Patent Application
20150105566
In recent years, there has been an increased demand for environmentally friendly techniques for manufacturing materials typically derived from petroleum sources. In view of the non-renewable nature of petroleum, it is highly desirable to provide non-petroleum alternatives for material manufacturing biofuels, waxes, plastics, cosmetics, personal care items, and the like. One of the methods to manufacture such materials is through generating compositions through the metathesis of natural oil feedstocks, such as vegetable and seed-based oils.
It is to be understood that unless specifically stated otherwise, references to “a,” “an,” and/or “the” may include one or more than one, and that reference to an item in the singular may also include the item in the plural.
The terms “natural oils,” “natural feedstocks,” or “natural oil feedstocks” may refer to oils derived from plants or animal sources. The term “natural oil” includes natural oil derivatives, unless otherwise indicated. The terms also include modified plant or animal sources (e.g., genetically modified plant or animal sources), unless indicated otherwise. Examples of natural oils include, but are not limited to, vegetable oils, algae oils, fish oils, animal fats, tall oils, derivatives of these oils, combinations of any of these oils, and the like. Representative non-limiting examples of vegetable oils include canola oil, rapeseed oil, coconut oil, corn oil, cottonseed oil, olive oil, palm oil, peanut oil, safflower oil, sesame oil, soybean oil (“SBO”), sunflower oil, linseed oil, palm kernel oil, tung oil, jatropha oil, mustard oil, pennycress oil, camelina oil, and castor oil. Representative non-limiting examples of animal fats include lard, tallow, poultry fat, yellow grease, and fish oil. Tall oils are by-products of wood pulp manufacture.
The term “natural oil derivatives” refers to derivatives thereof derived from natural oil. The methods used to form these natural oil derivatives may include one or more of addition, neutralization, overbasing, saponification, transesterification, esterification, amidification, hydrogenation, isomerization, oxidation, alkylation, acylation, sulfurization, sulfonation, rearrangement, reduction, fermentation, pyrolysis, hydrolysis, liquefaction, anaerobic digestion, hydrothermal processing, gasification or a combination of two or more thereof. Examples of natural derivatives thereof may include carboxylic acids, gums, phospholipids, soapstock, acidulated soapstock, distillate or distillate sludge, fatty acids, fatty acid esters, as well as hydroxy substituted variations thereof, including unsaturated polyol esters. In some embodiments, the natural oil derivative may comprise an unsaturated carboxylic acid having from about 5 to about 30 carbon atoms, having one or more carbon-carbon double bonds in the hydrocarbon (alkene) chain. The natural oil derivative may also comprise an unsaturated fatty acid alkyl (e.g., methyl) ester derived from a glyceride of natural oil. For example, the natural oil derivative may be a fatty acid methyl ester (“FAME”) derived from the glyceride of the natural oil. In some embodiments, a feedstock includes canola or soybean oil, as a non-limiting example, refined, bleached, and deodorized soybean oil (i.e., RBD soybean oil).
The term “low-molecular-weight olefin” may refer to any one or combination of unsaturated straight, branched, or cyclic hydrocarbons in the C2 to C14 range. Low-molecular-weight olefins include “alpha-olefins” or “terminal olefins,” wherein the unsaturated carbon-carbon bond is present at one end of the compound. Low-molecular-weight olefins may also include dienes or trienes. Examples of low-molecular-weight olefins in the C2 to C6 range include, but are not limited to: ethylene, propylene, 1-butene, 2-butene, isobutene, 1-pentene, 2-pentene, 3-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-butene, cyclopentene, 1-hexene, 2-hexene, 3-hexene, 4-hexene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-methyl-2-pentene, 3-methyl-2-pentene, 4-methyl-2-pentene, 2-methyl-3-pentene, and cyclohexene. Other possible low-molecular-weight olefins include styrene and vinyl cyclohexane. In certain embodiments, it is preferable to use a mixture of olefins, the mixture comprising linear and branched low-molecular-weight olefins in the C4-C10 range. In one embodiment, it may be preferable to use a mixture of linear and branched C4 olefins (i.e., combinations of: 1-butene, 2-butene, and/or isobutene). In other embodiments, a higher range of C11-C14 may be used.
The term “metathesis monomer” refers to a single entity that is the product of a metathesis reaction which comprises a molecule of a compound with one or more carbon-carbon double bonds which has undergone an alkylidene unit interchange via one or more of the carbon-carbon double bonds either within the same molecule (intramolecular metathesis) and/or with a molecule of another compound containing one or more carbon-carbon double bonds such as an olefin (intermolecular metathesis).
The term “metathesis dimer” refers to the product of a metathesis reaction wherein two reactant compounds, which can be the same or different and each with one or more carbon-carbon double bonds, are bonded together via one or more of the carbon-carbon double bonds in each of the reactant compounds as a result of the metathesis reaction.
The term “metathesis trimer” refers to the product of one or more metathesis reactions wherein three molecules of two or more reactant compounds, which can be the same or different and each with one or more carbon-carbon double bonds, are bonded together via one or more of the carbon-carbon double bonds in each of the reactant compounds as a result of the one or more metathesis reactions, the trimer containing three bonded groups derived from the reactant compounds.
The term “metathesis tetramer” refers to the product of one or more metathesis reactions wherein four molecules of two or more reactant compounds, which can be the same or different and each with one or more carbon-carbon double bonds, are bonded together via one or more of the carbon-carbon double bonds in each of the reactant compounds as a result of the one or more metathesis reactions, the tetramer containing four bonded groups derived from the reactant compounds.
The term “metathesis pentamer” refers to the product of one or more metathesis reactions wherein five molecules of two or more reactant compounds, which can be the same or different and each with one or more carbon-carbon double bonds, are bonded together via one or more of the carbon-carbon double bonds in each of the reactant compounds as a result of the one or more metathesis reactions, the pentamer containing five bonded groups derived from the reactant compounds.
The term “metathesis hexamer” refers to the product of one or more metathesis reactions wherein six molecules of two or more reactant compounds, which can be the same or different and each with one or more carbon-carbon double bonds, are bonded together via one or more of the carbon-carbon double bonds in each of the reactant compounds as a result of the one or more metathesis reactions, the hexamer containing six bonded groups derived from the reactant compounds.
The term “metathesis heptamer” refers to the product of one or more metathesis reactions wherein seven molecules of two or more reactant compounds, which can be the same or different and each with one or more carbon-carbon double bonds, are bonded together via one or more of the carbon-carbon double bonds in each of the reactant compounds as a result of the one or more metathesis reactions, the heptamer containing seven bonded groups derived from the reactant compounds.
The term “metathesis octamer” refers to the product of one or more metathesis reactions wherein eight molecules of two or more reactant compounds, which can be the same or different and each with one or more carbon-carbon double bonds, are bonded together via one or more of the carbon-carbon double bonds in each of the reactant compounds as a result of the one or more metathesis reactions, the octamer containing eight bonded groups derived from the reactant compounds.
The term “metathesis nonamer” refers to the product of one or more metathesis reactions wherein nine molecules of two or more reactant compounds, which can be the same or different and each with one or more carbon-carbon double bonds, are bonded together via one or more of the carbon-carbon double bonds in each of the reactant compounds as a result of the one or more metathesis reactions, the nonamer containing nine bonded groups derived from the reactant compounds.
The term “metathesis decamer” refers to the product of one or more metathesis reactions wherein ten molecules of two or more reactant compounds, which can be the same or different and each with one or more carbon-carbon double bonds, are bonded together via one or more of the carbon-carbon double bonds in each of the reactant compounds as a result of the one or more metathesis reactions, the decamer containing ten bonded groups derived from the reactant compounds.
The term “metathesis oligomer” refers to the product of one or more metathesis reactions wherein two or more molecules (e.g., 2 to about 10, or 2 to about 4) of two or more reactant compounds, which can be the same or different and each with one or more carbon-carbon double bonds, are bonded together via one or more of the carbon-carbon double bonds in each of the reactant compounds as a result of the one or more metathesis reactions, the oligomer containing a few (e.g., 2 to about 10, or 2 to about 4) bonded groups derived from the reactant compounds. In some embodiments, the term “metathesis oligomer” may include metathesis reactions wherein greater than ten molecules of two or more reactant compounds, which can be the same or different and each with one or more carbon-carbon double bonds, are bonded together via one or more of the carbon-carbon double bonds in each of the reactant compounds as a result of the one or more metathesis reactions, the oligomer containing greater than ten bonded groups derived from the reactant compounds.
As used herein, the terms “metathesize” and “metathesizing” may refer to the reacting of a natural oil feedstock in the presence of a metathesis catalyst to form a metathesized natural oil product comprising a new olefinic compound and/or esters. Metathesizing may refer to cross-metathesis (a.k.a. co-metathesis), self-metathesis, ring-opening metathesis, ring-opening metathesis polymerizations (“ROMP”), ring-closing metathesis (“RCM”), and acyclic diene metathesis (“ADMET”). As a non-limiting example, metathesizing may refer to reacting two triglycerides present in a natural feedstock (self-metathesis) in the presence of a metathesis catalyst, wherein each triglyceride has an unsaturated carbon-carbon double bond, thereby forming an oligomer having a new mixture of olefins and esters that may comprise one or more of: metathesis monomers, metathesis dimers, metathesis trimers, metathesis tetramers, metathesis pentamers, and higher order metathesis oligomers (e.g., metathesis hexamers, metathesis, metathesis heptamers, metathesis octamers, metathesis nonamers, metathesis decamers, and higher than metathesis decamers and above).
Metathesis is a catalytic reaction generally known in the art that involves the interchange of alkylidene units among compounds containing one or more double bonds (e.g., olefinic compounds) via the formation and cleavage of the carbon-carbon double bonds. Metathesis may occur between two like molecules (often referred to as self-metathesis) and/or it may occur between two different molecules (often referred to as cross-metathesis). Self-metathesis may be represented schematically as shown in Equation A below.
R1—CH═CH—R2+R1—CH═CH—R2R1—CH═CH—R1+R2—CH═CH—R2 Equation A
wherein R1 and R2 are organic groups.
Cross-metathesis may be represented schematically as shown in Equation B below.
R1—CH═CH—R2+R3—CH═CH—R4R1—CH═CH—R3+R1—CH═CH—R4+R2—CH═CH—R3+R2—CH═CH—R4+R1—CH═CH—R1+R2—CH═CH—R2+R3—CH═CH—R3+R4—CH═CH—R4 Equation B
wherein R1, R2, R3, and R4 are organic groups.
The metathesis reaction of the natural oil feedstock having polyol esters (of fatty acids) results in the oligomerization of the natural oil feedstock having a mixture of olefins and esters that may comprise one or more of: metathesis monomers, metathesis dimers, metathesis trimers, metathesis tetramers, metathesis pentamers, and higher order metathesis oligomers (e.g., metathesis hexamers, metathesis heptamers, metathesis octamers, metathesis nonamers, metathesis decamers, and higher than metathesis decamers).
Natural oils of the type described herein typically are composed of triglycerides of fatty acids. These fatty acids may be either saturated, monounsaturated or polyunsaturated and contain varying chain lengths ranging from C8 to C30. The most common fatty acids include saturated fatty acids such as lauric acid (dodecanoic acid), myristic acid (tetradecanoic acid), palmitic acid (hexadecanoic acid), stearic acid (octadecanoic acid), arachidic acid (eicosanoic acid), and lignoceric acid (tetracosanoic acid); unsaturated acids include such fatty acids as palmitoleic (a C16 acid), and oleic acid (a C18 acid); polyunsaturated acids include such fatty acids as linoleic acid (a di-unsaturated C18 acid), linolenic acid (a tri-unsaturated C18 acid), and arachidonic acid (a tetra-unsubstituted C20 acid). The natural oils are further comprised of esters of these fatty acids in random placement onto the three sites of the trifunctional glycerine molecule. Different natural oils will have different ratios of these fatty acids, and within a given natural oil there is a range of these acids as well depending on such factors as where a vegetable or crop is grown, maturity of the vegetable or crop, the weather during the growing season, etc. Thus, it is difficult to have a specific or unique structure for any given natural oil, but rather a structure is typically based on some statistical average. For example soybean oil contains a mixture of stearic acid, oleic acid, linoleic acid, and linolenic acid in the ratio of 15:24:50:11, and an average number of double bonds of 4.4-4.7 per triglyceride. One method of quantifying the number of double bonds is the iodine value (IV) which is defined as the number of grams of iodine that will react with 100 grams of vegetable oil. Therefore for soybean oil, the average iodine value range is from 120-140. Soybean oil may comprises about 95% by weight or greater (e.g., 99% weight or greater) triglycerides of fatty acids. Major fatty acids in the polyol esters of soybean oil include saturated fatty acids, as a non-limiting example, palmitic acid (hexadecanoic acid) and stearic acid (octadecanoic acid), and unsaturated fatty acids, as a non-limiting example, oleic acid (9-octadecenoic acid), linoleic acid (9,12-octadecadienoic acid), and linolenic acid (9,12,15-octadecatrienoic acid).
When a polyol ester comprises molecules having more than one carbon-carbon double bond, self-metathesis may result in oligomerization or polymerization of the unsaturates in the starting material. For example, Equation C depicts metathesis oligomerization of a representative species (e.g., a polyol ester) having more than one carbon-carbon double bond. In Equation C, the self-metathesis reaction results in the formation of metathesis dimers, metathesis trimers, and metathesis tetramers. Although not shown, higher order oligomers such as metathesis pentamers, hexamers, heptamers, octamers, nonamers, decamers, and higher than decamers, and mixtures of two or more thereof, may also be formed. The number of metathesis repeating units or groups in the metathesized natural oil may range from 1 to about 100, or from 2 to about 50, or from 2 to about 30, or from 2 to about 10, or from 2 to about 4. The molecular weight of the metathesis dimer may be greater than the molecular weight of the unsaturated polyol ester from which the dimer is formed. Each of the bonded polyol ester molecules may be referred to as a “repeating unit or group.” Typically, a metathesis trimer may be formed by the cross-metathesis of a metathesis dimer with an unsaturated polyol ester. Typically, a metathesis tetramer may be formed by the cross-metathesis of a metathesis trimer with an unsaturated polyol ester or formed by the cross-metathesis of two metathesis dimers.
R1—HC═CH—R2—HC═CH—R3+R1—HC═CH—R2—HC═CH—R3R1—HC═CH—R2—HC═CH—R2—HC═CH—R3+(other products)
R1-R2—HC═CH—R2—HC═CH—R3+R1—HC═CH—R2—HC═CH—R3R1—HC═CH—R2—HC═CH—R2—HC═CH—R2—HC═CH—R3+(other products)
R1—HC═CH—R2—HC═CH—R2—HC═CH—R2—HC═CH—R3+R1—HC═CH—R2—HC═CH—R3R1—HC═CH—R2—HC═CH—R2—HC═CH—R2—HC═CH—R2—HC═CH—R3+(other products) Equation C
where R1, R2, and R3 are organic groups.
As noted, the self-metathesis of the natural oil occurs in the presence of a metathesis catalyst. As stated previously, the term “metathesis catalyst” includes any catalyst or catalyst system that catalyzes a metathesis reaction. Any known metathesis catalyst may be used, alone or in combination with one or more additional catalysts. Suitable homogeneous metathesis catalysts include combinations of a transition metal halide or oxo-halide (e.g., WOCl4 or WCl6) with an alkylating cocatalyst (e.g., Me4Sn), or alkylidene (or carbene) complexes of transition metals, particularly Ru, Mo, or W. These include first and second-generation Grubbs catalysts, Grubbs-Hoveyda catalysts, and the like. Suitable alkylidene catalysts have the general structure:
M[X1X2L1L2(L3)n]=Cm=C(R1)R2
where M is a Group 8 transition metal, L1, L2, and L3 are neutral electron donor ligands, n is 0 (such that L3 may not be present) or 1, m is 0, 1, or 2, X1 and X2 are anionic ligands, and R1 and R2 are independently selected from H, hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, substituted heteroatom-containing hydrocarbyl, and functional groups. Any two or more of X1, X2, L1, L2, L3, R1 and R2 can form a cyclic group and any one of those groups can be attached to a support.
First-generation Grubbs catalysts fall into this category where m=n=0 and particular selections are made for n, X1, X2, L1, L2, L3, R1 and R2 as described in U.S. Pat. Appl. Publ. No. 2010/0145086, the teachings of which related to all metathesis catalysts are incorporated herein by reference.
Second-generation Grubbs catalysts also have the general formula described above, but L1 is a carbene ligand where the carbene carbon is flanked by N, O, S, or P atoms, preferably by two N atoms. Usually, the carbene ligand is part of a cyclic group. Examples of suitable second-generation Grubbs catalysts also appear in the '086 publication.
In another class of suitable alkylidene catalysts, L1 is a strongly coordinating neutral electron donor as in first- and second-generation Grubbs catalysts, and L2 and L3 are weakly coordinating neutral electron donor ligands in the form of optionally substituted heterocyclic groups. Thus, L2 and L3 are pyridine, pyrimidine, pyrrole, quinoline, thiophene, or the like.
In yet another class of suitable alkylidene catalysts, a pair of substituents is used to form a bi- or tridentate ligand, such as a biphosphine, dialkoxide, or alkyldiketonate. Grubbs-Hoveyda catalysts are a subset of this type of catalyst in which L2 and R2 are linked. Typically, a neutral oxygen or nitrogen coordinates to the metal while also being bonded to a carbon that is α-, β-, or γ- with respect to the carbene carbon to provide the bidentate ligand. Examples of suitable Grubbs-Hoveyda catalysts appear in the '086 publication.
The structures below provide just a few illustrations of suitable catalysts that may be used:
Heterogeneous catalysts suitable for use in the self- or cross-metathesis reaction include certain rhenium and molybdenum compounds as described, e.g., by J. C. Mol in Green Chem. 4 (2002) 5 at pp. 11-12. Particular examples are catalyst systems that include Re2O7 on alumina promoted by an alkylating cocatalyst such as a tetraalkyl tin lead, germanium, or silicon compound. Others include MoCl3 or MoCl5 on silica activated by tetraalkyltins.
For additional examples of suitable catalysts for self- or cross-metathesis, see U.S. Pat. Nos. 4,545,941, 5,312,940, 5,342,909, 5,710,298, 5,728,785, 5,728,917, 5,750,815, 5,831,108, 5,922,863, 6,306,988, 6,414,097, 6,696,597, 6,794,534, 7,102,047, 7,378,528, and U.S. Pat. Appl, Publ. No. 2009/0264672 A1, and PCT/US2008/009635, pp. 18-47, all of which are incorporated herein by reference. A number of metathesis catalysts that may be advantageously employed in metathesis reactions are manufactured and sold by Materia, Inc. (Pasadena, Calif.).
A process for metathesizing a natural oil and treating the resulting metathesized natural oil is illustrated in
In certain embodiments, the natural oil feedstock is chemically treated under conditions sufficient to diminish the catalyst poisons in the feedstock through a chemical reaction of the catalyst poisons. In certain embodiments, the feedstock is treated with a reducing agent or a cation-inorganic base composition. Non-limiting examples of reducing agents include bisulfate, borohydride, phosphine, thiosulfate, and combinations thereof.
In certain embodiments, the natural oil feedstock is treated with an adsorbent to remove catalyst poisons. In one embodiment, the feedstock is treated with a combination of thermal and adsorbent methods. In another embodiment, the feedstock is treated with a combination of chemical and adsorbent methods. In another embodiment, the treatment involves a partial hydrogenation treatment to modify the natural oil feedstock's reactivity with the metathesis catalyst. Additional non-limiting examples of feedstock treatment are also described below when discussing the various metathesis catalysts.
Additionally, in certain embodiments, the low-molecular-weight olefin may also be treated prior to the metathesis reaction. Like the natural oil treatment, the low-molecular-weight olefin may be treated to remove poisons that may impact or diminish catalyst activity.
As shown in
In certain embodiments, the low-molecular-weight olefin 14 is in the C2 to C6 range. As a non-limiting example, in one embodiment, the low-molecular-weight olefin 14 may comprise at least one of the following: ethylene, propylene, 1-butene, 2-butene, isobutene, 1-pentene, 2-pentene, 3-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-butene, cyclopentene, 1-hexene, 2-hexene, 3-hexene, 4-hexene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-methyl-2-pentene, 3-methyl-2-pentene, 4-methyl-2-pentene, 2-methyl-3-pentene, and cyclohexene. In another embodiment, the low-molecular-weight olefin 14 comprises at least one of styrene and vinyl cyclohexane. In another embodiment, the low-molecular-weight olefin 14 may comprise at least one of ethylene, propylene, 1-butene, 2-butene, and isobutene. In another embodiment, the low-molecular-weight olefin 14 comprises at least one alpha-olefin or terminal olefin in the C2 to C10 range.
In another embodiment, the low-molecular-weight olefin 14 comprises at least one branched low-molecular-weight olefin in the C4 to C10 range. Non-limiting examples of branched low-molecular-weight olefins include isobutene, 3-methyl-1-butene, 2-methyl-3-pentene, and 2,2-dimethyl-3-pentene. By using these branched low-molecular-weight olefins in the metathesis reaction, the metathesized natural oil product will include branched olefins, which can be subsequently hydrogenated to iso-paraffins. In certain embodiments, the branched low-molecular-weight olefins may help achieve the desired performance properties for a fuel composition, such as jet, kerosene, or diesel fuel.
As noted, it is possible to use a mixture of various linear or branched low-molecular-weight olefins in the reaction to achieve the desired metathesis product distribution. In one embodiment, a mixture of butenes (1-butene, 2-butenes, and, optionally, isobutene) may be employed as the low-molecular-weight olefin, offering a low cost, commercially available feedstock instead a purified source of one particular butene. Such low cost mixed butene feedstocks are typically diluted with n-butane and/or isobutane.
In certain embodiments, recycled streams from downstream separation units may be introduced to the metathesis reactor 20 in addition to the natural oil 12 and, in some embodiments, the low-molecular-weight olefin 14. For instance, in some embodiments, a C2-C6 recycle olefin stream or a C3-C4 bottoms stream from an overhead separation unit may be returned to the metathesis reactor. In one embodiment, as shown in
The metathesis reaction in the metathesis reactor 20 produces a metathesized natural oil product 22. In one embodiment, the metathesized natural oil product 22 enters a flash vessel operated under temperature and pressure conditions which target C2 or C2-C3 compounds to flash off and be removed overhead. The C2 or C2-C3 light ends are comprised of a majority of hydrocarbon compounds having a carbon number of 2 or 3. In certain embodiments, the C2 or C2-C3 light ends are then sent to an overhead separation unit, wherein the C2 or C2-C3 compounds are further separated overhead from the heavier compounds that flashed off with the C2-C3 compounds. These heavier compounds are typically C3-C5 compounds carried overhead with the C2 or C2-C3 compounds. After separation in the overhead separation unit, the overhead C2 or C2-C3 stream may then be used as a fuel source. These hydrocarbons have their own value outside the scope of a fuel composition, and may be used or separated at this stage for other valued compositions and applications. In certain embodiments, the bottoms stream from the overhead separation unit containing mostly C3-C5 compounds is returned as a recycle stream to the metathesis reactor. In the flash vessel, the metathesized natural oil product 22 that does not flash overhead is sent downstream for separation in a separation unit 30, such as a distillation column.
Prior to the separation unit 30, in certain embodiments, the metathesized natural oil product 22 may be introduced to an adsorbent bed to facilitate the separation of the metathesized natural oil product 22 from the metathesis catalyst. In one embodiment, the adsorbent is a clay bed. The clay bed will adsorb the metathesis catalyst, and after a filtration step, the metathesized natural oil product 22 can be sent to the separation unit 30 for further processing. Separation unit 30 may comprise a distillation unit. In some embodiments, the distillation may be conducted, for example, by steam stripping the metathesized natural oil product. Distilling may be accomplished by sparging the mixture in a vessel, typically agitated, by contacting the mixture with a gaseous stream in a column that may contain typical distillation packing (e.g., random or structured), by vacuum distillation, or evaporating the lights in an evaporator such as a wiped film evaporator. Typically, steam stripping will be conducted at reduced pressure and at temperatures ranging from about 100° C. to 250° C. The temperature may depend, for example, on the level of vacuum used, with higher vacuum allowing for a lower temperature and allowing for a more efficient and complete separation of volatiles.
In another embodiment, the adsorbent is a water soluble phosphine reagent such as tris hydroxymethyl phosphine (THMP). Catalyst may be separated with a water soluble phosphine through known liquid-liquid extraction mechanisms by decanting the aqueous phase from the organic phase. In other embodiments, the metathesized natural oil product 22 may be contacted with a reactant to deactivate or to extract the catalyst.
In the separation unit 30, in certain embodiments, the metathesized natural oil product 22 is separated into at least two product streams. In one embodiment, the metathesized natural oil product 22 is sent to the separation unit 30, or distillation column, to separate the olefins 32 from the esters 34. In another embodiment, a byproduct stream comprising C7's and cyclohexadiene may be removed in a side-stream from the separation unit 30. In certain embodiments, the separated olefins 32 may comprise hydrocarbons with carbon numbers up to 24. In certain embodiments, the esters 34 may comprise metathesized glycerides. In other words, the lighter end olefins 32 are preferably separated or distilled overhead for processing into olefin compositions, while the esters 34, comprised mostly of compounds having carboxylic acid/ester functionality, are drawn into a bottoms stream. Based on the quality of the separation, it is possible for some ester compounds to be carried into the overhead olefin stream 32, and it is also possible for some heavier olefin hydrocarbons to be carried into the ester stream 34.
In one embodiment, the olefins 32 may be collected and sold for any number of known uses. In other embodiments, the olefins 32 are further processed in an olefin separation unit 40 and/or hydrogenation unit 50 (where the olefinic bonds are saturated with hydrogen gas 48, as described below). In other embodiments, esters 34 comprising heavier end glycerides and free fatty acids are separated or distilled as a bottoms product for further processing into various products. In certain embodiments, further processing may target the production of the following non-limiting examples: fatty acid methyl esters; biodiesel; 9DA esters, 9UDA esters, and/or 9DDA esters; 9DA, 9UDA, and/or 9DDA; alkali metal salts and alkaline earth metal salts of 9DA, 9UDA, and/or 9DDA; diacids, and/or diesters of the transesterified products; and mixtures thereof. In certain embodiments, further processing may target the production of C15-C18 fatty acids and/or esters. In other embodiments, further processing may target the production of diacids and/or diesters. In yet other embodiments, further processing may target the production of compounds having molecular weights greater than the molecular weights of stearic acid and/or linolenic acid.
As shown in
In certain embodiments, the olefins 32 may be oligomerized to form poly-alpha-olefins (PAOs) or poly-internal-olefins (PIOs), mineral oil substitutes, and/or biodiesel fuel. The oligomerization reaction may take place after the distillation unit 30 or after the overhead olefin separation unit 40. In certain embodiments, byproducts from the oligomerization reactions may be recycled back to the metathesis reactor 20 for further processing.
As mentioned, in one embodiment, the olefins 32 from the separation unit 30 may be sent directly to the hydrogenation unit 50. In another embodiment, the center-cut olefins 42 from the overhead olefin separation unit 40 may be sent to the hydrogenation unit 50. Hydrogenation may be conducted according to any known method in the art for hydrogenating double bond-containing compounds such as the olefins 32 or center-cut olefins 42. In certain embodiments, in the hydrogenation unit 50, hydrogen gas 48 is reacted with the olefins 32 or center-cut olefins 42 in the presence of a hydrogenation catalyst to produce a hydrogenated product 52.
In some embodiments, the olefins are hydrogenated in the presence of a hydrogenation catalyst comprising nickel, copper, palladium, platinum, molybdenum, iron, ruthenium, osmium, rhodium, or iridium, individually or in combinations thereof. Useful catalyst may be heterogeneous or homogeneous. In some embodiments, the catalysts are supported nickel or sponge nickel type catalysts.
In some embodiments, the hydrogenation catalyst comprises nickel that has been chemically reduced with hydrogen to an active state (i.e., reduced nickel) provided on a support. The support may comprise porous silica (e.g., kieselguhr, infusorial, diatomaceous, or siliceous earth) or alumina. The catalysts are characterized by a high nickel surface area per gram of nickel.
Commercial examples of supported nickel hydrogenation catalysts include those available under the trade designations “NYSOFACT”, “NYSOSEL”, and “NI 5248 D” (from BASF Catalysts LLC, Iselin, N.J.). Additional supported nickel hydrogenation catalysts include those commercially available under the trade designations “PRICAT 9910”, “PRICAT 9920”, “PRICAT 9908”, “PRICAT 9936” (from Johnson Matthey Catalysts, Ward Hill, Mass.).
The supported nickel catalysts may be of the type described in U.S. Pat. No. 3,351,566, U.S. Pat. No. 6,846,772, EP 0168091, and EP 0167201, incorporated by reference herein. Hydrogenation may be carried out in a batch or in a continuous process and may be partial hydrogenation or complete hydrogenation. In certain embodiments, the temperature ranges from about 50° C. to about 350° C., about 100° C. to about 300° C., about 150° C. to about 250° C., or about 100° C. to about 150° C. The desired temperature may vary, for example, with hydrogen gas pressure. Typically, a higher gas pressure will require a lower temperature. Hydrogen gas is pumped into the reaction vessel to achieve a desired pressure of H2 gas. In certain embodiments, the H2 gas pressure ranges from about 15 psig (1 atm) to about 3000 psig (204.1 atm), about 15 psig (1 atm) to about 90 psig (6.1 atm), or about 100 psig (6.8 atm) to about 500 psig (34 atm). In certain embodiments, the reaction conditions are “mild,” wherein the temperature is approximately between approximately 50° C. and approximately 100° C. and the H2 gas pressure is less than approximately 100 psig. In other embodiments, the temperature is between about 100° C. and about 150° C., and the pressure is between about 100 psig (6.8 atm) and about 500 psig (34 atm). When the desired degree of hydrogenation is reached, the reaction mass is cooled to the desired filtration temperature.
During hydrogenation, the carbon-carbon double bond containing compounds in the olefins are partially to fully saturated by the hydrogen gas 48. In one embodiment, the resulting hydrogenated product 52 includes hydrocarbons with a distribution centered between approximately C10 and C12 hydrocarbons for naphtha- and kerosene-type jet fuel compositions. In another embodiment, the distribution is centered between approximately Cis and Cis for a diesel fuel composition.
In certain embodiments, based upon the quality of the hydrogenated product 52 produced in the hydrogenation unit 50, it may be preferable to isomerize the olefin hydrogenated product 52 to assist in targeting of desired fuel properties such as flash point, freeze point, energy density, cetane number, or end point distillation temperature, among other parameters. Isomerization reactions are well-known in the art, as described in U.S. Pat. Nos. 3,150,205; 4,210,771; 5,095,169; and 6,214,764, herein incorporated by reference. In one embodiment, the isomerization reaction at this stage may also crack some of the C15+ compounds remaining, which may further assist in producing a fuel composition having compounds within the desired carbon number range, such as 5 to 16 for a jet fuel composition.
In certain embodiments, the isomerization may occur concurrently with the hydrogenation step in the hydrogenation unit 50, thereby targeting a desired fuel product. In other embodiments, the isomerization step may occur before the hydrogenation step (i.e., the olefins 32 or center-cut olefins 42 may be isomerized before the hydrogenation unit 50). In yet other embodiments, it is possible that the isomerization step may be avoided or reduced in scope based upon the selection of low-molecular-weight olefin(s) 14 used in the metathesis reaction.
In certain embodiments, the hydrogenated product 52 comprises approximately 15-25 weight % C7, approximately <5 weight % C8, approximately 20-40 weight % C9, approximately 20-40 weight % C10, approximately <5 weight % C11, approximately 15-25 weight % C12, approximately <5 weight % C13, approximately <5 weight % C14, approximately <5 weight % C15, approximately <1 weight % Cm, approximately <1 weight % C17, and approximately <1 weight % C18+. In certain embodiments, the hydrogenated product 52 comprises a heat of combustion of at least approximately 40, 41, 42, 43 or 44 MJ/kg (as measured by ASTM D3338). In certain embodiments, the hydrogenated product 52 contains less than approximately 1 mg sulfur per kg hydrogenated product (as measured by ASTM D5453). In other embodiments, the hydrogenated product 52 comprises a density of approximately 0.70-0.75 (as measured by ASTM D4052). In other embodiments, the hydrogenated product has a final boiling point of approximately 220-240° C. (as measured by ASTM D86)
The hydrogenated product 52 produced from the hydrogenation unit 50 may be used as a fuel composition, non-limiting examples of which include jet, kerosene, or diesel fuel. In certain embodiments, the hydrogenated product 52 may contain byproducts from the hydrogenation, isomerization, and/or metathesis reactions. As shown in
With regard to the esters 34 from the distillation unit 30, in certain embodiments, the esters 34 may be entirely withdrawn as an ester product stream 36 and processed further or sold for its own value, as shown in
In certain embodiments, the ester stream 34 is sent to a transesterification unit 70. Within the transesterification unit 70, the esters 34 are reacted with at least one alcohol 38 in the presence of a transesterification catalyst. In certain embodiments, the alcohol comprises methanol and/or ethanol. In one embodiment, the transesterification reaction is conducted at approximately 60-70° C. and approximately 1 atm. In certain embodiments, the transesterification catalyst is a homogeneous sodium methoxide catalyst. Varying amounts of catalyst may be used in the reaction, and, in certain embodiments, the transesterification catalyst is present in the amount of approximately 0.5-1.0 weight % of the esters 34.
The transesterification reaction may produce transesterified products 72 including saturated and/or unsaturated fatty acid methyl esters (“FAME”), glycerin, methanol, and/or free fatty acids. In certain embodiments, the transesterified products 72, or a fraction thereof, may comprise a source for biodiesel. In certain embodiments, the transesterified products 72 comprise 9DA esters, 9UDA esters, and/or 9DDA esters. Non-limiting examples of 9DA esters, 9UDA esters and 9DDA esters include methyl 9-decenoate (“9-DAME”), methyl 9-undecenoate (“9-UDAME”), and methyl 9-dodecenoate (“9-DDAME”), respectively. As a non-limiting example, in a transesterification reaction, a 9DA moiety of a metathesized glyceride is removed from the glycerol backbone to form a 9DA ester.
In another embodiment, a glycerin alcohol may be used in the reaction with a glyceride stream. This reaction may produce monoglycerides and/or diglycerides. In certain embodiments, the transesterified products 72 from the transesterification unit 70 can be sent to a liquid-liquid separation unit, wherein the transesterified products 72 (i.e., FAME, free fatty acids, and/or alcohols) are separated from glycerin. Additionally, in certain embodiments, the glycerin byproduct stream may be further processed in a secondary separation unit, wherein the glycerin is removed and any remaining alcohols are recycled back to the transesterification unit 70 for further processing.
In one embodiment, the transesterified products 72 are further processed in a water-washing unit. In this unit, the transesterified products undergo a liquid-liquid extraction when washed with water. Excess alcohol, water, and glycerin are removed from the transesterified products 72. In another embodiment, the water-washing step is followed by a drying unit in which excess water is further removed from the desired mixture of esters (i.e., specialty chemicals). Such specialty chemicals include non-limiting examples such as 9DA, 9UDA, and/or 9DDA, alkali metal salts and alkaline earth metal salts of the preceding, individually or in combinations thereof.
In one embodiment, the specialty chemical (e.g., 9DA) may be further processed in an oligomerization reaction to form a lactone, which may serve as a precursor to a surfactant.
In certain embodiments, the transesterifed products 72 from the transesterification unit 70 or specialty chemicals from the water-washing unit or drying unit are sent to an ester distillation column 80 for further separation of various individual or groups of compounds, as shown in
The 9DA esters, 9UDA esters, and/or 9DDA esters may be further processed after the distillation step in the ester distillation column. In one embodiment, under known operating conditions, the 9DA ester, 9UDA ester, and/or 9DDA ester may then undergo a hydrolysis reaction with water to form 9DA, 9UDA, and/or 9DDA, alkali metal salts and alkaline earth metal salts of the preceding, individually or in combinations thereof.
In certain embodiments, the fatty acid methyl esters from the transesterified products 72 may be reacted with each other to form other specialty chemicals such as dimers.
Multiple, sequential metathesis reaction steps may be employed. For example, the metathesized natural oil product may be made by reacting a natural oil in the presence of a metathesis catalyst to form a first metathesized natural oil product. The first metathesized natural oil product may then be reacted in a self-metathesis reaction to form another metathesized natural oil product. Alternatively, the first metathesized natural oil product may be reacted in a cross-metathesis reaction with a natural oil to form another metathesized natural oil product. Also in the alternative, the transesterified products, the olefins and/or esters may be further metathesized in the presence of a metathesis catalyst. Such multiple and/or sequential metathesis reactions can be performed as many times as needed, and at least one or more times, depending on the processing/compositional requirements as understood by a person skilled in the art. In some embodiments of a multiple metathesis reaction, the second or subsequent metathesis will produce a distinguishable product if the composition is altered. For example, if soybean oil is cross metathesized with a low weight olefin, such as 1-butene, in a first metathesis, it will produce a higher molecular weight oligomeric mixture upon a second metathesis if the olefins that were present during the first metathesis have been partially removed prior to or during the second metathesis. This generally is done by stripping the olefins, in this instance from the butenolyzed soybean oil. This “compositional shift” allows further reaction to occur during the second metathesis. Absent such a shift, adding more catalyst to a system at equilibrium will result in little or no change.
As used herein, a “metathesized natural oil product” or “metathesized natural composition” may include products that have been once metathesized and/or multiply metathesized. These procedures may be used to form metathesis dimers, metathesis trimers, metathesis tetramers, metathesis pentamers, and higher order metathesis oligomers (e.g., metathesis hexamers, metathesis heptamers, metathesis octamers, metathesis nonamers, metathesis decamers, and higher than metathesis decamers). These procedures can be repeated as many times as desired (for example, from 2 to about 50 times, or from 2 to about 30 times, or from 2 to about 10 times, or from 2 to about 5 times, or from 2 to about 4 times, or 2 or 3 times) to provide the desired metathesis oligomer or polymer which may comprise, for example, from 2 to about 100 bonded groups, or from 2 to about 50, or from 2 to about 30, or from 2 to about 10, or from 2 to about 8, or from 2 to about 6 bonded groups, or from 2 to about 4 bonded groups, or from 2 to about 3 bonded groups. In certain embodiments, it may be desirable to use the metathesized natural products produced by cross metathesis of a natural oil, or blend of natural oils, with a C2-C100 olefin, as the reactant in a self-metathesis reaction to produce another metathesized natural oil product. Alternatively, metathesized natural products produced by cross metathesis of a natural oil, or blend of natural oils, with a C2-C100 olefin can be combined with a natural oil, or blend of natural oils, and further metathesized to produce another metathesized natural oil product.
The metathesized natural oil product may have a number average molecular weight in the range from about 100 g/mol to about 150,000 g/mol, or from about 300 g/mol to about 100,000 g/mol, or from about 300 g/mol to about 70,000 g/mol, or from about 300 g/mol to about 50,000 g/mol, or from about 500 g/mol to about 30,000 g/mol, or from about 700 g/mol to about 10,000 g/mol, or from about 1,000 g/mol to about 5,000 g/mol. The metathesized natural oil product may have a weight average molecular weight in the range from about from about 1,000 g/mol to about 100,000 g/mol, from about 2,500 g/mol to about 50,000 g/mol, from about 4,000 g/mol to about 30,000 g/mol, from about 5,000 g/mol to about 20,000 g/mol, and from about 6,000 g/mol to about 15,000 g/mol. The metathesized natural oil product may have a z-average molecular weight in the range from about from about 5,000 g/mol to about 1,000,000 g/mol, for example from about 7,500 g/mol to about 500,000 g/mol, from about 10,000 g/mol to about 300,000 g/mol, or from about 12,500 g/mol to about 200,000 g/mol. The polydispersity index is calculated by dividing the weight average molecular weight by the number average molecular weight. Polydispersity is a measure of the breadth of the molecular weight distribution of the metathesized natural oil product, and such products generally exhibit a polydispersity index of about 1 to about 20, or from about 2 to about 15. The number average molecular weight, weight average molecular weight, and z-average molecular weight may be determined by gel permeation chromatography (GPC), gas chromatography, gas chromatography mass-spectroscopy, NMR spectroscopy, vapor phase osmometry (VPO), wet analytical techniques such as acid number, base number, saponification number or oxirane number, and the like. In some embodiments, gas chromatography and gas chromatography mass-spectroscopy can be used to analyze the metathesized natural oil product by first transforming the triglycerides to their corresponding methyl esters prior to testing. The extent to which the individual triglyceride molecules have been polymerized can be understood as being directly related to the concentration of diester molecules found in the analyzed fatty acid methyl esters. In some embodiments, the molecular weight of the metathesized natural oil product can be increased by transesterifying the metathesized natural oil product with diesters. In some embodiments, the molecular weight of the metathesized natural oil product can be increased by esterifying the metathesized natural oil product with diacids. In certain embodiments, the metathesized natural oil product has a dynamic viscosity between about 1 centipoise (cP) and about 10,000 centipoise (cP), between about 30 centipoise (cP) and about 5000 cP, between about 50 cP and about 3000 cP, and from between about 80 cP and about 1500 cP.
In some embodiments, a metathesized natural oil composition may comprise a blend of (i) a high molecular weight metathesized natural oil, and (ii) at least 10% of a metathesized natural oil back blended with the high molecular weight metathesized natural oil. In such embodiments, the blend has a number average molecular weight in the range from about 300 g/mol to about 76,000 g/mol, a weight average molecular weight in the range from about 300 g/mol to about 81,000 g/mol, a z-average molecular weight in the range from about 300 g/mol to about 87,000 g/mol, and a polydispersity index of about 0.5 to about 1.5. Furthermore, the metathesized natural oil composition blend is metathesized at least once, and in some embodiments, at least twice. In some embodiments, the metathesized natural oil composition has a dynamic viscosity at 40° C. of between about 200 centipoise and 1400 centipoise. In some embodiments, the metathesized natural oil composition is subject to steam stripping at a temperature between about 150° C. and about 200° C.
The metathesis process can be conducted under any conditions adequate to produce the desired metathesis products. For example, stoichiometry, atmosphere, solvent, temperature, and pressure can be selected by one skilled in the art to produce a desired product and to minimize undesirable byproducts. The metathesis process may be conducted under an inert atmosphere. Similarly, if a reagent is supplied as a gas, an inert gaseous diluent can be used. The inert atmosphere or inert gaseous diluent typically is an inert gas, meaning that the gas does not interact with the metathesis catalyst to substantially impede catalysis. For example, particular inert gases are selected from the group consisting of helium, neon, argon, nitrogen, individually or in combinations thereof.
In certain embodiments, the metathesis catalyst is dissolved in a solvent prior to conducting the metathesis reaction. In certain embodiments, the solvent chosen may be selected to be substantially inert with respect to the metathesis catalyst. For example, substantially inert solvents include, without limitation, aromatic hydrocarbons, such as benzene, toluene, xylenes, etc.; halogenated aromatic hydrocarbons, such as chlorobenzene and dichlorobenzene; aliphatic solvents, including pentane, hexane, heptane, cyclohexane, etc.; and chlorinated alkanes, such as dichloromethane, chloroform, dichloroethane, etc. In one particular embodiment, the solvent comprises toluene. The metathesis reaction temperature may be a rate-controlling variable where the temperature is selected to provide a desired product at an acceptable rate. In certain embodiments, the metathesis reaction temperature is greater than about −40° C., greater than about −20° C., greater than about 0° C., or greater than about 10° C. In certain embodiments, the metathesis reaction temperature is less than about 150° C., or less than about 120° C. In one embodiment, the metathesis reaction temperature is between about 10° C. and about 120° C.
The metathesis reaction can be run under any desired pressure. Typically, it will be desirable to maintain a total pressure that is high enough to keep the cross-metathesis reagent in solution. Therefore, as the molecular weight of the cross-metathesis reagent increases, the lower pressure range typically decreases since the boiling point of the cross-metathesis reagent increases. The total pressure may be selected to be greater than about 0.1 atm (10 kPa), in some embodiments greater than about 0.3 atm (30 kPa), or greater than about 1 atm (100 kPa). Typically, the reaction pressure is no more than about 70 atm (7000 kPa), in some embodiments no more than about 30 atm (3000 kPa). A non-limiting exemplary pressure range for the metathesis reaction is from about 1 atm (100 kPa) to about 30 atm (3000 kPa). In certain embodiments it may be desirable to run the metathesis reactions under an atmosphere of reduced pressure. Conditions of reduced pressure or vacuum may be used to remove olefins as they are generated in a metathesis reaction, thereby driving the metathesis equilibrium towards the formation of less volatile products. In the case of a self-metathesis of a natural oil, reduced pressure can be used to remove C12 or lighter olefins including, but not limited to, hexene, nonene, and dodecene, as well as byproducts including, but not limited to cyclohexadiene and benzene as the metathesis reaction proceeds. The removal of these species can be used as a means to drive the reaction towards the formation of diester groups and cross linked triglycerides.
The metathesized natural oil compositions described herein may be utilized independently and/or incorporated into various formulations and used as functional ingredients in dimethicone replacements, laundry detergents, fabric softeners, personal care applications, such as emollients, hair fixative polymers, rheology modifiers, specialty conditioning polymers, surfactants, UV absorbers, solvents, humectants, occlusives, film formers, or as end use personal care applications, such as cosmetics, lip balms, lipsticks, hair dressings, sun care products, moisturizer, fragrance sticks, perfume carriers, skin feel agents, shampoos/conditioners, bar soaps, hand soaps/washes, bubble baths, body washes, facial cleansers, shower gels, wipes, baby cleansing products, creams/lotions, and antiperspirants/deodorants.
The metathesized natural oil compositions described herein may also be incorporated into various formulations and used as functional ingredients in lubricants, functional fluids, fuels and fuel additives, additives for such lubricants, functional fluids and fuels, plasticizers, asphalt additives, friction reducing agents, antistatic agents in the textile and plastics industries, flotation agents, gelling agents, epoxy curing agents, corrosion inhibitors, pigment wetting agents, in cleaning compositions, plastics, coatings, adhesives, skin feel agents, film formers, rheological modifiers, release agents, conditioners dispersants, hydrotropes, industrial and institutional cleaning products, oil field applications, gypsum foamers, sealants, agricultural formulations, enhanced oil recovery compositions, solvent products, gypsum products, gels, semi-solids, detergents, heavy duty liquid detergents (HDL), light duty liquid detergents (LDL), liquid detergent softeners, antistat formulations, dryer softeners, hard surface cleaners (HSC) for household, autodishes, rinse aids, laundry additives, carpet cleaners, softergents, single rinse fabric softeners, I&I laundry, oven cleaners, car washes, transportation cleaners, drain cleaners, defoamers, anti-foamers, foam boosters, anti-dust/dust repellants, industrial cleaners, institutional cleaners, janitorial cleaners, glass cleaners, graffiti removers, concrete cleaners, metal/machine parts cleaners, pesticides, agricultural formulations and food service cleaners, plasticizers, asphalt additives and emulsifiers, friction reducing agents, film formers, rheological modifiers, biocides, biocide potentiators, release agents, household cleaning products, including liquid and powdered laundry detergents, liquid and sheet fabric softeners, hard and soft surface cleaners, sanitizers and disinfectants, and industrial cleaning products, emulsion polymerization, including processes for the manufacture of latex and for use as surfactants as wetting agents, and in agriculture applications as formulation inerts in pesticide applications or as adjuvants used in conjunction with the delivery of pesticides including agricultural crop protection turf and ornamental, home and garden, and professional applications, and institutional cleaning products, oil field applications, including oil and gas transport, production, stimulation and drilling chemicals and reservoir conformance and enhancement, organoclays for drilling muds, specialty foamers for foam control or dispersancy in the manufacturing process of gypsum, cement wall board, concrete additives and firefighting foams, paints and coalescing agents, paint thickeners, or other applications requiring cold tolerance performance or winterization (e.g., applications requiring cold weather performance without the inclusion of additional volatile components).
The following examples and data merely illustrate the invention. It is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein includes any such modifications that may fall within the scope of the appended claims.
Viscosity measurements for Sample C were performed at 40° C.
Various compositional fractions of MSBO. Reference
Metathesis Reaction of Triolein (Oleyl Triglyceride) with Grubbs 2nd Generation Catalyst
1 gram Triolein in a flask was heated to 45° C. under N2 protection. 0.01 gram Catalyst was added. They reaction was kept at 45° C. for 16 hours and quenched with ethyl vinyl ether. The mixture was dissolved in Ethyl acetate and filtered through celite. The MS of resultant samples was tested on a triple quadrupole mass spectrometer with electrospray ionization source for Micromass Quattro LC. Reference
Refined bleached and deodorized canola oil (170 g) was loaded into a 250 ml 2-neck round bottom flask with a magnetic stir bar. The top joint of the flask was fitted with a 320 mm cold coil condenser fed by a chiller circulator set to 15° C. To the top of the condenser was fitted a hose adapter connected to an oil bubbler via Tygon tubing. The side arm neck was fitted with a rubber septum through which was fed a needle type thermocouple and an 18 gauge stainless steel needle for the purpose of supplying the flask with a nitrogen source. The oil was heated, with magnetic stirring, for 2 hr at 200° C. while being sparged with dry nitrogen. After 2 hr, the oil was allowed to cool to 70° C., before adding the metathesis catalyst. The catalyst (Materia C827) was added via canola oil slurry through the top joint of the flask with a nitrogen sweep being maintained throughout the slurry addition. At this time the coil condenser was replaced. The reaction mixture was sparged with nitrogen an additional five minutes, to insure an inert atmosphere, before the nitrogen supply was closed. Metathesis was carried out for 3 hr at 70° C., with no nitrogen sweep, before raising the temperature of the reaction mixture to 100° C. for the purpose of deactivating the catalyst. Following 1 hr at 100° C., the reaction mixture was allowed to cool to ambient temperature overnight, under a slow nitrogen sweep.
The next day, the rubber septum was exchanged for PTFE thermocouple adapter, and the coil condenser was exchanged for a short path distillation head with jacketed condenser equipped with a 100 ml receiving flask. The reaction mixture was stripped to a pot temperature of 250° C. at a pressure of 300 mTorr for 4.5 hr. Stripping resulted in the removal of 17.4 wt. % lights and yielded a slightly burnt looking oil product. Brookfield viscosity of the final product was measured as 710 cP at 40° C. Conversion of the product to its corresponding fatty acid methyl esters was accomplished prior to analysis by gas chromatography. The resulting mixture of fatty acid methyl esters was found to contain 27 wt. % diesters as shown by gas chromatography,
In the Data Sets below, Mn refers to number average molecular weight, Mw refers to weight average molecular weight, Mz refers to z average molecular weight, MP refers to peak molecular weight, PDI refers to polydispersity index, TGA refers to thermogravimetric analysis, and IV refers to intrinsic viscosity. Also, MSBO refers to metathesized soybean oil, MCO refers to metathesized canola oil, and 2× refers to twice metathesized.
In some embodiments, the metathesized natural oil composition is metathesized soybean oil (MSBO). The MSBO was synthesized as follows: Soybean oil (SBO) was charged into a 5 liter reactor with overhead mechanical stirring, nitrogen sparge tube, and nitrogen outlet. The SBO was stirred and sparged with nitrogen for thirty minutes at ambient temperature. The SBO was then heated to 200° C. for two hours, continuously sparging nitrogen. The SBO was cooled to room temperature overnight.
The reaction was stirred and sparged with nitrogen at room temperature for 30 minutes. The sparge tube was pulled above oil level to maintain nitrogen pad during reaction. The SBO was heated to 70° C. When the reactor reached desired temperature 40 ppm of ruthenium catalyst (C827) was added. The reaction was continued until the oil reached a dynamic viscosity of 235 cPs at 25° C. with a spindle speed of 10 RPM. Then, 5 wt % of Oildri B80 clay was added to the reactor, and heated to 80° C. for 1 hour for catalyst removal. The oil/clay mixture was filtered through a sand bed in a pressure filter at 60 PSI. Following filtration, the oil was stripped at 200° C. for 2 hours under vacuum.
The stripped MSBO was then loaded into a reactor equipped with a nitrogen sparge tube, overhead mechanical stirring and nitrogen outlet. The MSBO was sparged with stirring at room temperature for 30 minutes. The reactor was heated to 70° C. and 40 ppm of ruthenium catalyst (C827) was added. The reaction was held at temperature until equilibrium, as determined by stable dynamic viscosity samples (taken at 30 minute intervals), was reached.
Several MSBO samples were analyzed using gel permeation chromatography (or GPC as used herein) and dynamic viscosity (or DV as used herein) at 40° C. The samples (concentration 10 mg/mL in THF) were analyzed using GPC with Agilent 2x Oligopore (300×7.5 mm) columns with THF as the eluting solvent at a constant flow rate of 1 mL/min at 35° C. The GPC system consisted of a Varian Pro-star 210 pump, 410 Auto-sampler, 325 Dual wavelength UV-Vis detector and 356 RI-detector. The molecular weights of the samples were determined using narrow polystyrene (Polymer standard service, Warwick, R.I., USA) GPC calibration standards (MW=17300-162) in Polymer lab and Cirrus GPC analysis software. Anhydrous THE stabilized with BHT was purchased from Pharmco-Aaper and used as received. The dynamic viscosity of these samples, shown in Table 1, indicated that 1064-6-4 is of lower conversion. The dynamic viscosity of the stripped material was not lower than the pre-stripped material (1033-96-7). Sample 1064-6-4 was used to generate the target viscosities for high molecular weight MSBO.
After observing the discontinuity in dynamic viscosity, GPC was utilized to compare the molecular weight distributions. The results are shown in
360 g of high molecular weight MSBO was synthesized in a 500 mL flask. The reaction was carried out using the same method as describe in the previous section, with the exception of catalyst loading and stirring with a magnetic stir bar. In an attempt to slow the reaction down catalyst was loaded at 30 ppm. Samples were taken every ten minutes after catalyst was added. Samples were analyzed using dynamic viscosity and GPC. The kinetic study for high molecular weight MSBO was not taken to equilibrium, as the purpose of this study was to determine the time point at which the target viscosity of 390 cP at 40° C. was achieved. Dynamic viscosity analyses of kinetic samples of high molecular weight MSBO were graphed in reference to time, as shown in
High molecular weight MSBO was blended with MSBO to determine the feasibility of back blending to hit target viscosities. The initial blend was estimated using the weighted average viscosity of the blend. After the initial blend was measured, further blends were adjusted to the target viscosity.
Using the results of the kinetic study and the blending study, a low conversion, high molecular weight MSBO, targeting 390 cP at 40° C. with a speed of 10 RPM, was synthesized. Using 30 ppm ruthenium catalyst (C827), and the time estimate determined by the kinetic study, high molecular weight MSBO was synthesized. During the reaction, samples were taken and analyzed using dynamic viscosity to determine reaction progression, the results of which are listed in Table 4. When the target viscosity was reached, the reaction was stopped by the addition of B80 clay and heating to 80° C. For previous studies of MSBO, the initial rise in viscosity was slow, and as conversion increases, viscosity increased at a faster rate. The extra time, past the target viscosity, was due to the time needed to measure the dynamic viscosity.
The viscosity of the 150° C. stripped sample was 855 cP at 40° C., where the target viscosity for this sample was 567 cP. In order to achieve the target viscosity, the sample was back blended with 24.9 wt % MSBO. This yielded a sample (BB9014) with a viscosity of 590 cP at 40° C. with a speed of 10 RPM. GPC was run on this blend sample for comparison to sample LF 2XMSBO @150° C., and the GPC reports showed similar profiles, as shown in
Another sample stripped at 200° C. also had to be back blended due to overshooting viscosity. After stripping at 200° C. the sample had a viscosity of 1010 cP at 40° C. with a speed of 10 RPM, and 14.4 wt % MSBO was back blended into the sample to yield a sample (BB9015) with a viscosity of 635 cP at 40° C. at 10 RPM. This was close to the target viscosity of 650 cP. GPC was run on the sample for comparison to sample 1064-64. These GPC reports had similar profiles, and similar viscosities, as shown in
Table 7 below states the reaction conditions for several of the lower conversion high molecular weight MSBO samples.
Two batches of MSBO were synthesized as described in Data Set #4. The MSBO was then loaded into a 5 L reactor equipped with a nitrogen sparge tube, overhead mechanical stirring and nitrogen outlet. The MSBO was sparged while stirring at room temperature for 30 minutes. The reactor was heated to 70° C. and the sparging tube was raised above oil level to keep positive nitrogen pressure. Then, 40 ppm of ruthenium catalyst (C827) was added to the reactor. The reaction was held at temperature until equilibrium, as determined by stable dynamic viscosity samples taken at 30-minute intervals, was reached.
Kinetic samples were removed from the reactor and placed into a freezer to stop the reaction progress. When the sample's temperature was below 40° C., dynamic viscosity was measured. After the dynamic viscosity was determined, the sample was placed back into freezer. Upon completion of the reaction, all kinetic samples were removed from the freezer to prepare GPC samples.
Synthesis of high molecular weight MSBO using standard metathesis conditions yielded a product with a pre-stripped viscosity between 1510-1610 cP at 40° C. and 10 RPM. The products viscosity was dependent on the starting MSBO'S viscosity. A lower viscosity starting material will produce a lower viscosity product. A percent difference of 6.8% between MSBO batches led to a 9.5% difference in the pre-stripped high molecular weight MSBO. The difference in the MSBO viscosity was due to 0.4 wt % difference in stripping levels.
Stripping of high molecular weight MSBO was done at 150° C. and 200° C. to show difference in products due to stripping level. Stripping at 150° C. for 2 hours was sufficient to remove any benzene made during the metathesis reaction. Comparison of stripped products was more difficult, as the high molecular weight MSBO was not stripped of the same wt %, and small changes in stripping can have a significant impact on viscosity. The reaction conditions of and viscosities of various MSBO and high molecular weight MSBO products are shown in Table 8 below.
Kinetic samples were evaluated using both GPC and with dynamic viscosity at 40° C. The dynamic viscosity was plotted versus time as shown in
This is a continuation application of International Application PCT/US2013/046735, with an international filing date of Jun. 20, 2013, which claims priority to U.S. Provisional Patent Application No. 61/781,892, filed Mar. 14, 2013, and U.S. Provisional Patent Application No. 61/662,318, filed Jun. 20, 2012; the disclosures of which are incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 61781892 | Mar 2013 | US | |
| 61662318 | Jun 2012 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2013/046735 | Jun 2013 | US |
| Child | 14576807 | US |
