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Fatty acids from Palm Oil Tree

Transcript of Fatty Acids

Cognis CollegeFatty acids

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F32 Fatty acids

Contents1. Occurrence of the fatty acids 2. Chemical structure 3. Properties of the fatty acids 4. Reference numbers of the fatty acids 5. Extraction of the fatty acids 6. Technical variations and specialties 7. Application areas 8. Market data 9. Trade Names at Cognis 10. 21 3 4 7 8 9 13 17 18 20 Keywords

F32 Fatty acids

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F32 Fatty acids

Chapter 1 Occurrence of the fatty acidsFatty acids are a component of the natural oils and fats. They are esterified with glycerine and form triglycerides.glycerine partH2

fatty acid part

o

c c c

o o o

co

R

H

co

R

H2Fig.. 1

c

R

Structure of the fatty acids

The percentage of fatty acids in the oils and fats is different from resource to resource. Coconuts or palm kernels deliver mainly C12 / C14, tallow or palm oil mainly C16 / C18, for example. The most important fatty acids in oleochemicals are found in the following natural oils and fats:C-chain distribution and quantityC8 C10 C12 C14 C16 C18 C20 C22 coconut palm kernel tallow palm oil rape rich poor sunflower soyaFig. 2

8 4

7 5

48 50

17 15 4 2

9 7 30 42 2 4 6 8

10 18 65 56 38 90 93 91 7 2 1 50 3

C-chain distribution in natural oils and fats

F32 Fatty acids

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Chapter 2 Chemical structureFatty acids belong to the chemical group of the carboxylic acids. The carboxylic acids are characterized by a carboxylic (or carboxo) group (COOH) that is attached to a hydrocarbon chain (abbreviated R). The carboxylic group is responsible for the acidic effect of these substances, because it is able to set free a hydrogen ion (H +) when solved in water.

carboxylic acids carboxylic group: consists carbonyl of group: hydroxylFig. 3

O R C O H

O C O H

O C O H

Structure of the carboxylic acids

The chemical name "carboxylic acid" is derived from the basic hydrocarbon to which the addition "acid" is connected to. The following table shows a carboxylic acid that is very important in oleochemicals:lauric acid, C12H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H O C O H

carbon chainFig. 4 Structure of the lauric acid

acid group

From the number of 4 carbon atoms in the hydrocarbon chain on, the carboxylic acids are called fatty acids. Fatty acids from natural oils or fats are always even-chained and have got an even number of carbon atoms. This is due to the elongation process that takes place in plants. A difference is made between saturated and unsaturated fatty acids. Saturated fatty acids contain only single bonds (C-C) in their hydrocarbon chain.

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F32 Fatty acids

Unsaturated fatty acids contain at least one double bond in their hydrocarbon chain (C=C). If more than one double bond exists, they are called multiple (double, triple etc.) unsaturated fatty acids. Here are examples of the C18 fatty acids (fatty acids with 18 carbon atoms):C 18 fatty acid, saturated stearic acid (octadecanoic acid) C17 H35 COOHH H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H H C H O C O H

C 18 fatty acid, single unsaturated oleic acid (octadecenoic acid) C17 H33 COOHH H C H H C H H C H H C H H C H H C H H C H H C H H C H C H C H H C H H C H H C H H C H H C H H C H O C O H

C 18 fatty acid, double unsaturated linoleic acid (octadecadienoic acid) C17 H31 COOHH H C H H C H H C H H C H H C H H C H C H C H H C H C H C H H C H H C H H C H H C H H C H H C H O C O H

C 18 fatty acid, triple unsaturated linolenic acid (octadecatrienoic acid)H H C H H C H H C H C H C H H C H C H C H

C17 H29 COOHH C H C H C H H C H H C H H C H H C H H C H H C H O C O H

Fig. 5

C 18-fatty acids

Apart from the chemical names there exist so-called trivial names of the fatty acids as well. These names were introduced most often with the discovery of the fatty acids. The dodecanoic acid for example was first found in the fruits of the laurel tree (Latin: Laurus nobilis) and was thus called lauric acid. In the oleochemical terminology still the trivial names are most often used. The most important fatty acids are the following: Saturated fatty acids C6 C8 C 10 C 12 C 14 C 16 C 18 Hexanoic acid Octanoic acid Decanoic acid Dodecanoic acid Tetradecanoic acid Hexadecanoic acid Octadecanoic acid Caproic acid Caprylic acid Caprinic acid Lauric acid Myristic acid Palmitic acid Stearic acid

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C 20 C 22 C 24

Eicosanoic acid Docosanoic acid Tetracosanoic acid

Arachidic acid Behenic acid Lignoceroic acid

Unsaturated fatty acids (number of double bonds /.) C 18 / 1 C 18 / 2 C 18 / 3 C 20 / 1 C 20 / 4 C 22 / 1 C 22 / 5 Octadecenic acid Octadecadienoic acid Octadecatrienoic acid Eicosenoic acid Eicosatetraenoic acid Docosenoic acid Docosapentanoic acid Oleic acid Linoleic acid Linolenic acid Gadoniloic acid Arachidic acid Erucic acid Clupanodonic acid

The ricinoleic acid is in a special position. It is a single unsaturated fatty acid that attaches a hydroxyl group (OH) to a C-atom. Castor oil contains 87 % of the ricinoleic acid that has the chemical name 12-OxyOctadecenic acid.Ricinoleic acidH H C H H C H H C H H C H H C H H C H H O C H H C H H C H C H C H H C H H C H H C H H C H H C H H C H O C O H

C17 H32 OH COOHFig. 6 Structure of the ricinoleic acid

To this additional hydroxyl group one can add for example ethylene oxide to get an emulsifier such as Eumulgin RO40.

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F32 Fatty acids

Chapter 3 Properties of the fatty acidsPure fatty acids are colorless substances. Their melting point rises with the increasing chain length, the unsaturated fatty acids have got a lower melting point (mp) than the saturated ones. In the oleo chemistry the solidification point (called Titer with fatty acids) is indicated which is usually a little lower than the melting point.fatty acids capronic acid caprylic acid capric acid lauric acid myristic acid palmitic acid stearic acid oleic acid erucic acid linoleic acid linolenic acidFig. 7

length C6 C8 C10 C12 C14 C16 C18 C18/1 C22/1 C18/2 C18/3

Titer/C -3,4 16 31,3 43,5 54,4 62,9 69,6 13,4 34,7 -5,0 -11

mp/C 4 17 31 43 54 63 71 16 34 -5 -11

Solidification points of the fatty acids

Even the boiling points increase with the rising chain length. By the raising of number of double bonds the boiling point decreases again. Not every acid can be measured at usual atmospherically pressure (1013 mbar). For some boiling points (Bp) one has to lower the pressure and get degrees of centigrade in vacuum. Therefore the figures /mbar are added. Otherwise the acids are cracked before they can reach the boiling points.fatty acid capronic acid caprylic acid Capric acid lauric acid myristic acid palmitic acid stearic acid oleic acid erucic acid linoleic acid linolenic acidFig. 8

length C6 C8 C10 C12 C14 C16 C18 C18/1 C22/1 C18/2 C18/3

Mp/C 4 17 31 43 54 63 71 16 34 -5 -11

Bp/C/mbar 101/1013 239/1013 270/1013 225/133 250/133 272/133 291/133 229/20 225/13 230/21 232/23

Boiling points of the fatty acids

The viscosity of the fatty acids rises as well with the increasing chain length and falls with the increasing number of double bonds. Fatty acids are soluble in organic solvents (e.g. alcohol, gasoline etc.). The solubility gets worse with the increasing chain length, but a higher temperature can compensate this. Water and fatty acids are only hardly soluble at room temperature; the short chain fatty acids have an advantage over the long chain.

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Chapter 4 Reference numbers of the fatty acidsThe reference numbers of the fatty acids are part of the quality specification. They are measured after the instructions of the Deutschen Gesellschaft fr Fettchemie (DGF) (German Society for Oleo chemistry) and they allow a clear characterization of the products. Since no 100 % clean fatty acid from natural oils and fats exists and since many products contain a mixture of fatty acids depending on the raw material (e.g. coconut oil fatty acid) it is important to indicate the distribution of the C-chains in percent. This C-chain spectrum (see Fig. 2) is measured after DGF C-VI 10 with the help of the gas chromatography or other chromatographically methods (such as HPLC).entry of sample separator tubeFig. 9

recorder detector

Schematic drawing of a gas chromatograph

Apart from the C-chain distribution a couple of other chemical and physical parameters are measured that serve the purity control of technical fatty acids. The iodine value indicates the amount of unsaturated components. The higher the iodine value, the more double bonds. Most often the measuring of the bromide value is carried out after Kaufmann (DGF C-V 11 d). The acid value (DGF C-V 2) indicates the amount of free fatty acids, measured in mg KOH, that are necessary to neutralize 1g of the test substance. The saponification value (DGF C-V 3) is a measure for the free and bound fatty acids in the test substance. It indicates the amount of mg KOH that are necessary to saponify 1 g of the substance.SAPONIFICATION VALUE: SV -> free fatty acids -> fatty acids bound to glycerine

Definition: SV indicates how many mg KOH are necessary for the saponification of 1g fat / oil. -> free fatty acids Definition: AV indicates how many mg KOH are necessary to neutralize the free fatty acids in 1g of fat / oil. -> inner esters Definition: EN indicates how many mg KOH are necessary for the saponification of the esters in 1g of fat / oil.

ACID VALUE: AV

ESTER VALUE: EV

SV -