Vegetable oil refining
Encyclopedia
Vegetable oil can be used as feedstock for an oil refinery
. There it can be transformed into fuel by hydrocracking (which breaks big molecules into smaller ones using hydrogen) or hydrogenation
(which adds hydrogen to molecules). These methods can produce gasoline
, diesel, and propane
. Some commercial examples of vegetable oil refining are NExBTL
, H-Bio
, and the ConocoPhilips process.
The majority of plant and animal oils are vegetable oils which are triglycerides and that is the type of oil these processes use. One type of algae, Botryococcus braunii
produces a different type of oil
, known as a triterpene
, which is transformed into alkanes by a different process.
is known as transesterification
. Vegetable oil and alcohol
are reacted, producing esters, or biodiesel, and the coproduct, glycerol
.
When refining vegetable oil, no glycerol is produced, only fuels. Refined diesel can be produced that is chemically identical to diesel fuel and does not have the problems specific to transesterified biodiesel. Any blending ratio can be used, and no modifications or checks are required for any diesel engine.
Oil refinery
An oil refinery or petroleum refinery is an industrial process plant where crude oil is processed and refined into more useful petroleum products, such as gasoline, diesel fuel, asphalt base, heating oil, kerosene, and liquefied petroleum gas...
. There it can be transformed into fuel by hydrocracking (which breaks big molecules into smaller ones using hydrogen) or hydrogenation
Hydrogenation
Hydrogenation, to treat with hydrogen, also a form of chemical reduction, is a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically...
(which adds hydrogen to molecules). These methods can produce gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...
, diesel, and propane
Propane
Propane is a three-carbon alkane with the molecular formula , normally a gas, but compressible to a transportable liquid. A by-product of natural gas processing and petroleum refining, it is commonly used as a fuel for engines, oxy-gas torches, barbecues, portable stoves, and residential central...
. Some commercial examples of vegetable oil refining are NExBTL
NExBTL
NExBTL is a renewable diesel production process commercialized by the Finnish oil and refining company Neste Oil. Whether as an admixture or in its pure form, NExBTL is able to supplement or partially replace diesel fuel without problems...
, H-Bio
H-Bio
H-Bio is an oil refinery process developed in Brazil by the state run oil company Petrobras for refining vegetable oil into standard petroleum products. The process uses hydrogenation to add hydrogen to molecules....
, and the ConocoPhilips process.
The majority of plant and animal oils are vegetable oils which are triglycerides and that is the type of oil these processes use. One type of algae, Botryococcus braunii
Botryococcus braunii
Botryococcus braunii is a green, pyramid shaped planktonic microalga that is of potentially great importance in the field of biotechnology. Colonies held together by a lipid biofilm matrix can be found in temperate or tropical oligotrophic lakes and estuaries, and will bloom when in the presence...
produces a different type of oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
, known as a triterpene
Triterpene
Triterpenes are terpenes consisting of six isoprene units and have the molecular formula C30H48.The pentacyclic triterpenes can be classified into lupane, oleanane or ursane groups.Animal- and plant-derived triterpenes exist, such as:*squalene...
, which is transformed into alkanes by a different process.
Comparison to biodiesel
The chemical reaction commonly-used to produce biodieselBiodiesel
Biodiesel refers to a vegetable oil- or animal fat-based diesel fuel consisting of long-chain alkyl esters. Biodiesel is typically made by chemically reacting lipids with an alcohol....
is known as transesterification
Transesterification
In organic chemistry, transesterification is the process of exchanging the organic group R″ of an ester with the organic group R′ of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst...
. Vegetable oil and alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
are reacted, producing esters, or biodiesel, and the coproduct, glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
.
When refining vegetable oil, no glycerol is produced, only fuels. Refined diesel can be produced that is chemically identical to diesel fuel and does not have the problems specific to transesterified biodiesel. Any blending ratio can be used, and no modifications or checks are required for any diesel engine.