Scott Radell, age 9, of Richmond, Virginia, for his question:
What exactly is propane?
Propane can help cook your dinner or keep you dry in the rain. It can help to clean your paint brushes or to put you painlessly to sleep while the doctor takes out your tonsils. Propane works with other substances to do dozens of other workaday jobs. Yet we never see it.
People who live way out in the country often used bottled gas. The pipelines that carry cooking gas to cities and towns do not peach their homes. So they use this bottled gas instead. It comes in a heavy tank with a valve to connect it to the gas pipes in the house. Inside the tank, this fuel is a liquid. It turns into invisible gas just as soon as it can escape, bit by bit, through that valve. Bottled gas may be sold as LPG liquid petroleum gases. Most of it is a mixture of propane and butane gases. Sometimes it is mostly butane and sometimes it is mostly propane.
Propane and butane are brother chemicals. At ordinary everyday temperatures they are both invisible gases. You cannot see them. Both of them are fuel gases, eager to burn and give off lots of heat. And both propane and butane are related to petroleum. This is that precious oil from which we get gasoline and thousands of other everyday items. It is a mixture of many chemicals called hydrocarbons. All hydrocarbons are molecule packages made from atoms of hydrogen and carbon. The hydrocarbons in petroleum were created in the bosom of the earth from the buried remains of little creatures that once lived in the seas.
The earth can make large or small molecules from hydrogen and carbon. One of the smallest is methane or marsh gas. Each of its molecules is a package of four hydrogen atoms and one carbon atom. The propane molecule has three carbon and eight hydrogen atoms. Butane is made of molecules that have four carbon and ten hydrogen atoms. These three hydrocarbons are lightweight gases. They tend to float to the top of petroleum and escape into the air. When trapped and sealed below ground, they rise and form pockets of natural gas sitting on top of the bil.
Some of the propane in the light mixture is piped off with this natural gas. But we cannot afford to burn up all of it as a fuel. Lots of propane is needed to perform dozens of useful chores behind the scenes of industry. It performs most of these duties with the help of butane and ethane and often other 1 ight hydrocarbons from petroleum. Propane is one of the invisible ingredients needed to make acetone for removing paint and to make antifreeze for autos. It also helps to supply hospitals with ether and chloroform and to make certain inks. Propane also is used to make dozens of up ¬to the minute plastics. It is used to make the vinyl on the kitchen floor and in your plastic raincoat.
In the past, most of our precious propane was burned as fuel gas. It is easy to chill it to its liquid state and ship it around sealed in sturdy metal bottles. Then our clever chemists beF:::.7 discovering new recipes for making more and more fascinating 20th century plastics. They found many of their ingredients among the hydrocarbon chemicals. And one of the most useful plastic making ingredients is propane.