Groups of oils
Fatty oils (referred to as sweet oil during sea transport) are fats , i.e. mixtures of fatty acid triglycerides that are liquid at room temperature. The low melting range is mainly caused by a high proportion of unsaturated or polyunsaturated fatty acids .
- Many vegetable oils (such as linseed oil , sunflower oil , olive oil , safflower oil ) are used, among other things, as food and are therefore also known as edible oils . Vegetable oils are also used as fuel, either in their natural state or in interesterified form as biodiesel . They are used as binders in oil paints .
- Animal oils (such. B. Tran , cod liver oil ) are sometimes used as food and find similar and vegetable oils used in the chemical industry , for example. B. as a raw material for the production of soaps .
Fatty oils can also be used as food grade lubricating oils in the food industry. They are also used as a biodegradable alternative to lubricants made from mineral oil, for example for the lubrication of drive chains or saw chains in the great outdoors.
Essential oils are oily, steam-volatile extracts from plants or parts of plants which, depending on the plant of origin, have a strong characteristic odor. They mostly consist of terpenes (examples: lemon oil , rose oil ).
Mineral oils are obtained from petroleum or coal and are hydrocarbon compounds . Chemically speaking, most of the compounds in the substance mixtures belong to the alkane group , straight-chain or branched. In addition to alkanes, most crude oils also contain aromatics , and often sulfur-containing organic chemical compounds.
Mineral oils are preferably used as an energy source and converted into fuel (" refined "). They are therefore one of the most important energy sources of our civilization (for example heating oil , diesel oil , heavy oil ). Mineral oils also serve as lubricating oil to avoid direct wear contact between moving surfaces, and as impregnating and separating agents ( white oil ).
So-called " synthetic oils " are also based on petroleum refinates and have a special molecular structure that does not occur in crude oil. Are synthetically produced hydrocarbons added. The assumption that synthetic oils are produced chemically and only contain substances that do not occur in nature is therefore incorrect.
" Silicone oils " are based on polymers and copolymers made from silicon - oxygen units and organic side chains. Silicone oil is relatively insensitive to oxidation , heat and other influences. It is used as a component of cosmetics, as a defoamer and lubricant. In the chemical laboratory, silicone oil is used as a heat transfer fluid .
- as a lubricant, see lubricating oil
- as a drug and drug ingredient; see Essential Oils # Medicine and Naturopathy
- Fuel / fuel : diesel fuel , heating oil
- Manufacturing oil
- Hydraulic fluid
- Solvents : There are many non-polar substances that dissolve well in oil. This is used in technical production processes and in food production.
- Thermal oils are used in heat transfer systems to transfer thermal energy ( heat transfer medium ). It is heated in heaters and transported via pipelines to the places where a product has to be heated. This takes place in a closed cycle . The big advantage of thermal oil over water is the significantly higher boiling point. In this way a temperature of over 300 ° C can be reached. Thermal oil can be made from synthetic oils as well as organic oils.
- Cutting oil is a non-water-miscible cooling lubricant to improve machining processes.
- Wave calming oil was used in shipping to reduce the waves on the high seas.
- Hardening oil is used as a quenching medium when hardening metals. Here the cooling rate is slower than when quenching with water.
- Under an oils are understood in the German-speaking Switzerland , a oil mill .
- Oil and water can be mixed with the help of surfactants (emulsifiers). It formed emulsions . Some foods are natural emulsions: (a) Milk is an emulsion of oil in water. (b) Butter is an emulsion of water in oil or fat .
- Fatty oils can be converted into solid fats ( margarine ) by hydrogenation (fat hardening) of the unsaturated fatty acids .
- The expression “It goes down like oil” describes the “ finish ” of beer, compare Danish l or English ale , but can also mean that a compliment is kindly acknowledged.
- M. Bockisch: Food fats and oils - Handbook of food technology. Eugen Ulmer Verlag, Stuttgart 1993, ISBN 3-8001-5817-5 .