utilized as an important solvent in manufacturing pharmaceutical products such as vitamins, hormones, streptomycin, and more.
One of the unique properties of methanol is that it increases the boiling point and lowers the freezing point of water-based liquids. As such, methanol is used as antifreeze in windshield washer fluids and pipelines. Methanol is also introduced in main natural gas pipelines to lower the freezing point of the gas.
In countries that comprise the European Union, methanol was once used in washing windshield washing or defrosting. But as of May 2019, the EU banned this method due to the risk of human exposure.
In the past, methanol was used to produce “denatured alcohol” or “methylated spirit.” This was a prevalent practice to discourage people from buying and consuming illegally produced liquor.
Some wastewater treatment plants use a small amount of methanol in the wastewater. The methanol provides a carbon food source for the enzymes and denitrifying bacteria. These bacteria convert nitrates in wastewater to harmless nitrogen gas.
Methanol is also used in new, experimental types of fuel cells, specifically direct-methanol fuel cells. These fuel cells are characterized by low-temperature and atmospheric pressure operation. These features allow them to be effectively miniaturized. Combined with safe storage of methanol, this technology can open up the way for fuel cell-powered (rather than battery powered) mobile phones, laptops, tablets, and other consumer electronics.
Mountaineers, hikers, and other outdoorsmen often use methanol as fuel for their camping stoves. Since methanol burns efficiently without the need of a pressurized burner, campers can bring very simple and compact alcohol stoves; some campers even make their own handy stoves from discarded cans. The simplicity and reliability of these alcohol stoves is an advantage in the wilderness. On the other hand, broken complex equipment in the outdoors can become a nightmare. Methanol can be processed into a gel, so outdoorsmen can carry them in their packs without the risk of spilling.