How do Solvents Work
Solvents are liquids that are used to dissolve other substances. Water, for example, is a solvent and can dissolve many things, but it cannot dissolve oily/greasy substances. Solvents work on the principle of "like dissolves like" e.g. solvents are chemically much more similar to greases than water and can therefore dissolve them more effectively.
Organic solvents can be classified into three groups based on their chemical structure:
- Oxygenated solvents - substances like alcohols, ketones, esters, and glycol ethers fall into this category. These types of solvents are used when high solvency power is needed. They can also be used for water-based formulations such as detergents and water-based paints.
- Hydrocarbon solvents - these are paraffinic, aliphatic and aromatic hydrocarbons. They are typically used in applications where there is low solvency power and good separation from water is required.
- Halogenated solvents - this category consists of chlorinated hydrocarbon solvents.
An organic solvent contains carbon molecules - one of the basic building blocks of life. Water is also a solvent, but is classified as inorganic because its chemical structure does not contain carbon.
How are solvents made?
With the exception of alcohol, all solvents are produced from oil. The amount of oil used for solvent production is, however, relatively low. Only about 1 - 2% of the world's oil production is used in solvent production. Many solvents are also recycled so that they can be used again.