Method to convert fermentation mixture into fuels

Abstract

The present disclosure provides methods to produce ketones suitable for use as fuels and lubricants by catalytic conversion of an acetone-butanol-ethanol (ABE) fermentation product mixture that can be derived from biomass.

Claims

1. A method of producing two or more compounds of Formula I, ##STR00030## wherein each R.sub.1 and R.sub.2 is independently an optionally substituted member selected from the group consisting of alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, and arylalkyl, wherein the method comprises: a) contacting biomass or sugars with a fermentation host to produce a fermentation product mixture, wherein the fermentation product mixture comprises acetone and two or more optionally substituted primary alcohols; b) combining the fermentation product mixture with metal-based catalyst in the presence of base, wherein the metal-based catalyst comprises rhodium, palladium, iridium, or platinum, or a combination thereof; and c) producing two or more compounds of Formula I, wherein at least two of the two or more compounds of Formula I are double-alkylated.

2. The method of claim 1, wherein each R.sub.1 and R.sub.2 is independently an optionally substituted C1-C20 alkyl.

3. The method of claim 1, wherein the biomass or sugars and the fermentation host are further contacted with an extractant having one or more of the following properties: i) is non-toxic to Clostridium; ii) has partition coefficients for acetone and butanol equal to or greater than 1; and iii) has a partition coefficient for ethanol of less than 0.5.

4. The method of claim 3, wherein the extractant is glyceryl tributyrate, glyceryl tripropionate, oleyl alcohol, polypropylene glycol, or a combination thereof.

5. The method of claim 1, wherein the fermentation product mixture has less than 5 wt % water.

6. The method of claim 1, wherein the fermentation product mixture comprises acetone, butanol, and ethanol.

7. The method of claim 1, wherein the metal-based catalyst comprises palladium supported or tethered on a solid support.

8. The method of claim 1, wherein the metal-based catalyst comprises Pd(OAc).sub.2, Pd.sub.2(dba).sub.3, Pd(OH).sub.2/C, Pd/C, Pd/CaCO.sub.3, Pd/Alumina, or Pd-polyethylenimines on silica.

9. The method of claim 1, wherein the base is K.sub.3PO.sub.4, KOH, Ba(OH).sub.2.8H.sub.2O, K.sub.2CO.sub.3, KOAc, KH.sub.2PO.sub.4, Na.sub.2HPO.sub.4, pyridine, Et.sub.3N, or a combination thereof.

10. The method of claim 1, wherein the two or more compounds of Formula I are produced at a temperature between 110 C. to 145 C.

11. The method of claim 1, wherein the two or more compounds of Formula I are produced at a temperature between 140 C. to 220 C.

12. The method of claim 1, wherein the yield of the two or more compounds of Formula I relative to the amount of acetone present in the fermentation product mixture is at least 10%.

13. The method of claim 1, wherein the yield of the double-alkylated compounds of Formula I relative to the amount of acetone present in the fermentation product mixture is at least 10%.

14. The method of claim 13, wherein the metal-based catalyst comprises Pd(OAc).sub.2, Pd.sub.2(dba).sub.3, Pd(OH).sub.2/C, Pd/C, Pd/CaCO.sub.3, Pd/Alumina, Pd-polytheylenimines on silica, PtCl.sub.2(COD), [Rh(COD)Cl].sub.2, or Pt/C.

Description

(1) In certain embodiments, the mixture of alkanes is selected from pentane, heptane, nonane, and undecane. In certain embodiments, the mixture of alkanes is selected from unbranched or branched pentane, unbranched or branched heptane, unbranched or branched nonane, unbranched or branched undecane, unbranched or branched tridecane, and/or unbranched or branched pentadecane. In some embodiments, the mixture of alkanes is selected from pentane, heptane, nonane, 2-methyl-nonane, undecane, 5-ethylundecane, 5,7-diethylundecane, 5,7-dibutylundecane, 9-ethyltridecane, 5,11-diethylpentadecane, 5-butylundecane, and/or 5-butyl-7-ethylundecane. In yet other embodiments, the mixture of alkanes is selected from pentane, heptane, nonane, 2-methyl-nonane, undecane. In yet other embodiments, the mixture of alkanes is selected from 5-ethylundecane, 5,7-diethylundecane, 5,7-dibutylundecane, 9-ethyltridecane, 5,11-diethylpentadecane, 5-butylundecane, and/or 5-butyl-7-ethylundecane.

DESCRIPTION OF THE FIGURES

(2) The present application can be understood by reference to the following description taken in conjunction with the accompanying drawing figures, in which like parts may be referred to by like numerals:

(3) FIG. 1 depicts one exemplary reaction for producing C5-C11 ketones from an ABE-mixture using a palladium-on-carbon (Pd/C) catalyst;

(4) FIG. 2 depicts various exemplary products that may be derived from converting an ABE mixture into double-alkylated ketones;

(5) FIG. 3 is a graph depicting the yield of A-F products from varying the metal-based catalysts in the alkylation of acetone in ABE mix;

(6) FIG. 4 is a graph depicting the yield of A-F products from varying the base in the alkylation of acetone in ABE mix;

(7) FIG. 5 is a graph depicting the yield of A-F products from varying the palladium-based catalyst in the alkylation of acetone in ABE mix;

(8) FIGS. 6A and 6B are graphs depicting the yield of A-F products from varying the temperature and the amount of base, respectively, in the alkylation of acetone in ABE mix;

(9) FIG. 7 is a graph depicting the yield of A-F products from varying the solvent in the alkylation of acetone in ABE mix;

(10) FIG. 8 is a graph depicting the product distribution of A-F products at specific times, from 15-1200 minutes;

(11) FIG. 9 is a graph depicting the yield of ketones and alcohols from varying the amount of base (mol % of K.sub.3PO.sub.4);

(12) FIG. 10 is a graph depicting the yield of ketones (A-F products) from the recycling of the catalyst (Pd/C) through three cycles;

(13) FIG. 11 is an exemplary reaction scheme for producing C11-C27 ketones from an ABE-mixture;

(14) FIG. 12 is a scheme depicting three exemplary reactions for producing biodiesel from an ABE-mixture;

(15) FIG. 13 is a process flow diagram for an exemplary process to convert the product mixture from an ABE fermentation to C5-C11 ketones;

(16) FIG. 14 depicts the time course of product formation in an exemplary fed-batch extraction fermentation of glucose with glyceryl tributyrate, in which the top graph shows the product formation in the extractant phase and the bottom graph shows the production formation in the aqueous phase;

(17) FIG. 15 depicts the time course of product formation in an exemplary fed-batch extraction fermentation of sucrose with glyceryl tributyrate, in which the top graph shows the product formation in the extractant phase and the bottom graph shows the production formation in the aqueous phase;

(18) FIG. 16 is a graph depicting the effect of water addition on alkylation reactions of an ABE-mixture;

(19) FIG. 17 is a graph that shows the product distribution over time during an exemplary palladium-catalyzed alkylation reaction of an ABE mixture, where o 2-pentanone, 4-heptanone, + 2-heptanone, 4-nonanone, 2-methyl-4-nonanone, 6-undecanone; and

(20) FIG. 18 is a graph showing the effect of inhibitors on ABE fermentation without extractant based on the amount of acetone, butanol and ethanol produced.

DETAILED DESCRIPTION

(21) The following description sets forth numerous exemplary configurations, processes, parameters, and the like. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure, but is instead provided as a description of exemplary embodiments.

(22) As used herein, fuel refers to a composition made up of a compound containing at least one carbon-hydrogen bond, which produces heat and power when burned. Fuel may be produced using plant-derived biomass as a feedstock, for example from the lignin biopolymer of lignocellulose. Fuel may also contain more than one type of compound, and includes mixtures of compounds. As used herein, the term transportation fuel refers to a fuel that is suitable for use as a power source for transportation vehicles.

(23) As used herein, the terms alkyl, alkenyl and alkynyl include straight-chain and branched-chain monovalent hydrocarbyl radicals, and combinations of these, which contain only C and H when they are unsubstituted. Examples include methyl, ethyl, propyl, isopropyl, butyl, 2-propenyl, 3-butynyl, and the like. The total number of carbon atoms in each such group is sometimes described herein, e.g., when the group can contain up to ten carbon atoms it can be represented as 1-10C or as C1-C10 or C1-10. When heteroatoms (N, O and S typically) are allowed to replace carbon atoms as in heteroalkyl groups, for example, the numbers describing the group, though still written as for example C1-C6, represent the sum of the number of carbon atoms in the group plus the number of such heteroatoms that are included as replacements for carbon atoms in the ring or chain being described.

(24) Alkyl, alkenyl and alkynyl groups are often substituted to the extent that such substitution makes sense chemically. Typical substituents may include, for example, halo, O, NCN, NOR, NR, OR, NR.sub.2, SR, SO.sub.2R, SO.sub.2NR.sub.2, NRSO.sub.2R, NRCONR.sub.2, NRCOOR, NRCOR, CN, COOR, CONR.sub.2, OOCR, COR, and NO.sub.2, wherein each R is independently H, C1-C8 alkyl, C2-C8 heteroalkyl, C3-C8 heterocyclyl, C4-C10 heterocyclylalkyl, C1-C8 acyl, C2-C8 heteroacyl, C2-C8 alkenyl, C2-C8 heteroalkenyl, C2-C8 alkynyl, C2-C8 heteroalkynyl, C6-C10 aryl, or C5-C10 heteroaryl, and each R is optionally substituted with halo, O, NCN, NOR, NR, OR, NR.sub.2, SR, SO.sub.2R, SO.sub.2NR.sub.2, NRSO.sub.2R, NRCONR.sub.2, NRCOOR, NRCOR, CN, COOR, CONR.sub.2, OOCR, COR, and NO.sub.2, wherein each R is independently H, C1-C8 alkyl, C2-C8 heteroalkyl, C3-C8 heterocyclyl, C4-C10 heterocyclylalkyl, C1-C8 acyl, C2-C8 heteroacyl, C6-C10 aryl or C5-C10 heteroaryl. Alkyl, alkenyl and alkynyl groups can also be substituted by C1-C8 acyl, C2-C8 heteroacyl, C6-C10 aryl or C5-C10 heteroaryl, each of which can be substituted by the substituents that are appropriate for the particular group. Where a substituent group contains two R or R groups on the same or adjacent atoms (e.g., NR.sub.2, or NRC(O)R), the two R or R groups can optionally be taken together with the atoms in the substituent group to which the are attached to form a ring having 5-8 ring members, which can be substituted as allowed for the R or R itself, and can contain an additional heteroatom (N, O or S) as a ring member.

(25) Alkanone refers to a ketone compound in a linear or branched arrangement. Examples of alkanones include pentanone, heptanone, heptanone, nonanone, and undecanone. In certain embodiments, the alkanones have a linear arrangement, such as 2-pentanone, 4-heptanone, 2-heptanone, 4-nonanone, and 6-undecanone. In other embodiments, the alkanones have a branched arrangement, such as 2-methyl-4-nonanone. Preferred alkanones include those with at least five carbons (C5+ alkanones), at least seven carbons (C7+ alkanones), at least nine carbons (C9+ alkanones), or at least (C11+ alkanones), or between five and twenty carbons (C5-C20 alkanones), between seven and twenty carbons (C7-C20 alkanones), or between eleven and twenty carbons (C11-C20 alkanones). In other embodiments, the alkanone may be substituted with substitutents that are suitable for the alkyl group as described above.

(26) Heteroalkyl, heteroalkenyl, and heteroalkynyl and the like are defined similarly to the corresponding hydrocarbyl (alkyl, alkenyl and alkynyl) groups, but the hetero terms refer to groups that contain 1-3 O, S or N heteroatoms or combinations thereof within the backbone residue; thus at least one carbon atom of a corresponding alkyl, alkenyl, or alkynyl group is replaced by one of the specified heteroatoms to form a heteroalkyl, heteroalkenyl, or heteroalkynyl group. The typical and preferred sizes for heteroforms of alkyl, alkenyl and alkynyl groups are generally the same as for the corresponding hydrocarbyl groups, and the substituents that may be present on the heteroforms are the same as those described above for the hydrocarbyl groups. For reasons of chemical stability, it is also understood that, unless otherwise specified, such groups do not include more than two contiguous heteroatoms except where an oxo group is present on N or S as in a nitro or sulfonyl group.

(27) Cycloalkyl may be used herein to describe a carbocyclic non-aromatic group that is connected via a ring carbon atom, and cycloalkylalkyl may be used to describe a carbocyclic non-aromatic group that is connected to the molecule through an alkyl linker. Examples of cycloalkyl substitutents may include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and decahydronaphthalenyl. Similarly, heterocyclyl may be used to describe a non-aromatic cyclic group that contains at least one heteroatom as a ring member and that is connected to the molecule via a ring atom, which may be C or N; and heterocyclylalkyl may be used to describe such a group that is connected to another molecule through a linker. The sizes and substituents that are suitable for the cycloalkyl, cycloalkylalkyl, heterocyclyl, and heterocyclylalkyl groups are the same as those described above for alkyl groups. As used herein, these terms also include rings that contain a double bond or two, as long as the ring is not aromatic.

(28) Arylalkyl groups as used herein are hydrocarbyl groups, and may be described by the total number of carbon atoms in the ring and alkylene or similar linker. Thus, a benzyl group is a C7-arylalkyl group, and phenylethyl is a C8-arylalkyl.

(29) Heteroarylalkyl as described above refers to a moiety that includes an aryl group that is attached through a linking group, and differs from arylalkyl in that at least one ring atom of the aryl moiety or one atom in the linking group is a heteroatom selected from N, O and S. The heteroarylalkyl groups are described herein according to the total number of atoms in the ring and linker combined, and they include aryl groups linked through a heteroalkyl linker; heteroaryl groups linked through a hydrocarbyl linker such as an alkylene; and heteroaryl groups linked through a heteroalkyl linker. Thus, for example, C7-heteroarylalkyl would include pyridylmethyl, phenoxy, and N-pyrrolylmethoxy.

(30) In general, any alkyl, cycloalkyl, alkenyl, alkynyl, aryl or arylalkyl group or any heteroform of one of these groups that is contained in a substituent may itself optionally be substituted by additional substituents. The nature of these substituents is similar to those recited with regard to the primary substituents themselves if the substituents are not otherwise described. However, alkyl substituted by aryl, amino, alkoxy, O, and the like would be included within the scope of the invention, and the atoms of these substituent groups are not counted in the number used to describe the alkyl, alkenyl, etc. group that is being described. Where no number of substituents is specified, each such alkyl, alkenyl, alkynyl, or aryl group may be substituted with a number of substituents according to its available valences; in particular, any of these groups may be substituted with fluorine atoms at any or all of its available valences, for example.

(31) Heteroform as used herein refers to a derivative of a group such as an alkyl, aryl, or acyl, wherein at least one carbon atom of the designated carbocyclic group has been replaced by a heteroatom selected from N, O and S. Thus the heteroforms of alkyl, alkenyl, alkynyl, acyl, aryl, and arylalkyl are heteroalkyl, heteroalkenyl, heteroalkynyl, heteroacyl, heteroaryl, and heteroarylalkyl, respectively. It is understood that no more than two N, O or S atoms are ordinarily connected sequentially, except where an oxo group is attached to N or S to form a nitro or sulfonyl group.

(32) Optionally substituted as used herein indicates that the particular group or groups being described may have no non-hydrogen substituents, or the group or groups may have one or more non-hydrogen substituents. If not otherwise specified, the total number of such substituents that may be present is equal to the number of H atoms present on the unsubstituted form of the group being described. Where an optional substituent is attached via a double bond, such as a carbonyl oxygen (O), the group takes up two available valences, so the total number of substituents that may be included is reduced according to the number of available valences.

(33) Halo, as used herein includes fluoro, chloro, bromo, and iodo.

(34) Amino as used herein refers to NH.sub.2, but where an amino is described as substituted or optionally substituted, the term includes NRR wherein each R and R may independently be H, or is an alkyl, alkenyl, alkynyl, acyl, aryl, or arylalkyl group or a heteroform of one of these groups, and each of the alkyl, alkenyl, alkynyl, acyl, aryl, or arylalkyl groups or heteroforms of one of these groups is optionally substituted with the substituents described herein as suitable for the corresponding group. The term also includes forms wherein R and R are linked together to form a 3-8 membered ring which may be saturated, unsaturated or aromatic and which contains 1-3 heteroatoms independently selected from N, O and S as ring members, and which is optionally substituted with the substituents described as suitable for alkyl groups or, if NRR is an aromatic group, it is optionally substituted with the substituents described as typical for heteroaryl groups.

(35) As used herein, primary alcohol refers to an alcohol where the carbon carrying the OH group is only attached to one alkyl group. Examples of primary alcohols may include methanol, ethanol, 1-propanol, 2-methyl-1-propanol, butanol, and pentanol. As used herein, secondary alcohol refers to an alcohol where the carbon carrying the OH group is attached to two alkyl groups. Examples of secondary alcohols may include 2-propanol, and cyclohexanol. As used herein, tertiary alcohol refers to an alcohol where the carbon carrying the OH group is attached to three alkyl groups. Examples of tertiary alcohols may include 2-methyl-2-butanol.

(36) As used herein, the term yield refers to the total amount of product relative to the amount of ketone present in the fermentation product mixture. For example, with reference to FIG. 1, the overall reaction yield refers to the combined molar yields of products A-F, calculated with respect to the molar amount of acetone present as a starting material in the fermentation product mixture.

(37) As used herein, the term about refers to an approximation of a stated value within an acceptable range. Preferably, the range is +/10% of the stated value.

(38) The following description relates to a process for converting a fermentation product mixture produced from biomass-derived sugars (e.g., glucose, sucrose, cellobiose, xylose) into fuels employing metal-catalyzed alkylation. With reference to FIG. 1, reaction 100 is an exemplary embodiment for producing C5-C11 ketones suitable for use in fuels. Starting materials 102 is an acetone-butanol-ethanol (ABE) mixture, produced by fermentation of biomass-derived sugars using Clostridia bacteria. This fermentation process produces an ABE mixture in a mass ratio of 3:6:1, respectively (or a molar ratio of 2.3:3.7:1). The acetone in the ABE mixture undergoes mono- and double-alkylation in the presence of metal-based catalyst 104 (i.e., Pd/C) and base 106 (i.e., K.sub.3PO.sub.4) in solvent 108 (i.e., toluene), at a reaction temperature of 145 C. over 20 hours. These reaction conditions yield products 110, which includes 2-pentanone (A), 4-heptanone (B), 2-heptanone (C), 4-nonanone (D), 2-methyl-4-nonanone (E), and 6-undecanone (F). Among these products, B, D and F are produced by double-alkylation of acetone.

(39) Under the reactions conditions described herein, in some preferred embodiments, the formation of one or more Guerbet products (e.g., aldehydes) in the product mixture is minimized. In certain preferred embodiments, ketone alkyation predominates, which yields a higher proportion of double-alkylated compounds in the product mixture. The reaction conditions described herein allow for greater kinetic control of the alkylation reaction to produce higher molecular weight ketones that are suitable for jet and diesel fuel compounds (e.g., C5-C20 alkanones).

(40) The process described herein employs various components, including a fermentation product mixture obtained from a fermentation process, a metal-based catalyst, a base, and solvent, to carry out the alkylation of a ketone, such as acetone, in the presence of two or more alcohols to produce one or more products suitable for use as fuels and other chemicals.

(41) The Fermentation Product Mixture

(42) The fermentation product mixture described herein may be derived from renewable sources, such as biomass. In some embodiments, the biomass is first converted into sugars, which is then used as the feedstock to produce the fermentation product mixture. Sugars suitable for use as feedstock to produce the fermentation product mixture may include, for example, monosaccharides, disaccharides, or oligosaccharides. In certain embodiments, the sugars may include any C5 saccharides or C6 saccharides, or a combination of C5 and C6 saccharides. In other embodiments, the sugars may include arabinose, lyxose, ribose, xylose, ribulose, xylulose, allose, altrose, glucose, sucrose, cellobiose, mannose, gulose, idose, galactose, talose, psicose, fructose, sorbose, or tagatose, or a mixture thereof. In one embodiment, the sugars may include glucose, sucrose or xylose, or a mixture thereof. In another embodiment, the sugars may include glucose or sucrose, or a mixture thereof. Any methods known in the art may be employed to produce sugars from the biomass. For example, the biomass may undergo pretreatment processes known in the art to more effectively liberate sugars from the biomass. The biomass is typically made up of organic compounds that are relatively high in oxygen, such as carbohydrates, and may also contain a wide variety of other organic compounds. In some embodiments, the biomass is made up of cellulose, hemicellulose, and/or lignin.

(43) It should be understood, however, that in other embodiments, the sugars used as feedstock in the fermentation process may be derived from non-renewable sources, or from both renewable and non-renewable sources.

(44) The fermentation product mixture may include a ketone and one or more alcohols. In certain embodiments, the fermentation product mixture may include a ketone and one alcohol, or a ketone and two alcohols. In certain embodiments, the ketone is acetone. The fermentation product mixture may be an ABE mixture produced by fermenting sugars using any host capable of producing hydrocarbons (e.g., ethanol and heavier hydrocarbons). For example in some embodiments, the fermentation host is bacteria from the Clostridia family (e.g., Clostridium acetobutylicum, Clostridium beijerinckii). Clostridia bacteria have the ability to convert biomass-derived carbohydrates into an ABE mixture from both hexoses and pentoses. It should be understood, however, that any fermentation host capable of converting sugars into a mixture of a ketone and one or more alcohols may be employed to provide the starting materials for the process described herein.

(45) In some embodiments, the fermentation product mixture may be used without further purification or isolation steps after the fermentation process. In other embodiments, the fermentation product mixture is isolated after the fermentation process. Any techniques known in the art may be used to isolate the fermentation product mixture (e.g., ABE mixture) after the fermentation process.

(46) While an ABE mixture is used as the starting materials in reaction 100, the starting materials used in the process described herein are not limited to butanol and ethanol as the alcohols. The alcohols may be any length. In some embodiments, the fermentation product mixture may include primary alcohols including, for example, methanol, ethanol, propanol, 2-methylpropan-1-ol, butanol, pentanol, and 2-ethyl-1-hexanol.

(47) While the ABE mixture in reaction 100 has a mass ratio of 3:6:1, the ratio of acetone to the two or more primary alcohols may vary. For example, the fermentation process may be optimized to reduce the amount of ethanol produced, so as to maximize butanol yields.

(48) Additional ketones and alcohols may be added to the fermentation product mixture to vary the range of molecular weights and structures obtained from the process described herein. In some embodiments, these additional ketones and alcohols may be added to the fermentation product mixture before use in the reaction with the catalyst and base. In other embodiments, these additional ketones and alcohols may be added during the reaction. These additions to the fermentation product mixture may be useful for improving the product properties for specific applications, such as biodiesel or lubricants. The alcohols and ketones added to the fermentation product mixture may be saturated or unsaturated. For example, oleyl alcohol may be added to the fermentation product mixture to adjust the molecular weight of the products produced by the methods described herein for use as lubricants.

(49) The fermentation product mixture may also include bio-derived ketones through ketonization of volatile fatty acids. For example, acetic acid may be ketonized via fermentation to form acetone, which can be converted into a mix of higher ketones using the methods described herein to produce gasoline and gasoline precursors. Propionic acid may also be ketonized via fermentation to form 3-pentanone, which can be converted into a mix of higher ketones using the methods described herein to produce gasoline and gasoline precursors.

(50) Further, in some embodiments, an extractant may also be used to selectively extract the fermentation product mixture from the aqueous phase into an organic (water immiscible) phase. In some embodiments, an extractant is a chemical used to recover certain products from the fermentation broth. For example, in one embodiment, an extractant is a chemical used to recover acetone and butanol from the fermentation broth. Suitable extractants may include tributyrin (also known as glyceryl tributyrate), oleyl alcohol, polypropylene glycol (of varying molecular weights), or mixtures of these extractants. In some embodiments, the extractant does not inhibit the growth of the microorganism producing the fermentation product mixture, or decrease the rate of formation of the fermentation products. In certain embodiments, the extractant can be chosen from a class of materials that are (a) not inhibitory to microorganisms (b) have very low solubility in water, and (c) have very low water solubility, referring to the amount of water that can be dissolved in the extractant.

(51) In certain embodiments, in situ extraction may be conducted during the fermentation, and can reduce the inhibitory effect of some of products generated from the fermentation process. For example, the fermentation process described above may yield metabolites, which have inherent toxicity that may affect the catalysis of the alkylation reaction under aqueous conditions. The use of a selective, non-toxic, water-immiscible extractant can remove in situ inhibitory metabolites produced during fermentation. Removal of such inhibitory products can increase solvent titers and yields, lower distillation costs, and reduce water usage and reactor sizes. When used during fermentation, the extractant employed should be non-inhibitory.

(52) In other embodiments, an extractant may be used on the fermentation product mixture after fermentation has taken place to selectively extract certain components of the fermentation product mixture from the aqueous phase into the organic phase. For example, in one embodiment, an extractant such as tributyrin may be used on the fermentation product mixture to relative amounts of acetone and butanol in the fermentation product mixture used in the alkylation reactions described herein. Such fermentation products can be recovered from the extractant by distillation. When the boiling points of the extractants employed are much higher than those of the fermentation products, the energy requirements for distillation can be reduced. Since the extractants have very little solubility for water, almost no water is present in the extractant, leaving primarily the fermentation products.

(53) Thus, in some embodiments, an extractant can selectively separate acetone and butanol from an ABE mixture in ratios suitable for subsequent alkylation reactions to yield fuel products, and minimize the amount of ethanol extracted. Minimizing the amount of ethanol in the ABE mixture undergoing alkyation may, in some instances, be desirable for controlling the molecular weight of the products, such as for producing longer chained products. The addition of an extractant to the fermentation culture may, in certain embodiments, reduce the formation the Guerbet product. In certain embodiments, the addition of an extractant to the fermentation culture produces at least 40%, 50%, 60%, 70%, 80% or 90% double-alkylated products.

(54) The use of an extractant, in certain embodiments, affords simultaneous removal of residual inhibitors and the desired product during biofuel fermentation, a key advantage over existing recovery technologies.

(55) Other techniques known in the art may be used to selectively separate ketones and alcohols from a fermentation mixture (e.g., acetone and butanol from an ABE mixture) for subsequent alkylation reactions to yield fuel products. For example, pervaporation is a membrane separation technique that can be utilized to separate liquid mixtures through a membrane via a solution-diffusion mechanism. First, permeation through the membrane takes place, and then the permeate is collected as a vapor on the other side of the membrane. The evaporation of the permeate on the permeate side of the membrane creates the driving force for the transfer of the permeate. The pervaporation membrane behaves as a selective barrier between the feed and the permeate; therefore, the selection of the pervaporation membrane is crucial to achieve high selectivity and fluxes. The permeability of the components through the membrane is the multiplication of their diffusion and solubility in the membrane material. For instance, for pervaporation of alcohol-water mixtures, the diffusivity of water is greater than the diffusivity of the alcohol due to the smaller dimension of the water molecule. Therefore, a membrane material with higher alcohol solubility should be selected to obtain high alcohol permselectivity. Polydimethylsiloxane (PDMS) is well known as a membrane material for ethanol separation from dilute aqueous ethanol mixture due to its hydrophobic nature and high free volume which allows excellent selectivity and high fluxes.

(56) Thus, in some embodiments, the methods described herein further include providing a pervaporation membrane, and contacting the fermentation product mixture with the pervaporation membrane to selectively separate the ketone and certain alcohols. In one embodiment, the pervaporation membrane is PDMS. In another embodiment, the pervaporation membrane is a poly(styrene-b-dialkylsiloxane-b-styrene) triblock copolymer that has a polydialkylsiloxane block and polystyrene end blocks. In certain embodiments, the triblock copolymer has a molecular weight in the range of about 110 kg/mol to about 1000 kg/mol. In other embodiments, the triblock copolymer has a molecular weight in the range of about 110 kg/mol to about 500 kg/mol. In some embodiments, the triblock copolymer has a molecular weight in the range of about 120 kg/mol to about 300 kg/mol. In some embodiments, the triblock copolymer has a molecular weight in the range of about 130 kg/mol to about 300 kg/mol. In some embodiments, the triblock copolymer has a morphology, and wherein the morphology is a cylindrical, lamellar, double diamond, or gyroid morphology. In some embodiments, the triblock copolymer has a morphology, and wherein the morphology is a cylindrical or lamellar morphology. In some embodiments, the triblock copolymer has a morphology, and wherein the morphology is a cylindrical morphology. In some embodiments, the triblock copolymer has a domain spacing (d), and wherein the domain spacing is in the range of about 20 to about 90 nanometers. In some embodiments, the triblock copolymer loses about 5% of weight at a temperature in the range of about 290 C. to about 350 C. In some embodiments, the polydialkylsiloxane is polydimethylsiloxane. In some embodiments, the polydialkylsiloxane block has a volume fraction of about 0.6 to about 0.95 relative to the polystyrene end blocks.

(57) The Metal-Based Catalyst

(58) While Pd/C is employed as metal-based catalyst 104 in reaction 100, any metal-based catalyst that can catalyze the alkylation of a ketone, while reducing the oligomerization of the ketone and formation the Guerbet product, may be employed in the process described herein. In other embodiments, any metal-based catalyst that can catalyze the double alkylation of acetone, while reducing the oligomerization of acetone and formation the Guerbet product, may be employed in the process described herein. For example, the metal-based catalyst may include transition metals such as nickel, ruthenium, rhodium, palladium, rhenium, iridium, or platinum. In other embodiments, the metal-based catalyst includes palladium or platinum. In certain embodiments, the metal-based catalyst is [Ir(COD)Cl].sub.2, RuCl.sub.2(COD), PtCl.sub.2(COD), [Rh(COD)Cl].sub.2, Ni/Si-Alumina, Ru/C, Rh/C, Pt/C, or Pd/C.

(59) In yet other embodiments, the metal-based catalyst is a palladium-based catalyst. Palladium-based catalysts may include palladium metal, and complexes of suitable ligands including those containing P and/or N atoms for coordinating to the palladium atoms, and other simple palladium salts either in the presence or absence of ligands. Palladium-based catalysts may also include palladium and palladium complexes supported or tethered on solid supports, such as palladium on carbon (Pd/C), as well as palladium black, palladium clusters, or palladium clusters containing other metals. Suitable examples of palladium-based catalysts may include Pd(OAc).sub.2, Pd.sub.2(dba).sub.3, Pd(OH).sub.2/C, Pd/C, Pd/CaCO.sub.3, Pd/Alumina, and Pd-polyethylenimines on silica.

(60) The metal-based catalyst may be recycled in the methods described herein. For example, additional fermentation product mixture (e.g., ABE mix) may be added to the reaction vessel to further increase the overall product yield.

(61) The Base

(62) While K.sub.3PO.sub.4 is employed as base 106 in reaction 100, any base that promotes alkylation of the ketone may be used. In certain embodiments, any base that promotes double alkylation of acetone. In other embodiments, the base may also promote the reduction of the oligomerization of the ketone and formation the Guerbet product.

(63) Suitable bases may include inorganic bases (e.g., hydroxides of alkali metals and alkaline earth metals), and organic bases. Examples of inorganic bases may include potassium hydroxide, barium hydroxide, cesium hydroxide, sodium hydroxide, strontium hydroxide, calcium hydroxide, lithium hydroxide, rubidium hydroxide, magnesium hydroxide. Examples of organic bases may include triethylamine, trimethylamine, pyridine, and methyl amine. In some embodiments, the base is KOH, Ba(OH).sub.2.8H.sub.2O, K.sub.2CO.sub.3, KOAc, KH.sub.2PO.sub.4, Na.sub.2HPO.sub.4, pyridine, or Et.sub.3N.

(64) The type of base used may be determined by the desired strength of the base and its ability to promote alkylation of a ketone, without producing undesirable side reactions or side products. The amount of base selected may affect the overall reaction yield, and the proportion of alkylated products. In certain embodiments, the type of base used may be determined by the desired strength of the base and its ability to promote double alkylation of acetone, without producing undesirable side reactions or side products. The amount of base selected may affect the overall reaction yield, and the proportion of double-alkylated products. For example, increasing the amount of base increases the overall reaction yield, as well as the selectivity for double-alkylation. In some embodiments, at least 0.3 mole equivalents of base are used. In other embodiments, between 0.32 to 1.3 mole equivalents of base are used. In yet other embodiments, between 0.9 to 1.5 mole equivalents of base are used. In yet other embodiments, between 0.95 to 1.3 mole equivalents of base are used. In certain embodiments, 0.95 mole equivalents of base are used.

(65) In yet other embodiments, the base used may be calcined. In such embodiments, the base can be pretreated at a high temperature to obtain a more active material. For example, in one embodiment where K.sub.3PO.sub.4 is the base used, the K.sub.3PO.sub.4 may be heated at about 600 C. to obtain a material that is more active in promoting the alkylation reaction described herein.

(66) The Solvent

(67) While toluene is employed as solvent 108 in reaction 100, it should be recognized that in some embodiments, the reaction may be performed neat, i.e., without addition of a solvent. In other embodiments, the reaction may be performed with a solvent. Any solvent that promotes alkylation of the ketone may be employed in the process described herein. In certain embodiments, any solvent that promotes double alkylation of acetone may be employed in the process described herein. For example, the solvent may be an organic solvent. Organic solvents may include hydrocarbons (e.g., toluene, benzene), ketones (e.g., acetone or methyl ethyl ketone), acetates (e.g., ethyl acetate or isopropylacetate), nitriles (e.g., acetonitrile), alcohols (e.g., butanol, ethanol, isopropanol), or ethers (e.g., diglyme, monoglyme, diglybu, THF). As used herein, diglyme refers to diethylene glycol dimethyl ether. As used herein, diglybu refers to diethylene glycol dibutyl ether.

(68) A suitable solvent employed in the process described herein is one that may be used in the fermentation process, may be used in the extraction of the fermentation product mixture from the fermentation process, or may be blended directly with the products from the fermentation process. Other considerations include the promotion of the reaction rate, the formation of the reaction products, and the reduction of the Guerbet product and oligomerization of the ketone (e.g., acetone). In some embodiments, the solvent may include toluene, ethyl acetate, diglyme, monoglyme, butanol, diglybu, oleyl alcohol, dibutyl phthalate, or mixtures of these solvents.

(69) The Reaction Conditions

(70) a) Reaction temperature

(71) While the mixture in reaction 100 was heated to 145 C., the temperature to which the reaction mixture is heated may vary. In some embodiments, the reaction mixture is heated to reflux. In other embodiments, the reaction mixture is heated to a temperature suitable to increase selectivity for double-alkylated products.

(72) The preferred temperature range may vary depending on the solvent, base, and catalyst used. For example, in a reaction mixture with toluene as the solvent, the preferred reaction temperature range is between about 110 C. to 145 C. In other embodiments, the reaction temperature range may increased to between, for example, 140 C. and 180 C. to increase selectivity for double-alkylated products.

(73) b) Reaction Time

(74) While the mixture in reaction 100 was reacted for 20 hours, the time of the reaction will also vary with the reaction conditions and desired yield. In some embodiments, the reaction time is determined by the rate of conversion of the starting material. In other embodiments, the reaction time is determined by the rate of double-alkylation of the starting material. In other embodiments, the reaction mixture is heated for 10 to 30 hours. In other embodiments, the reaction mixture is heated for 10 to 20 hours. In yet other embodiments, the reaction mixture is heated for 1 to 10 hours. In yet other embodiments, the reaction mixture is heated for 5 to 10 hours.

(75) Further, it should be understood that the reaction can be tuned to produce gasoline versus jet/diesel products. In some embodiments, gasoline products may include the shorter-chained products, such as 2-pentanone, 4-heptanone, and 2-heptanone. In other embodiments, jet/diesel products may include the heavier-chained products, such as 4-nonanone, 2-methyl-4-nonanone, and 6-undecanone.

(76) With reference to FIGS. 6A, 6B and 17, in some embodiments, gasoline products may be produced at lower temperatures, lower base loadings and shorter reaction times. In some embodiments, gasoline products may be produced at higher yields relative to jet/diesel products when one or more of the following conditions occur: (a) temperature is between 90 C. and 170 C.; (b) between 1 and 3 mole equivalents of base are used; and (c) the reaction mixture is heated for less than about 90 minutes. In other embodiments, gasoline products may be produced at higher yields relative to jet/diesel products when one or more of the following conditions occur: (a) temperature is between 100 C. and 120 C.; (b) between 1.2 and 1.7 mole equivalents of base are used; and (c) the reaction mixture is heated for less than about 60 minutes. In yet other embodiments, gasoline products may be produced at higher yields relative to jet/diesel products when one or more of the following conditions occur: (a) temperature is about 110 C.; (b) about 1.5 mole equivalents of base are used; and (c) the reaction mixture is heated for between 10 to 60 minutes. In some embodiments, two or more of the conditions may occur to produce gasoline products at higher yields relative to jet/diesel fuel products. In other embodiments, all three conditions may occur to produce gasoline products at higher yields relative to jet/diesel products.

(77) Further, it should be understood that, in other embodiments, jet/fuel products may be produced at higher temperatures, higher base loadings and longer reaction times. In some embodiments, jet/diesel products may be produced at higher yields relative to gasoline products when one or more of the following conditions occur: (a) temperature is above 170 C.; (b) between 3 and 9 mole equivalents of base are used; and (c) the reaction mixture is heated for greater than about 90 minutes. In other embodiments, jet/diesel products may be produced at higher yields relative to gasoline products when one or more of the following conditions occur: (a) temperature is between 180 C. and 240 C.; (b) between 4.5 and 6 mole equivalents of base are used; and (c) the reaction mixture is heated for between 2 and 25 hours. In yet other embodiments, jet/diesel products may be produced at higher yields relative to gasoline products when one or more of the following conditions occur: (a) temperature is about 180 C.; (b) about 6 mole equivalents of base are used; and (c) the reaction mixture is heated for between 90 to 200 minutes. In some embodiments, two or more of the conditions may occur to produce jet/diesel products at higher yields relative to gasoline products. In other embodiments, all three conditions may occur to produce jet/diesel products at higher yields relative to gasoline products.

(78) The Ketones and their Uses

(79) The reaction conditions described herein allows for greater control of the molecular weight of the ketones (e.g., alkanones) produced. In certain embodiments, the reaction conditions yields alkanones with molecular weights suitable for use as fuels Alkanones suitable for use as fuels may include those with at least 5 carbons, at least 7 carbons, or at least 11 carbons. In certain embodiments, the alkanones produced using the methods described herein are unbranched. In other embodiments, the alkanones produced are branched.

(80) While reaction 100 produces products 110 that is made up of products A-F, including double-alkylated products such as 4-heptanone (B), 4-nonanone (D), and 6-undecanone (F), it should be understood that the product mixture may vary depending on the composition of the fermentation product mixture used and reaction conditions employed in the process described herein.

(81) In certain embodiments, R.sub.1 and R.sub.2 may be independently substituted or unsubstituted alkyls. The alkyls may be any length. In some embodiments, each R.sub.1 and R.sub.2 is independently methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, or heptyl.

(82) In other embodiments, the one or more compounds of Formula I are C5-C19 ketones. In other embodiments, the one or more compounds of Formula I are C5-C11 ketones. In yet other embodiments, the one or more compounds of Formula I are C11-C19 ketones.

(83) In certain embodiments, the one or more compounds of Formula I may include

(84) ##STR00008## ##STR00009##

(85) While mono-alkylated products may be produced according to the process described herein, in certain embodiments, at least one of one or more compounds of Formula I is a double-alkylated product. In some embodiments, at least 50% of the product mixture is made up of one or more double-alkylated products. In other embodiments, less than 20% of the product mixture is made up of one or more mono-alkylated products.

(86) Following the production of one or more compounds of Formula I, these one or more compounds may be further hydrogenated, deformylated, isomerized, hydrodeoxygenated, or catalytically reformed. The double-alkylated products may be subsequently converted to either corresponding alcohols or alkanes, suitable for the manufacture of a fuel or lubricant.

(87) Examples of alcohols produced from the methods described herein include:

(88) ##STR00010## ##STR00011##

(89) Examples of alcohols produced from the methods described herein include:

(90) ##STR00012##

(91) In some embodiments, the one or more compounds of Formula I may be converted into their corresponding alcohols in the presence of a metal-based catalyst. In certain embodiments, the metal-based catalyst includes platinum. In a specific embodiment, the second metal-based catalyst is palladium on carbon (Pd/C).

(92) In other embodiments, the one or more compounds of Formula I may be converted into their corresponding alkanes in the presence of a metal-based catalyst. In certain embodiments, the metal-based catalyst includes platinum, nickel-molybdenum (NiMo), nickel-tungsten (NiW), cobalt-molybdenum (CoMo), or combinations of these metals. In specific embodiments, the second metal-based catalyst is NiOMoO.sub.3/Al.sub.2O.sub.3, Pt/SiO.sub.2Al.sub.2O.sub.3, or combinations of these catalysts.

(93) FIG. 2 depicts an exemplary embodiment of C7-C11 alkanes produced by double-alkylation of the ABE mixture using the process described herein that may be converted into a fuel or lubricant. For example, 4-heptanone, 4-nonanone, and 6-undecanone, may be further deoxygenated to produce heptane, nonane, and undecane, respectively. These alkanes may be blended into diesel and jet fuel, or may be used independently as fuels following minor refinery upgrading. In some embodiments, the double-alkylated products obtained from the process described herein may be suitable for use as fuels that can power transportation vehicles (e.g., jets, diesel vehicles) and other combustion turbine applications.

(94) It should be understood that the methods described herein may produce a mixture of compounds of Formula I or a mixture of alkanones. In certain embodiments, each of the compounds of Formula I, or each of the alkanones, in the product mixture can be separated before use in producing the corresponding alcohol or alkane.

(95) Other Reactions to Produce Biodiesel

(96) The alkylation of the fermentation product mixture using the methods described herein may produce an amount of Guerbet product. As depicted in FIG. 11, an exemplary reaction scheme, the dimerization of butanol via Guerbet reaction may be followed by alkylation with acetone or 2-butanone in a one-pot two-step process to yield one or more ketones ranging from C11-C27.

(97) With reference to FIG. 12, exemplary reactions 1200, 1210, and 1220 are depicted. In reaction 1200, starting material 1202 may be reacted with butanol to yield biodiesel and various biofuel-related precursors or products. In reaction 1210, starting material 1212 may be reacted with acetone and/or butanol to yield biodiesel and various biofuel-related precursors or products. In reaction 1220, starting material 1222 may be reacted with acetone and/or butanol to yield biodiesel and various biofuel-related precursors or products.

EXAMPLES

(98) The following Examples are merely illustrative and are not meant to limit any aspects of the present disclosure in any way.

(99) All reactions were carried out in closed system using 12 mL Q-Tube (pressure tube) in a parallel optimizer. All the metal sources were purchased from either Aldrich or Strem Chemicals and used as received. Acetone, ethanol and butanol, as well as other chemicals, were obtained from Aldrich and used without further purification. All the reactions were analyzed by gas chromatography using dodecane as internal standard. Gas chromatography (GC) analysis was performed on a Varian CP-3800 instrument with a FID detector and VF5 ms column (5% phenyl and 95% methylpolysiloxane) using helium as carrier gas.

Example 1

Metal-Catalyzed Alkylation of Acetone Using ABE-Mix

(100) ##STR00013##

(101) A metal-based catalyst (0.01 mmol) selected from the list in Table 1 below, K.sub.3PO.sub.4 (954 mg, 4.5 mmol), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, 1.5 mL of toluene was added. Then, acetone (0.17 mL, 2.3 mmol), ethanol (60 L, 1 mmol), and butanol (0.34 mL, 3.7 mmol) were also added to each tube. Each tube was sealed, and kept at 145 C. in a pre-heated metal block. Each reaction mixture was stirred for 20 hours at 145 C., and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis of each reaction mixture yielded the ratio of A-F products in Table 1 below and as depicted in FIG. 3. Yields were determined based on acetone.

(102) TABLE-US-00001 TABLE 1 Variation of metal-based catalysts in alkylation of acetone in ABE mix Metal-based Yield (%) catalyst A B C D E F Total [Ir(COD)Cl].sub.2 0 0 0 0 0 0 0 RuCl.sub.2(COD) 0 0.2 0.1 1.1 0.4 2.4 4.2 PtCl.sub.2(COD) 0.1 0.4 0.6 2.8 0.5 8.8 13.2 [Rh(COD)Cl].sub.2 0 0.6 0.1 2.7 3.6 4.1 11.1 Ni/Silica- 0 0 0 0 0 0 0 Alumina Ru/C 0 0 0 0 0 0 0 Rh/C 0.1 0.3 0.2 1 0.8 1.2 3.6 Pt/C 0 0.6 0.5 6.5 1.1 13.9 22.6 Pd/C 2.7 2.4 9.6 21.5 2.9 39.1 78.2

Example 2

Alkylation of Acetone Using ABE-Mix with Various Bases

(103) ##STR00014##

(104) 5% palladium on carbon (containing 50% of water, 42 mg, 0.01 mmol), a base (4.5 mmol) selected from the list in Table 2 below, and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, 1.5 mL of toluene was added. Then, acetone (0.17 mL, 2.3 mmol), ethanol (60 L, 1 mmol), and butanol (0.34 mL, 3.7 mmol) were also added to each tube. Each tube was sealed, and kept at 145 C. in a pre-heated metal block. The reaction mixture was stirred for 20 hours at 145 C., and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis of each reaction mixture yielded the ratio of A-F products in Table 2 below and as depicted in FIG. 4. Yields were determined based on acetone.

(105) TABLE-US-00002 TABLE 2 Variation of base in alkylation of acetone in ABE mix Yield (%) Base A B C D E F Total K.sub.3PO.sub.4 4.4 2.1 18.4 15.9 2 29.3 72.1 KOH 3.5 0 13.9 1 3.1 2.1 23.6 Ba(OH).sub.28H.sub.2O 2.5 0 12.6 0 0 0 15.1 K.sub.2CO.sub.3 4.8 0 10.5 0 0 0 15.3 KOAc 0 0 0 0 0 0 0 KH.sub.2PO.sub.4 0 0 0 0 0 0 0 Na.sub.2HPO.sub.4 0 0 0 0 0 0 0 Pyridine 0 0 0 0 0 0 0 Et.sub.3N 0 0 7.1 0 0 0 7.1

Example 3

Alkylation of Acetone Using ABE-Mix with Various Palladium-Based Catalysts

(106) ##STR00015##

(107) A palladium-based catalyst (0.01 mmol) selected from the list in Table 3 below, K.sub.3PO.sub.4 (3 mmol), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, 1.5 mL of toluene was added. Then, acetone (0.17 mL, 2.3 mmol), ethanol (60 L, 1 mmol), and butanol (0.34 mL, 3.7 mmol) were also added to each tube. Each tube was sealed, and kept at 110 C. in a pre-heated metal block. The reaction mixture was stirred for 20 hours at 110 C., and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis of each reaction mixture yielded the ratio of A-F products in Table 3 below and as depicted in FIG. 5. Yields were determined based on acetone.

(108) TABLE-US-00003 TABLE 3 Variation of palladium-based catalysts in alkylation of acetone in ABE mix Yield (%) Pd-Source A B C D E F Total Pd(OAc).sub.2 2 2 5 6 4 6 25 PdCl.sub.2 1 0 0 0 0 0 1 Pd.sub.2(dba).sub.3 3 2 12 14 4 23 58 Pd(OH).sub.2/C 7 3 18 15 4 19 66 Pd/C 10 1 31 13 3 21 79 Pd/CaCO.sub.3 0 0 7 4 7 13 31 Pd/Alumina 3 2 8 12 6 15 46 Pd/BaCO.sub.3 2 0 2 1 1 1 7 [Pd]* (i.e.,Pd- 2 1 4 4 5 4 20 Polyethylenimines on Silica) PdCl.sub.2(CH.sub.3CN).sub.2 0 0 1 1 1 1 4

Example 4

Alkylation of Acetone Using ABE-Mix at Various Reaction Temperatures

(109) ##STR00016##

(110) 5% palladium on carbon (containing 50% of water, 42 mg, 0.01 mmol), K.sub.3PO.sub.4 (3 mmol), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, 1.5 mL of toluene was added. Then, acetone (0.17 mL, 2.3 mmol), ethanol (60 L, 1 mmol), and butanol (0.34 mL, 3.7 mmol) were also added to each tube. Each tube was sealed, and kept in a pre-heated metal block at one of the temperatures listed in Table 4 below. Each reaction mixture was stirred for 20 hours at that temperature, and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis of each reaction mixture yielded the ratio of A-F products in Table 4 below and as depicted in FIG. 6A. Yields were determined based on acetone.

(111) TABLE-US-00004 TABLE 4 Variation of temperature in alkylation of acetone in ABE mix Yield (%) Temp A B C D E F Total 110 C. 10.4 1 30.7 12.9 2.4 21.1 78.5 130 C. 5.4 2 20.4 14.7 1.7 25.6 69.8 145 C. 4.4 2.1 18.4 15.9 2 29.3 72.1 160 C. 4.1 1.7 20.7 15.6 1.9 31.7 75.7 180 C. 1.3 0.6 18.9 12.7 1.5 32.5 67.5

Example 5

Alkylation of Acetone Using ABE-Mix with Various Amounts of K3PO4

(112) ##STR00017##

(113) 5% palladium on carbon (containing 50% of water, 42 mg, 0.01 mmol), K.sub.3PO.sub.4 (mmol varied according to amounts in Table 5), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, 1.5 mL of toluene was added. Then, acetone (0.17 mL, 2.3 mmol), ethanol (60 L, 1 mmol), and butanol (0.34 mL, 3.7 mmol) were also added to each tube. Each tube was sealed, and kept at 145 C. in a pre-heated metal block. The reaction mixture was stirred for 20 hours at 145 C., and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis of the reaction mixture yielded the ratio of A-F products in Table 5 below and as depicted in FIG. 6B. Yields were determined based on acetone.

(114) TABLE-US-00005 TABLE 5 Variation of amount of K.sub.3PO.sub.4 in alkylation of acetone in ABE mix K.sub.3PO.sub.4 K.sub.3PO.sub.4 Yield (%) (mmol) (mol %).sup.[a] A B C D E F Total 1.5 32 11 1 30 6 1 10 59 3.0 64 5 2 19 16 2 29 73 4.5 96 1 2 7 20 3 44 77 6.0 128 1 2 4 23 5 51 86 .sup.[a]calculated based on alcohols

(115) It should be understood that 1.5 to 6 mmol of K.sub.3PO.sub.4 was used in this Example, which is 32 to 128 mol %, or 0.32 to 1.3 molar equivalents to the amount of alcohol used in the reaction. For example, 1.5 mmol of K.sub.3PO.sub.4 to 4.7 mmol of alcohols equals 0.32 molar equivalents (or 32 mol %) of K.sub.3PO.sub.4.

Example 6

Alkylation of Acetone Using ABE-Mix with Various Solvents

(116) ##STR00018##

(117) 5% palladium on carbon (containing 50% of water, 42 mg, 0.01 mmol), K.sub.3PO.sub.4 (4.5 mmol), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, 1.5 mL of solvent selected from Table 6 below was added. The solvents were selected for use in this Example based on their suitability for the extraction of the starting materials from the fermentation process, or for direct blending with the products from the fermentation process. For example, ethyl acetate can be produced from biomass. Monoglyme and diglyme can be used after fermentation for separation of the ABE mixture from water. Butanol can be blended directly with the bio-butanol produced by fermentation.

(118) Then, acetone (0.17 mL, 2.3 mmol), ethanol (60 L, 1 mmol), and butanol (0.34 mL, 3.7 mmol) were also added to each tube. Each tube was sealed, and kept at 145 C. in a pre-heated metal block. Each reaction mixture was stirred for 20 hours at 145 C., and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis of each reaction mixture yielded the ratio of A-F products in Table 6 below. Yields were determined based on acetone.

(119) TABLE-US-00006 TABLE 6 Variation of solvent in alkylation of acetone in ABE mix Yield (%) Solvent A B C D E F Total Toluene 1 2 7 20 3 44 77 Ethyl acetate 28 12 8 7 0 2 57 Diglyme 5 3 3 20 4 39 74 Diglybu 1 3 6 22 6 35 73 Butanol.sup.[a] 0 1 3 8 2 60 74 Neat.sup.[b] 5 2 5 14 8 27 61 Oleyl alcohol.sup.[a] 3.2 1 11.5 7.2 2 12.6 37.5 Dibutyl phthalate 1.2 0.2 10.3 3.1 1.7 14.2 30.7 .sup.[a]1.5 mmol K.sub.3PO.sub.4 was used in the reaction .sup.[b]5 mol Pd/C (with respect to alcohols)

Example 7

Alkylation of Acetone Using ABE-Mix at Various Reaction Temperatures to Form Mono-Alkylated Products

(120) ##STR00019##

(121) 5% palladium on carbon (containing 50% of water, 42 mg, 0.01 mmol), K.sub.3PO.sub.4 (1.5 mmol), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, 1.5 mL of toluene was added. Then, acetone (0.17 mL, 2.3 mmol), ethanol (60 L, 1 mmol), and butanol (0.34 mL, 3.7 mmol) were also added to each tube. Each tube was sealed, and kept in a pre-heated metal block at one of the temperatures listed in Table 7 below. Each reaction mixture was stirred for 20 hours at that temperature, and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis of each reaction mixture yielded the ratio of A-F products in Table 7 below. Yields were determined based on acetone.

(122) TABLE-US-00007 TABLE 7 Variation of temperature in alkylation of acetone in ABE mix to form mono-alkylated products Yield (%) Temp A B C D E F Total 110 C. 8.5 0.5 19.9 2.7 0 3.3 34.9 130 C. 9.2 0.8 29.8 6.1 0.4 10.5 56.8 145 C. 11.4 0.8 37.9 5.9 0.4 9.9 66.3 160 C. 8.6 0.8 36.8 6.3 0.5 12.9 65.9 180 C. 3.1 0.6 21.4 7.1 0.5 24.2 56.9

Example 8

Alkylation of Acetone Using ABE-Mix Over Time

(123) ##STR00020##

(124) 5% palladium on carbon (0.02 mmol), K.sub.3PO.sub.4 (9 mmol), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, 3 mL of toluene was added. Then, acetone (4.6 mmol), ethanol (2 mmol), and butanol (7.4 mmol) were also added to each tube. Each tube was sealed, and kept at 145 C. in a pre-heated metal block. Each reaction mixture was stirred at 145 C. over 20 hours. Samples were taken during the 20 hours according to the times listed in Table 8. Each sample was cooled to room temperature. To each sample, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis of each reaction sample yielded the ratio of A-F products in Table 8 below and as depicted in FIG. 8. Yields were determined based on acetone.

(125) TABLE-US-00008 TABLE 8 Product distribution during reaction at given times Time Yield (%) (min) A B C D E F Total 15 19.2 1.3 31.6 4.9 1.6 5.6 64.2 30 20.7 2 32.2 8.4 2.3 10.6 76.2 45 15.4 2.3 23.1 12.5 3.1 18.7 75.1 60 14.2 2.7 22.7 14.5 3.2 21.6 78.9 75 6.8 2.4 15.3 16.4 3.6 27.5 72 90 4.6 2.3 11.8 17.1 3.7 30.1 69.6 105 4.5 2.3 10.5 17.7 3.8 31.6 70.4 120 3.1 2.4 9.1 18.3 4 33.2 70.1 180 1.8 2.4 4.2 19.3 4.2 37.1 69 240 0.7 2.3 1.8 19.6 4.3 38.9 67.6 360 0.13 2.3 0.5 19.6 4.4 40.4 67.33 480 0.13 2.3 0.5 19.6 4.5 40.3 67.33 600 0.1 2.4 0.5 19.8 4.4 40.6 67.8 720 0.1 2.3 0.7 20.1 4.5 40.4 68.1 840 0.06 2.4 0.5 19.9 4.4 40.5 67.76 960 0.06 2.2 0.6 19.9 4.4 41.1 68.26 1080 0.04 2.3 0.6 20.4 4.5 40.9 68.74 1200 0.02 1.8 0.4 20.1 4.4 41.2 67.92

Example 9

One-Pot Alkylation and Hydrogenation Using ABE-Mix

(126) ##STR00021##

(127) 5% palladium on carbon (0.01 mmol), K.sub.3PO.sub.4 (4.5 mmol), and a magnetic stir bar were added to a high-pressure reaction vessel (HEL parallel synthesizer). To the tube, 1.5 mL of toluene was added. Then, acetone (2.3 mmol), ethanol (1 mmol), and butanol (3.7 mmol) were also added to the tube. The tube was sealed, and kept at 145 C. in a pre-heated metal block. The reaction mixture was stirred at 145 C. over 20 hours. A sample of the reaction mixture was taken for GC analysis.

(128) To this reaction mixture, 5% platinum on carbon (0.02 mmol) was added, and the reaction vessel was pressurized with H.sub.2 gas (150 psi). The reaction mixture was stirred at 110 C. for 14 hours, and then cooled to room temperature. GC analysis of the reaction mixture yielded the ratio of A-F products as shown in the reaction scheme above. Yields were determined based on acetone. The yields in parentheses denote the corresponding yields of the ketones.

Example 10

One-Pot Alkylation and Hydrogenation Using ABE-Mix with Various Amounts of Base, Temperature, H2 Gas to Produce Corresponding Alcohols

(129) ##STR00022##

(130) 5% palladium on carbon (0.01 mmol), K.sub.3PO.sub.4 (mol % varied according to the amounts in Table 9), and a magnetic stir bar were added to a high-pressure reaction vessel (HEL parallel synthesizer). To each vessel, 1.5 mL of toluene was added. Then, acetone (2.3 mmol), ethanol (1 mmol), and butanol (3.7 mmol) were also added to each vessel. Each vessel was sealed, and kept at 145 C. in a pre-heated metal block. Each reaction mixture was stirred at 145 C. over 20 hours.

(131) To this reaction mixture, 5% platinum on carbon (0.02 mmol) was added, and the reaction vessel was pressurized with H.sub.2 gas (pressure as shown in Table 9). Each reaction mixture was stirred at one of the temperatures listed in Table 9 below for 14 hours, and then cooled to room temperature. Note that reactions 4, 8, and 12 were performed neat. GC analysis of each final reaction mixture yielded the ratio of ketones and A-F products in Table 9. FIG. 9 also depicts effect of varying the concentration of base used on the yield of ketones and alcohols.

(132) TABLE-US-00009 TABLE 9 Alcohol product distribution from ketones produced from alkylation of acetone in ABE mix Total Base Temp H.sub.2 Ketone Molar Yield of Alcohols (%) Entry (mmol) ( C.) (psi) Yield (%) A B C D E F Total 1 1.5 RT 90 20.2 6.3 0 19 0.6 0.01 0.8 46.91 2 3.0 RT 90 25.67 6.1 0.7 20.9 4 0.05 5.8 63.22 3 4.5 RT 90 19.83 3.9 0 12.8 10.8 0.3 17.3 64.93 4.sup.[a] 1.5 RT 90 61.2 4.4 0.9 13.3 5.6 0.1 8.9 94.4 5 1.5 110 150 9.4 10.3 0.8 42.9 6.5 0.1 10.7 80.7 6 3.0 110 150 13.5 5.6 1.1 20.1 10 0.2 21.5 72 7 4.5 110 150 2.72 3.5 1.8 12.6 16.2 2.1 34.1 73.02 8.sup.[a] 1.5 110 150 4.3 3.3 1.3 9.7 10.3 3.6 20.2 52.7 9 1.5 110 150 7.5 6.1 0.5 26.0 3.9 0.1 6.3 50.3 10 3.0 110 150 3.2 6.7 1.1 21.9 9.8 1.0 23.3 66.9 11 4.5 110 150 4.3 5.3 0.0 15.5 18.9 3.2 40.3 87.4 12.sup.[a] 1.5 110 150 4.9 3.8 1.2 10.8 9.9 3.9 20.6 55.0 .sup.[a]Neat reaction. RT = room temperature

Example 11

One-Pot Alkylation of ABE-Mix and Reduction of Ketones to Produce Corresponding Alkanes

(133) ##STR00023##

(134) 5% palladium on carbon (0.01 mmol), K.sub.3PO.sub.4 (4.5 mmol), and a magnetic stir bar are added to two 12-mL Q-Tubes (pressure tubes). To both tubes, acetone (2.3 mmol), ethanol (1 mmol), and butanol (3.7 mmol) are added. Each tube is sealed, and kept at 145 C. in a pre-heated metal block. Each reaction mixture is stirred at 145 C. over 20 hours.

(135) Next the reaction mixture from each tube is filtered, and the liquid products collected. The first ketone-containing reaction mixture is added to a reactor containing sulfided NiOMoO.sub.3/Al.sub.2O.sub.3. The reactor is pressurized to 40 bar with hydrogen gas and heated to 250 C. After 10 hours the reactor is cooled to room temperature and the products analyzed by GC for yields of A-F products. The second ketone-containing reaction mixture is passed over Pt/SiO.sub.2Al.sub.2O.sub.3 in a plug-flow bed reactor at 200 C. with a hydrogen pressure of 30 bar. GC analysis of the reactor effluent reveals the yield of A-F products.

Example 12

Recycling of Catalysts in the Conversion of ABE Mixture into Ketones

(136) 5% palladium on carbon, K.sub.3PO.sub.4 (96 mol %), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To the tube, 3 mL of toluene was added. Then, acetone (4.6 mmol), ethanol (2 mmol), and butanol (7.4 mmol) were also added to the tube. The tube was sealed, and kept at 145 C.

(137) At 10, 20, and 30 hours, 100 mol % excess of the ABE mixture was added to the tube. Samples were taken at 10, 20, and 30 hours. Each sample was cooled to room temperature. To each sample, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis was performed on each reaction sample. Overall yields were determined at 10, 20, and 30 hours. The overall yield based on the total acetone feed for each time point was: 80% at 10 hours, 72% at 20 hours, and 61% at 30 hours. This demonstrated that the metal and base catalysts remained active, and continued to convert each new aliquot of starting material.

(138) The procedures described in this Example were repeated by adding excess ABE mixture at 5 and 10.5 hours. Overall yields were determined based on each time point, and the results are depicted in FIG. 10.

Example 13

Palladium-Catalyzed Guerbet Reaction of Butanol

(139) ##STR00024##

(140) 5% palladium on carbon (x mmol), K3PO4 (y mol %) and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, 1.5 mL of toluene and butanol (5 mmol) was added, and stirred at 145 C. for 24 hours. Each sample was cooled to room temperature. GC analysis was performed with internal standard (dodecane) on each reaction sample to determine product yields. The yields provided in Table 10 below correspond to product G, i.e., the 2-ethyl-1-hexanol.

(141) TABLE-US-00010 TABLE 10 Palladium-catalyzed Guerbet reaction of butanol Reaction Pd/C (x mol %) K.sub.3PO.sub.4 (y mol %) Conversion Yield 1 0.2 60 71.2 53.9 2 0.2 90 79.5 60.6 3 0.2 120 79.6 58.9 4 0.3 60 50.2 34.2 5 0.2 60 71.2 53.9 6 0.1 60 84.8 65.4 7 0.05 60 92.4 64.2 8 0.025 60 92 64.6 9 0.0125 60 81.2 60.7

Example 14

Extraction Using Glyceryl Tributyrate

(142) Simulated clostridia fermentation media was prepared with the following components: glucose (20 g/L), yeast extract (5 g/L), ammonium acetate (2 g/L), butyric acid (2 g/L), acetoin (3 g/L), ethanol (20 g/L), acetone (20 g/L), 1-butanol (20 g/L), and lactic acid (10 g/L). 5 mL of simulated fermentation media was combined with 5 mL of glyceryl tributyrate, and mixed for 5 minutes by inversion. The mixtures were then spun down at 5300 rpms for 5 minutes, and the extractant phase removed for GC analysis. Distribution coefficients were calculated based on the following equation:

(143) $K_{\mathrm{Di}}=\frac{\mathrm{Kg}\mathrm{of}{\mathrm{compound}}_i\mathrm{in}\mathrm{the}\mathrm{extractant}\mathrm{phase}}{\mathrm{Kg}\mathrm{of}{\mathrm{compound}}_i\mathrm{in}\mathrm{the}\mathrm{aqueous}\mathrm{phase}}$

(144) ABE extraction experiments were run in quadruplicate. Miscanthus giganteus, obtained from the University of Illinois, Urbana-Champaign, was first ground and placed through a 4 mm size sieve. 5% w/w of Miscanthus giganteus was mixed with 1% H.sub.2SO.sub.4 in sealed Teflon tubes and reacted under the following conditions: 30 minutes at 30 C., 6 minute ramp to 180 C., 2 minutes at 180 C. The liquid hydrolysate was pH adjusted to 5.0 using concentrated KOH. 3 mL of hydrolysate was combined with 3 mL of glyceryl tributyrate and thoroughly mixed for 5 minutes by inversion. The mixtures were then centrifuged for 5 minutes at 5300 rpms, and the aqueous phase was removed Inhibitors remaining in the aqueous phase were measured by first extracting into ethyl acetate, followed by drying with Na.sub.2SO.sub.4. The dried solution was then incubated with bis(trimethylsilyl)trifluoracetamide at 70 C. for 30 minutes. Inhibitor concentrations were analyzed by GC/MS with isopropylphenol as an internal standard.

(145) Glyceryl tributyrate recovered both acetone (K.sub.D=1.1) and 1-butanol (K.sub.D=2.6) from aqueous solution. Ethanol, however, was observed to remain in the aqueous phase (K.sub.D=0.2). Additionally, glyceryl tributyrate removed several of the inhibitors of biofuel fermentation found in acid-pretreated lignocellulosic biomass (as summarized in Table 11 below).

(146) TABLE-US-00011 TABLE 11 Extraction of inhibitors generated by acid pretreatment of lignocellulosic biomass K.sub.D Compound Name Initial Conc. (mg/L) (extractant/water) 4-hydroxybenzaldehyde 15.8 4.9 vanillin 30.8 7.6 syringaldehyde 18.9 5.3 vanillic acid 14.5 1.3 p-coumaric acid 35.5 3.8 ferulic acid 41.8 4.2 furural 1926.1 6.5 hydroxymethyl furfural 205.1 0.5

(147) Thus, use of glyceryl tributyrate allows for simultaneous removal of residual inhibitors and the desired product (e.g., acetone and butanol) during biofuel fermentation, a key advantage over existing recovery technologies.

Example 15

Toxicity Studies on Clostridium acetobutylicum

(148) Growth inhibition and cell viability was examined in a study using up to 1:1 volume ratios of extractant to media. This study showed that glyceryl tributyrate was non-toxic to Clostridium acetobutylicum.

Example 16

Effect of Glyceryl Tributyrate on Glucose Fermentation

(149) A 60-hour 2 L-fermentation of Clostridium acetobutylicum on glucose with a 1:1 volume ratio of medium and glyceryl tributyrate was performed, and observed to produce 40.8 grams of solvents with 16.4 g of 1-butanol, 3.7 g of acetone, and 0.8 g of ethanol, respectively partitioning into the extractant phase. With reference to FIG. 13, these solvents were produced from 105 g of glucose and 1.6 g of acetate, achieving an overall ABE weight yield of 90% the theoretical maximum.

(150) In a separate reactor, 5% palladium on carbon, K.sub.3PO.sub.4 (954 mg, 4.5 mmol), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To the tube, 1.5 mL of toluene was added. Then, the acetone, ethanol and butanol prepared from fermentation described above were also added to the reactor. The reaction mixture was stirred for 20 hours at 145 C., and then cooled to room temperature. The reaction mixture was diluted with tetrahydrofuran and the GC analysis of the reaction mixture was carried out.

(151) FIG. 13 illustrates the yields of the products from the reaction. The overall molar yield based on acetone was 93%, which represented a 97% conversion. In particular, 17% of higher alkylated products were observed, and 0% of alcohol and related products were observed, as determined using FID response factor. The products yields are further summarized in Table 12 below. Total Mass values (g) were based on fermentative production and recovery of 153.5 mmol acetone, 333.8 mmol butanol and 158.7 mmol ethanol. Assuming complete recovery of acetone, butanol and ethanol from both phases, 20 g of C7 and higher products were produced. 15 g of lower molecular weight products were also produced.

(152) TABLE-US-00012 TABLE 12 Summary of amount of alkylated products (C7+) produced Alkylated Products C7+ Reaction Mass (mg) Total Mass (g) 4-Heptanone 2.8 0.2 2-Heptanone 7.6 0.7 4-Nonanone 48.5 4.2 2-Methyl-4-nonanone 0.8 0.1 6-Undecanone 89.9 7.7 Higher MW products 22.2 1.9 Alcohols and other products 61.7 5.3 Overall 233.5 20.0

(153) In contrast, FIG. 18 illustrates the effect of inhibitors on ABE fermentation without extractant.

Example 17

Fed-Batch Extractive Fermentation of Glucose Using Glyceryl Tributyrate

(154) Clostridium acetobutylicum ATCC824 was grown in clostridial growth medium (CGM) as previously described in Example 14 above. Fed-batch fermentations were conducted in 3-L bioreactors (Bioengineering AG, Switzerland) with a 2 L working volume. Additional glucose and yeast extract were added intermittently to the culture using a concentrated solution of 450 g/L and 50 g/L, respectively. Cultures were grown at 37 C. anaerobically by sparging 100 mL/min of N.sub.2 gas until solvent production was initiated. The culture pH was adjusted to 5.5 prior to inoculation. After inoculation the bioreactor pH was controlled at pH of at least 4.8.

(155) Sugars and major metabolites (glucose, sucrose, lactate, acetate, butyrate, acetoin, ethanol, acetone, and 1-butanol) were measured in the aqueous phase using an Agilent (Santa Clara, Calif.) HPLC system equipped with refractive index and UV/Vis detectors. A Bio-Rad (Hercules, Calif.) Aminex HPX-87H ion exchange column with a Cation H guard column at 30 C. was used with a mobile phase of 0.05 mM sulfuric acid flowing at 0.7 mL min.sup.1. Acetone, 1-butanol and ethanol concentrations in the extractant phase were measured by GC/FID.

(156) FIG. 14 depicts product formation in fed-batch extractive fermentation of glucose with glyceryl tributyrate over 60 hours. With reference to FIG. 14, glyceryl tributyrate was observed to primarily extract butanol and acetone from the aqueous phase into the extractant phase.

Example 18

Fed-Batch Extractive Fermentation of Sucrose Using Glyceryl Tributyrate

(157) The fed-batch extractive fermentation procedure described in Example 17 above was performed using sucrose instead of glucose as the primary carbon source. The initial sucrose concentration was 60 g/L. Specifically, extractive fermentation with sucrose was carried out in 100-mL shake flasks with 25 mL of clostridia growth media inoculated with 2 mLs of OD.sub.600 (0.6-1.0) cells. Cultures were grown at 37 C. in an anaerobic chamber and pH adjusted to 4.8 using 1M KOH during the first 12 hours of growth. After 16 hours, 25 mL of glyceryl tributyrate was added to the culture.

(158) FIG. 15 depicts product formation in fed-batch extractive fermentation of sucrose with glyceryl tributyrate over 60 hours. With reference to FIG. 15, glyceryl tributyrate was observed to primarily extract butanol and acetone from the aqueous phase into the extractant phase.

Example 19

Effect of Water on Alkylation Reaction of ABE Mixture

(159) 5% palladium on carbon (containing 50% of water, 42 mg, 0.01 mmol), potassium phosphate tribasic (954 mg, 4.5 mmol), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To the tube, 1.5 mL of toluene was added. Then, acetone (0.17 mL, 2.3 mmol), ethanol (60 L, 1 mmol), and butanol (0.34 mL, 3.7 mmol) were also added to the tube. Water was also added to each tube in the amount (w:v %) depicted in FIG. 16. Each tube was sealed, and kept at 145 C. in a pre-heated metal block. The reaction mixture was stirred for 20 hours at 145 C., and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis of each reaction mixture yielded the amount of products as depicted in FIG. 16. Yields were determined based on acetone.

(160) As seen in FIG. 16, the presence of water was observed to decrease the overall reaction rate, resulting in less double alkylation and lower overall yields.

Example 20

Alkylation Reaction of ABE Mixture in Neat Conditions

(161) 5% palladium on carbon (containing 50% of water, mmol varied according to amounts in Table 13), K.sub.3PO.sub.4 (mmol varied according to amounts in Table 13), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, acetone (4.6 mmol), ethanol (2 mmol), and butanol (7.4 mmol) were added. Each tube was sealed, and kept in a pre-heated metal block at one of the temperatures listed in Table 13 below. Each reaction mixture was stirred for 20 hours at that temperature, and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis of each reaction mixture yielded the ratio of C.sub.5-C.sub.11 and C.sub.11+ products in Table 13 below. Yields were determined based on acetone.

(162) TABLE-US-00013 TABLE 13 Alkylation reaction products in neat conditions Base Pd/C (Y Temp Yield (%).sup.[a] (X mol %) mol %) ( C.) C.sub.5-C.sub.11 C.sub.11+ Total TON.sup.[b] Solvent 0.025 32 145 27 15 42 1574 Neat 180 36 19 55 2072 0.0125 32 145 22 19 41 3074 180 26 17 43 3220 0.0125 16 145 17 11 28 2080 180 31 14 45 3386 .sup.[a]GC weight yield .sup.[b]Turn Over Number (TON) based on alcohols

Example 21

Time Course Product Distribution

(163) 5% palladium on carbon (containing 50% of water, 0.02 mmol), K.sub.3PO.sub.4 (9 mmol), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To the tube, toluene (3 mL), acetone (4.6 mmol), ethanol (2 mmol), and butanol (7.4 mmol) were added. The tube was sealed, and kept in a pre-heated metal block at 145 C. The reaction mixture was stirred for up to 1200 minutes, and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis was performed on the reaction mixture to determine yields of the products. Yields were determined based on acetone. FIG. 17A shows the product distribution over time.

(164) As seen in FIG. 17A, monoalkylation of acetone with butanol and ethanol was observed to occur within the first 1-1.5 hours of the reaction to produce 2-pentanone and 2-heptanone. These species were then observed to undergo further reaction to form double alkylated products. Surprisingly, no aldehydes were observed during the reaction, suggesting that the aldehyde intermediates were present in very low concentrations and reacted rapidly with acetone and other ketones. Hence, the formation of Guerbet products was observed to be minimized, and acetone alkylation was observed to predominate.

Example 22

Double Alkylation Reactions to Yield C11-C19 Products

(165) ##STR00025##

(166) In a 12 mL Q-tube, 5 wt. % palladium on carbon (0.011 g, 0.0026 mmol, water ca. 50%), potassium phosphate tribasic (0.034 g, 0.16 mmol) and a magnetic stir bar were placed. To the reaction mixture, acetone (0.058 g, 1 mmol), 2-ethyl-1-hexanol (1.30 g, 10 mmol), butanol (0.22 g, 3 mmol) and 1 mL toluene were sequentially added. The Q-tube was sealed and the reaction mixture was stirred for 20 hours at 200 C. in a pre-heated metal block. The reaction mixture was cooled to room temperature and dodecane (internal standard) was added. The reaction mixture was diluted with tetrahydrofuran and the GC analysis of the reaction mixture was carried out (85% overall yield, 2-C11: 4%, 6-C11: 22%, C15: 37%, C19: 22%). Thus, this Example showed the selective production of the Guerbet product (2-ethyl-hexanol) in the presence of acetone.

Example 23

Double Alkylation Reactions to Yield C19 Product

(167) ##STR00026##

(168) 5% palladium on carbon (containing 50% of water, 0.05 mol %), potassium phosphate tribasic (0.16 mol %) and magnetic stir bar were added to a 12 mL Q-Tube (pressure tube). To the reaction mixture, acetone (0.058 g, 1 mmol), 2-ethyl-1-hexanol (0.326 g, 2.5 mmol), and toluene (1 mL) were sequentially added. The Q-tube was sealed and the reaction mixture was stirred for 20 hours at 200 C. in a pre-heated metal block. The reaction mixture was cooled to room temperature and dodecane (internal standard) was added. The reaction mixture was diluted with tetrahydrofuran and the GC analysis of the reaction mixture was carried out (72% overall yield).

Example 24

Variation of Alkylation Reaction Conditions of ABE Mixture to Control Molecular Weight of Products

(169) ##STR00027##

(170) Alkylation of an ABE mixture was performed under different reaction conditions to control the production of higher molecular weight compounds. In particular, the ratio of ABE, the amount of base, and temperature were varied. Distillation of the ABE mixture with an extractant was also performed in one of the reactions described below.

(171) In the first reaction, 5% palladium on carbon (containing 50% of water, 1 mol %), K.sub.3PO.sub.4 (0.95 equiv), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, acetone (2.3 mmol), ethanol (1 mmol), and butanol (3.7 mmol) were added. The tube was sealed, and kept in a pre-heated metal block at a temperature between 190 C. and 210 C. The reaction mixture was stirred for 20 hours, and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis was performed on the reaction mixture. Overall yield (57%; C5-C11: 57%; C15: trace amount).

(172) In the second reaction, 5% palladium on carbon (containing 50% of water, 1 mol %), K.sub.3PO.sub.4 (1.3 equiv), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To the reaction tube, acetone (1.6 mmol), ethanol (1.7 mmol), and butanol (3.7 mmol) were added. The tube was sealed, and kept in a pre-heated metal block at a temperature of about 145 C. The reaction mixture was stirred for 20 hours, and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis was performed on the reaction mixture. Overall yield (78%; C5-C11: 72%; C13 (5-ethylundecan-b-one): 4%, C15: 2%).

(173) In the third reaction, 5% palladium on carbon (containing 50% of water, 1 mol %), K.sub.3PO.sub.4 (0.95 equiv), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, acetone (2.3 mmol), ethanol (1 mmol), and butanol (3.7 mmol) were added. The tube was sealed, and kept in a pre-heated metal block at a temperature of about 145 C. The reaction mixture was stirred for 20 hours, and then cooled to room temperature. Subsequently, dodecane (internal standard) was added and diluted with ethyl acetate. GC analysis was performed on the reaction mixture. Overall yield (79%; C5-C11: 77%; C13: 2%).

(174) In the fourth reaction, the reaction conditions of the third reaction described above were repeated, except that the ABE mixture was first distilled with an extractant (tributyrin). Distillation with the extractant yielded an ABE mixture that mainly included acetone and butanol, which was used in the alkylation reaction. Overall yield (93%; C5-C11: 67.3%, higher alkylated products: 17%, alcohol and related products: 9%).

(175) All yields described above were determined based on acetone.

Example 25

Ir-Catalyzed ABE Condensation Reaction

(176) ##STR00028##

(177) An iridium catalyst (x mol %) listed in Table 14 below, K.sub.3PO.sub.4 (0.94 mmol) and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, 1.5 mL of toluene and acetone (2.3 mmol), ethanol (1 mmol), and butanol (3.7 mmol) were added. Each tube was sealed, and kept in a pre-heated metal block at a temperature of about 145 C. The reaction mixture was stirred for 20 hours, and then cooled to room temperature. GC analysis was performed with internal standard (dodecane) on each reaction sample to determine yields of A-F products as shown in the reaction scheme above. Yields were determined based on acetone.

(178) TABLE-US-00014 TABLE 14 Variation of type and amount of Iridium catalyst Ir Catalyst Yield (%) Entry (mol %) A B C D E F Total 1 [Cp*IrCl.sub.2].sub.2 0.7 10.8 3.5 5.0 0.9 19.8 41 (0.5) 2 [Cp*IrCl.sub.2].sub.2 0.3 6.7 1.9 2.8 2.7 15.2 30 (0.2) 3 [Cp*IrCl.sub.2].sub.2 0.2 7.4 1.4 2.2 3.1 11.5 26 (0.08) 4 [Ir(COD)Cl].sub.2 1.4 19.3 4.8 4.7 0.4 10.2 41 (1.7)

Example 26

Pd-Catalyzed ABE ReactionRecycling Experiment Using Calcined Base

(179) ##STR00029##

(180) The K.sub.3PO.sub.4 used in this Example was first calcined at 600 C. for 24 hours prior to use. 5% palladium on carbon (containing 50% of water, 0.01 mmol), K.sub.3PO.sub.4 (6.98 mmol), and a magnetic stir bar were added to a 12-mL Q-Tube (pressure tube). To each tube, acetone (2.3 mmol), ethanol (1 mmol), butanol (3.7 mmol), and toluene (2.5 ml) were added. Each tube was sealed, and kept in a pre-heated metal block at a temperature of about 145 C. The reaction mixture was stirred for 10 hours (i.e., Cycle 1 in Table 15 below). Additional acetone (2.3 mmol), ethanol (1 mmol), butanol (3.7 mmol) were added twice at 10 hour intervals to the reaction mixture (i.e., Cycles 2 and 3, respectively in Table 15 below) to show that the base-metal mixture can be recycled. GC analysis of samples taken at the end of each cycle was performed with internal standard (dodecane) on each reaction sample to determine yields of A-F products as shown in the reaction scheme above. Yields were determined based on acetone.

(181) TABLE-US-00015 TABLE 15 Results from recycling of base-metal mixture Yield (%) Entry A B C D E F Total Cycle 1 0.8 3.7 6.5 23.2 1.5 63.7 99 Cycle 2 0.4 3.2 21.6 15.1 0.7 32.0 73 Cycle 3 0 0.9 28.6 6.4 0.2 15.8 52