GUERBET CONDENSATION REACTION

Field of the invention

This invention concerns a process for the preparation of a Guerbet alcohol. This invention concerns a catalyst suitable for the preparation of a Guerbet alcohol.

Background to the invention

The Guerbet reaction is an organic condensation reaction, whereby a primary or secondary alcohol with a methylene group adjacent to the hydroxylated carbon atom is condensed with the same alcohol (self-condensation) or with another alcohol (cross-condensation), with the release of water. This reaction requires a catalyst and elevated temperatures. The alcohols derived from this reaction are called Guerbet alcohols.

Due to the specific branching pattern of the product alcohols, the Guerbet reaction has many interesting applications. In comparison to their linear isomers, branched-chain Guerbet alcohols have extremely low melting points and excellent fluidity. Because of the increasing availability of bio-based alcohol feedstock, this reaction is of growing importance and interest in terms of renewable value chains for the chemical and biof uel industry.

Because the dehydrogenation is generally considered to be the rate-determining step in liquid phase Guerbet reactions, most of the catalytic systems described in the literature include the utilization of transition or noble metals in homogeneous phase as catalysts. Although high conversions and selectivity can be obtained with these types of homogeneous-homogeneous systems (base and catalyst, respectively), issues related to the product purification, recovery and cost of the catalyst and waste treatment are important for the industrial production of Guerbet alcohols.

In addition to the higher alcohols formed by the condensation process, side reactions result in the formation of other compounds, such as esters and carboxylic acids, or salts thereof. Next to lowering the process efficiency, these unwanted products often poison the catalytic stream. There is a need for processes and catalysts that are more stable. There is a need for processes and catalysts that have an improved conversion. There is a need for processes and catalysts that have an improved selectivity. There is a need for processes and catalysts that have a sustained selectivity. There is a need for processes and catalysts that have less leaching. There is a need for processes and catalysts that have less sensitivity to water. There is a need for catalysts that can be re-used without loss of properties. There is a need for catalysts that can be used with or without pre-activation.

Summary of the invention

One or more of these problems may be wholly or partially overcome by the processes and catalysts of the present invention. One or more of these problems may be wholly or partially overcome by preferred embodiments of the processes and catalysts of the present invention. According to a first aspect, the invention comprises a process for the preparation of a Guerbet alcohol. Preferably, the process comprises the steps of: (a) providing at least one alcohol, wherein said at least one alcohol has a carbon atom bearing at least one hydrogen atom adjacent to the hydroxyl group;

(b) providing a catalyst composition, wherein said catalyst composition comprises an alkaline catalyst and a copper-nickel catalyst comprised in a hydrotalcite;

(c) mixing alcohol (a) with catalyst composition (b), thereby obtaining a mixture; and,

(d) heating said mixture;

thereby obtaining a Guerbet alcohol.

In some preferred embodiments, the hydrotalcite is a compound of formula (I)

[M ²⁺ _! _ _x M ³⁺ _x (OH) ₂ ] ^x+ (A ⁿ ) _x/n mH ₂ 0 (I), wherein,

x is selected from 0.1 to 0.33;

m is an integer selected from 1 , 2, 3, 4 or 5;

M ²⁺ is selected from the group comprising Mg, Ni, Zn, Cu, Co, Fe, Pd, Pt, and Ru ; preferably Mg, Ni and Cu ;

M ³⁺ is selected from the group comprising Al, Cr, Mn, Co, Fe, and Ga; preferably Al;

A is selected from the group comprising C0 ₃ ^2~ with n=2; OH ^" with n=1 ; NOV with n=1 ;

S0 ₄ ^2" with n=2; preferably C0 ₃ ^2~ with n=2; and

optionally wherein one or more M ²⁺ and/or M ³⁺ ions are isomorphously substituted by M ⁺ or M ⁴⁺ , wherein M ⁴⁺ is selected from the group comprising Ge, Sn, and Pb.

In some preferred embodiments, the Cu:Ni molar ratio in the copper-nickel catalyst is at least 0.1 :9.9 and at most 6.0:4.0, preferably at least 0.2:9.8 and at most 5.0:5.0, preferably at least

0.4:9.6 and at most 4.0:6.0, preferably at least 0.5:9.5 and at most 3.0:7.0, preferably at least

0.6:9.4 and at most 2.5:7.5, preferably at least 0.8:9.2 and at most 2.0:8.0, preferably at least

0.9:9.1 and at most 1 .5:8.5, preferably about 1 .0:9.0.

In some preferred embodiments, the copper-nickel catalyst comprised in a hydrotalcite is subjected to a thermal treatment prior to step (b).

In some preferred embodiments, the copper-nickel catalyst is present in an amount of 0.05 to 5.0% by weight, based on the weight of said at least one alcohol.

In some preferred embodiments, the alkaline catalyst is present in an amount of 0.5 to 5.0% by weight, based on the weight of said at least one alcohol, and wherein the alkaline catalyst is selected from the group comprising alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates and alkali earth metal carbonates, alkali metal phosphates, alkaline earth metal oxides, zeolites, alkyl amines or mixtures thereof.

In some preferred embodiments, the at least one alcohol is a C ₂ -C ₃₆ alcohol, preferably a C ₆ - C ₂₄ alcohol, more preferably a C ₈ -Ci ₈ alcohol.

In some preferred embodiments, the at least one alcohol comprises at least one aliphatic diol, preferably selected from the group comprising: 1 ,3-propanediol, 1 ,4-butanediol, 1 ,2- butanediol, 1 ,3-butanediol, 2,3-butanediol, 2, 2-dimethyl-1 ,3-propanediol, and 1 ,5-pentanediol. In some preferred embodiments, in step (a) at least one second alcohol is provided. In some preferred embodiments, in step (a) methanol, an aldehyde, and/or a ketone is provided.

In some preferred embodiments, step (d) is performed at a temperature of 170 to 280 °C and at a pressure of 1 to 50 bars.

In some preferred embodiments, step (d) is performed after pre-reduction of the copper-nickel catalyst comprised in a hydrotalcite.

In some preferred embodiments, the copper-nickel catalyst comprised in a hydrotalcite is recovered and used for a subsequent process according to the first aspect of the invention.

According to a second aspect, the present invention relates to a Guerbet alcohol obtainable by the process according to the first aspect. Preferred embodiments for the first aspect of the invention are also preferred embodiments for the second aspect of the invention.

According to a third aspect, the present invention relates to a Guerbet alcohol. Preferred embodiments for the first or second aspect of the invention are also preferred embodiments for the third aspect of the invention.

According to a fourth aspect, the present invention relates to the use of a copper-nickel catalyst comprised in a hydrotalcite to prepare a Guerbet alcohol. Preferred embodiments for the first, second, or third aspect of the invention are also preferred embodiments for the third aspect of the invention.

According to a fifth aspect, the present invention relates to a copper-nickel catalyst comprised in a hydrotalcite. Preferred embodiments for the first, second, third, or fourth aspect of the invention are also preferred embodiments for the third aspect of the invention. Preferably the copper-nickel catalyst is comprised in a hydrotalcite of formula (I)

[ ²⁺ i - _x M ³⁺ _x (OH) ₂ ] ^x+ (A ⁿ ) _x/n mH ₂ 0 (I), wherein,

x is selected from 0.1 to 0.33;

m is an integer selected from 1 , 2, 3, 4 or 5;

n is an integer selected from 1 or 2;

M ²⁺ is selected from the group comprising Mg, Ni, Zn, Cu, Co, Fe, Pd Pt, and Ru; preferably Mg, Ni and Cu;

M ³⁺ is selected from the group comprising Al, Cr, Mn, Co, Fe, and Ga; preferably Al;

A is selected from the group comprising C0 ₃ ^2" with n=2; OH ^" with n=1 ; NOV with n=1 ;

S0 ₄ ^2" with n=2; preferably C0 ₃ ^2" with n=2; and

optionally wherein one or more M ²⁺ and/or M ³⁺ ions are isomorphously substituted by M ⁺ or M ⁴⁺ , wherein M ⁴⁺ is selected from the group comprising Ge, Sn, and Pb.

According to a sixth aspect, the present invention relates to a process for preparing a copper- nickel catalyst comprised in a hydrotalcite. Preferred embodiments for the first, second, third, fourth, or fifth aspect of the invention are also preferred embodiments for the sixth aspect of the invention. The process for preparing a copper-nickel catalyst comprised in a hydrotalcite preferably comprises the step of adding a solution (A) comprising metal salts to a solution (B) comprising precipitating agents, thereby obtaining solids.

Brief description of the figures

FIG. 1 illustrates the water-removal configurations described in Example 5. The rectangular frame corresponds to the thermally insulated part of the Dean-Stark configuration, while (10) refers to the molecular sieve.

FIG. 2 illustrates a product obtained from a 1 :1 molar ratio of n-C8-OH and n-C18-OH as reacted in example 20.

FIG. 3 illustrates the Guerbet product from example 22 from the self-condensation of isostearyl alcohol.

FIG. 4 illustrates a chromatogram of the products obtained in example 26. Two C16 Guerbet (GB) products have been formed.

FIG. 5 illustrates Guerbet products obtained from the cross-condensation of stearyl alcohol with hexanol, octanol, decanol or dodecanol in a 1 :1 molar ratio.

Detailed description of invention

Before the present system and method of the invention are described, it is to be understood that this invention is not limited to particular systems and methods or combinations described, since such systems and methods and combinations may, of course, vary. It is also to be understood that the terminology used herein is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

As used herein, the singular forms "a", "an", and "the" include both singular and plural referents unless the context clearly dictates otherwise.

The terms "comprising", "comprises" and "comprised of" as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. It will be appreciated that the terms "comprising", "comprises" and "comprised of" as used herein comprise the terms "consisting of", "consists" and "consists of".

The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within the respective ranges, as well as the recited endpoints.

The term "about" or "approximately" as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of +/-10% or less, preferably +/-5% or less, more preferably +/-1 % or less, and still more preferably +/-0.1 % or less of and from the specified value, insofar such variations are appropriate to perform in the disclosed invention. It is to be understood that the value to which the modifier "about" or "approximately" refers is itself also specifically, and preferably, disclosed.

Whereas the terms "one or more" or "at least one", such as one or more or at least one member(s) of a group of members, is clear per se, by means of further exemplification, the term encompasses inter alia a reference to any one of said members, or to any two or more of said members, such as, e.g., any >3, >4, >5, >6 or >7 etc. of said members, and up to all said members.

All references cited in the present specification are hereby incorporated by reference in their entirety. In particular, the teachings of all references herein specifically referred to are incorporated by reference.

Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

In the following passages, different aspects of the invention are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous. Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the appended claims, any of the claimed embodiments can be used in any combination.

In the present description of the invention, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration only of specific embodiments in which the invention may be practiced. Parenthesized or emboldened reference numerals affixed to respective elements merely exemplify the elements by way of example, with which it is not intended to limit the respective elements. It is to be understood that other embodiments may be utilised and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

According to a first aspect, the present invention relates to a process for the preparation of a Guerbet alcohol. The process comprises the steps of: (a) providing at least one alcohol, wherein said at least one alcohol has a carbon atom bearing at least one hydrogen atom adjacent to the hydroxyl group;

(b) providing a catalyst composition, wherein said catalyst composition comprises an alkaline catalyst and a copper-nickel catalyst comprised in a hydrotalcite;

(c) mixing alcohol (a) with catalyst composition (b), thereby obtaining a mixture; and,

(d) heating said mixture;

thereby obtaining a Guerbet alcohol.

The at least one alcohol may be any alcohol that is suitable to undergo a Guerbet reaction. The at least one alcohol may be linear or branched. The at least one alcohol may be saturated or unsaturated. The at least one alcohol may comprise substitutions.

In some embodiments, the at least one alcohol is a C ₂ -C ₃ 6 alcohol, preferably a C ₆ -C ₂ 4 alcohol, more preferably a C ₈ -Ci ₈ alcohol. In some embodiments, the at least one alcohol is selected from the group comprising: 1 -octanol, n-stearyl alcohol, isostearyl alcohol, citronellol, n- hexanol, and n-decanol.

The at least one alcohol is preferably a bio-based alcohol. The at least one alcohol may comprise cellulose. In some embodiments, the at least one alcohol is derived from a natural source. In some embodiments, the at least one alcohol is a fatty acid, preferably a fatty acid derived from a natural source. In some examples, the natural source is palm oil, algal oil, canola oil, castor bean oil, coconut oil, corn oil, cotton oil, fish oil, flaxseed oil, hempseed oil, jatropha oil, lard, mustard seed oil, nut oil, olive oil, palm kernel oil, peanut oil, rapeseed oil, safflower seed oil, soybean oil, sunflower oil, tall oil, tallow, or yellow grease.

In some embodiments, the at least one alcohol comprises at least one aliphatic diol, preferably a biomass-derived aliphatic diol. Suitable examples of biomass-derived aliphatic diols may be selected from the group comprising: 1 ,3-propanediol, 1 ,4-butanediol, 1 ,2-butanediol, 1 ,3- butanediol, 2,3-butanediol, 2,2-dimethyl-1 ,3-propanediol, and 1 ,5-pentanediol.

In some embodiments, the at least one alcohol comprises an alcohol as described in US20150148569, hereby incorporated in its entirety by reference.

In some embodiments, in step (a) a second alcohol is provided and mixed in step (c), wherein the second alcohol is different from the at least one alcohol. Preferably, the second alcohol is a Ci-C ₃ 6 alcohol, preferably a C ₆ -C ₂ 4 alcohol, more preferably a C ₈ -Ci ₈ alcohol. Preferably, the second alcohol is an aliphatic diol, preferably a biomass-derived aliphatic diol. Suitable examples of biomass-derived aliphatic diols may be selected from the group comprising: 1 ,3- propanediol, 1 ,4-butanediol, 1 ,2-butanediol, 1 ,3-butanediol, 2,3-butanediol, 2, 2-dimethyl-1 ,3- propanediol, and 1 ,5-pentanediol.

In some embodiments, in step (a) a second alcohol is provided and mixed in step (c), wherein the second alcohol is different from the at least one alcohol, and wherein the at least one alcohol and the second alcohol are selected from the group comprising: C ₆ alcohol, C ₈ alcohol, Ci o alcohol, Ci2 alcohol, C _M alcohol, Ci ₆ alcohol, Ci ₈ alcohol, C ₂₀ alcohol, C ₂₂ alcohol, C ₂₄ alcohol, and C ₂₆ alcohol.

In some embodiments, in step (a) a second alcohol is provided and mixed in step (c), wherein the second alcohol is different from the at least one alcohol, and wherein the at least one alcohol and the second alcohol are selected from the group comprising: C ₆ alcohol, C ₈ alcohol, Ci o alcohol, and C ₁₂ alcohol. In some embodiments, the at least one alcohol is a C ₆ alcohol and the second alcohol is selected from the group comprising: C ₈ alcohol, Ci o alcohol, and Ci ₂ alcohol. In some embodiments, the at least one alcohol is a C ₈ alcohol and the second alcohol is selected from the group comprising: C ₆ alcohol, Ci o alcohol, and Ci ₂ alcohol. In some embodiments, the at least one alcohol is a C ₁₀ alcohol and the second alcohol is selected from the group comprising: C ₆ alcohol, C ₈ alcohol, and Ci ₂ alcohol. In some embodiments, the at least one alcohol is a C ₁₂ alcohol and the second alcohol is selected from the group comprising: C ₆ alcohol, C ₈ alcohol, and Ci o alcohol.

In some embodiments, in step (a) a second alcohol is provided and mixed in step (c), wherein the second alcohol is different from the at least one alcohol, and wherein the at least one alcohol and the second alcohol are selected from the group comprising: C ₁₄ alcohol, C ₁₆ alcohol, Ci ₈ alcohol, C ₂₀ alcohol, C ₂₂ alcohol, C ₂₄ alcohol, and C ₂₆ alcohol. Preferably, the reaction temperature is at least 200*Ό and at most 280 *Ό.

In some embodiments, in step (a) a second alcohol is provided and mixed in step (c), wherein the second alcohol is different from the at least one alcohol, the at least one alcohol is selected from the group comprising: C ₆ alcohol, C ₈ alcohol, C ₁₀ alcohol, and C ₁₂ alcohol; and the second alcohol is selected from the group comprising: C alcohol, Ci ₆ alcohol, Ci ₈ alcohol, C ₂₀ alcohol, C ₂₂ alcohol, C ₂₄ alcohol, and C ₂₆ alcohol.

The resulting Guerbet alcohol may be solid, and the catalyst may be recovered by a hotfilter. In some embodiments, the at least one alcohol and the second alcohol are selected from the group comprising: 1 -octanol, n-stearyl alcohol, isostearyl alcohol, citronellol, n-hexanol, and n- decanol.

In some embodiments, in step (a) an aldehyde and/or a ketone is provided and mixed in step (c). Preferred aldehydes and/or ketones are biomass-derived aldehydes and/or ketones. In some embodiments, the aldehyde and/or ketone is selected from the group comprising: hydroxylmethylfurfural, furfural, 2-ethylhexanal, decanal, dodecanal, tridecanal, isobutyraldehyde, acetaldehyde, propionaldehyde, butyraldehyde, and C ₃ -C ₆ methyl ketones (such as acetone, butan-2-one, pentan-2-one, or hexan-2-one), or a combination thereof. In some embodiments, the hydrotalcite is a compound of formula (I)

[M ²⁺ _! _ _x M ³⁺ _x (OH) ₂ ] ^x+ (A ⁿ ) _x/n mH ₂ 0 (I), wherein,

x is selected from 0.1 to 0.33;

m is an integer selected from 1 , 2, 3, 4 or 5;

n is an integer selected from 1 or 2; M ²⁺ is selected from the group comprising Mg, Ni, Zn, Cu, Co, Fe, Pd Pt, and Ru; preferably Mg, Ni and Cu; preferably wherein M ²⁺ comprises all three of Mg, Ni and Cu;

M ³⁺ is selected from the group comprising Al, Cr, Mn, Co, Fe, and Ga; preferably Al;

A is selected from the group comprising C0 ₃ ^2" with n=2; OH ^" with n=1 ; N0 ₃ ^" with n=1 ; S0 ₄ ^2" with n=2; preferably C0 ₃ ^2" with n=2; and

optionally, wherein one or more M ²⁺ and/or M ³⁺ ions are isomorphously substituted by M ⁺ or M ⁴⁺ ions, preferably wherein M ⁴⁺ is selected from the group comprising Ge, Sn, and Pb.

In some embodiments, the hydrotalcite is a compound of formula (I)

[M ²⁺ _! _ _x M ³⁺ _x (OH) ₂ ] ^x+ (A ^n" ) _x/n mH ₂ 0 (I), wherein,

x is selected from 0.1 to 0.33;

m is an integer selected from 1 , 2, 3, 4 or 5;

n is an integer selected from 1 or 2;

M ²⁺ is selected from the group comprising Mg, Ni and Cu; preferably wherein M ²⁺ comprises all three of Mg, Ni and Cu;

M ³⁺ is selected from the group comprising Al, Cr, Mn, Co, Fe, and Ga; preferably Al;

A is selected from the group comprising C0 ₃ ^2" with n=2; OH ^" with n=1 ; N0 ₃ ^" with n=1 ; S0 ₄ ^2" with n=2; preferably C0 ₃ ^2" with n=2; and

optionally, wherein one or more M ²⁺ and/or M ³⁺ ions are isomorphously substituted by M ⁺ or

M ⁴⁺ ions, preferably wherein M ⁴⁺ is selected from the group comprising Ge, Sn, and Pb.

In some embodiments, the hydrotalcite is a compound of formula (I)

[M ² V _X M ³⁺ _x (OH) ₂ ] ^x+ (A ^n" ) _x/n mH ₂ 0 (I), wherein,

x is selected from 0.1 to 0.33;

m is an integer selected from 1 , 2, 3, 4 or 5;

n is an integer selected from 1 or 2;

M ²⁺ is selected from the group comprising Mg, Ni, Zn, Cu, Co, Fe, Pd Pt, and Ru; preferably

Mg, Ni and Cu; preferably wherein M ²⁺ comprises all three of Mg, Ni and Cu;

M ³⁺ is Al;

A is selected from the group comprising C0 ₃ ^2" with n=2; OH ^" with n=1 ; N0 ₃ ^" with n=1 ; S0 ₄ ^2" with n=2; preferably C0 ₃ ^2" with n=2; and

optionally, wherein one or more M ²⁺ and/or M ³⁺ ions are isomorphously substituted by M ⁺ or

M ⁴⁺ ions, preferably wherein M ⁴⁺ is selected from the group comprising Ge, Sn, and Pb.

In some embodiments, the hydrotalcite is a compound of formula (I)

[M ² V _X M ³⁺ _x (OH) ₂ ] ^x+ (A ^n" ) _x/n mH ₂ 0 (I), wherein,

x is selected from 0.1 to 0.33;

m is an integer selected from 1 , 2, 3, 4 or 5;

n is 2;

M ²⁺ is selected from the group comprising Mg, Ni, Zn, Cu, Co, Fe, Pd Pt, and Ru; preferably Mg, Ni and Cu; preferably wherein M ²⁺ comprises all three of Mg, Ni and Cu; M ³⁺ is selected from the group comprising Al, Cr, Mn, Co, Fe, and Ga; preferably Al;

A is C0 ₃ ^2" ; and

optionally, wherein one or more M ²⁺ and/or M ³⁺ ions are isomorphously substituted by M ⁺ or M ⁴⁺ ions, preferably wherein M ⁴⁺ is selected from the group comprising Ge, Sn, and Pb.

In some embodiments, the hydrotalcite is a compound of formula (I)

[ ²⁺ i - _x M ³⁺ _x (OH) ₂ ] ^x+ (A ⁿ ) _x/n mH ₂ 0 (I), wherein,

x is selected from 0.1 to 0.33;

m is an integer selected from 1 , 2, 3, 4 or 5;

n is an integer selected from 1 or 2;

M ²⁺ is selected from the group comprising Mg, Ni and Cu; preferably wherein M ²⁺ comprises all three of Mg, Ni and Cu;

M ³⁺ is Al;

A is selected from the group comprising C0 ₃ ^2" with n=2; OH ^" with n=1 ; NOV with n=1 ; S0 ₄ ^2~ with n=2; preferably C0 ₃ ^2" with n=2; and

optionally, wherein one or more M ²⁺ and/or M ³⁺ ions are isomorphously substituted by M ⁺ or

M ⁴⁺ ions, preferably wherein M ⁴⁺ is selected from the group comprising Ge, Sn, and Pb.

In some embodiments, the hydrotalcite is a compound of formula (I)

[M ²⁺ _! _ _x M ³⁺ _x (OH) ₂ ] ^x+ (A ⁿ ) _x/n mH ₂ 0 (I), wherein,

x is selected from 0.1 to 0.33;

m is an integer selected from 1 , 2, 3, 4 or 5;

n is 2;

M ²⁺ is selected from the group comprising Mg, Ni and Cu; preferably wherein M ²⁺ comprises all three of Mg, Ni and Cu;

M ³⁺ is selected from the group comprising Al, Cr, Mn, Co, Fe, and Ga; preferably Al;

A is C0 ₃ ^2" ; and

optionally, wherein one or more M ²⁺ and/or M ³⁺ ions are isomorphously substituted by M ⁺ or M ⁴⁺ ions, preferably wherein M ⁴⁺ is selected from the group comprising Ge, Sn, and Pb.

In some embodiments, the hydrotalcite is a compound of formula (I)

[M ² V _X M ³⁺ _x (OH) ₂ ] ^x+ (A ⁿ ) _x/n mH ₂ 0 (I), wherein,

x is selected from 0.1 to 0.33;

m is an integer selected from 1 , 2, 3, 4 or 5;

n is 2;

M ²⁺ is selected from the group comprising Mg, Ni, Zn, Cu, Co, Fe, Pd Pt, and Ru; preferably Mg, Ni and Cu; preferably wherein M ²⁺ comprises all three of Mg, Ni and Cu;

M ³⁺ is AI;

A is C0 ₃ ^2" ; and

optionally, wherein one or more M ²⁺ and/or M ³⁺ ions are isomorphously substituted by M ⁺ or M ⁴⁺ ions, preferably wherein M ⁴⁺ is selected from the group comprising Ge, Sn, and Pb. In some embodiments, the hydrotalcite is a compound of formula (I)

[ ²⁺ i - _x M ³⁺ _x (OH) ₂ ] ^x+ (A ⁿ ) _x/n mH ₂ 0 (I), wherein,

x is selected from 0.1 to 0.33;

m is an integer selected from 1 , 2, 3, 4 or 5;

n is 2;

M ²⁺ is selected from the group comprising Mg, Ni and Cu; preferably wherein M ²⁺ comprises all three of Mg, Ni and Cu;

M ³⁺ is Al;

A is C0 ₃ ^2" ; and

optionally, wherein one or more M ²⁺ and/or M ³⁺ ions are isomorphously substituted by M ⁺ or M ⁴⁺ ions, preferably wherein M ⁴⁺ is selected from the group comprising Ge, Sn, and Pb.

In some preferred embodiments, the hydrotalcite has an M ²⁺ :M ³⁺ ratio of at least 2:1 ; preferably the hydrotalcite has an M ²⁺ :M ³⁺ ratio of at least 2:1 to at most 4:1 , for example about 3:1 .

In some preferred embodiments, M ²⁺ is selected from the group comprising Mg, Ni and Cu, preferably wherein M ²⁺ comprises all three of Mg, Ni and Cu; and the hydrotalcite has an M ²⁺ :M ³⁺ ratio of at least 2:1 ; preferably the hydrotalcite has an M ²⁺ :M ³⁺ ratio of at least 2:1 to at most 4:1 , for example about 3:1 . In some preferred embodiments, M ³⁺ is Al, and the hydrotalcite has an M ²⁺ :M ³⁺ ratio of at least 2:1 ; preferably the hydrotalcite has an M ²⁺ :M ³⁺ ratio of at least 2:1 to at most 4:1 , for example about 3:1 . In some preferred embodiments, M ²⁺ is selected from the group comprising Mg, Ni and Cu, preferably wherein M ²⁺ comprises all three of Mg, Ni and Cu; M ³⁺ is Al, and the hydrotalcite has an M ²⁺ :M ³⁺ ratio of at least 2:1 ; preferably the hydrotalcite has an M ²⁺ :M ³⁺ ratio of at least 2:1 to at most 4:1 , for example about 3:1 .

In some preferred embodiments, the copper-nickel catalyst comprises nickel in an atomic percent from 0.5% to 40% based on the total mole of metals present in said copper-nickel catalyst; more preferably an atomic percent of 0.5% to 20%; the most preferably an atomic percent of 0.5% to 10%; for example from 1 .5% to 10%; for example from 2.0% to 9.0%; for example from 2.5% to 7.5%.

In some preferred embodiments, the copper-nickel catalyst comprises copper in an atomic percent from 0.5% to 40% based on the total mole of metals present in said copper-nickel catalyst, more preferably an atomic percent of 0.5% to 20%; the most preferably an atomic percent of 0.5% to 10%; for example from 1 .5% to 10%; for example from 2.0% to 9.0%; for example from 2.5% to 7.5%.

In some preferred embodiments, the copper-nickel catalyst comprises magnesium in an atomic percent from 20% to 90% based on the total mole of metals present in said copper- nickel catalyst; preferably an atomic percent from 30% to 85%; preferably an atomic percent from 40% to 80%; for example from 50% to 75%; for example from 60% to 70%; for example about 65%.

In some preferred embodiments, the copper-nickel catalyst comprised in a hydrotalcite is subjected to a thermal treatment prior to step (b).

In some preferred embodiments, the copper-nickel catalyst is present in an amount of 0.05 to 5.0% by weight, based on the weight of said at least one alcohol, more preferably in an amount of 0.05 to 2.5% by weight; most preferably in an amount of 0.05 to 1 .0% by weight. In some preferred embodiments, the Cu:Ni molar ratio in the copper-nickel catalyst is at least 0.1 :9.9 and at most 6.0:4.0, preferably at least 0.2:9.8 and at most 5.0:5.0, preferably at least 0.4:9.6 and at most 4.0:6.0, preferably at least 0.5:9.5 and at most 3.0:7.0, preferably at least 0.6:9.4 and at most 2.5:7.5, preferably at least 0.8:9.2 and at most 2.0:8.0, preferably at least 0.9:9.1 and at most 1 .5:8.5, preferably about 1 .0:9.0.

In some embodiments, the Cu:Ni molar ratio in the copper-nickel catalyst is at most 2.0:8.0. In some preferred embodiments, the Cu:Ni molar ratio in the copper-nickel catalyst is at most 1 .5:8.5, preferably at most 1 .4:8.6, preferably at most 1 .3:8.7, preferably at most 1 .2:8.8, preferably at most 1 .1 :8.9, preferably about 1 .0:9.0. In some preferred embodiments, the Cu:Ni molar ratio in the copper-nickel catalyst is at least 0.1 :9.9 and at most 1 .5:8.5, preferably at least 0.2:9.8 and at most 1 .4:8.6, preferably at least 0.4:9.6 and at most 1 .3:8.7, preferably at least 0.6:9.4 and at most 1 .2:8.8, preferably at least 0.8:9.2 and at most 1 .1 :8.9, preferably about 1 .0:9.0.

In some preferred embodiments, the Cu:Ni molar ratio in the copper-nickel catalyst is at most 1 .5:8.5, preferably at most 1 .4:8.6, preferably at most 1 .3:8.7, preferably at most 1 .2:8.8, preferably at most 1 .1 :8.9, preferably about 1 .0:9.0; and the copper-nickel catalyst comprises magnesium in an atomic percent from 20% to 90% based on the total mole of metals present in said copper-nickel catalyst; preferably an atomic percent from 30% to 85%.

In some preferred embodiments, the Cu:Ni molar ratio in the copper-nickel catalyst is at most 1 .5:8.5, preferably at most 1 .4:8.6, preferably at most 1 .3:8.7, preferably at most 1 .2:8.8, preferably at most 1 .1 :8.9, preferably about 1 .0:9.0; and the copper-nickel catalyst comprises magnesium in an atomic percent from 40% to 80%; for example from 50% to 75%; for example from 60% to 70%; for example about 65%.

In some preferred embodiments, the Cu:Ni molar ratio in the copper-nickel catalyst is at least 0.1 :9.9 and at most 1 .5:8.5, preferably at least 0.2:9.8 and at most 1 .4:8.6, preferably at least 0.4:9.6 and at most 1 .3:8.7, preferably at least 0.6:9.4 and at most 1 .2:8.8, preferably at least 0.8:9.2 and at most 1 .1 :8.9, preferably about 1 .0:9.0; and the copper-nickel catalyst comprises magnesium in an atomic percent from 20% to 90% based on the total mole of metals present in said copper-nickel catalyst; preferably an atomic percent from 30% to 85%.

In some preferred embodiments, the Cu:Ni molar ratio in the copper-nickel catalyst is at least 0.1 :9.9 and at most 1 .5:8.5, preferably at least 0.2:9.8 and at most 1 .4:8.6, preferably at least 0.4:9.6 and at most 1 .3:8.7, preferably at least 0.6:9.4 and at most 1 .2:8.8, preferably at least 0.8:9.2 and at most 1 .1 :8.9, preferably about 1 .0:9.0; and the copper-nickel catalyst comprises magnesium in an atomic percent from 40% to 80%; for example from 50% to 75%; for example from 60% to 70%; for example about 65%.

In some preferred embodiments, the alkaline catalyst is selected from the group comprising alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates and alkali earth metal carbonates, alkali metal phosphates, alkaline earth metal oxides, zeolites, alkyl amines or mixtures thereof. Preferably, the alkaline catalyst is selected from alkali metal hydroxides and alkaline earth metal hydroxides. Preferably, the alkaline catalyst is selected from the group comprising KOH, K phosphates, K carbonates, and 3-ethylamine. Preferably, the alkaline catalyst is KOH.

In some preferred embodiments, the alkaline catalyst is present in an amount of 0.5 to 5.0% by weight, based on the weight of said at least one alcohol; more preferably in an amount of 1 .0 to 4.0% by weight, more preferably in an amount of 1 .5 to 3.0% by weight.

In some preferred embodiments, the process according to the first aspect of the invention further comprises the step (e) of removing the water formed in step (d). Preferably, this step is performed by a Dean-Stark apparatus.

In some preferred embodiments, step (d) is performed at a temperature of 170 to 280 ^q C. In some preferred embodiments, step (d) is performed at a pressure of 1 to 50 bars. In some preferred embodiments, step (d) is performed at a temperature of 170 to 280* and at a pressure of 1 to 50 bars. In some preferred embodiments, step (d) is performed under inert atmosphere, preferably selected from the group comprising: N ₂ , He, and Ar. In some preferred embodiments, step (d) is performed from 30 min up to 48 hours.

In some preferred embodiments, step (d) is performed after pre-reduction of the copper-nickel catalyst comprised in a hydrotalcite. The pre-reduction may for example be performed in a high-pressure reaction system. The catalyst may be suspended in alcohol, for example 1 - octanol and then transferred to the high-pressure reaction system. After closing the high- pressure reaction system, the headspace may be purged several times, for example with N ₂ . The activation process may be performed at 240 ^Q C, during 6 h, under autogenously pressurized conditions (approx. 6 bars overpressure). The high-pressure reaction system may then be cooled at room temperature, slowly degassed and finally, the activated catalyst may be transferred (still moistened by the 1 -octanol) to the atmospheric pressure reaction system in order to perform the Guerbet condensation reaction.

The inventors have surprisingly found that re-use of the catalyst does not result in a loss of selectivity, and may even improve selectivity. In some preferred embodiments, the copper- nickel catalyst comprised in a hydrotalcite is recovered after the process according to the first aspect, and then used for subsequent process according to the first aspect, or preferred embodiments thereof. In some embodiments, the copper-nickel catalyst comprised in a hydrotalcite is used in at least 2 subsequent processes according to the first aspect, or preferred embodiments thereof, for example in at least 3 subsequent processes, for example in at least 4 subsequent processes. As used herein, the term "subsequent processes" refers to processes that were performed after each other, without treatment of the catalyst, such as regeneration of the catalyst, between the processes.

According to a second aspect, the present invention relates to a Guerbet alcohol obtainable by the process according to the first aspect. Preferred embodiments for the first aspect of the invention are also preferred embodiments for the second aspect of the invention.

According to a third aspect, the present invention relates to a Guerbet alcohol. Preferred embodiments for the first aspect of the invention are also preferred embodiments for the third aspect of the invention.

In some preferred embodiments, the present invention relates to a Guerbet alcohol selected from the list comprising:

(A) a C26-Guerbet alcohol resulting from the cross-condensation of 1 -octanol and n-stearyl alcohol;

(B) a C36-Guerbet alcohol resulting from the self-condensation of isostearyl alcohol;

(C) a C20-Guerbet alcohol resulting from the self-condensation of citronellol; and,

(D) a C20-Guerbet alcohol resulting from the cross-condensation of n-hexanol and n-decanol. The chemical structures of these preferred Guerbet alcohols are shown below.

(A) a C26-Guerbet alcohol resulting from the cross-condensation of 1 -octanol and n-stearyl alcohol:

(B) a C36-Guerbet alcohol resulting from the self-condensation of isostearyl alcohol:

alcohol resulting from the self-condensation of citronellol:

(D) a C20-Guerbet alcohol resulting from the cross-condensation of n-hexanol and n-decanol:

In some embodiments, the Guerbet alcohol is selected from the list comprising: (A), (B), and (IC). In some embodiments, the Guerbet alcohol is selected from the list comprising: (A), (B), and (D). In some embodiments, the Guerbet alcohol is selected from the list comprising: (A), (C), and (D). In some embodiments, the Guerbet alcohol is selected from the list comprising: (B), (D), and (D).

In some embodiments, the Guerbet alcohol is selected from the list comprising: (A) and (B). In some embodiments, the Guerbet alcohol is selected from the list comprising: (A) and (C). In some embodiments, the Guerbet alcohol is selected from the list comprising: (A) and (D). In some embodiments, the Guerbet alcohol is selected from the list comprising: (B) and (C). In some embodiments, the Guerbet alcohol is selected from the list comprising: (B) and (D). In some embodiments, the Guerbet alcohol is selected from the list comprising: (C) and (D).

In some embodiments, the Guerbet alcohol is (A). In some embodiments, the Guerbet alcohol is (B). In some embodiments, the Guerbet alcohol is (C). In some embodiments, the Guerbet alcohol is (D).

In a particularly preferred embodiment according to the first, second, or third aspect, the Guerbet alcohol has a viscosity of at most 100 Pa.s, wherein the viscosity is measured at 25 °C using Brookfield Viscometer according to the ASTM D 4889 standard. In some preferred embodiments, preferably in the case of the C36 Guerbet alcohol, the melting point is at least 40 ^< Ό and at most 50 ^< Ό, preferably at least 40 ^< Ό and at most 50 ^< Ό, preferably at least 41 °C and at most 49 ^< Ό, preferably at least 42 °C and at most 48 ^< Ό, preferably at least 43 °C and at most 47 ^< Ό. The melt temperature is preferably measured using an IA9000 series Digital Melting Point Apparatus from Electrothermal to measure the capillary melting point.

The chemical structure of the Guerbet alcohol can be distinguished by using different analytical techniques, such as: mass spectrometry, 1 H and 13C NMR, elemental analysis (CHN), among others. According to a fourth aspect, the present invention relates to the use of a copper-nickel catalyst comprised in a hydrotalcite to prepare a Guerbet alcohol. Preferred embodiments for the first, second, or third aspect of the invention are also preferred embodiments for the fourth aspect of the invention.

According to a fifth aspect, the present invention relates to a copper-nickel catalyst comprised in a hydrotalcite. Preferred embodiments for the first, second, third, or fourth aspect of the invention are also preferred embodiments for the fifth aspect of the invention. More particularly, preferred embodiments for the copper-nickel catalyst comprised in a hydrotalcite as described above for the process according to the first aspect are also preferred embodiments for the copper-nickel catalyst comprised in a hydrotalcite according to the fifth aspect.

According to a sixth aspect, the present invention relates to a process for preparing a copper- nickel catalyst comprised in a hydrotalcite. Preferred embodiments for the first, second, third, fourth, or fifth aspect of the invention are also preferred embodiments for the sixth aspect of the invention. The hydrotalcite is preferably prepared by co-precipitation under high supersaturation conditions, as reported elsewhere (J. Catal., 225, 2004, 316-326).

The process for preparing a copper-nickel catalyst comprised in a hydrotalcite preferably comprises the step of adding a solution (A) comprising metal salts to a solution (B) comprising precipitating agents, thereby obtaining solids.

In some preferred embodiments, solution (A) comprises from at least 0.2 M to at most 5 M metal salts, preferably from at least 0.5 M to at most 2.5 M, more preferably from at least 0.5 M to at most 1 .5 M. Metal salts of solution (A) are preferably selected from metal nitrates, chlorides or sulphates; preferably metal nitrates. In some preferred embodiments, solution (A) comprises from at least 0.2 M to at most 5 M metal nitrates, preferably from at least 0.5 M to at most 2.5 M, more preferably from at least 0.5 M to at most 1 .5 M. Preferably, the metal salts comprise Ni and Cu, and optionally comprise Mg and/or Al. Preferably, the metal nitrates comprise Ni and Cu, and optionally comprise Mg and/or Al.

In some embodiments, the Cu:Ni molar ratio used in solution (A) is at least 0.1 :9.9 and at most 6.0:4.0; preferably at least 0.2:9.8 and at most 5.0:5.0; preferably at least 0.4:9.6 and at most 4.0:6.0; preferably at least 0.5:9.5 and at most 3.0:7.0; preferably at least 0.6:9.4 and at most 2.5:7.5; preferably at least 0.8:9.2 and at most 2.0:8.0; preferably at least 0.9:9.1 and at most 1 .5:8.5, preferably about 1 .0:9.0.

In some preferred embodiments, solution (B) comprises NaOH and/or Na ₂ C0 ₃ . In some preferred embodiments, solution (B) comprises from at least 1 .5 M to at most 5.5 M NaOH, preferably from at least 2.0 M to at most 3.0 M. In some preferred embodiments, solution (B) comprises from at least 0.05 M to at most 1 .5 M Na ₂ C0 ₃ , preferably from at least 0.15 M to at most 0.5 M. In some preferred embodiments, solution (B) comprises from at least 1 .5 M to at most 5.5 M NaOH and from at least 0.05 M to at most 1 .5 M Na ₂ C0 ₃ , preferably from at least 2.0 M to at most 3.0 M NaOH and from at least 0.15 M to at most 0.5 M Na ₂ C0 ₃ .

In some embodiments, solution (B) comprises KOH or NH ₄ OH instead of NaOH, preferably at the concentrations as described above. In some embodiments, solution (B) comprises K ₂ C0 ₃ instead of Na ₂ C0 ₃ , preferably at the concentrations as described above.

Preferably, solution B is kept in an ultrasonic bath during addition of solution (A). An ultrasonic bath frequency of 20-400 kHz is used, preferably of 20-50 kHz. The addition in ultrasonic bath is preferably performed at room temperature, or at elevated temperature. Other agitation methods may comprise mechanical or magnetic stirring, or shaking. After addition an ageing step may be applied at room temperature or at elevated temperature (e.g. reflux at 50-80°C). Other treatments that may be applied after addition are hydrothermal or microwave treatments.

In some embodiments, the obtained solids are washed, for example by centrifugation or filtration. In some embodiments, the obtained solids are dried, for example using the following temperature profile: in 0.5-5 O/min to 100-120^ and keep at this temperature for 4-24 hrs. In some embodiments, the obtained solids are calcined, for example using the following temperature profile: in 0.5-3°C/min to 375-600 ^< Ό, preferably to 450-550 ^< Ό, and keep at this calcination temperature for 4-16 hrs.

The process for preparing a copper-nickel catalyst comprised in a hydrotalcite may comprise co-precipitation at low saturation conditions, sol-gel-synthesis, combustion synthesis, or an induced hydrolysis method.

Typically, a solution (A) containing the desired amount of 1 M solution of metal nitrates is mixed thoroughly to make a homogeneous solution. Then, solution (A) is added dropwise on a solution (B) containing precipitating agents. During the addition, solution (B) may be kept in ultrasonic bath, at room temperature. The obtained solids can be washed by centrifugation, and dried in an air oven. All materials may be calcined in air, in order to obtain the respective mixed oxides.

According to a seventh aspect, the present invention relates to a process for the preparation of a Guerbet acid, comprising the steps of:

(i) preparing a Guerbet alcohol according to the first aspect of the invention, and preferred embodiments thereof; and

(ii) oxidizing the Guerbet alcohol;

thereby obtaining a Guerbet acid,

preferably wherein the Guerbet alcohol is selected from the list comprising: (A) a C26-Guerbet alcohol resulting from the cross-condensation of 1 -octanol and n-stearyl alcohol, (B) a C36- Guerbet alcohol resulting from the self-condensation of isostearyl alcohol, (C) a C20-Guerbet alcohol resulting from the self-condensation of citronellol, (D) a C20-Guerbet alcohol resulting from the cross-condensation of n-hexanol and n-decanol, or any one of the specific combinations as described above.

Examples and Comparative Examples

The following examples are illustrative and should not be interpreted in any way so as to limit the scope of the invention.

Material preparation: Copper-nickel hydrotalcite-derived catalysts

The hydrotalcite was prepared by co-precipitation under high supersaturation conditions, as reported elsewhere (J. Catal., 225, 2004, 316-326). Typically, a solution (A) containing the desired amount of 1 M solution of metal nitrates (Ni and/or Cu, Mg and Al, where the M(II)/AI molar ratio was 3.0, the (Cu+Ni)/(Cu+Ni+Mg+AI) ratio was 0.1 and the Mg/(Cu+Ni+Mg+AI) was 0.65) were mixed thoroughly to make a homogeneous solution. Then, solution (A) was added dropwise on a solution (B) containing the precipitating agents (i.e., NaOH and Na ₂ C0 ₃ ; 2.2 M NaOH and 0.15 M Na ₂ C0 ₃ ). During the addition, solution (B) was kept in ultrasonic bath, at room temperature. The obtained solids were washed by centrifugation (until nitrates and sodium were totally absent in the washing liquids), and dried in an air oven at 100 °C for at least 12 h. All materials were calcined at 500 °C (with a heating rate of 2 ^Q C/min) for 4 h in air, in order to obtain the respective mixed oxides.

In order to prepare batches of about 250 g (on calcined basis) the following recipe was developed: A 2,5 M metal solution was added dropwise to a basic solution containing 0,37M Na ₂ C0 ₃ and 5 M NaOH while stirring mechanically at room temperature. The washing, drying and calcination step were used as described above.

The calcined materials had the following formula:

Nio _.2 Cuo. ₆ Mg _5.2 AI ₂ C>9 = Ni(2.5)Cu(7.5);

Nio.4Cuo. ₄ Mg _5.2 AI ₂ C>9 = Ni(5.0)Cu(5.0);

Nio.6Cuo _.2 Mg _5.2 AI ₂ C>9 = Ni(7.5)Cu(2.5); and,

Nio.72Cuo.o8Mg _5.2 AI ₂ C>9 = Ni(9.0)Cu(1 .0).

Material preparation: Copper-nickel supported on v-AI ₂ 0 ₃ or MgO catalysts

The copper-nickel supported catalysts were synthesized by a wet impregnation method, ensuring a copper/nickel molar ratio of 2.5/7.5 and a total loading of copper and nickel metals in the whole catalyst of 12 wt%. In a typical procedure, the appropriated amounts of Ni(N0 ₃ ) ₂ .6H ₂ 0 and Cu(N0 ₃ ).3H ₂ 0 salts were dissolved in 150 mL of distilled water, in order to impregnate 4 g of support. Then, the desired support (γ-ΑΙ ₂ 0 ₃ or MgO) was added to the cationic solution and then, it was kept under vigorous stirring during 2 h, at room temperature. Afterwards, the excess of solvent was removed at low pressure at 50 ^Q C, until having a totally dried solid. Finally, the material was calcined in presence of air at 500 ^Q C, during 4h.

Example 1

A 100 mL five-neck flask equipped with; a magnetic stirring-bar, a temperature probe, a nitrogen inlet, a condenser and a Dean-Stark system for separating the water formed by the reaction, was charged with 40 g of 1 -octanol, 0.6 g of granular potassium hydroxide (1 .5 wt%) and 0.4 g of copper-nickel catalyst comprised in a hydrotalcite (the Cu/Ni molar ratio was 2.5/7.5; and the total content of copper and nickel metals in the whole catalyst was 13% by weight). The temperature was elevated under N ₂ flow (rate of 50 to 60 mL/min) up to the boiling point of the alcohol (195 ⁹ C). The time when the reaction mixture reached 190 to 200 QC (reflux) was designed as the point of initiation of the reaction. The highest temperature allowed for the reaction to be conducted was 225 ^Q C. The reaction was terminated after 8 hours. Then, the liquid reaction mixture was cooled and centrifuged to remove the copper- nickel catalyst and the precipitated soap-type products (potassium carboxylates). The composition of the final reaction mixture was analysed by GC, as follow: 83.4% 2-hexyl-1 - decanol; 5.3% C16-non-Guerbet; 5.3% C24-products; 2.1 % 1 -octanol.

The 1 -octanol conversion, 2-hexyl-1 -decanol (C16-Guerbet alcohol) product selectivity, C16- Guerbet (alcohol) product yield after 6 hours reaction and the C16-non-Guerbet (alcohol) (such as 2-hexyl-2-decenal, 2-hexyldecanal and 2-hexyl-2-decen-1 -ol) product yield after 6 hours reaction are shown in Table 1 . A purity of the final target product (2-hexyl-1 -decanol (C16-Guerbet alcohol)) was calculated considering the losses in the mass balance during the reaction (due to the formation of carboxylic salts and 1 -octanol evaporation) and subtracting the un reacted 1 -octanol. This value is a good agreement with the purity of the Cl 6-Guerbet estimated after distillation of the final reaction mixture.

Table 1. Data obtained after 6 hours reaction.

Comparative Example 1

The reaction was carried out under the same conditions as described in Example 1 except that the copper-nickel catalyst in a hydrotalcite was not used. After 8 h reaction, the temperature of the system did not rise, being it constant at the reflux point. A very low 1 -octanol conversion and a negligible production of 2-hexyl-1 -decanol were observed (Table 1 ).

Comparative example 2

The reaction was carried out under the same conditions as described in Example 1 except that 0.4 g of a physical mixture (50%:50% by weight) of commercially available copper-supported and Ni-supported catalysts (Cu-Pricat (Pricat Cu 60/35 P) and Ni-Pricat (Pricat Ni 62/15 P)) was used instead of copper-nickel catalyst comprised in a hydrotalcite. As can be seen in Table 1 , the use of a mixture of commercial Cu-Pricat and Ni-Pricat catalysts did not favour the selectivity of the process to the C16-Guerbet product. In addition, an intense blue-green colour was observed in the final reaction product, meaning high leaching of Cu and Ni cations during the process.

Comparative example 3

The reaction was carried out under the same conditions as described in Example 1 except that 0.4 g of a copper-nickel catalyst supported on alumina (the copper/nickel molar ratio was 2.5/7.5 and the total content of copper and nickel metal in the whole catalyst was 12% by weight) was used instead of copper-nickel catalyst comprised in a hydrotalcite. Conversion, selectivity, yields, and purity after 6 hours reaction are presented in Table 1 .

Comparative example 4

The reaction was carried out under the same conditions as described in Example 1 except that 0.4 g of a copper-nickel catalyst supported on MgO (the copper/nickel molar ratio was 2.5/7.5 and the total content of copper and nickel metal in the whole catalyst was 12% by weight) was used instead of copper-nickel catalyst comprised in a hydrotalcite. Conversion, selectivity, yields, and purity after 6 hours reaction are presented in Table 1 .

Example 2

The reaction was carried out under the same conditions as described in Example 1 except that the copper-nickel catalyst comprised in a hydrotalcite was pre-reduced just before to proceed with the condensation of 1 -octanol. The pre-reduction process was performed in a high- pressure reaction system (PARR reactor, 160 imL stainless-steel vessel), as follow: typically, 0.4 g of catalyst were suspended in 100 g of 1 -octanol and then, transferred to the PARR reactor. After closing the reactor, the headspace was purged several times with N ₂ . The activation process was performed at 240 ^Q C, during 6 h, under autogenously pressurized conditions (approx. 6 bars overpressure). The reactor was then cooled at room temperature, slowly degassed and finally, the activated catalyst was transferred (still moistened by the 1 - octanol) to the atmospheric pressure reaction system in order to perform the condensation reaction. The composition of the final reaction mixture was characterized as follow: 87.3% 2- hexyl-1 -decanol; 3.8% C16-non-Guerbet alcohol products; 6.8% C24-products; 2.1 % 1 - octanol. The pre-reduction of the copper-nickel catalyst decreases the concentration of C16- non-Guerbet alcohol products in the final reaction product in around 2%. Conversion, selectivity, yields, and purity after 6 hours reaction are presented in Table 2.

Example 3

The reaction was carried out under the same conditions as described in Example 1 except that the composition of the copper-nickel catalyst comprised in a hydrotalcite carrier was modified (the Cu/Ni molar ratio was 1 .0/9.0; the total content of copper and nickel metals in the whole catalyst was kept at 13% by weight). The composition of the final reaction mixture was characterized as follow: 94.5% 2-hexyl-1 -decanol; 1 .1 % C16-non-Guerbet alcohol products; 4.4% 1 -octanol. The increment in the Ni-to-Cu ratio highly favoured the selectivity of the process and the pre-reduction step can be avoided. Conversion, selectivity, yields, purity after 6 hours reaction are presented in Table 2.

Table 2. Data obtained after 6 hours reaction.

Example 4:

The reaction was carried out under the same conditions as described in Example 1 . At the end of the reaction (8 hours), the copper-nickel catalyst comprised in a hydrotalcite was removed by centrifugation and re-used as such up to 3 times (the recovered catalyst was mixed 40g of new 1 -octanol and 0.6 g of new granular potassium hydroxide). Conversion, selectivity and yields after 6 hours reaction are presented in Table 3. As can be seen in Table 3, the re-use of the copper-nickel catalyst (example 4) promoted the selectivity of the process compared to example 1 .

Table 3. Data obtained after 6 hours reaction

Comparative example 5

The reaction was carried out under the same conditions as described in Example 4 (catalyst recovery and reuse) except that 0.4 g of a copper-nickel catalyst supported on an alumina (the copper/nickel molar ratio was 2.5/7.5 and the total content of copper and nickel metal in the whole catalyst was 12% by weight) was used instead of copper-nickel catalyst comprised in a hydrotalcite. Conversion, selectivity, yields, and purity after 6 hours reaction are presented in Table 3. During the first re-use, the catalytic performance of the mentioned system remained as good as the fresh catalyst (see Table 1 , comparative example 3); however, after the second reuse of the catalyst, the efficiency of the process was strongly affected, achieving only 44.9 % conversion of octanol and 18.7% yield to the targeted Guerbet alcohol after 6 h reaction (see Table 3).

Comparative example 6

The reaction was carried out under the same conditions as described in Example 3 (catalyst recovery and reuse) except that 0.4 g of a copper-nickel catalyst supported on MgO (the copper/nickel molar ratio was 2.5/7.5 and the total content of copper and nickel metal in the whole catalyst was 12% by weight) was used instead of copper-nickel catalyst comprised in a hydrotalcite. Conversion, selectivity and yields after 6 hours reaction are presented in Table 3. In analogy to the comparative example 6, the copper-nickel catalyst supported on MgO shown a good stability during the first re-use, being it as good as the fresh catalyst (Table 1 , comparative example 4). Nevertheless, the second reuse of the catalyst caused a relevant diminishing in the efficiency of the process, reaching 67,2 % conversion of octanol and 36.6% yield to the targeted Guerbet alcohol after 6 h reaction (Table 3; comparative example 6, 2nd reuse).

Thus, between the copper-nickel catalysts evaluated, only the copper-nickel catalyst comprised in a hydrotalcite can be reused more than two times without losing its catalytic efficiency during the self-condensation of octanol, while copper-nickel catalysts supported on MgO or Al ₂ 0 ₃ do not show this reusability.

Example 5

The effect of the elimination of water during the reaction was evaluated by using different water-removal configurations described as follow (see fig. 1 ): i) typical Dean-Stark configuration, as described in example 1 . ii) Dean-Stark plus molecular sieve configuration; where 10 g of molecular sieve were placed just between the connection of the distillation receiver Dean-Stark and the reflux condenser, iii) A water removal configuration where an addition funnel was filled with 3 g of molecular sieve.

The reaction was carried out under the same conditions as described in Example 1 , using the three different water-removal configurations described before. Conversion, selectivity and yields after 6 hours reaction are presented in Table 4.

Table 4. Data obtained after 6 hours reaction.

Entry 1 -Octanol C16-Guerbet C16- C16-non- Purity C16- conversion selectivity (%) Guerbet Guerbet yield Guerbet (%)

(%) yield (%) (%)

Example 5. 93.5 65.7 61 .4 2.5 87.0

Config. i).

Example 5. 97.2 69.8 67.8 0.8 91 .0

Config. ii).

Example 5. 95.6 72.4 69.2 1 .0 90.0 Config. iii).

The presence of the molecular sieve in the water-removal configurations ii) and iii) seems to promote an increase in the C16-Guerbet yield (up to 7.8%). Nevertheless, at the end of the reaction, the molecular sieve was also impregnated with 1 -octanol, which could cause an overestimation of the conversion and yield calculations. In any case, by using the copper- nickel catalyst comprised in a hydrotalcite described in example 1 , the most simple water- removal configuration i) is good enough in order to achieve a good selectivity in the self- condensation reaction of 1 -octanol to the respective C16-Guerbet alcohol.

Example 6

The effect of the copper/nickel molar ratio in the structure of the copper-nickel catalysts comprised in a hydrotalcite carrier was evaluated, going from the single Ni or Cu catalysts to the bimetallic ones. The different Ni/Cu molar ratios analysed were selected as follow: 10/0; 2.5/7.5; 5.0/5.0; 7.5/2.5 and 0/10. The reaction was carried out under the same conditions as described in Example 1 , using the five different copper-nickel catalysts described before. Conversion, selectivity, yields and purity after 6 hours reaction are presented in Table 5.

Table 5. Data obtained after 6 hours reaction.

Clearly, the increment in the content of Ni in the structure of the catalysts has a positive influence in the selectivity of the process, favouring the production of the target C16-Guerbet alcohol. Nevertheless, the presence of Cu is also important in order to keep a high conversion of the starting alcohol, which suggests a synergistic interaction between the copper and nickel during the catalytic reaction. One could think that the copper is preferably involved in the first dehydrogenation step of the 1 -octanol, driving at the same time the generation of reduced nickel species, and then the reduced nickel can promote the final hydrogenation of the aldol condensation products.

Example 7

The reaction was carried out under the same conditions as described in example 3 except that the concentration of KOH used for the reaction was 3, 4, or 5 wt% instead of 1 .5 wt%. Conversion, selectivity, yields and purity after 6 hours reaction are presented in Table 6.

Table 6. Data obtained after 6 hours reaction.

Entry 1 -Octanol C16-Guerbet C16- C16-non- Purity C16-

As can be observed in Table 6, an increment in the KOH concentration in the reaction has a positive influence in the selectivity of the process to the target C16-Guerbet alcohol. However, although the concentration of C16-non-Guerbet species decreases with the increment of base, the formation of solid carboxylated-type species is also increased. A good compromise in the selectivity of the reaction and generation of those solid species can be achieved by using 3wt% KOH as homogeneous base and 1 wt% copper-nickel catalyst comprised in a hydrotalcite (Cu/Ni molar ratio was 1 .0/9.0; the total content of copper and nickel metals in the whole catalyst was kept at 13% by weight).

Example 8

The reaction was carried out under the same conditions as described in Example 1 except that the concentration of KOH used was 3 wt% instead of 1 .5 wt%. Conversion, selectivity and yields after 3 hours reaction are presented in Table 6. As previously shown in example 7, the increment in the concentration of the KOH favours the conversion, selectivity and purity of the process.

Example 9

The reaction was carried out under the same conditions as described in Example 1 except that the concentration of the copper-nickel catalyst comprised in a hydrotalcite carrier was 0.5 wt% instead of 1 .0 wt%. Conversion, selectivity, yields and purity are presented in Table 6 after 10 h reaction. Although the copper-nickel catalyst-to-KOH ratio is the same as presented in example 8, a lower yield to the C16-Guerbet alcohol and reaction rate were observed. Thus, 10 h reaction were needed in order to achieve the steady state conversion.

Table 7. Data obtained after 3 h (example 8) and 10 h (example 9) reaction, respectively.

Example 10

The reaction was carried out under the same conditions as described in Example 1 except that the vessel was charged with 40 g of a mixture of 1 -octanol :1 -decanol 50%:50% by weight. The composition of the final reaction mixture was characterized as follow: 1 .3% 1 -octanol; 1 .0% 1 - decanol; 23.8% C16-Guerbet; 1 .2% C16-non-Guerbet; 44.9% C18-Guerbet; 2.2% C18-non- Guerbet; 20.7% C20-Guerbet; 1 .0% C20-non-Guerbet; 3.8% trimer-type molecules. The selectivity and stability of the copper-nickel catalyst was as good as shown in Example 1 , achieving a total yield to Guerbet products of 89.4%.

Leaching data: ICP-AES analysis data of the reaction mixtures

Besides good catalytic results (conversion, selectivity, yield & purity), a good catalyst stability is also desired. For a selection of examples and comparative examples the leaching data of the reaction mixtures (after centrifugation) as measured by ICP-AES are presented in table 8. Table 8. ICP-AES data obtained after 6 hours reaction.

All examples in table 8 of tested copper-nickel catalysts in a hydrotalcite show very low Cu and Ni leaching, except for example 6 (Ni:Cu = 0:10) that shows significant Cu leaching (134 ppm Cu). The combination of Cu and Ni is favourable for the catalyst stability against leaching.

Leaching is also low after 2 ^nd reuse of comparative examples 5 and 6 (respectively 10 wt% of nickel + copper in a 7.5:2.5 Ni:Cu ratio impregnated on MgO or Al ₂ 0 ₃ ), yet comparative examples 5 and 6 showed poor reusability results (see comparative examples 5 and 6, Table 3). This points towards some changes in the Cu and Ni configuration or migration of the metal ions on the MgO and Al ₂ 0 ₃ supports upon 2 ^nd reuse, which is not the case for the copper- nickel catalyst in a hydrotalcite upon 2 ^nd and 3 ^rd re-use since the C16-Guerbet selectivity, C16- Guerbet yield and C16-Guerbet purity remains high (see example 4, 2 ^nd and 3 ^rd re-use, Table 3).

Example 11

The reaction was carried out in the same vessel as used in Example 1 except that 40 g of stearyl alcohol was used as starting alcohol. The amounts of potassium hydroxide and copper- nickel catalyst (Cu/Ni molar ratio = 2.5/7.5) were kept also the same as in Example 1 . Neither cooling nor Dean-Stark system were used for the reaction. On top of the reactor an open glass tube with quartz wool is placed. In a typical experiment, the alcohol was first melted and then, after reaching 240 ^Q C, the base and then the copper-nickel catalyst were added. After this point, the reaction was performed during 2 to 12.5 hours. The water produced during the condensation was released through the top of the five-necked flask, where quartz wool was placed in order to avoid the losses of alcohol. After completion of the reaction, the final reaction product is hot-filtered at 120 ^Q C. This process allows the recovery of the final reaction product, while the catalyst and the biggest part of the soap-type products formed (Potassium stearate) remains on the glass filter. The composition of the final reaction mixture (after 12.5 hours) was characterized by HT-GC-FID as follow: 2.0% stearyl alcohol; 70.4% dimers (C36- Guerbet product and C36-aldehydes); 20.5% trimers (C54) and 7.3% tetramers (C72).

Example 12

The reaction was carried out as in Example 1 1 using 40 g of n-stearyl alcohol as starting alcohol and with the copper-nickel catalyst (Cu/Ni molar ratio = 2.5/7.5) except that 0.1 g of the copper-nickel catalyst was used (0.25 wt%) and 0.3 g of potassium hydroxide (0.75 wt%). The composition of the reaction mixtures after 12 hours and 24 hours at 240*Ό was characterized by HT-GC-FID and is given in Table 9.

Table 9. Data obtained after 12 and 24 hours reaction.

Example 13

The reaction was carried out as in Example 12 using 40 g of n-stearyl alcohol as starting alcohol and with an amount of 0.1 g of the copper-nickel catalyst (0.25 wt%) and 0.3 g of potassium hydroxide (0.75 wt%), except that a copper-nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 was used (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%). The composition of the reaction mixtures after 12 hours and 24 hours at 240*Ό was characterized by HT-GC-FID and is given in Table 10.

Table 10. Data obtained after 12 and 24 hours reaction.

Example 14 The reaction was carried out as in Example 13 using 40 g of n-stearyl alcohol as starting alcohol and 0.3 g of potassium hydroxide (0.75 wt%) and using a copper-nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%), but with varying amounts of the copper-nickel catalyst, being 1 wt%, 0.5 wt% or 0.25 wt%. The composition of the reaction mixtures after 12 hours at 240 *Ό was characterized by HT-GC-FID and is given in Table 1 1 .

Table 11. Data obtained after 12 hours reaction.

Example 15

The reaction was carried out as in Example 13 using 40 g of n-stearyl alcohol as starting alcohol and 0.3 g of potassium hydroxide (0.75 wt%) and 0.1 g of a copper-nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%), but applying vacuum (800 mbar) instead of working at atmospheric pressure.

The composition of the reaction mixture after 12 hours at 240*Ό was characterized by HT-GC- FID and is given in Table 13.

Table 13. Data obtained after 12 hours reaction.

Example 16

The reaction was carried out as in Example 13 using 40 g of n-stearyl alcohol as starting alcohol and 0.3 g of potassium hydroxide (0.75 wt%) and 0.1 g of a copper-nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%), but with molecular sieve instead of quart wool in the glass vessel on top of the reactor. The composition of the reaction mixture after 12 hours at 240*Ό was characterized by HT-GC- FID and is given in Table 14.

Table 14. Data obtained after 12 hours reaction. Entry C18-0H C36 C36 C36 Trimers Tetramers Conv. Guerbet Aldehyde Others (C54) (C72)

(%) (%) (%) (%) (%) (%)

Example 16 86.0 67.1 3.5 4.3 6.5 1 .8

Example 17

The reaction was carried out as in Example 13 using 40 g of n-stearyl alcohol as starting alcohol and 0.3 g of potassium hydroxide (0.75 wt%) and 0.1 g of copper-nickel catalyst a copper-nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%), but at 250 ^< Ό instead of 240 ^< Ό for 12 hours.

The composition of the reaction mixture after 12 hours at 250*Ό was characterized by HT-GC- FID and is given in Table 15.

Table 15. Data obtained after 12 hours reaction at 250 °C.

Example 18

The reaction was carried out as in Example 13 using 40 g of n-stearyl alcohol as starting alcohol and with 0.1 g of a copper-nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%), but with varying amounts of potassium hydroxide, being 0.3 g (0.75 wt%), 0.4 g (1 .0 wt%) or 0.5 g (1 .25 wt%).

The composition of the reaction mixtures after 12 hours at 240*Ό was characterized by HT-

GC-FID and is given in Table 16.

Table 16. Data obtained after 12 hours reaction.

Example 19

The reaction was carried out as in Example 13 using 40 g of n-stearyl alcohol as starting alcohol and using 0.5 g potassium hydroxide and 0.1 g of a copper-nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%), but with re-use of the catalyst (up to 2 times) (the recovered catalyst was mixed with 40 g of new molten n-stearyl alcohol and 0.5 g of new granular potassium hydroxide).

The composition of the reaction mixtures after 12 hours at 240*Ό was characterized by HT- GC-FID and is given in Table 17.

Table 17. Data obtained after 12 hours reaction.

Example 20

The reaction was carried out in the same vessel as used in Example 1 (for the self- condensation of 1 -octanol) except that a 1 :1 molar ratio of a middle-range alcohol (1 -octanol, C8-OH) and a long-range alcohol (n-stearyl alcohol, n-C18-OH) was used (respectively 15.0 g C8-OH and 31 .1 g C18-OH).

0.82 g of potassium hydroxide is used providing a ratio of total moles of alcohols to moles of KOH of 15.8. 0.2 g of a copper-nickel catalyst was used with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%), and nitrogen flow is added in the head space. Reaction time was 12 hours and the reaction was performed at 225 ^q C. A creamy product was obtained (see FIG. 2), with a melting point of 38-44^0. This Guerbet alcohol product is expected to be a mixture of C16-Guerbet, C26-Guerbet and C36 Guerbet. A new Guerbet alcohol, the C26-Guerbet alcohol resulting from the cross-condensation of C8 and C18 alcohols, was formed. FIG. 2 illustrates a product obtained from a 1 :1 molar ratio of n-C8-OH and n-C18-OH as reacted in example 20.

Example 21

Other combinations that were performed are the cross coupling reactions of C18-OH in a 1 :1 molar ratio with C6-OH, C8-OH, C10-OH or C12-OH.

Standard conditions were: T=225 ^q C; 0,1753 g catalyst (copper-nickel catalyst (the Cu/Ni molar ratio was 1 .0/9.0) was used according to the conditions used in example 20. The ratio of total moles alcohols to moles of KOH of 15.8 was used. The reaction time is 24 hours and a nitrogen flow is added in the head space. Solid products were obtained (see FIG. 5. These solid products are expected to be mixtures of:

C18-OH : C6-OH = C12-Guerbet, C24-Guerbet and C36-Guerbet;

C18-OH : C8-OH = C16-Guerbet, C26-Guerbet and C36-Guerbet;

C18-OH : C10-OH = C20-Guerbet, C28-Guerbet and C36-Guerbet; and, C18-OH : C12-OH = C24-Guerbet, C30; Guerbet and C36-Guerbet.

Example 22

The reaction was carried out in the same vessel as used in Example 1 but the vessel was charged with 40 g of isostearyl alcohol (iso-C18-OH). The reaction conditions used were: 0.25 wt% of a copper-nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%), 1 .25 wt% potassium hydroxide. Reaction time was 12 hours and the reaction was performed at 240 °C. A gel-type product was obtained (see FIG. 3) as the result of the Guerbet self-condensation reaction of isostearyl alcohol (while a solid product was obtained in examples 1 1 -19 from the self-condensation of n-stearylalcohol). A new Guerbet alcohol, the C36-Guerbet alcohol resulting from the self-condensation of isostearyl alcohol, was formed.

FIG. 3 illustrates the Guerbet product from example 22 from the self-condensation of isostearyl alcohol.

Example 23

The reaction was carried out in the same vessel as used in Example 1 but the vessel was charged with 40 g of citronellol (C20-alcohol) (a-citronellol: 0,35 %, β-citronellol: 97,35%). The reaction conditions used were: 1 wt% copper-nickel catalyst (the Cu/Ni molar ratio was 1 .0/9.0), 3 wt% potassium hydroxide. Reaction time was 1 hour 15 min and the reaction was performed at 250 *Ό. The composition of the reaction mixtures was analysed by GC and is shown in Table 18. A new Guerbet alcohol, the C20-Guerbet alcohol resulting from the self- condensation of citronellol, was formed.

Table 18. Data obtained after 1 hour 15 min reaction.

Example 24

The reaction was carried out as in example 23, except that the reaction temperature was elevated to 260 °C.

The composition of the reaction mixtures was analysed by GC and is shown in Table 18. A new Guerbet alcohol, the C20-Guerbet alcohol resulting from the self-condensation of citronellol, was formed.

Example 25

The reaction was carried out as in example 23, except that 1 wt% of a copper-nickel catalyst with Cu/Ni molar ratio of 2.5/7.5 was used. The composition of the reaction mixtures was analysed by GC and is shown in Table 18. A new Guerbet alcohol, the C20-Guerbet alcohol resulting from the self-condensation of citronellol, was formed.

Example 26

The reaction was carried out in the same vessel as used in Example 1 but the vessel was charged with 40 g of a 1 :1 molar ratio n-hexanol and n-decanol. The Dean-Stark configuration was filled with 50:50 molar ratio n-hexanol :n-decanol mixture

The reaction conditions used were: 1 wt% copper-nickel catalyst (the Cu/Ni molar ratio was 2.5/7.5), 3 wt% potassium hydroxide. Reaction time was 6 hour and the reaction was performed at 255 *Ό. The GC data are shown in Table 19 and 19b.

A GC chromatogram is shown in FIG. 4.

It is clear that two types of C16 Guerbet cross-products have been formed as new Guerbet alcohol products, which are different than the C16 Guerbet alcohol as obtained from the self- condensation of 1 -octanol.

FIG. 4 illustrates a chromatogram of the products obtained in example 26. Two C16 Guerbet (GB) products have been formed.

Table 19. Data obtained after 6 hours reaction.

Table 19b. Data obtained after 6 hours reaction.

Example 27

The reaction was carried out in the same vessel as used in Example 26, except that the catalyst used was 1 wt% of a copper-nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%). The GC data of example 27 are shown in Table 19 and 19b.

Example 28

Cross coupling reactions were performed using 1 :1 molar ratio combinations of the starting alcohol C6-OH with C8-OH, C10-OH or C12-OH. The reaction conditions used were: 1 wt% of a copper-nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%), 3 wt% potassium hydroxide. -The reaction was performed at 225 ^< Ό, 240 ^< Ό or 250 ^< Ό. The data obtained for the cross-condensation of C6-OH with C8-OH at 225 ^< Ό are given in Table 20.

Table 20. Data obtained after 6 hours reaction (as peak area wt%) at 225*Ό.

Example 29

Cross coupling reactions were performed using 1 :1 molar ratio combinations of the starting alcohol C8-OH with C10-OH or C12-OH. The reaction conditions used were: 1 wt% a copper- nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%), 3 wt% potassium hydroxide. Reaction time was 2 and 4 hours and the reaction was performed at 225 °C, 240 °C or 250 °C.

Example 30

Cross coupling reactions were performed using 1 :1 molar ratio combinations of the starting alcohol C10-OH with C12-OH. The reaction conditions used were: 1 wt% copper-nickel catalyst a copper-nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%), 3 wt% potassium hydroxide. Reaction time was 2 and 4 hours and the reaction was performed at 225°C, 240°C or 250 ^< Ό.

Example 31

Self-condensation reaction was performed using C22-OH (actually mixture C18:C20:C22). Standard conditions for the C22 self-condensation were a reaction temperature of 240 *Ό; 0,25 wt% of a copper-nickel catalyst with Cu/Ni molar ratio of 1 .0/9.0 (the theoretical molar ratio of moles (Cu+Ni) to total moles of metals (Cu+Ni+Mg+AI) was 13% and the molar ratio of moles Mg to total moles of metals was 65%), and 1 ,25 wt% KOH.