Acetylene is a colorless and flammable gas that has a distinct garlic-like odor. It is composed of a mixture of two hydrogen and two carbon atoms and is member of a group of hydrocarbons known as alkynes or acetylenes. Acetylene is a common component of many chemicals and plastics and is also commonly used as a fuel for both welding and metal cutting torches.
Although it was discovered in the early 1800s by Edmund Davy, acetylene was not widely used until the late 1800s. While trying to find a more economical process of producing aluminum, a man named Thomas Wilson inadvertently discovered an inexpensive but effective method of producing calcium carbide by heating coal and lime in a furnace. Wilson then discovered that combining calcium carbide with water produced acetylene.
This discovery led to the widespread use of the gas as a lighting fuel due to the bright and clear light that it produces when combusting. Many street lights, interior lights, automobile headlights, lanterns, mining lamps and other general lighting during the late 1800s and early 1900s were fueled by acetylene. It is still used as a fuel for lighting in areas where electric or natural gas light is not possible or practical.
Today there are two main methods of manufacturing acetylene. In addition to combining calcium carbide with water, the gas can also be produced through a process known as thermal cracking. A natural gas, generally methane, is heated in a process that separates the hydrocarbons in the gas. The hydrocarbons are then rebonded to form a new compound that is different from the original.
When used as a fuel for welding or cutting torches, acetylene is typically combined with oxygen to produce temperatures higher than possible with acetylene alone. Oxygen-acetylene torches can produce a flame of 6,000 degrees Fahrenheit (3,315.55° Celsius.) The high temperature makes oxygen-acetylene torches the only type of welding and cutting torches that are hot enough to melt all commercial metals.
Acetylene is extremely volatile, as it combusts when it comes into contact with oxygen. The properties of the gas are so unstable that even a small leak can cause serious consequences. It is therefore very important that it is handled carefully and stored properly. To decrease the potential hazard and reduce its volatility, acetylene is typically dissolved in acetone and stored in specially designed tanks with a porous material.