WO2008023338A1

WO2008023338A1 - Production of esters

Info

Publication number: WO2008023338A1
Application number: PCT/IB2007/053354
Authority: WO
Inventors: Douglas Francis Foster; Hendrik Van Rensburg; Robert Paul Tooze
Original assignee: Sasol Technology (Proprietary) Limited
Priority date: 2006-08-23
Filing date: 2007-08-22
Publication date: 2008-02-28

Abstract

This invention relates to a process for the hydroesterification of olefins in which a hydrocarbon stream containing olefins is reacted with CO and an alcohol in the presence of a catalyst to form a hydrocarbon stream containing esters, wherein the alcohol has more than one carbon atom. The hydroesterification reaction is typically carried out in the presence of a catalyst comprising cobalt and a nitrogen-containing additive such as pyridine and the olefins may be branched. The invention also relates to a process for preparing an alkoxylated ester suitable for use as a surfactant molecule in detergent formulations.

Description

PRODUCTION OF ESTERS

BACKGROUND OF THE INVENTION

THIS invention reiates to the production of esters.

United States patent no. 3,507,891 discloses a process for preparing lower alkyl esters of aliphatic carboxylic acids by the carbonylation (hydroesterification) of nonacetiynic olefinically unsaturated aliphatic hydrocarbons using a modified cobalt carbonylation catalyst in the presence of an aliphatic alcohol. The preferred alcohol is methanol, and the cobalt carbonylation catalyst contains pyridine. The substituted pyridine-to- cobait molar ratio is disclosed as being generally at least 2:1, preferably at least 4:1 , and in some instances between 6:1 and 18:1.

It is an object of this invention to provide an improved process for the production of esters. SUMMARY QF THE INVENTION

A first aspect of this Invention relates to a process for the hydroesteriflcation of olefins in which a hydrocarbon stream containing olefins is reacted with CO and an alcohol in the presence of a catalyst to form a hydrocarbon stream containing esters, wherein the alcohol has more than one carbon atom.

The hydroesterification reaction is typically carried out in the presence of a catalyst comprising cobalt and a nitrogen-containing additive.

The nitrogen containing additive may be a heterocyclic structure wherein at least one heteroatom of the heterocyclic structure is nitrogen. The heterocyclic structure may have at least one double bond between two ring atoms. The heterocyclic structure may be aromatic and preferably it is pyridine.

Preferably, the nitrogen-containing additive/cobalt ratio is greater than 8:1, typically greater than 18:1 , preferably from 20:1 to 40:1 , more preferably from 24:1 to 40:1, more preferably 30:1 to 35:1 , most preferably 32:1.

The olefins may be branched.

The branched olefins may have on average more than 0.3 branches per olefin molecule, typically more 0,5 branches per olefin molecule but less than 3 branches per molecule, preferably more than 0.8 branches per molecule but less than 2 branches per molecule.

The branched olefins may include internal branched olefins. Preferably more than 50% of the branched olefins are internal branched olefins.

The branches of the branched olefin may be methyl and/or ethyl and/or other alkyl branches. The branching may be achieved via skeletal isomerization or via dimerization.

The alcohol having more than one carbon atom may be a primary alcohol selected from the group EtOH, 1-PrOH, 1-BuOH or 1-octanoI.

According to a preferred embodiment of the invention, the alcohol is a branched alcohol.

The branched alcohol may be a primary alcohol, for example 4-methyM- pentanol, 3,7-dimethyl-1-octanol, or 2-ethy!-1-hexanol. Diols, triols and polyols may also be used, e.g. 1 ,4-butandiol, trimethylolpropane, neopentylgiycol and glycerol.

According to a second aspect of the invention, an alkoxylated ester suitable for use as a surfactant molecule in detergent formulations is produced in a hydroesterification reaction in which an olefin or olefins is/are reacted with CO and a polyether glycol in the presence of a catalyst.

The polyether glycol may be selected from ethylene glycol, tetraethylene glycol, hexaethylene glycol or monoaikylether capped glycols like ethyleneglycol monomethylether, ethyleneglycol monoethylether, triethylenegiycol monomethylether, di(propyleneglycol) monomethylether or methoxypolyethylene glyco! (ave mol wt 350).

The nitrogen containing additive may be a heterocyclic structure wherein at least one heteroatom of the heterocyclic structure is nitrogen. The heterocyclic structure may have at least one double bond between two ring atoms. The heterocyclic structure may be aromatic and preferably it is pyridine. Preferably, the nitrogen-containing additive/cobalt ratio is greater than 8:1 , typically greater than 18:1 , preferably from 20:1 to 40:1 , more preferably from 24:1 to 40:1, more preferably 30:1 to 35:1, most preferably 32:1.

The olefins may be branched olefins.

The branched olefins may have on average more than 0.3 branches per olefin molecule, preferably more than 0.5 branches per molecule but less than 3 branches per molecule, more preferably more than 0.8 branches per molecule but less than 2 branches per molecule.

The branches of the branched olefin may be methyl and/or ethyl branches and/or other alkyl branches.

The hydroesterification reaction is generally performed at temperatures between 120-170⁰C and CO pressures between 80-150 bar.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1A is a graph showing gas up-take curves of Methoxy vs Ethoxycarbonylation of 4-octene;

Figure 1B is a graph showing gas up-take curves of Methoxy vs Ethoxycarbonylation of 1-octene;

Figure 1D{a) is a graph showing gas up-take curves of Methoxy- and Ethoxycarbonylation of 2-ethyl-1-butene;

Figure 1D(b) is a graph showing gas up-take curves of Methoxy- and Ethoxycarbonylation of 3-methyl-2-pentene; Figure 1D(c) is a graph showing gas up-take curves of Methoxy- and Ethoxycarbonylation of 4-methy!~2-pentene;

Figure 1D(d) is a graph showing gas up-take curves of Methoxy- and Ethoxycarbonylation of 2-methyl-2-pentene;

Figure 1 D(e) is a graph showing gas up-take curves of Methoxy- and Ethoxycarbonylation of 2-methyl-1-pentene;

Figure 1 H is a graph showing gas up-take curves of Methoxy- and Ethoxycarbonylation of C11-C12-FT derived olefins;

Figure 2 is a graph showing gas-uptake curves of ethene Aikoxycarbonylation using different alcohols;

Figure 3 is a GC trace of an n-propyl propionate reaction mixture; and

Figure 4 is a GC trace of an n-octyl propionate reaction mixture.

DESCRIPTiON OF PREFERRED EMBODIMENTS

In a hydroestehfication reaction, olefins in a feed stream are reacted with CO and an alcohol in the presence of a catalyst to produce a wide range of aikoxy esters. In the case of C_H-CM olefins, C₁₂-C_1S alky! esters are produced and in the case of Ci₀-C₁₅ olefins, Ci₁-C₁₆ aikyl esters may be produced.

In accordance with a first aspect of the present invention, the hydroesterification reaction is carried out in the presence of a catalyst comprising cobalt and a nitrogen containing additive. The nitrogen containing additive may be a heterocyclic structure wherein at least one heteroatom of the heterocyclic structure is nitrogen. The heterocyclic structure may have at least one double bond between two ring atoms. The heterocyclic structure may be aromatic and preferably is pyridine. Pyridines that may be used include, pyridine, aikyl- aryl or amido-substituted pyridines (preferably non-ortho substituted) and isoquinolines. The cobalt/pyridine catalyzed hydroesterification reaction ailows for the production of a wide range of alkoxy esters. Pyridine acts as a catalytic promoter in this reaction, enhancing both activity and selectivity to desired linear products. The preferred Pyridine/Cobalt ratio is greater than 8:1, typically greater than 18:1 , preferably from 20:1 to 40:1, more preferably from 24:1 to 40:1 , more preferably 30:1 to 35:1 , most preferably 32:1. The hydroesterification reaction is generally performed at temperatures between 120-200⁰C and CO pressures between 80-150 bar.

The alcohol has more than one carbon atom and may be a primary alcohol or a branched alcohol. The primary alcohol may be selected from the group EtOH, 1-PrOH, 1-BuOH or 1-octanol.

With reference to Example 1A below, in a hydroesterification reaction using 4-Octene as the olefin, test results show that despite good conversion results obtained with MeOH at lower Py:Co ratio (8:1), the rate is slower than that observed with EtOH at Py:Co (32:1 ). Furthermore, although it was found that a lower Py:Co ratio of the MeOH reactions were advantageous with regards to rate and conversion, the ester linearities were lower at lower Py:Co ratios.

With reference to Examples 1D to 1 H below, in hydroesterification reactions using commercially available methyl-branched internal olefins, dimerized 1- pentene feeds, a Pacol (paraffin dehydrogenation) derived C11C12 (mainly) internal olefins and Fischer Tropsch derived olefins as feeds, tests show better reaction rates using ethanol instead of methanol and a high Py:Co ratio of 32:1 , as well as better conversions and linearity.

From Example 1 , it is evident using EtOH rather than MeOH with Py:Co ratios of above 18:1, preferably from 20:1 to 40:1, more preferably from 24:1 to 40:1, more preferably from 30:1 to 35:1 , most preferably 32:1 afforded unexpected advantages, including reaction rate, conversion and linearity. The benefits are more pronounced when internal and internal / branched olefins were used. In addition to this, from Example 7, it is clear that apart from MeOH other primary alcohols afford good ethylene esterifications with a Py:Co ratio of above 18:1 , typically 32:1.

Esters produced in the hydroesterification mentioned above may be converted to detergent range alcohols by hydrogenation reactions. For example, the hydroesterification reaction described above may be used in step 2 of the process for producing alcohols described in co-pending South African patent application no. 2007/04830 (the content of which is incorporated herein by reference). In addition, long chain esters may be converted to ester sulfonates or ester ethoxyiates and used as surfactants.

in a preferred embodiment of the invention, the olefin is branched and the alcohol is a branched alcohol.

The branched olefins typically have on average more than 0.3, preferably more than 0.5 but less than 3, most preferably more than 0.8 but less than 2 branches per molecule and may include internal branched olefins. Preferably more than 50% of the branched olefins are internal branched olefins. The branches of the branched olefin may be methyl and/or ethyl and/or other alkyl branches, with the branching being achieved via skeletal isomerization or via dimerizatlon.

The branched alcohol may be a primary alcohol, for example 4-methyl-1~ pentanol or 3,7-dimethyi-1~octanoi, 2-ethy!-1-hexano! or any other primary branched alcohol for example those commercially available from Sasol namely the Safol, lsalchem and LIAL alcohols and those from The Shell Chemical Company namely the Neodo! alcohols, aiso Guerbet alcohols, for example EUTANOL G16 from Cognis Corporation. Diols may also be used, e.g. 1 ,4-butandiol.

Example 2 below shows cobalt/pyridine catalyzed hydroesterification reactions with Py:Co ratios of above 18:1 , preferably 20:1 or above, typically 32:1 , using: 4-methy!-1-pentene and 4-methyi-1-pentano! substrates which afforded esters with aSkyl branching on both sides of the ester functionality; and dimerized 1-pentene (a range of C10 olefins consisting of skeletal isomers as shown in Example 1 E) and 4-methyl-1- pentanol afforded a mixture of C1 1-4-methylpentyl esters.

Example 3 below shows a hydroesterification reaction of the invention using a dioi or triol as the alcohol.

Esters produced in the hydroesterification of this embodiment of the invention may be used in personal care compositions.

According to a second aspect of the invention (Example 4), there is provided a new method for producing alkoxylated esters including ethoxylated esters and propoxylated esters, which are surfactant molecules used in detergent formulations for example liquid soap.

In this aspect of the present invention, an alkoxylated ester suitable for use as a surfactant molecule in detergent formulations is produced in a hydroesterification reaction in which an olefin or olefins is/are reacted with CO and a polyether glycol in the presence of a catalyst comprising cobalt and pyridine. The preferred Pyridine/Cobalt ratio is 8:1 or greater, typically greater than 18:1; preferably from 20:1 to 40:1, more preferably from 24:1 to 40:1 , more preferably from 30:1 to 35:1 , most preferably 32:1. The hydroesterification reaction is generally performed at temperatures between 120-200⁰C and CO pressures between 80-150 bar.

The polyether glycol may be ethylene glycol, tetraethylene glycol, hexaethylene glycol or monoaikylether capped glycols like ethyleneglycoi monomethylether, ethyleneglycol monoethylether, tπethyleneglycol monomethylether, di(propyleneglycol) monomethytether or methoxypolyethylene glycol (ave mol wt 350). Alkoxylated esters that may be produced by the process of this invention include ethoxylated and propoxylated esters using the above-mentioned glycols and linear or branched alpha or internal oiefins such as triethyleneg!ycolmonomethylether-C9~esters using octene as olefin and triethyleneglycol monomethylether as alcohol source.

The Invention will now be explained in more detail in the following non- limiting examples: Co₂(CO)_s (from Strem) was used as catalyst precursor. All reactions were carried out in a 50mi autoclave at 16O⁰C and IOObar CO (unless stated differently), CO was fed from a 160ml ballast vessel connected to the autoclave and CO was fed on demand at a constant pressure of I OObar. Pseudo rates (k h^"1) were calculated over the first -60% olefin conversion from -ln(1 -conversion )/time plots generated from mass CO consumed from the ballast vessel.

Example 1

This example relates to the hydroesterification (alkoxy carbonylation) reaction and shows the benefits of using a high Py:Co ratio of greater than 18:1, and the use of ethanol as the alcohol in the reaction.

The reaction conditions used to evaluate the hydroesterification of olefins to alcohols were:

Co₂(CO)₈ 266mg, ~4000ppm, 5OmM

Temperature 16O⁰C

CO pressure IOObar

Reaction time ~15h

Example 1A

Tests were conducted using 4-Octene (10ml) as the olefin and EtOH (I8mi) or MeOH (18ml) as alcohols. The results of the tests shown in Figure 1A below show that despite the good conversion results obtained with MeOH at lower Py:Co ratio (8:1), the rate was still slower than that observed with EtOH at Py:Co (32:1). Furthermore, although it was found that a lower Py:Co ratio of the MeOH reactions were advantageous with regards to rate and conversion, the ester linearities were lower at lower Py:Co ratios: Py:Co ratio Alcohol k{rf¹) Conversion Ester linearity

8:1 MeOH 0.2/h 98% 71%

32:1 MeOH 0.11/h 60% 74%

32:1 EtOH 0.32 99% 78%

Example 1 B

Using 1-octene (10ml) as substrate, the results obtained were much more comparable between MeOH and EtOH. However, the conversion, rate and ester linearity were still superior when using EtOH and a high Py:Co ratio. Py:Co ratio Alcohol k(h"¹) % Conv. Ester linearity

8:1 MeOH 0.23/h 98% 76%

32:1 MeOH 0.52/h 83% 82%

32:1 EtOH 0.70/h 99% 83%

Example 1C

Apart form methanol and ethanol other alcohols were also evaluated. 1- Octene was used as olefin and [Co] = 5OmM, temperature = 16O⁰C and CO pressure = 100bar. Py : Co = 32:1 was used for all the entries apart from the MeOH entry (8:1). Anisole was used as co-solvent for the p-cresol entry.

Tabie iC

Alcohol k(h^"1) Conversion Ester linearity

MeOH 0.52 83% (18h) 82%

EtOH 0.70 99% (1Oh) 83%

1-Propanol 0.45 99% (14h) 81%

1~Butanol 0.30 99% (14h) 81 %

1-Pentanol 0.29 99% (14h) 81 %

1-Hexanol 0.28 99% (14h) 81 %

2-Ethylhexanol 0.13 97% (2Oh) 79% p-Cresol dnd 96% (6h) 82% i-Propanol 0.09 94% (21 h) 76%

Example 1 D

Commercially available methyl-branched! internal olefins were also tested and all tests showed better reaction rates using ethanol instead of methanol and a high Py:Co ratio of 32:1. These tests also show that the high Py:Co ratio and use of ethanoi leads to better reaction rates and conversions: Reaction conditions: Olefin (5ml, apart from 2-ethyl-1-butene 10ml); 16O⁰C; IOObar CO; [Co] = ~4000ppm, when EtOH (18ml) was used as alcohol; Py:Co = 32:1 and when MeOH (18mi) was used; Py:Co = 8:1 (for entry 2- ethy!-1-butene also Py:Co = 32:1). The results are summarized in Table 1D.

Table summarizing Example 1 D

Olefin Rate (h^-<) Rate (h ) Conversion Conversion

EtOH ¹ MeOH ² EtOH ¹ MeOH ²

2-Et-1-bιrtene 0.20 0.11 96%(15h) 76%(17h)

3-Me-2-pentene 0.27 0.18 98%(22h) 88%(18h)

4-Me-2-pentene 0.47 0.22 98%(22h) 88%(23h)

2-Me-2-pentene 0.22 0.15 98%(22h) 82%(22h)

2-Me~1-pentene 0.25 0.13 98%(22h) 75%(22h)

¹Py:Co = 32;1 , ²Py:Co = 8:1

Example 1 E

Dimerization of 1-pentene using a nickel catalyst afforded a range of C10 olefins consisting of the following skeletal isomers (position of double bonds not shown, since Ni isomerization catalyst); 21%

Methoxy- and ethoxycarbonylation (16O⁰C, IOObar CO, olefin 10rnl, alcohol 18ml) of this feed were done affording the following results: Co (4000ppm) / Py{N:Co 32:1) / MeOH conversion = 33% (24h) Co (4000ppm) / Py(N:Co 32: 1 ) / EtOH conversion = 96% (24h)

Example 1F

Using tungsten as dimerization catalyst for 1-pentene the following C10- olefin distribution was obtained.

+ few minor isomers

Methoxy- and ethoxycarbonylation (16O⁰C, IOObar CO, olefin 10ml, alcohol 18ml) of this feed were done affording the following results: Co (4000ppm) / Py(N:Co 32: 1 ) / MeOH conversion = 40% (24h) Co (4000ppm) / Py(N:Co 32: 1 ) / EtOH conversion = 91 % (24h). Example 1G

Using Pacol derived (paraffin dehydrogenated) C1 1C12 mainly internal linear olefins as feed, both methoxy- (Py:Co 32:1 and 8:1) and ethoxycarbonylation were conducted (Figure 2). Conditions: [Co] = 5OmM, 16O⁰C and CO = 100bar, olefin 10ml, alcohol 18ml.

Using EtOH afforded considerably better results both in terms of rate and linearity:

Entry k /h Conv.(22h) Ester Lin

Co/MeOH/Py(N:Co 32:1) 0.05/h 58% 67%

Co/MeOH/Py(N:Co 8:1) 0,15/h 92% 64%

Co/EtOH/Py(N:Co 32:1) 0.28/h 100% 70%

Example 1H

Using Fischer Tropsch (FT) derived C11C12 and C13C14 condensate containing a complex mixture of olefins (-40-50%, linear and branched olefins having greater than 0.3 branches per olefin molecule) and paraffins (-50-60%), both methoxy- and ethoxycarbonylation were conducted. Figure 1 H and end of reaction GC analysis showed that ethanol performed much better than methanol in terms of rate and olefin conversion. Reaction conditions: FT-feed = 13ml, Alcohol = 18ml, [Co] = 43mM, pyridine = 4ml, 16O⁰C, CO pressure = 100bar, Reaction time 2Oh FT-Feed Alcoho! Conversion

C11 C12 MeOH -68%

C11 C12 EtOH -98%

C13C14 MeOH -64%

C13C14 EtOH -94%

Example 2

Preparation of esters with branching on both sides of the ester functionality. Exampie 2A

Cobalt (266mg) / pyridine (N:Co, 32:1) aikoxycarbonyiation (16O⁰C, IOObar CO) using 4-methyl-1-pentene (5m!) and 4-methyl-1-pentanol (18m!) as substrates afforded esters (99%, 24h) with alkyl branching on both sides of the ester functionality.

Major isomers

Example 2B

Dimerization of 1-pentene using a nicke! catalyst afforded a range of C10 olefins consisting of skeletal isomers as shown in Example 1 E, Cobalt (4000ppm) / pyridine (N:Co 32:1) esterification (16O⁰C, IOObar CO) of this olefin mixture (5m!) using a branched alcohol, 4-methyl-1~pentano! (12ml) afforded a mixture of C11-4-methyipentyl esters (99% olefin conversion, 3Oh).

R=ClO alkyl Example 3 This example relates to a process of the invention using a diol or trio! (or polyol) as the alcohol.

Example 3A - Excess diόl

1 -octene: 2m!

1,4-butanediol: 16ml

[Co]: 4000ppm

Pyridine: 4ml

Anisoie (solvent): 8ml

CO = 100bar; Temperature = 16O⁰C; Reaction time 2Oh; Olefin conversion = 99%; selectivity to monoester = 99% (1% diester).

Example 3B - Excess olefin

1 -octene: 10ml

1 ,4-butanediol: 1.4ml

[Co]: 4000ppm

Pyridine: 4m!

Anisoie (solvent): 14ml

CO = 100bar; Temperature = 16O⁰C; Reaction time 2Oh; Diol conversion 99%; selectivity to diester = -98% (-2% monoester).

Example 3C

1 -octene: 10ml (excess)

Trimethylolpropane: 1.5g

Co₂(CO)₈: 266mg

Pyridine: 4ml

Anisoie (solvent): 16ml

CO = 100bar; Temperature = 16O⁰C; Reaction time 48h; Triol conversion

99%; selectivity to Westers = -98% Example 3D

1-octene: 10mI (excess)

Neopentylglycol: 2g

Co₂(CO)₈: 26δmg

Pyridine: 4m!

Anisole (solvent): 16m!

CO = "lOObar; Temperature = 16O⁰C; Reaction time 18h; sefectivity to diesters - -98%

Example 3E

1-octene: 15ml, 0.096mol

Glycerol: 2.45g, 0.026mol

Co₂(CO)₈: 266mg

Pyridine: 4ml

Dioxane (solvent): 12ml

CO = 100bar; Temperature = 16O⁰C; Reaction time 18h

Glycerol conversion: >98%; Selectivity to esters >98% of which -91% tri- esters and 9% di-esters.

Example 3F

1-octene: 5ml, 0.032mo!

Glycerol: 2.Og, 0.021 mo!

Co₂(CO)₃: 266mg

Pyridine: 4ml

Dioxane (solvent): 20ml

CO - 100bar; Temperature = 160⁰C; Reaction time 18h

Olefin conversion: >98%; Selectivity to esters >98% of which -23% tri- esters and 77% di-esters.

Example 3G 4-Methyl-1 -pentene: 12.1 ml, 0.096mo!

Glycerol: 2.45g, 0.026moi

Co₂(CO)₈: 266mg

Pyridine: 4ml

Dioxane (solvent): 13ml

CO = 100bar; Temperature = 16O⁰C; Reaction time 18h

Olefin conversion: >98%; Selectivity to esters >98% of which -82% tri- esters and 18% di-esters.

Example 4

Synthesis of glyco! esters / ester ethoxylates

Example 4A

Olefin: 1-Octene 4.7ml

Alcohol: Ethylene glycol 5ml

Solvent: Anisole 20ml

[Co]: 4000ppm

Pyridine: N:Co = 32:1

Reaction time: 13h

Conversion: 80%

Product distribution: 91 % mono-ester and 9% di-ester

Example 4B

1-Octene 1OmI

Ethyieneglycol monoethyiether 18ml

Co₂(CO)₈: 266mg

Pyridine: 4m!, N:Co = 32:1

Reaction time: 17h

Conversion: 99%

Rate k(/h): 0.67/h

Ester linearity: 81 % -10-

Example 4C

1-Octene 10ml

Ethyleneglycol monomethylether 18ml

Co₂(CO)₈: 266 mg

Pyridine: 4ml, N:Co = 32:1

Reaction time: 15h

Conversion: 99%

Rate k{/h): 0.65/h

Ester linearity: 81%

Example 4D

1-Hexene 10ml

Tetraethyleneglycol 3.6ml

Anisole 12ml

Co₂(CO)₈: 266mg

Pyridine: 4ml, N:Co = 32:1

Reaction time: 48h

Glycol conversion: 99%

Product: Di-ester isomers

Example 4E

1-Octene 10ml

Hexaethyleneglycol 18ml

[Co]: 4000ppm

Pyridine: N:Co = 32:1

Reaction time: 14h

Conversion: 93%

Example 4F 1-Octene 10ml

Di(propyleneglycol)monomethy!βther 18ml

ECo]: 4000ppm

Pyridine: N:Co = 32:1

Reaction time: 21 h

Olefin conversion: 90%

Example 4G

1-Octene 10ml

1 -Methoxy-2-propanoI 18ml

[Co]: 5OmM

Pyridine: N:Co = 32:1

Reaction time: 2Oh

Olefin conversion: 98%

Example 4H

1-Octene 10ml

Triethyleneglycoi monomethylether 18ml

[Co]: 4000ppm

Pyridine: N:Co = 32:1

Reaction time: 7h

Conversion: 96%

O _Λ Co/F

' ^*— -^¹OMS ^"go^"

Example 4!

Ni-derived C10-branched olefins 10ml (see Example 1 E)

Triethylenegiycσl monomethylether 18ml

[Co]: 4000ppm

Pyridine: N:Co = 32:1

Reaction time: 24h

Conversion: 83%

Ni-derived _H0

C10-branched ⁺ olefins

and various other isomers Example 5

Methoxy- and ethoxycarbonylation of methyl- and ethyl-10-undecenoate. Reaction conditions: lOObar CO, 16O⁰C, Co₂(CO)₈ (266mg), Pyridine (4m!).

Example 5A

MethyM O-undecenoate 10m!

MeOH 18ml

Reaction time 16h

Conversion 44%

Product Methyl di-esters

Example 5B

Ethyi-1 O-undecenoate 10ml

EtOH 18ml

Reaction time 3h

Conversion 85%

Product Ethyl di-esters

Example 6

The use of N-additives other than pyridine

1-Octene (10ml) was used as feed, Co₂(CO)₈ (266mg), 160⁰C, I OObar CO, alcohol 18ml.

Amine (N/Co) Alcohol Time Conv Rate

Pyrazine (24) MeOH 15h 44% 0.07/h

3-Pyridinepropano! (24) MeOH 4h 66% 0.2/h

3,5-Lutidine (32) MeOH 7h 52% 0.1/h

2,6-Lutidine (32) MeOH 6h 20% <0.05/h

3,5-Lutidine (32) EtOH 16h 92% 0.2/h

2,6-Lutidine (32) EtOH 16h 43% <0.05/h -_£.£-

Isoquinoline (32) MeOH 5h 78% 0.29/h

Isoquinoline (32) EtOH 5h 92% 0.46/h

Example 7

Propionates could be prepared via esterification of propionic acid.

Propionates could also be produced directly from ethylene and the appropriate alcohol using cobalt/pyridine as catalyst. This system was employed for the conversion of ethylene to methyl, ethyi, n-propyl, n-butyl, n-penty! and n-octyl propionate.

Reaction procedures:

Co₂(CO)₈: 270mg = 1.δmmol Co

Pyridine: N:Co 32:1 ; 4ml (MeOH entry was also done using N:Co 8:1

= 1 ml)

Alcohol: 20ml

CO: 120bar

Temperature: 16O⁰C

Add the alcohol and pyridine in a 50ml autoclave and degas well with CO.

Add the Co₂(CO)₈ and heat to 16O⁰C under - 50bar CO. When the reaction mixture reached 16O⁰C, ethylene was injected using CO (120bar) and CO was fed on demand from a ballast vessel at a constant pressure of 120bar.

Figure 2 compares the rates using different alcohols and showed that

MeOH at high Py:Co ratio did not work well. At Py:Co 8:1 the MeOH reaction worked much better but was still considerably slower than the

EtOH equivalent. 1-Propanol, 1-butanol and 1-pentanoi also afforded similar rates to EtOH while 1-octanol was a bit slower. 2-Propanol was also employed as alcohol affording the equivalent isopropyl propionate in high yield and selectivity albeit at a lower rate than the primary alcohols.

GC analysis (see traces below of the 1-propanol and 1-octanol reactions) showed that very clean reaction mixtures were produced with no significant by-product formation.

Claims

1. A process for the hydroesterification of olefins in which a hydrocarbon stream containing olefins is reacted with CO and an alcohol in the presence of a catalyst to form a hydrocarbon stream containing esters; wherein the the alcohol has more than one carbon atom.

2. The process according to claim 1 , wherein the reaction is carried out in the presence of a catalyst comprising cobalt and a nitrogen- containing additive.

3. The process according to claim 2, wherein the nitrogen containing additive has a heterocyclic structure and at least one heteroatom of the heterocyclic structure is nitrogen.

4. The process according to claim 3, wherein the heterocyclic structure has at least one double bond between two ring atoms.

5. The process according to claim 3 or 4, wherein the heterocyclic structure is aromatic.

6. The process according to claim 5, wherein the nitrogen containing additive is pyridine.

7. The process according to any one of the preceding claims, wherein the nitrogen-containing additive/cobalt ratio of the catalyst is greater than 8:1.

8. The process according to claim 7, wherein the nitrogen-containing additive/cobalt ratio of the catalyst is greater than 18:1.

9. The process according to claim 8, wherein the nitrogen-containing additive/cobalt ratio of the catalyst is from 20:1 to 40:1.

10. The process according to ciaim 9, wherein the nitrogen-containing additive/cobalt ratio of the catalyst is from 24:1 to 40:1.

11. The process according to ciaim 10, wherein the nitrogen-containing additive/cobalt ratio of the catalyst is from 30:1 to 35:1.

12. The process according to claim 11, wherein the nitrogen-containing additive/cobalt ratio of the catalyst is 32:1.

13. The process according to claim 12, wherein the olefins are branched.

14. The process according to claim 13, wherein the branched olefins have on average more than 0.3 branches per olefin molecule.

15. The process according to claim 14, wherein the branched olefins have on average more than 0.5 branches per olefin molecule but less than 3 branches per molecule.

16. The process according to claim 15, wherein the branched olefins have on average more than 0.8 branches per molecule but less than 2 branches per molecule.

17. The process according to any one of claims 13 to 16, wherein the branched olefins include internal branched olefins.

18. The process according to claim 17, wherein more than 50% of the branched olefins are internal branched olefins.

19. The process according to any one of claim 13 to 18, wherein the branches of the branched olefin are methyl and/or ethyl and/or other aikyl branches. -Zb-

20. The process according to any one of claims 13 to 19, wherein the branching of the olefin is achieved via skeletal isomerization or via dimerization.

21. The process according to any one of the preceding claims, wherein the alcohol having more than one carbon atom is a primary alcohol selected from the group EtOH, 1-PrOH, 1-BuOH or 1-octanoi.

22. The process according to any one of claims 1 to 20, wherein the alcohol is a branched alcohol.

23. The process according to claim 22, wherein the branched alcohol is a primary alcohol.

24. The process according to claim 22, wherein the branched alcohol is 4-methyl-i-pentanol, 3,7-dimethyl-1-octanol, or 2-ethyl-1-hexanol.

25. The process according to any one of claims 1 to 20, wherein the alcohol is a diol, triol or polyol.

26. The process according to claim 25, wherein the alcohol is 1 ,4- butandiol, trimethylolpropane, neopentylgiycoi or glycerol.

27. A process for producing an alkoxylated ester suitable for use as a surfactant molecule in detergent formulations: in a hydroesteπfi cation reaction in which an olefin or olefins is/are reacted with CO and a polyether glycol in the presence of a catalyst.

28. The process according to claim 27, wherein the polyether glycol is selected from ethylene glycol, tetraethylene glycol, hexaethylene glycol or monoalkylether capped glycols.

29. The process according to claim 28, wherein the polyether glycol is ethylenegfycol monomethylether, ethyleneglycol monoethylether, triethyleπeglycol monomethylether, di(propyleneglycol) monomethylether or methoxypolyethylene glycol (ave mol wt 350).

30. The process according to any one of claims 27 to 29, wherein the hydroesterification reaction is carried out in the presence of a catalyst comprising cobalt and a nitrogen-containing additive.

31. The process according to ciaim 30, wherein the nitrogen containing additive has a heterocyclic structure and at least one heteroatom of the heterocyclic structure is nitrogen.

32. The process according to claim 31 , wherein the heterocyclic structure has at least one double bond between two ring atoms.

33. The process according to claim 31 or 32, wherein the heterocyclic structure is aromatic.

34. The process according to claim 33, wherein the nitrogen containing additive is pyridine.

35. The process according to any one of claims 27 to 34, wherein the nitrogen-containing additive/cobalt ratio of the catalyst is greater than 8:1.

36. The process according to claim 35, wherein the nitrogen-containing additive/cobalt ratio of the catalyst is greater than 18:1.

37. The process according to ciaim 36, wherein the nitrogen-containing additive/cobalt ratio of the catalyst is from 20:1 to 40:1.

38. The process according to claim 37, wherein the nitrogen-containing additive/cobalt ratio of the catalyst is from 24:1 to 40:1.

39. The process according to claim 38, wherein the nitrogen-containing additive/cobalt ratio of the catalyst is from 30:1 to 35:1.

40. The process according to claim 39_» wherein the nitrogen-containing additive/cobalt ratio of the catalyst is 32:1.

41. The process according to any one of claims 27 to 40, wherein the olefins are branched olefins.

42. The process according to claim 41 , wherein the branched olefins may have on average more than 0.3 branches per olefin molecule.

43. The process according to claim 42, wherein the branched olefins have on average more than 0.5 branches per olefin molecule but less than 3 branches per molecule.

44. The process according to claim 43, wherein the branched olefins have on average more than 0.8 branches per molecule but less than 2 branches per molecule.

45. The process according to any one of claims 41 to 44, wherein more than 50% of the branched olefins are internal branched olefins.

46. The process according to any one of claims 41 to 45, wherein the branches of the branched olefin are methyl and/or ethyl branches and/or other alkyl branches.

47. The process according to any one of the preceding claims, wherein the hydroesterification reaction is performed at temperatures between 120- 17O⁰C and CO pressures between 80-150 bar.