Hydrogenation is a chemical reaction in which hydrogen (H₂) is added to a compound, typically an unsaturated hydrocarbon, to convert it into a saturated hydrocarbon. This process involves the addition of hydrogen atoms to the double or triple bonds of alkenes or alkynes, thus converting them into alkanes.
Process:
1. Reaction with Alkenes:
When an alkene, such as ethene (C₂H₄), reacts with hydrogen in the presence of a catalyst (usually nickel, platinum, or palladium), the double bond breaks, and hydrogen atoms are added across the double bond to form an alkane. Example:
C₂H₄ + H₂ → C₂H₆ (Ethene + Hydrogen → Ethane)
2. Reaction with Alkynes:
Alkynes undergo similar hydrogenation, where the triple bond is reduced to a double bond and then to a single bond (in the case of excess hydrogen).Example:
C₂H₂ + 2H₂ → C₂H₆ (Ethyne + Hydrogen → Ethane)
Industrial Applications:
- Food Industry: Hydrogenation is widely used in the food industry to convert liquid vegetable oils into solid fats, such as margarine and shortening. This process improves the shelf life and texture of these products.
- Petroleum Industry: Hydrogenation is used in the refining of petroleum to produce cleaner, more stable fuels like gasoline. It also helps remove impurities such as sulfur.
- Manufacturing of Plastics: Hydrogenation is used in the production of various types of plastics, particularly in creating more stable and durable polymers.