Hydrogenation

Many of the carbon compounds found in crude petroleum are of little use. These compounds may contain multiple bonds, but can be converted to saturated compounds by catalytic hydrogenation. This is one source for much of the gasoline that we use today. Other chemicals besides gasoline are made from petroleum, and for these, too, the first step from crude oil may be hydrogenation.

Another commercial use of the hydrogenation reaction is the production of fats and oils in more useful forms. Fats and oils are not hydrocarbons, like the simple molecules we have been looking at, since they contain oxygen atoms, too. But they do contain long chains of carbon and hydrogen, joined together in part by carbon-carbon double bonds. Partial hydrogenation of these molecules, so that some, but not all of the double bonds react, gives compounds with different cooking characteristics, more satisfactory for consumers in some situations than the original oils. This is the source of the "partially hydrogenated vegetable oil" on the grocery shelf.