FR2920768A1 - Co-production of olefins and esters or acids, comprises synthesizing ethanol by fermentation, dehydrating the ethanol to produce ethylene and water mixture, and carrying out unsaturated fatty body or ester, ethylene and catalyst - Google Patents

Abstract

Process for co-production of olefins and esters or acids, comprises: (a) synthesizing ethanol by fermentation of at least a plant material; (b) dehydrating the obtained ethanol to produce ethylene and water mixture; and (c) contacting unsaturated fatty body comprising mono or dicarboxylic fatty acid (consisting at least an ethylenic unsaturation), or ester formed between mono or dicarboxylic fatty acid (consisting of ethylenic unsaturation and aliphatic monoalcohol or aliphatic polyol), excess ethylene produced in step (b), and catalyst, in metathesis condition.

Description

The present invention relates to a process for the co-production of olefins and esters or acids from renewable raw materials. More specifically, the subject of the invention is a process for the co-production of olefins and esters or of acids by a metathesis reaction starting from unsaturated fatty substances, for example vegetable oils or their esters. and on the other hand ethylene obtained by dehydration of an alcohol such as ethanol derived from the fermentation of vegetable matter. Vegetable matter has the advantage of being able to be grown in large quantities, depending on the demand, on most of the terrestrial globe and to be renewable.

The metathesis reaction of olefins is a well-known reaction of organic chemistry. This reaction, which is carried out in the presence of a suitable catalytic system, consists of the exchange of alkylidene groups between two olefins according to the following equations: 1. First case, called "self metathesis" or "homometathesis" (c ') that is, metathesis of an olefin molecule on a molecule of the same olefin): 2R1CH = CHR2 c-> RICH = CHRI + R2CH = CHR2

2. Second case, called "cross-metathesis" or "cross-metathesis" (that is, metathesis between two different olefins): R1CH = CHR2 + R3CH = CHR4 c-> R1CH = CHR3 + R1CH = CHR4 + R2CH = CHR3 + R2CH = CHR4

The metathesis reaction of olefins is a balanced reaction. It can occur in the presence of a large variety of catalysts, most often based on transition metals of groups IVA to VIII, among which tungsten, molybdenum, rhenium and ruthenium, either in homogeneous phase, or in heterogeneous phase. Many journals and scientific books deal with this aspect. For example, K. J. Ivin and J. C. Mol in "Olefin Metathesis and Metathesis Polymerization", San Diego, Academic Press (1997);

"Handbook of Metathesis" R. H. Grubbs (Ed) Wiley-VCH, Weinheim (2003); J .C. Mol "Industrial Applications of Olefin Metathesis" J. Mol. Catal. 213, 39 (2004);

D. Séméril and PH Dixneuf, in "Novel Metathesis Chemistry: Well-Defined Initiator Systems for Specialty Chemical Synthesis, Tailored Polymers and Advanced Material Applications" Y. Imamoglu and L. Bencze (Eds) Kluwer Academic Publishers, The Netherlands (2003) 1 -21.

If one of the olefins is an unsaturated fatty acid ester, represented for example by methyl oleate, the reaction leads to the production of one or more olefins and one or more unsaturated esters. The reaction can be written as: CH3 (CH2) 7CH = CH- (CH2) 7000CH3 + R, CH = CHR2 c-> CH3 (CH2) 7CH = CHR1 + R2CH = CH- (CH2) 7000CH3 + CH3 (CH2) 7CH = CHR2 + R1CH = CH- (CH2) 7000CH3 When the olefin R1 HC = CHR2 is ethylene and is used in excess sufficient to shift the equilibrium, the reaction can lead to an alpha-olefin and an unsaturated ester, which are, in the particular case envisaged, decene-1 and 9-decenoate methyl. The particular reaction can be written: CH3 (CH2) 7CH = CH- (CH2) 7000CH3 + (excess) CH2 = CH2 c-> CH3 (CH2) 7CH = CH2 + CH2 = CH- (CH2) 7000CH3

This reaction is potentially of great interest, since it makes it possible to envisage the manufacture from a raw material essentially of plant or animal origin, hence renewable, products such as an alpha-olefin, in which the particular case envisaged decene-1, which is a sought-after intermediate for petrochemicals, usually entirely manufactured from raw materials such as ethylene. This metathesis reaction by ethenolysis applied to fatty acid esters has been reported in numerous publications or scientific journals. As examples, among the most recent references are:

"Application of Olefin Metathesis in Oleochemistry: An Example of Green Chemistry" by J. C. Mol, Green Chemistry, 4, 5-13 (2002); The Metathesis of Polyunsaturated Fatty Esters Using the Homogeneous W (O-2,6-C6H3X2) 2C14 / Me4Sn Catalyst Systems by B. B. Marvey et al. J. Mol. Catal. 213, 151-157 (2004); "Technological and Economical Aspects of the Metathesis of Unsaturated Esters" by M. Sibeijn et al. JAOCS, 71, 6 (1994);

"Polymer and Surfactants on the Basis of Renewable Resources" by S. Warwel et al. Chemosphere 43, 39-48 (2001);

"Catalysis Metathesis of Unsaturated Fatty Acid Esters and Oils" by J. C. Mol, Topics in Catalysis, 27, 1, (2004).

To date, no one has been interested in the industrial manufacturing processes of the gaseous carbon source, namely ethylene upstream of the co-production of olefins and ester by metathesis. The process used primarily for the manufacture of gaseous carbon sources such as gaseous hydrocarbons is based on the high temperature cracking of the oil. This process requires high temperatures (at least 800 ° C) is very energy intensive, and further requires a complex and expensive separation of ethylene from other co-products. This type of process becomes economically viable only for very large units increasingly delocalised near the gas or oil producing sites, where the energy is cheap. In addition, it implements oil whose deposits are depleted rapidly; its extraction is increasingly difficult (wells of great depths), requiring heavy and expensive equipment, having to withstand high temperatures (400-500 ° C). The cost of manufacturing cracking gases is increasing day by day, which goes against the mass production of olefin and metathesis esters at low cost, which is essential to ensure commercial outlets in applications. putting these products into play. The method according to the invention makes it possible to overcome the consumption of oil, to reduce energy consumption, and to use gaseous sources derived from the cultivation of plants. In addition to the advantages mentioned above, the method for co-producing olefins and esters or acids according to the invention makes it possible to significantly improve productivity. It also allows a lower manufacturing cost and a favorable energy balance. On the other hand, all the carbons present in the final molecule are of renewable origin. Production units using ethenolysis are sized by the amount of oil to be treated, and are therefore small consumers of ethylene. Olefin production by dehydration of ethanol is particularly suitable for small delocalised production. An advantage of the olefin coproduction by dehydration of ethanol and the production of esters or acids according to the invention is a very good scale integration of the two processes. The invention relates to a process for the co-production of olefins and esters or acids comprising the following steps: a) the synthesis of ethanol by fermentation of at least one plant material; b) dehydrating the ethanol obtained in a) to produce a mixture of ethylene and water; and c) bringing into contact, under metathesis conditions, at least: an unsaturated fatty substance comprising at least one mono- or dicarboxylic fatty acid comprising at least one ethylenic unsaturation or at least one ester formed between at least one fatty acid; mono or dicarboxylic having at least one ethylenic unsaturation and at least one aliphatic monoalcohol or at least one aliphatic polyol, - excess ethylene produced in step b), and a catalyst.

In the process of the invention, the fatty acid can be treated either in its acid form or in its ester form. The passage from one form to the other is carried out by methanolysis, esterification or hydrolysis. For the sake of simplicity, the remainder of the description will be directed primarily to the ester, knowing that the reaction is immediately transposable to the acid. Similarly, the reaction applies to both monocarboxylic fatty acids and diacids. These can be produced either by fermentation or by homometathesis of unsaturated carboxylic acids. For the sake of ease of presentation, the remainder of the description will be directed mainly to monoacid or monoester.

The first step of the process according to the invention comprises the fermentation of at least one plant material to produce ethanol. This plant material may especially be chosen from sugars, starch and plant extracts containing it, among which may be mentioned beet, sugar cane, cereals such as wheat, barley, sorghum or wheat. corn, as well as the potato, without this list being exhaustive. It can alternatively be biomass (mixture of cellulose, hemicellulose and lignin). Then, by fermentation, for example with the aid of Saccharomyces cerevisiae, ethanol is obtained. The plant material used is generally in hydrolysed form before the fermentation stage.

This preliminary hydrolysis step thus allows, for example, the saccharification of starch to transform it into glucose, or the transformation of sucrose into glucose. These fermentation processes are well known to those skilled in the art. They include for example the fermentation of vegetable matter in the presence of one or more yeasts, followed by distillation to recover ethanol as a more concentrated aqueous solution which is then treated to further increase its molar concentration. ethanol. In the second step of the process according to the invention, the ethanol obtained by fermentation is dehydrated preferably in a first reactor in a mixture of alkene and water. It is preferred that the ethanol is injected at the top of the first reactor.

This dehydration step is generally carried out in the presence of a catalyst, which may in particular be based on yumalumine in the case of ethanol. An example of a catalyst suitable for the dehydration of ethanol is in particular marketed by the company EUROSUPPORT under the trade name ESM 110. It is an undoped trilobal alumina containing little residual Na2O (usually 0.04%). Those skilled in the art will be able to choose the optimal operating conditions for this dehydration step. By way of example, it has been demonstrated that a ratio of liquid ethanol volume flow rate to catalyst volume of 1 hr and an average catalyst bed temperature of 400 ° C resulted in an almost total conversion of the catalyst. ethanol with an ethylene selectivity of the order of 98%. The ethylene obtained in this stage of the process according to the invention is intended to be used in excess in a metathesis reaction with a fatty substance.

The method of the invention is used to obtain particular compositions of products, which will be separated into several distinct fractions each having a different use. Stage c) of the process which is the subject of the invention is directed to any fatty substance comprising at least one mono- or dicarboxylic fatty acid or an ester formed between at least one mono or dicarboxylic fatty acid and at least one hydroxylated saturated aliphatic compound ( monoalcohol or polyol), the monoalcohol being for example an aliphatic monoalcohol of 1 to 8 carbon atoms, and a particular polyol being glycerol (case of unsaturated vegetable oils).

Step c) preferably takes place in a second reactor. The method which is the subject of the invention may furthermore comprise a step during which an olefinic fraction containing diolefins and monoolefins is separated off; and a composition containing esters or diacids. For the purposes of the present invention, the term "fatty acid" means a monocarboxylic or dicarboxylic acid comprising at least 10, preferably at least 12, or 14 carbon atoms and comprising at least one ethylenic unsaturation. Preferably, said fatty acid is a natural fatty acid derived from plant or animal media, including algae, more generally from the plant kingdom.

Examples of such acids include C 10 acids, obtusilic (cis-4-decenoic) acids, C 12 acids, lauroleic (cis-5-dodecenoic) and linderic (cis-4) acids. -dodecenoic), C14 acids, myristoleic (cis-9-tetradecenoic), physeteric (cis-5-tetradecenoic) and tsuzuic (cis-4-tetradecenoic) acids, C16 acid, palmitoleic acid (cis Hexadecenoic acid), C18 acids, oleic (cis-9-octadecenoic), elaidic (trans-9-octadecenoic), petroselinic (cis-6-octadecenoic), vaccenic (cis-11-octadecenoic) and ricinoleic acids (12-hydroxy-cis-9-octadecenoic), C20 acids, gadoleic (cis-9-eicosenoic), gondoic (cis-11-eicosenoic), cis-5-eicosenoic and acidic acids. lesquerolic (14-hydroxy-cis-11-eicosenoic), C22 acids, ketoleic (cis-11-docosenoic) and erucic (cis-13-docosenoic) acids. Examples of unsaturated diacids that may be mentioned are C12 diacids (5-dodecenedioic acid and 4-dodecenedioic acid), C14 diacids, (5-tetradecenedioic acid, 4-tetradecenedioic acid), C16 diacid (7-hexadecenedioic acid), C18 diacids ( 9-octadecenedioic, 6-octadecenedioic, 7-octadecenedioic and 7-hydroxy-9-octadecenedioic), diacids in C20 (9-eicosenedioic, 5-eicosenedioic and 7-hydroxy-9-eicosenoic), diacids in C22, ( 11-docosedioic and 9-docosenedioic).

These various acids are derived from vegetable oils extracted from various plants such as sunflower, rapeseed, castor oil, lesquerella, olive, soy, palm, coriander, celery, dill, carrot, fennel, the Limnanthes Alba (meadowfoam). They are also derived from the terrestrial or marine animal world, and in the latter case, both in the form of fish, mammals and algae. These are usually fats derived from ruminants, fish such as cod, or marine mammals such as whales or dolphins. More particularly, the process of the invention can be applied to esters of oleic acid, a fatty acid whose chain carries a single unsaturation. In this case, the ethenolysis reaction leads to the formation of only two products, decene-1 and a 9-decenoic acid ester. However, in nature there are no fatty substances of plant or animal origin whose fatty chains consist exclusively of oleic chains. Obtaining an ester of pure oleic acid therefore requires the use of a separation and purification operation. Similarly, for other unsaturated fatty acids that are all present as mixtures. If one of the olefins is a di-unsaturated fatty acid ester, such as a linoleic acid methyl ester and the other ethylene olefin, used in sufficient excess, the metathesis reaction will lead to obtaining an olefin, heptene-1, a di-olefin, pentadiene-1,4 and an unsaturated ester, methyl 9-decenoate.

The reaction can be written: ## STR3 ## In this reaction, it is assumed that the metathesis reaction by ethenolysis is complete, that is to say that all the unsaturations of the linoleate chain have reacted with ethylene used in excess. However, an incomplete metathesis reaction, i.e. involving only one of the two unsaturations of the linoleate chain, may lead to the following products: CH 3 (CH 2) 4 -CH = CH-CH 2 -CH = CH- ( CH2) 7-COOCH3 + CH2 = CH2 c-> CH3 (CH2) 4-5 CH = CH-CH2-CH = CH2 + CH2 = CH-CH2-CH = CH- (CH2), - COOCH3 The same may be applied reactions to all unsaturated chains of known fatty acids, for example linolenic tri-unsaturated acid chains. The number of potentially possible products will be all the more important as the

The number of unsaturations carried by the chain will be high. The metathesis reaction by ethenolysis may also apply, no longer to an unsaturated fatty acid monoalcohol ester, but to the corresponding triglyceride. The reaction could for example be written:

CH3 (CH2) 7-CH = CH- (CH2) 7-COOCH2CH3 (CH2) 7-CH = CH- (CH2) 7-OOCH + 1 3CH2 = CH2 aCH3 (CH2) 7-CH = CH- (CH2) 7-COOCH2 CH2 = CH- (CH2) 7-COOCH2

CH2 = CH- (CH2) 7-000CH + 3 CH3 (CH2) 4-CH = CH2

CH 2 = CH- (CH 2) 7 -COOCH 2 If this metathesis reaction is applied by ethenolysis, either to a single fatty acid chain, for example oleic or linoleic, as

25 previously, but to a mixture of these fatty acid chains, as is the case in reality when we are dealing with products of plant or animal origin, we will obtain a mixture of products from metathesis by ethenolysis of each of the fatty chains involved.

The nature of the products obtained, as well as their quantity, will therefore depend on the fatty acid composition (nature and abundance) of the fat raw material used.

Obtaining products rich in decene-1 involves for example the use of a raw material rich in oleic acid esters. In this case, the vegetable oil used (or the monoalcohol ester of this oil) is chosen from oleic sunflower oil or oleic rapeseed oil (or the monoalcohol esters of these oils). These particular oils and esters of monoalcohols derived from these oils are characterized by their fatty acid composition, in particular by the nature and the proportion of their unsaturated fatty acids. In these oils, the acids or in the monoalcohol esters of these acids, in general at least 80% of the fatty acid chains consist of oleic chains, the content of linoleic fatty chains does not exceed 12% and the content of linolenic fatty chains does not exceed 0.3%. No other olefinic chain is present in these oils or in the monoalcohol esters of these oils at a content greater than 0.3%, whereas the content of saturated chains, for example palmitic or stearic, is between 5% and 15%. / 0. These oils can be used in their natural triglyceride form or in the form of a mixture of monoalcohol esters, for example methanol, ethanol, propanol or, more generally, any monoalcohol containing from 1 to 8 carbon atoms. The reactions and the products formed are the following in the case of an ester of a monoalcohol represented for example by methanol of an oleic sunflower or oleic rapeseed oil: CH 3 (CH 2) 4 -CH = CH-CH 2 CH = CH- (CH2) 7-COOCH3 + CH3 (CH2) 7CH = CH- (CH2) 7000CH3 + (excess) CH2 = CH2 C-> CH3 (CH2) 4-CH = CH2 + CH2 = CH-CH2-CH = CH2 + CH2 = CH- (CH2) 7-COOCH3 + CH3 (CH2) 7CH = CH2

In all cases, the saturated fatty acid esters present in the oleic sunflower oil or the oleic rapeseed oil or in the monoalcohol esters of these oils are not reactive in the metathesis reactions and are recovered at the same time. end of the operation. They are not represented here in the equations.

In all cases, when the metathesis reaction is complete, the products obtained can be classified into four families: alphaolefin-type monoolefins: decene-1 and heptene-1; a diolefin, 1,4-pentadiene; unsaturated esters, whether in the form of 9-decenoate of monoalcohol or in the form of triglyceride of 9-decenoic acid; the saturated esters present in the raw material and which are not affected by the metathesis reaction. If the metathesis reaction is not complete, there will be added to these products esters of residual oleic and linoleic acids in the form of monoalcohol esters or in the form of triglycerides. The process according to the present invention may comprise a step of separating olefins by evaporation. Indeed, it is easy to separate the monoolefins (pa r example decene-1 and hepten-1) and diolefin (pentadiene-1,4) from the reaction medium by evaporation, their respective boiling temperatures being 166.5 ° C. 94 ° C and 26 ° C, therefore much lower than that of esters present and formed. In the process according to the present invention, the previously isolated olefin mixture can then be subjected to distillation to separate 1,4-pentadiene, 1-heptene and 1-decene, as well as any excess ethylene. The excess ethylene can be reused in a new metathesis reaction, while each of the other mono- (or di-) olefins can be recovered and used separately. After evaporation of the pure olefinic fraction (mono- and di-olefins), the residual reaction medium contains accordingly a mixture of esters, that is to say an ester of 9-decenoic acid in the form of monoalcohol or in the triester form of glycerol, depending on the raw material used (oil or monoalcohol ester of this oil), and also the esters of saturated acids present in the raw material, that is to say the esters of palmitic acids and stearic in the form of monoalcohol esters or triesters of glycerol, depending on the raw material used. These saturated structures are not concerned by the metathesis reaction. This ester fraction can be defined by its composition, which results from the composition of the oil or the mixture of esters of monoalcohol oil used initially. From an oil as defined above (oleic sunflower oil or oleic rapeseed oil) or a mixture of monoalcohol esters of one of these oils, the composition of mono- and di-olefins may be be as indicated below. By metathesis reaction of oleic sunflower oil or oleic rapeseed oil or their monoalcohol esters with ethylene, used in excess, it is possible to obtain in isolation: on the one hand, an olefinic fraction containing predominantly (ie at least 80%) decene-1, as well as hepten-1 and pentadiene-1,4; and on the other hand, a monoalcohol ester composition or glycerol rich in C10 unsaturated acid ester. From an oil of which more than 80% of the fatty chains consist of oleic acid or a mixture of monoalcohol esters of such an oil, a metathesis reaction by ethenolysis will lead, if the yield of this reaction is at least 80%, on the one hand, with an olefinic fraction predominant in decene-1; and secondly, after removal by evaporation of the mono- and di-olefins, a mixture of esters of which more than half of the chains will consist of unsaturated C10 chains. Such a composition does not correspond to any known fatty substance.

Such a mixture of esters is characteristic in that its concentration of unsaturated C10 chains is very high. It is also characterized by the position of the unsaturation located between the carbon atom in position 9 and that in position 10 on the carbon chain. This position of unsaturation is different from that observed in natural products.

For example, a methyl ester of an oleic sunflower oil whose composition is as follows: methyl oleate: about 83% by weight, methyl linoleate: about 10% by weight, methyl palmitate: about 3% by weight mass, methyl stearate: about 4% by weight.

When the metathesis reaction is complete - that is to say when each unsaturation carried by the fatty chains has reacted with one mole of ethylene according to the reaction scheme described above - it will lead to a mixture having the following composition: decene -1: about 35.8% by weight, heptene-1: about 3.0% by weight, pentadiene-1,4: about 2.1% by weight, methyl 9-decenoate: about 52.7% by weight methyl palmitate: about 2.75% by weight, methyl stearate: about 3.65% by weight.

An evaporation operation at a temperature below 180 ° C. will make it possible to isolate an olefinic fraction having the following composition: decene-1: about 87.5% by mass 1-heptene: about 7.3% by weight pentadiene-1 , 4: about 5.1% by weight. These compounds can be separated by distillation in a subsequent step according to known methods. The unvaporated ester fraction will have the following composition methyl 9-decenoate: about 89.2% by weight methyl palmitate: about 4.6% by weight methyl stearate: about 6.2% by weight

If the raw material used is oleic sunflower oil in its triglyceride form, the olefinic fraction will be comparable and the esters obtained will be of triglyceride type instead of being in the form of methyl ester. In this case, for the same reaction yield, the fatty acid compositions will be very little different. Thus, in a particular embodiment of the invention, an unsaturated fatty substance selected from oleic sunflower oils and oleic rapeseed oils is subjected to the metathesis reaction to produce both an olefinic fraction and a glycerol ester composition of which at least a part of the chains consists of unsaturated C10 chains. Alternatively, the unsaturated fatty substance selected from the mixtures of monoalcohol esters of oleic sunflower oils and oleic rapeseed oils is subjected to the metathesis reaction, to produce both an olefinic fraction and a composition of monoalcohol esters of which at least a part of the chains consists of unsaturated C10 chains. In the case of a mixture of esters of a monoalcohol different from methanol, the mass ratio between the olefinic and ester fractions will depend on the molar mass of the monoalcohol considered; however, the molar ratio between the products obtained will remain the same, since it depends only on the yield of the reactions.

By total or partial hydrogenation of the unsaturations, such a mixture will lead to a mixture of esters whose composition is comparable to that of coconut oil or palm kernel or their derived esters, in the sense that the majority of the chains are saturated and with a carbon number of less than 12. Known and possible applications of these oils - which are not grown on a large scale in Europe - or their derivatives may be considered for ester fractions derived from metathesis of the oils of the invention or their monoalcohol esters. These applications concern especially the manufacture of soaps by saponification, the manufacture of fatty acids by hydrolysis, etc. Decene-1 is a highly sought-after synthetic intermediate. He is involved in the manufacture of poly alpha olefins, which are synthetic lubricants, as well as in the preparation of alcohols and in many other manufacturing processes in industrial chemistry.

Heptene-1 and pentadiene-1,4 are synthetic intermediates generally derived from the cracking of petroleum cuts or coal. By the method according to the invention, these compounds are therefore accessible, not only from raw material of fossil origin, but mainly or completely from renewable raw materials derived from biomass, such as oleic sunflower oil or oleic rapeseed oil on the one hand, and ethylene on the other hand. For example one mole of decene-1 can be obtained from a fatty acid chain and half a mole of ethylene. The catalysts used in the process of the invention, in step c), to carry out the metathesis reaction of the unsaturated fatty substances with excess ethylene can consist of any known metathesis catalyst and in particular catalysts comprising at least one least one ruthenium compound. The ruthenium catalysts are preferably selected from filled or uncharged catalysts of the general formula: (X1) a (X2) bRu (carbene C) (L1) c (L2) d wherein: • a, b, c, d are integers with a and b equal to 0, 1 or 2; c and d are 0, 1, 2,3 or 4; X1 and X2, identical or different, each represent a mono- or multi-chelating ligand, charged or not; by way of examples, mention may be made of halides, sulphate, carbonate, carboxylates, alcoholates, phenates, amides, tosylate, hexafluorophosphate, tetrafluoroborate, bis-trifluoride, tetraphenylborate and derivatives. X1 or X2 may be bonded to Y1 or Y2 or (carbene C) to form a bidentate ligand (or chelate) on ruthenium; and L1 and L2, which are identical or different, are electron donor ligands such as a phosphine, phosphite, phosphonite, phosphinite, arsine, stilbine, an olefin or an aromatic, a carbonyl compound, an ether, an alcohol, an amine, a pyridine or derivative, an imine, a tioether, or a heterocyclic carbene L1 or L2 may be bonded to "carbene C" so as to form a bidentate ligand or chelate, "carbene C" may be represented by the general formula: Wherein R1 and R2 are the same or different such as hydrogen or any other saturated or unsaturated, cyclic, branched or linear hydrocarbon group or aromatic group. By way of examples, mention may be made of ruthenium alkylidene complexes, or cumulenes such as vinylidenes Ru = C = CHR or allenylidenes Ru = C = C = CR 1 R 2 or indenylidenes. A functional group for improving the retention of the ruthenium complex in the ionic liquid may be scored on at least one of the ligands X1, X2, L1, L2, or on the carbene C. This functional group may or may not be charged. charged, such as preferably an ester, an ether, a thiol, an acid, an alcohol, an amine, a nitrogen heterocycles, a sufonate, a carboxylate, a quaternary ammonium, a guanidinium, a quaternary phosphonium, a pyridinium, an imidazolium, a morpholinium or a sulfonium. Preferably, the catalyst is used in a proportion of between 0.001 mol% and 10 mol% relative to the starting unsaturated fatty substance. Example 1 Synthesis of Ethylene This example illustrates steps a) and b) of the method which is the subject of the invention. 96% ethanol is vaporized in a vaporizer, then preheated in a heat exchanger, before being injected at the top of a first reactor 127 mm in diameter containing a catalyst bed heated to 300-400 ° C and constituted of a layer of alumina ESM110 EUROSUPPORT, representing a volume of 12700 cm3 and a mass of 6500 g, the ratio of the volume flow rate of ethanol to the catalyst volume being 1h-1. The mixture of water and ethylene produced in the reactor is cooled in the heat exchanger, before being sent to a gas-liquid separator where ethylene and water (possibly mixed with by-products) are separated.

Example 2 Fermentation of Oleic Acid

In this example, the yeast strain Candida tropicalis deposited on September 24, 1980, under the accession number FERM-P 5713, is used with Fermentation Research Institute, The Agency of Industrial Science and Technology, as described in Example 1 of the US Pat. 4474882. The cultured yeast is cultured at pH = 7, in a medium containing 20 g of sorbitol, trace elements, urea and in one liter of deionized water, and 0.3 ml of oleic acid. The mixture is then sterilized at 120 ° C for 15 minutes. A strain 104-04 of Candida Tropicalis is then inoculated into the culture medium. The culture is maintained at 30 ° C. A soda solution is continuously added to maintain the medium at a pH of 7.0 to 7.5. After 48 hours of culture, the unsaturated diacid is recovered by extraction with diethyl ether. After removal of the solvent by evaporation, 19 mg of crystals can be recovered which after recrystallization have a melting point of 69 ° C., ie equivalent to that described for 9-octadecenedioic diacid. An analysis of the culture medium makes it possible to measure a concentration of 9-octadecenedioic diacid of 1.5 g / l.

Example 3 Cross Metathesis of 9-octadecenedioic diacid

This example illustrates step c) of the method which is the subject of the invention. 9-Decenoic acid is synthesized from 9-octadecenedioic diacid. This second step of the process is cross-metathesis with ethylene. For this reaction, the bispyridine ruthenium complex catalyst (8) described in Chen-Xi Bai et al., Org. Biomol. Chem., (2005), 3, 4139-4142. The reaction is carried out in CH 2 Cl 2, at a concentration of 0.05 M of 9-octadecenedioic acid and 0.1 M of ethylene at a temperature of 80 ° C, and for 12 hours in the presence of the catalyst at a concentration of 1 % mole relative to 9-octadecenedioic acid. Yields are determined by chromatographic analysis. A yield of 9-decenoic acid CH 2 = CH- (CH 2) 7 -COOH of 65 mol% can be measured.

Example 4: Etholysis of methyl oleate. This example illustrates the ethenolysis of methyl oleate (step c) of the process which is the subject of the invention. For this reaction is used the complex catalyst [RuCl 2 (= CHPh) (IMesH 2) (PCy 3)] whose formula (A) is given below. The reaction is carried out in CH 2 Cl 2, at a concentration of 0.05M methyl oleate and 0.2M ethylene at a temperature of 55 ° C, and for 6 hours, in the presence of the catalyst at a concentration of 5%. % mole relative to methyl oleate. Yields are determined by chromatographic analysis. A yield of methyl 9-decenoate CH 2 = CH- (CH 2) 7 -COOCH 3 and 1-decene of 55 mol% can be measured. Catalyst of Formula (A) CH 3 Ph Formula (A) Example 5: Etholysis of methyl oleate

This example illustrates step c) of the method which is the subject of the invention. The experiments are carried out under Argon atmosphere in a glove box. The purified oleic acid methyl ester (15 g) was loaded by filtration on activated alumina in a stirred glass reactor. A solution of 1000 ppm (relative to the methyl ester) of the metathesis catalyst (reference 57972-6, CAS [172222-30-9] purchased from Sigma-Aldrich) is prepared in dichloromethane and is added to the oleate of methyl. The reactor is equipped with a pressure probe and a port of introduction. The closed system is removed from the glove box and connected to the ethylene line. The reactor is then purged 3 times with ethylene, then pressurized at 10 atm and placed in an oil bath at 40 ° C for 2 hours. Before chromatographic analysis, the reaction is stopped by adding a 1 M solution of tris-hydroxymethylphosphine in isopropanol. The samples are heated for 1 h at 60 ° C, the samples are diluted with distilled water and extracted with hexane before analysis by gas chromatography. The analysis reveals a yield of 30% decene-1 and 30% of methyl 9-decenoate.

Claims (10)

claims A process for the co-production of olefins and esters or acids comprising the following steps: a) the synthesis of ethanol by fermentation of at least one plant material; b) dehydrating the ethanol obtained in a) to produce a mixture of ethylene and water; and c) bringing into contact, under metathesis conditions, at least: an unsaturated fatty substance comprising at least one mono- or dicarboxylic fatty acid comprising at least one ethylenic unsaturation or at least one ester formed between at least one fatty acid; mono or dicarboxylic having at least one ethylenic unsaturation and at least one aliphatic monoalcohol or at least one aliphatic polyol, - excess ethylene produced in step b), and a catalyst. 2. Method according to claim 1, characterized in that the plant material is selected from beet, potato, biomass, a source of cellulose, sugar cane, and a cereal selected from corn, wheat, barley and sorghum. 3. Method according to claim 2, characterized in that the cereal is corn. 4. Method according to any one of claims 1 to 3, characterized in that step b) is carried out using a catalyst based on γ-alumina. 5. Method according to any one of claims 1 to 4, characterized in that the fatty acid comprises at least 12 carbon atoms and the alcohol is an aliphatic monoalcohol containing 1 to 8 carbon atoms or glycerol. 6. Process according to any one of Claims 1 to 4, characterized in that the unsaturated fatty substance chosen from oleic sunflower oils and oleic rapeseed oils is subjected to the metathesis reaction, to produce at the same time an olefinic fraction and a glycerol ester composition of which at least a part of the chains consists of C10 unsaturated chains. 7. Process according to any one of Claims 1 to 4, characterized in that the unsaturated fatty substance chosen from the mixtures of monoalcohol esters of oleic sunflower oils and rapeseed oils is subjected to the metathesis reaction. olefins, to produce both an olefinic moiety and a monoalcohol ester composition of which at least a portion of the chains are unsaturated C 10 chains. Process according to any one of Claims 1 to 7, characterized in that at least one ruthenium compound is used as catalyst during stage c). 9. Process according to claim 8, characterized in that the catalyst is used in a proportion of between 0.001 mol% and 10 mol% relative to the starting unsaturated fatty substance. 10. Method according to one of claims 1 to 9 characterized in that it further comprises a step in which is separated an olefinic fraction containing diolefins and monoolefins and a composition containing esters or diacids.