WO2014165424A1

WO2014165424A1 - PROCESS FOR PREPARING C10 to C30 ALCOHOLS

Info

Publication number: WO2014165424A1
Application number: PCT/US2014/032311
Authority: WO
Inventors: David Morris Hamilton
Original assignee: Shell Internationale Research Maatschappij BV; Shell Oil Co
Current assignee: Shell Internationale Research Maatschappij BV; Shell USA Inc
Priority date: 2013-04-03
Filing date: 2014-03-31
Publication date: 2014-10-09
Anticipated expiration: 2015-10-03

Abstract

The present invention provides a process for preparing C10 to C30 alcohols, comprising the following steps: (i) reacting aliphatic, non-cyclic C10 to C30 olefins with N2O to obtain an oxidation reaction product comprising a C10 to C30 carbonyl; (ii) reducing at least part of the C10 to C30 carbonyls in the oxidation reaction product to the corresponding C10 to C30 alcohols, wherein the aliphatic, non-cyclic C10 to C30 olefins are reacted with the N₂O by in step (i): (i-a) providing a liquid olefin feed comprising aliphatic, non-cyclic C10 to C30 olefins; (i-b) providing an oxidant feed comprising at least 5% by volume of N₂O, based on the total oxidant feed; and (i-c) contacting the liquid olefin feed and the oxidant feed in a reactor at a temperature in the range of from 150 to 500 C and a pressure in the range of from 10 to 300 bar. In another aspect the invention provides a process or producing surfactant compounds and a method of treating a crude oil containing formation.

Description

PROCESS FOR PREPARING C10 to C30 ALCOHOLS

Field of the Invention

The present invention relates to a process for preparing C10 to C30 alcohols and a process for preparing surfactants compounds. In another aspect the invention provides a method of treating a crude oil containing formation.

Background of the Invention

A large variety of products useful, for instance, as nonionic surfactants, wetting and emulsifying agents, solvents and chemical intermediates are prepared by the addition reaction (alkoxylation reaction) of alkylene oxides (epoxides) with organic compounds having one or more active hydrogen atoms. For example, particular mention may be made of the alcohol ethoxylates prepared by the reaction of ethylene oxide with aliphatic, non-cyclic alcohols of 10 to 30 carbon atoms. Such ethoxylates, and to a lesser extent corresponding propoxylates and compounds containing mixed oxyethylene and oxypropylene groups, are widely employed as nonionic detergent components in cleaning and personal care formulations.

Sulfonated alcohol alkoxylates have a wide variety of uses as well, especially as anionic surfactants. Sulfonated higher secondary alcohol ethoxylates (SAES) offer comparable to better properties in bulk applications relative to anionics like linear alkyl benzene sulfonates and primary alcohol ethoxy sulfates, as well as methyl ester sulfonates. These materials may be used to produce household detergents including laundry powders, laundry liquids, dishwashing liquids and other household cleaners, as well as lubricants and personal care compositions.

The secondary alcohol ethoxylates and its sulfonated products are significantly more environmentally benign compared to the linear alkyl benzene based surfactants and have better pour point and surface tension reduction behaviour compared to primary alcohol ethoxylates and derived surfactants.

Another application of the above described alcohols is in chemically enhanced oil recovery. In particular secondary alcohol ethoxylates and/or propoxylates and their sulfonated products are used in chemically enhanced oil recovery.

Primary alkoxylated alcohols may for instance be made by an ethylene oligomerization process to give primary olefin and hydroformylating the primary olefins into an oxo-alcohol. Alkoxylation of the resulting alcohol by reaction with a suitable alkylene oxide such as ethylene oxide or propylene oxide will give the primary alkoxylated alcohols. The above described process for preparing is less suitable for preparing secondary alcohol alkoxylates, due to the difficulty to hydroformulate secondary olefins. Alternatively, secondary alcohols may be made directly from paraffins. A well know method for preparing secondary alcohols from paraffins is by oxidation of the paraffins using boric acid as a catalyst. Such a process is for instance described in WO2009058654. Although the boron reagents used herein are referred to as catalyst, strictly speaking, they are not a catalyst as they are consumed in the reaction. Its function is to protect the oxygenate (sec-alcohol) by reaction to give an oxidation-resistant borate ester. Oxidation of paraffins with oxygen using boric acid as for instance described in WO2009058654 is a complex process including many separate process steps. The steps include at least (1) mixing part of the paraffin and boric acid, (2) dehydrating the mixture to form metaboric acid, (3) adding remaining paraffin, (4) adding oxidant to form secondary alcohol borate esters, (5) separating unreacted paraffins and by-products, (6) hydrolyzing, methanolyzing or alcoholyzing the borate esters to form secondary alcohols and boric acid or borates, (7) separation of the secondary alcohol from boric acid and subsequently (8) recovering the alcohols.

One disadvantage is of this process is the need to replenish the boric acid catalyst. According to US3796761, the boric acid recovery and recycle is challenging and make the process economically unattractive. Boric acid cannot just be recycled but would need to be dehydrated prior to being used again. In addition to the need to replenish the boric acid catalyst, another distinct disadvantage is that most of these steps are carried out using different reaction conditions requiring several reheating, and optionally cooling cycles.

IN2002DE01134 discloses a process for preparing secondary alcohols by liquid phase oxidation. The invention is particularly concerned with a catalytic process for preparing of secondary alcohols by oxidation of n-alkanes with molecular oxygen in presence of boric acid solution. According to IN2002DE01134, boric acid oxidations result in poor activity and low yields because of density differences between boric acid and hydrocarbon phase. IN2002DE01134 further mentions that boric acid oxidations result in a large amount of by-products (acids/esters/carboxyl compounds) making separation and isolation difficult. GB1183511 discloses a process for the production of alcohols by subjecting normal saturated hydrocarbons having from 10 to 30 carbon atoms or mixtures thereof to oxidation with molecular-oxygen in the presence of a dehydrated form of ortho-boric acid, distilling unreacted hydrocarbon and a ketone containing fraction from the reaction mixture and recycling them to the oxidation step, hydrolyzing the reaction mixture residue and recovering alcohols there from. According to

GB 1183511, alcohols that are formed from boric acid oxidation of paraffins and are further ethoxylated and used as detergents tend to bloom or discolour upon spray drying which interferes with general use.

An alternative process for preparing alcohols is disclosed in US6548718. In US6548718, either saturated or unsaturated aliphatic hydrocarbons are hydroxylated directly to the corresponding alcohol in the presence of a catalyst using N₂O as the oxidant. Starting from a paraffinic feedstock, the process of US6548718 may prepare a mixture of mono-, di- and higher alcohols. This is mainly due to the presence of the catalyst, which needs to be highly active to allow direct hydroxylation of the paraffins, but in return makes it difficult to control the degree of hydroxylation, i.e. mono-, di, or higher substitution. Moreover, the catalytic direct hydroxylation process cannot be directed at making either primary or secondary alcohols, rather a random mixture of primary and secondary alcohols be obtained. Where the process of US6548718 is used to convert olefins to alcohols, the obtained alcohols are inevitably unsaturated alcohols, comprising one or more double bonds. These unsaturated alcohols are less suitable for the above described applications such as detergents and chemically enhanced oil recovery.

There is a need in the art for a process for making secondary alcohols and derivatives thereof by a process having a reduced complexity, which omits the need for a catalyst.

Summary of the Invention

It has now been found that C10 to C30 alcohols may be prepared from their corresponding olefins by a non-catalytic oxidation with N₂O.

Accordingly, the present invention provides a process for preparing C10 to C30 alcohols, comprising the following steps: (i) reacting aliphatic, non-cyclic C10 to C30 olefins with N₂O to obtain an oxidation reaction product comprising a C10 to C30 carbonyl

(ii) reducing at least part of the C10 to C30 carbonyls in the oxidation reaction product to the corresponding C10 to C30 alcohols,

wherein the aliphatic, non-cyclic C10 to C30 olefins are reacted with the N₂O by in step (i):

(i-a) providing a liquid olefin feed comprising aliphatic, non-cyclic C10 to C30 olefins;

(i-b) providing an oxidant feed comprising at least 5% by volume of N₂O, based on the total oxidant feed; and

(i-c) contacting the liquid olefin feed and the oxidant feed in a reactor at a temperature in the range of from 150 to 500° C and a pressure in the range of from 10 to 300 bar.

The process according to the present invention is particularly useful to prepare secondary alcohols from secondary olefins. The process according to the present invention is particularly useful to prepare saturated alcohols, i.e. not comprising double bonds, more particularly saturated mono-alcohols.

The process according to the present invention has the advantage that is non- catalytic, thus omitting the need to use and replenish an expensive boric acid catalyst.

Furthermore, the process is less complex compared to prior art processes, requiring significantly less changes cooling/reheating cycles of the reaction mixture.

In addition the process according to the present invention uses N₂O as an oxidant. N₂O is a greenhouse gas, which is produced as a by-product of chemical processes such as processes for the production of adipic acid. In the process according to the invention the N₂O is converted into nitrogen gas.

In another aspect the invention provides a process for producing surfactant compounds, comprising:

a) producing aliphatic, non-cyclic C10 to C30 alcohols according to the process for preparing C10 to C30 alcohols according to the invention;

b) reacting aliphatic, non-cyclic C10 to C30 alcohols with ethylene oxide or propylene oxide at temperature above 100°C and in the presence of a catalyst to produce ethoxylated or propoxylated alcohol surfactant compound. In a further aspect the invention provides a method of treating a crude oil containing formation comprising admixing at least one of a C10 to C30 alcohol prepared according to the process for preparing C10 to C30 alcohols according to the invention and a surfactant compound prepared according to the process for preparing surfactant compounds according to the invention with water and/or brine, preferably from the formation from which crude oil is to be extracted, to form an injectable fluid and then injecting the injectable fluid into the formation.

Detailed description of the invention

The present invention provides a process for preparing aliphatic, non-cyclic

C10 to C30 alcohols. The process may be used to prepare aliphatic, non-cyclic C10 to C30 primary alcohols, however the process according to the invention is particularly suitable for preparing secondary C10 to C30 alcohols as it allows for the production of secondary C10 to C30 alcohols in the absence of an oxidation catalyst. Preferably, the aliphatic, non-cyclic C10 to C30 olefins reacted, i.e. oxidised, with the N₂O in the absence of an oxidation catalyst.

Preferably, the aliphatic, non-cyclic C10 to C30 alcohols are saturated alcohols. A particular advantage of the process according to the present invention is that is allows for the production of saturated aliphatic, non-cyclic C10 to C30 mono- alcohols. During the process, the N₂O reacts with a mono-olefin at the double bond, to from a saturated mono-carbonyl, which subsequently is reduced to a saturated mono-alcohol. The process may therefore also be referred to as process for making saturated C10 to C30 mono- alcohols. Preferably, an oxidation catalyst as referred to herein includes transition metal-containing materials such as transition metal- containing metals, transition metal-containing alloys, transition metal-containing salts, transition metal-containing metal oxides, transition metal-containing metal complexes, transition metal-containing he teropoly acids, in as such formulation or supported on solid carriers.

In the process according to the invention, aliphatic, non-cyclic C10 to C30 olefins are directly oxidised with N₂O to form carbonyl compounds, in particular ketones and aldehydes, which are subsequently reduced to their corresponding alcohol. Reference herein to C10 to C30 olefins is to one or more olefins comprising in the range of from 10 to 30 carbon atoms and mixtures thereof. In the process according to the invention, (i) aliphatic, non-cyclic C10 to C30 olefins are directly oxidised with N₂O to form C10 to C30 carbonyl compounds, in particular ketones and aldehydes, which are (ii) subsequently reduced to their corresponding alcohol. Reference herein to C10 to C30 olefins is to one or more olefins comprising in the range of from 10 to 30 carbon atoms and mixtures thereof.

The oxidation of C2 to C8 cyclic and aromatic olefins to carbonyl compounds using N₂O has been described in for instance WO03/078370 and US2008/0021247. In the present invention, C10 to C30 aliphatic, non-cyclic olefins may be, via a carbonyl intermediate, converted to C10 to C30 alcohols, preferably aliphatic, saturated, non-cyclic C10 to C30 alcohols. Reference herein to C10 to C30 alcohols is to one or more alcohols comprising in the range of from 10 to 30 carbon atoms or mixtures thereof. Reference herein to saturated alcohols is to alcohols that do not comprise an olefinic bond. Preferably, the C10 to C30 aliphatic, non-cyclic olefins are secondary olefins (also referred to as internal olefins) and the secondary olefins are converted to secondary alcohols, aliphatic, saturated, non-cyclic secondary C10 to C30 alcohols.

In the process of the present invention, C10 to C30 alcohols are prepared by providing (i-a) a liquid olefin feed comprising aliphatic, non-cyclic C10 to C30 olefins and (i-b) an oxidant feed comprising at least 5% by volume of N₂O, based on the total oxidant feed.

The liquid olefin feed preferably comprises aliphatic, non-cyclic C10 to C30 secondary olefins. The advantage of providing a feedstock comprising secondary olefins is that the secondary olefins may be converted, via their corresponding ketones, to secondary alcohols whereas the use of a feedstock comprising primary olefins inevitably leads to a mixture of primary and secondary alcohols. These secondary alcohols are particularly suitable as a starting material to produce secondary alcohol alkoxylates surfactant compounds and secondary alcohol alkoxysulfate, alkoxysulfonate or alkoxycarboxylate surfactant compounds.

Preferably, the liquid olefins feed comprises at least 50wt% of secondary olefins, based on the olefins in the liquid olefin feed, more preferably at least 75wt%, even more preferably 90wt% of secondary olefins based on the olefins in the liquid olefin feed. Preferably, the liquid olefins feed comprises in the range of from 50 to 100wt% of secondary olefins, based on the olefins in the liquid olefin feed, more preferably in the range of from 75 to 100wt%, even more preferably 90 to 100wt% of secondary olefins based on the olefins in the liquid olefin feed.

In one preferred embodiment, the process according to the invention is a process for preparing C10 to C30 secondary alcohols, comprising the following steps:

(i) reacting aliphatic, non-cyclic C10 to C30 secondary olefins with N₂O to obtain an oxidation reaction product comprising C10 to C30 secondary carbonyls;

(ii) reducing at least part of the C10 to C30 secondary carbonyls in the

oxidation reaction product to the corresponding C10 to C30 secondary alcohols,

(i-a) providing a liquid olefin feed comprising aliphatic, non-cyclic C10 to C30 secondary olefins;

The liquid olefin feed may preferably further comprise compounds that may act as diluents. Preferably, the liquid olefin feed comprises at least one

hydrocarbonaceous diluent. Preferably, the diluents are inert with respect to N₂O under the reaction conditions of step (i-c). The term inert herein refers to compounds which either do not react with N₂O under the reaction conditions selected in (i-c), or react to such a limited extent compared to the reaction of olefins with N₂O that at most 15% by weight, preferably at most 10% by weight and more preferably at most 5% by weight, of their reaction product with N₂O is present in the oxidation reaction product, based on the weight of the oxidation reaction product obtained from step (i).

The at least one diluent may be any diluent that is inert as defined herein above, preferably, the diluent does not react at all with the N₂O. Particularly suitable diluents are paraffins, alcohols, ketones, aldehydes, and mixtures thereof. More particularly C10 to C30 paraffins, aliphatic C10 to C30 alcohols, aliphatic C10 to C30 ketones, aliphatic C10 to C30 aldehydes, and mixtures thereof. Preferably such diluents are obtained as part of the process according to the invention for producing C10 to C30 alcohols or as part of a process for preparing the liquid olefinic feed to the process. A particularly preferred diluent is a paraffinic diluent, more preferably a C10 to C30 paraffinic diluent, still more preferably C10 to C30 non-cyclic paraffinic diluent. Even more preferably a paraffinic diluent that was obtained as part of a process for preparing the liquid olefinic feed to the process.

Preferably, the liquid olefin feed comprises in the range of from 5 to 95wt% of aliphatic, non-cyclic C10 to C30 olefins, more preferably of from 10 to 90wt%, even more preferably of from 10 to 80wt% of aliphatic, non-cyclic C10 to C30 olefins, based on the liquid olefin feed. Still more preferably, the liquid olefin feed comprises in the range of from 25 to 75wt%, preferably 50 to 75wt% of aliphatic, non-cyclic C10 to C30 olefins, based on the liquid olefin feed.

In a preferred embodiment, the liquid olefin feed comprises in the range of from 1 to 99wt% of aliphatic, non-cyclic C10 to C20 olefins, more preferably C12 to C18 olefins, based on the olefins in the liquid olefin feed. Any resulting alcohol and/or surfactant compound prepared from C10 to C20, preferably C12 to C18 olefins are particularly suitable for detergent and personal care applications. More preferably, the liquid olefin feed comprises in the range of from 5 to 95wt%, even more preferably 10 to 90wt%, still more preferably of from 10 to 80wt% of aliphatic, non-cyclic C12 to C20 olefins, more preferably C12 to C18 olefins, based on the olefins in liquid olefin feed. Still even more preferably, the C12 to C20 olefins, preferably C12 to C18 olefins, are secondary olefins.

In another preferred embodiment, the liquid olefin feed comprises in the range of from 1 to 99wt% of aliphatic, non-cyclic C20 to C30 olefins, based on the olefins in the liquid olefin feed. Any resulting alcohol and/or surfactant compound prepared from C20 to C30 olefins are particularly suitable for chemically enhanced oil recovery applications. More preferably, the liquid olefin feed comprises in the range of from 5 to 95wt%, even more preferably 10 to 90wt%, still more preferably of from 10 to 80wt% of aliphatic, non-cyclic C20 to C30 olefins, based on the olefins in liquid olefin feed. Still even more preferably, the C20 to C30 olefins are secondary olefins. Preferred olefins are linear or low branched olefins. Where the olefins contain branching it is preferred that methyl branches represent between in the range of from 20% to 99% of the total number of branches present in the branched olefin. In some embodiments, methyl branches may represent greater than 50% of the total number of branches in the olefin. The number of ethyl branches in the alcohol may represent, in certain embodiments, less than 30% of the total number of branches. In other embodiments, the number of ethyl branches, if present, may be in the range of from 0.1% and 2% of the total number of branches. Branches other than methyl or ethyl, if present, may be less than 10% of the total number of branches. In some embodiments, less than about 0.5% of the total number of branches are neither ethyl or methyl groups. In an embodiment, an average number of branches per olefin molecule ranges from about 0 to about 2.5. In other embodiments, an average number of branches per alcohol ranges from about 0 to about 0.5.

Preferably, the liquid olefin feed as provided to the process comprises no more than 10wt%, more preferably no more than 5wt%, even more preferably no more than 1 wt% of di-olefins or higher unsaturated olefins. Di-olefins may lead to gum formation and other undesired byproducts. Di-olefins may be removed prior to the reaction of the liquid olefin feed with the oxidant feed, e.g. by selectively hydrogenating the di-olefins or higher unsaturated olefins in the liquid olefin feed to mono-olefins.

Preferably, the liquid olefin feed as provided to the process comprises no more than 10wt%, more preferably no more than 5wt%, even more preferably no more than 1 wt% of non-hydrocarbonaceous compounds, such as water.

The oxidant feed may be pure N₂O or a mixture of N₂O with one or more diluents. The oxidant feed may be provided as a gaseous, liquid or supercritical feed, preferably a gaseous or supercritical feed. The oxidant feed comprises at least 5% by volume of N₂O, based on the total oxidant feed. The reference herein to the composition of the oxidant feed is to the composition as determined at ambient pressure and temperature (1 bar, 25°C). By providing at least 5% by volume of N₂O, sufficient oxidant is provided to sustain the oxidation reaction and ensure sufficient conversion. Although, an oxidant feed consisting of pure N₂O could be used, it is preferred to add a diluent to reduce the risk of forming an explosive mixture. In addition, introducing the oxidant at a molar ratio of N₂O to olefin double bond in the range of from 0.5 to 5, preferably of from 0.6 to 1.5, more preferably 0.9 to 1.1, is preferred to increase selectivity of the reaction. Reference herein in to olefin double bonds is to the moiety of double bonds in the liquid olefin feed introduced to the process in step (i-a). More preferably, the process of step (i) is N₂O lean, i.e. the molar ratio of N₂O to olefin double bond is below 1, to ensure most if not all of the

N₂O is consumed and little to no N₂O remains in the oxidation reaction product. This would be undesired in view of the subsequent carbonyl reduction step (ii) to form the alcohol.

Preferably, the oxidant feed comprises in the range of from 5 to 35% by volume of N₂O, based on the volume of the oxidant feed. More preferably, the oxidant feed comprises in the range of from 7 to 20% by volume of N₂O, based on the volume of the oxidant feed.

As mention above preferably the oxidant feed comprises a diluent, more preferably an inert diluent. The term "inert gas" as used herein refers to diluents which, with regard to the reaction of N₂O with the olefins in the liquid olefin feed, behave inertly. Suitable inert diluents include, for example, nitrogen, carbon dioxide, carbon monoxide, argon, methane, ethane and propane.

Although not particularly preferred, the oxidant feed may also comprise diluent compounds, i.e. other than N₂O, that are not inert, such as oxygen. However, in case compounds, other than N₂O, which are not inert are present in the diluent, preferably the oxidant feed comprises at most 0.5% by volume, based on the volume of the oxidant mixture, of compounds, other than N₂O, that are not inert.

In the process according to the present invention, the liquid olefin feed is contacted and reacted with the oxidant feed in a reactor to obtain an oxidation reaction product comprising C10 to C30 carbonyls, including ketones and aldehydes.

Reference herein to C10 to C30 carbonyls is to one or more carbonyls comprising in the range of from 10 to 30 carbon atoms or mixtures thereof. During the contacting of the liquid olefin feedstock with the oxidant feedstock the N₂O reacts with the double bond of the olefin to form a ketone or aldehyde and N₂. Where the olefin is a secondary olefin, predominantly ketones will be formed. In case of primary olefins a mixture of ketones and aldehydes are formed. Preferably, the oxidation reaction product will comprise in the range of from 70 to 100 wt% of ketones, based on the carbonyls in the oxidation mixture. More preferably, the oxidation reaction product will comprise in the range of from 90 to 100 wt% of ketones, based on the carbonyls in the oxidation mixture. The content of ketones in the oxidation reaction product will be largely driven by the secondary olefin content in the olefin feed. A high ketone content in the oxidation reaction product is preferred as these can conveniently be converted into the particularly preferred secondary alcohols.

The position of the carbonyl group along length of the hydrocarbon chain is determined by the position of the double bond. As the presence of an catalyst may result in the undesired formation of hydroxylate groups at other positions along length of the hydrocarbon chain, due to the direct hydroxylation non-olefinic carbon atoms in the olefin, such as for instance described in US6548718, it is preferred that the liquid olefin feed is reacted with the oxidant feed in the absence of a catalyst.

The liquid olefin feed and the oxidant feed are contacted at temperatures in the range of from 150 to 500°C in step (i-c). Preferably, at temperatures in the range of from 150 to 350°C, more preferably 180 to 320°C.

The liquid olefin feed and the oxidant feed are contacted at pressures in the range of from 10 to 300 bar, preferably in the range from 10 to 250 bar and more preferably in the range from 25 to 250 bar. Reference herein to the unit "bar" is to "bar absolute", unless mentioned otherwise.

Preferably, the conditions under which the liquid olefin feed and the oxidant feed are contacted are chosen such that the liquid olefin feed remains liquid or supercritical during step (i). Evaporation of the olefins in the liquid olefin feed is disadvantageous as the reaction between the olefin and the N₂O is less selective when the olefins are in the gas phase.

The oxidant feed may be contacted with the liquid olefins feed by any means for contacting, including mixing, dispersing or dissolving the oxidant feed with or within the liquid olefin feed. The oxidant feed may be provided at once or a staged feeding of the oxidant feed may be applied. In the later case, the oxidant feed may be provided at several stages during step (i) of the process. This has the advantage that the N₂O concentration at any time during step (i) may be maintained at a lower level compared the concentration of N₂O that would be attained when the whole of the oxidant feed is contacted with the liquid olefin feed at the start of step (i). By lowering the N₂O concentration the formation of by-products may be suppressed. In one preferred embodiment, the oxidant feed is combined with the liquid olefin feed prior to step (i) at temperatures below 150°C, preferably below 100°C. Preferably, the oxidant feed is combined with the liquid olefin feed at elevated pressure, more preferably pressures in the range of from 1.1 to 300 bar, more preferably 10 to 250, even more preferably the same pressure as the pressure at which the liquid olefin feed and oxidant feed are contacted in step (i-c). The oxidant feed may be combined with the liquid olefin feed by mixing at least part of the oxidant feed with the liquid olefin feed, by dispersing at least part of the oxidant feed in the liquid olefin feed or by dissolving at least part of the oxidant feed in the liquid olefin feed.

In another embodiment, the liquid olefin feed and oxidant feed are not combined prior to step (i), however the liquid olefin feed is preheated prior to contacting with the oxidant feed. Preferably, the liquid olefin feed is preheated to a temperature in the range of from 25 to 320°C, more preferably 150 to 320°C.

Where, the liquid olefin feed and/or the oxidant are introduced at a temperature below the desired reaction temperature of step (i), it is preferred to increase the temperature in step (i) gradually, more preferably in the range of from 1 to 10°C/min, preferably of from 1.5 to 5°C/min and more preferably of from 2 to 4°C/min.

The reaction of step (i) may be performed in any suitable way, including batch- wise, as a semi-continuous or continuous process. Preferably, the process is operated as a continuous process. Examples of suitable continuous processes would include the use of continuous stirred tank reactors or tubular reactor. Most preferred is to operate the process in a continuous mode under plug-flow conditions in a tubular, or multi-tubular, reactor. The process may be operated in one or more reactors or reactor stages operated either in series or in parallel. Where a staged feeding to the oxidant feed is preferred this may include feeding separate fractions of the oxidant feed to one or more reactors or reactor stages.

The oxidation reaction product obtained in step (i) will contain carbonyl compounds, in particular C10 to C30 carbonyls. Where the liquid olefin feed comprised predominantly C12 to C30 olefins, respectively C12 to C18 olefins, the oxidation reaction product will comprise predominantly C12 to C30 carbonyls, respectively C12 to C18 carbonyls. In the process according to the invention, the carbonyls in the oxidation reaction product are converted to alcohols (step (ii)). The ketones are primarily reduced to secondary alcohols, whereas the aldehydes are primarily converted to primary alcohols. The carbonyls are converted to alcohols by reducing the carbonyl group to form a hydroxyl group. Preferably, the reduction of the carbonyl to its corresponding alcohol is done in the presence of a hydrogenation catalyst and hydrogen. Examples of suitable hydrogenation catalysts include Ni/AI₂O₃, and catalyst including CoMo, NiMo, W, Cu, Pt or Pd metals on silica, alumina, zirconia, titania comprising supports. Preferably, the carbonyls in the oxidation reaction product are reduced in the presence of the hydrogenation catalyst and hydrogen at temperatures in the range of from 50 to 140°C, more preferably of from 75 to 130°C, and pressures in the range of from 50 to 100 bar. The reduction of the carbonyls in the oxidation reaction mixture may be done batch wise, or in a semi- continuous or continuous manner. Preferably, the reduction of the carbonyls in the oxidation reaction mixture is done continuously. It is a particular advantage of the present invention that the carbonyl reduction of step (ii) is performed at a temperature below that of step (i). As such there is no need to reheat the oxidation reaction product, while at the same time the oxidation reaction product may be used to preheat the liquid olefin feed and/or the oxidant feed being provided to step (i), in order to cool the oxidation reaction product to the temperature preferred for step (ii). Optionally, additional cooling is applied to further cool the oxidation reaction product. This may again be done by heat exchange with other reactant or product streams or by other means.

Part or all of the oxidation reaction product may be provided to step (ii). The oxidation reaction mixture may comprise in addition to the desired carbonyls, unreacted olefin and diluents. It will also comprise nitrogen. Optionally, nitrogen is removed prior to step (ii), e.g. by flashing. If desired the carbonyls may be separated from the remainder of the compounds in oxidation reaction product prior to step (ii) of the process. An advantage of providing at least the hydrocarbonaceous compounds, i.e. e.g. hydrocarbons and carbonyls, in the oxidation reaction product to step (ii) is that there is no need to first separate these components, which may require additional cooling and subsequent reheating steps. Furthermore, separation the alcohols obtained in step (ii) from the remaining hydrocarbons may be energetically advantageous compared to separating the carbonyls from the oxidation reaction product. Any unreacted olefin and diluents may be recycled to step (i) of the process according to the invention. The recycled diluents may comprise carbonyls and/or alcohols prepared in one or more steps of the process according to the invention. Such compounds are suitable diluents and there for do not need to be removed. This has the advantage that not all carbonyls/alcohols need to be recovered following step (il), or where appropriate step (i). This allows for the use of more energy benign and cheaper separation methods to recover the alcohol. Therefore in a preferred embodiment, a recycle comprising at least part of the unreacted olefin and diluent obtained in step (i) or step (ii) is provided to step (i) or to a process for producing olefins for the liquid olefin feed. Preferably, such recycle comprises in the range of from 0 to 10wt% of carbonyls and/or alcohols.

Where the diluent is a paraffinic diluent it may alternatively be provided to a process for preparing olefins. Preferably, such a paraffinic diluent is selectively hydrogenated to remove any residual olefins.

The liquid olefin feed may comprise any suitable olefins, preferably secondary olefins. One preferred process for providing the olefins is by a paraffin

dehydrogenation process, typically a catalytic paraffin dehydrogenation process. One example of a suitable paraffin dehydrogenation process is the UOP PACOL process. One advantage of the use of paraffin dehydrogenation processes to provide at least part of the liquid olefin feed is the fact that such processes produce predominantly secondary olefins, which can conveniently be converted to secondary alcohols in the process according to the invention. Moreover, the effluent of such a process is typically a mixture of olefin and unconverted paraffin. Such a mixture could be used directly as liquid olefin feed to step (i-a) of the process, whereby the paraffin acts as diluent.

A further advantage of use of paraffin dehydrogenation processes to provide at least part of the liquid olefin feed is that as a by-product hydrogen is produced, which may preferably be used in step (ii) of the process to reduce the carbonyls in the oxidation reaction product to alcohols.

Therefore, preferably, step (i-a) of the process comprises providing a liquid olefin feed comprising aliphatic, non-cyclic C10 to C30 olefins, which liquid olefin feed was prepared by the catalytic dehydrogenation of a paraffin feedstock.

Preferably, such liquid olefin feedstock prepared by the catalytic dehydrogenation process comprises aliphatic, non-cyclic olefins and paraffins, more preferably in the range of from 5 to 95wt% of aliphatic, non-cyclic C10 to C30 olefins, more preferably of from 10 to 90wt%, even more preferably of from 10 to 80wt% of aliphatic, non-cyclic C10 to C30 olefins, based on the liquid olefin feed. Still more preferably, the liquid olefin feed comprises in the range of from 25 to 75wt%, preferably 50 to 75wt% of aliphatic, non-cyclic C10 to C30 olefins, based on the liquid olefin feed. Preferably, the paraffin feedstock subjected to the catalytic dehydrogenation comprises C10 to C30 paraffins. Reference herein to C10 to C30 paraffins is to one or more paraffins comprising in the range of from 10 to 30 carbon atoms or mixtures thereof.

An alternative process for providing the olefins is by an ethylene

oligomerization process. One such process is the Shell SHOP process. Ethylene oligomerization processes typically produces predominantly primary olefins. As mentioned above, preferred liquid olefin feeds comprise significant amounts of secondary olefins. Therefore, it is preferred to isomerise at least part of the primary olefins obtained from an ethylene oligomerization process to secondary olefins. The secondary olefins that are used to make the secondary alcohols olefin sulfonates of the present invention may be made by skeletal isomerization. Suitable processes for making the secondary olefins from the primary olefins include those described in US5510306, US5633422, US5648584, US5648585, US5849960, and EP0830315

Bl, all of which are herein incorporated by reference in their entirety.

The N₂O in the oxidant feed may be any available N₂O. The N₂O may be produced purposely for the process according to the invention, e.g. by thermally decomposing ammonium nitrate at a temperature of approximately 250°C.

Alternatively, the N₂O can be prepared by the catalytic oxidation of ammonia.

However, preferably the N₂O is obtained as a by-product from a commercial nitrogen chemistry manufacturing processes, including, but not limited to, processes for the production of dodecanedioic acid, hydroxylamine and nitric acid manufacture. A particularly preferred source of N₂O is a process for producing adipic acid. It is envisaged that the N₂O by-product from one world scale adipic acid plant, would be sufficient to produce in the range of 400-500 kta of C10 to C30 alcohols.

In a further aspect the present invention provides a process for producing surfactant compounds. The process for producing surfactant compounds includes producing alcohols according the process for producing C10 to C30 alcohols according to the invention.

The alcohols may be directly sulfonated, sulfated or carboxylated to produce surfactant compounds. However, preferably, the alcohols are first ethoxylated and/or propoxylated, further referred to as alkoxylated. Such alkoxylated alcohols (or alcohol alkoxylate) may be used as surfactant compounds, but may also be sulfonated, sulfated or carboxylated to produce further surfactant compounds

The alcohols may be alkoxylated by reacting them with ethylene oxide (EO) and/or propylene oxide (PO) in the presence of an appropriate alkoxylation catalyst.

The alkoxylation catalyst may be sodium hydroxide which is commonly used commercially for alkoxylating alcohols. The alcohols may be alkoxylated using a double metal cyanide catalyst as described in US6977236 which is herein incorporated by reference in its entirety. The alcohols may also be alkoxylated using a lanthanum-based or a rare earth metal-based alkoxylation catalyst as described in US5059719 and US5057627, both of which are herein incorporated by reference in their entirety.

The alcohol alkoxylates may be prepared by adding to the alcohols a calculated amount, for example in the range of from 0.1 wt% to 0.6 wt%, of a strong base, typically an alkali metal or alkaline earth metal hydroxide such as sodium hydroxide or potassium hydroxide, which serves as a catalyst for alkoxylation. An amount of ethylene oxide and/or propylene oxide calculated to provide the desired number of moles of ethylene oxide or propylene oxide per mole of alcohol is then introduced and the resulting mixture is allowed to react until the alkoxy compounds are consumed. Suitable reaction temperatures are typically above 100°C, preferably in the range of from 120 to 220°C.

The alcohol alkoxylates of the present invention may be prepared by using a multi-metal cyanide catalyst as the alkoxylation catalyst. The catalyst may be contacted with the alcohol and then both may be contacted with the ethylene or propylene oxide reactant which may be introduced in gaseous form. Preferably, elevated pressure is used to maintain the alcohol substantially in the liquid state.

It should be understood that the alkoxylation procedure serves to introduce a desired average number of ethylene oxide and/or propylene oxide units per mole of alcohol. For example, treatment of an alcohol with 1.5 moles of propylene oxide per mole of alcohol serves to effect the propoxylation of each alcohol molecule with an average of 1.5 propylene oxide moieties per mole of alcohol moiety, although a substantial proportion of alcohol moieties will have become combined with more than 1.5 propylene oxide moieties and an approximately equal proportion will have become combined with less than 1.5. In a typical alkoxylation product mixture, there is also a minor proportion of unreacted alcohol. Preferably, in the range of from 1 to 10 alkoxy groups are reacted per alcohol. These alkoxylated alcohols are suitable surfactant compounds.

In the preparation of the sulfonates derived from the alkoxylated alcohols of the present invention, the alkoxylates are reacted with epichlorohydrin, preferably in the presence of a catalyst such as tin tetrachloride at an elevated temperature, preferably in the range of from 110 to 120 °C for in the range of from 3 to 5 hours at a pressure of in the range of from 1 to 1.1 bar in toluene. Next, the reaction product is reacted with a base such as sodium hydroxide or potassium hydroxide at elevated temperature, preferably in the range of from 85 to 95 °C for in the range of from 2 to 4 hours at a pressure of in the range of from 1 to 1.1 bar. The reaction mixture is cooled and separated in two layers. The organic layer is separated and the product isolated. It is then reacted with sodium bisulfite and sodium sulfite at an elevated temperature, preferably in the range of from 140 to 160°C for in the range of from 3 to 5 hours at an elevated pressure, preferably in the range of from 4 to 5.5 bar. The reaction is cooled and the product sulfonate is recovered as about a 25 wt% alcohol alkoxysulfonate solution in water.

The alcohol alkoxylates may be sulfated using one of a number of sulfating agents including sulfur trioxide, complexes of sulfur trioxide with (Lewis)bases, such as the sulfur trioxide pyridine complex and the sulfur trioxide trimethylamine complex, chlorosulfonic acid and sulfamic acid. The sulfation may be carried out at a temperature preferably not above 80°C. The sulfation may be carried out at temperature as low as -20°C, but higher temperatures are more economical. For example, the sulfation may be carried out at a temperature in the range of from 20 to 70°C, preferably of from 20 to 60°C, and more preferably of from 20 to 50°C. Sulfur trioxide is the most economical sulfating agent.

The alcohol alkoxylates may be reacted with a gas mixture which in addition to at least one inert gas contains on the range of 1 to 8 percent by volume, relative to the gas mixture, of gaseous sulfur trioxide, preferably in the range of from 1.5 to 5 percent volume. In principle, it is possible to use gas mixtures having less than 1 percent by volume of sulfur trioxide but the space-time yield is then decreased unnecessarily. Inert gas mixtures having more than 8 percent by volume of sulfur trioxide in general may lead to difficulties due to uneven sulfation, lack of consistent temperature and increasing formation of undesired by-products. Although other inert gases are also suitable, air or nitrogen are preferred, as a rule because of easy availability.

The reaction of the alcohol alkoxylate with the sulfur trioxide containing inert gas may be carried out in falling film reactors. Such reactors utilize a liquid film trickling in a thin layer on a cooled wall which is brought into contact in a continuous current with the gas. Kettle cascades, for example, would be suitable as possible reactors. Other reactors include stirred tank reactors, which may be employed if the sulfation is carried out using sulfamic acid or a complex of sulfur trioxide and a (Lewis) base, such as the sulfur trioxide pyridine complex or the sulfur trioxide trimethylamine complex. These sulfation agents would allow an increased residence time of sulfation without the risk of ethoxylate chain degradation and olefin elimination by (Lewis) acid catalysis.

The molar ratio of sulfur trioxide to alkoxylate may be 1.4 to 0.8, preferably 1.0 to 0.8. Sulfur trioxide may be used to sulfate the alkoxylates and the temperature may in the range of from -20 °C to 50 °C, preferably of from 5 °C to 40 °C, and the pressure may be in the range from 1 to 5 bar. The reaction may be carried out continuously or discontinuously. The residence time for sulfation may range from 0.5 seconds to 10 hours, but is preferably from 0.5 seconds to 20 minutes.

The sulfation may be carried out using chlorosulfonic acid at a temperature from -20 C to 50 C, preferably from 0 C to 30 C. The mole ratio between the alkoxylate and the chlorosulfonic acid may range from about 1:0.8 to about 1:1.2, preferably about 1:0.8 to 1:1. The reaction may be carried out continuously or discontinuously for a time between fractions of seconds (i.e., 0.5 seconds) to 20 minutes.

Unless they are only used to generate gaseous sulfur trioxide to be used in sulfation, the use of sulfuric acid and oleum should be omitted. Subjecting any ethoxylate to these reagents leads to ether bond breaking - expulsion of 1,4-dioxane (back-biting) - and finally conversion of alcohol to an internal olefin.

Following sulfation, the liquid reaction mixture may be neutralized using an aqueous alkali metal hydroxide, such as sodium hydroxide or potassium hydroxide, an aqueous alkaline earth metal hydroxide, such as magnesium hydroxide or calcium hydroxide, or bases such as ammonium hydroxide, substituted ammonium hydroxide, sodium carbonate or potassium hydrogen carbonate. The neutralization procedure may be carried out over a wide range of temperatures and pressures. For example, the neutralization procedure may be carried out at a temperature in the range of from 0 C to 65°C and a pressure in the range of from 1 to about 2 bar. The neutralization time may be in the range of from 0.5 hours to 1 hour but shorter and longer times may be used where appropriate. The alcohol alkoxysulfates and alcohol

alkoxysufonates thus produced are suitable surfactant compounds.

The alkoxylated alcohols of this invention may be carboxylated by any of a number of well-known methods. It may be reacted with a halogenated carboxylic acid to make a carboxylic acid. Alternatively, the alcoholic end group - CH₂OH - may be oxidized to yield a carboxylic acid. In either case, the resulting carboxylic acid may then be neutralized with an alkali metal base to form a carboxylate surfactant.

In a specific example, an alkoxylated alcohol may be reacted with potassium t-butoxide and initially heated at, for example, 60°C under reduced pressure for, for example, 10 hours. It would be allowed to cool and then sodium chloroacetate would be added to the mixture. The reaction temperature would be increased to, for example, 90°C under reduced pressure for, for example, 20 to 21 hours. It would be cooled to room temperature and water and hydrochloric acid added. This would be heated to, for example, 90°C for, for example, 2 hours. The organic layer may be extracted by adding ethyl acetate and washing it with water.

The alcohol alkoxycarboxylates thus produced are suitable surfactant compounds.

The alcohol sulfates and sulfonates, alkoxylated alcohols, alcohol alkoxy sulfate and alcohol alkoxysulfonate as well as the alcohol alkoxycarboxylates surfactant compounds produced using the process for producing surfactant compounds are preferably secondary alcohol sulfates and sulfonates, alkoxylated secondary alcohols, secondary alcohol alkoxysulfate and secondary alcohol alkoxysulfonate as well as secondary alcohol alkoxycarboxylates surfactant compounds. These secondary alcohol based surfactants may be obtained by the process of the present invention, by using secondary olefins as the olefins in the liquid olefin feedstock.

The surfactant compounds herein described have better biodegradability compared to established alkyl benzene based surfactants, while the secondary alcohol based surfactant tend to outperform their primary based alcohol counterparts with respect to e.g. surface tension reduction. These surfactant compounds may be used to produce household detergents including laundry powders, laundry liquids, dishwashing liquids and other household cleaners, as well as lubricants and personal care compositions.

One particular suitable application of the alcohols and surfactant compounds prepared by the processes of the present invention is chemically enhanced oil recovery, wherein a crude oil reservoir is treated with at least one of the alcohol or surfactant compounds prepared by the processes of the present invention to enable the recovery of crude oil from the reservoir.

In a further aspect the invention therefore provides a method of treating a crude oil containing formation comprising admixing at least one of a C10 to C30 alcohol prepared according to the process for preparing C10 to C30 alcohols according to the invention and a surfactant compound prepared according the process for preparing surfactant compounds according to the invention with water and/or brine, preferably from the formation from which crude oil is to be extracted, to form an injectable fluid and then injecting the injectable fluid into the formation. Preferred alcohols and surfactant compounds for use in such method of treating a crude oil containing formation are those that were prepared from a liquid olefin feed comprising in particular C20 to C30 olefins, more preferably C20 to C30 secondary olefins.

In chemically enhanced oil recovery (cEOR) applications, surface active compounds are provided to the reservoir to improve mobilization of the

hydrocarbons. A class of surface active compounds, or surfactants, that is particularly suitable for cEOR application are secondary (also referred as internal) olefin sulfonates. Secondary olefin sulfonates are chemically suitable for EOR because they have a low tendency to form ordered structures/liquid crystals (which can be a major issue because long range ordered molecular structuring tends to dramatically increase fluid viscosities and can to lead decreased mobility of fluids within the hydrocarbon formations, and reduced recoveries) because they are a complex mixture of surfactants with different chain lengths. Secondary olefin sulfonates show a low tendency to adsorb on reservoir rock surfaces arising from negative-negative charge repulsion between the surface and the surfactant.

The alcohols and surfactant compounds, optionally together with other components in a thus formed hydrocarbon recovery composition, may interact with hydrocarbons in at least a portion of a hydrocarbon containing formation. Interaction with the hydrocarbons may reduce interfacial tension of the hydrocarbons with one or more fluids in the hydrocarbon containing formation. In other embodiments, alcohols and surfactant compounds may reduce the interfacial tension between the hydrocarbons and an overburden/underburden of a hydrocarbon containing formation. Reduction of the interfacial tension may allow at least a portion of the hydrocarbons to mobilize through the hydrocarbon containing formation.

The method of treating a crude oil containing formation preferably comprises admixing at least an alcohol and/or surfactant compound prepared according to a process according to the invention with water and/or brine from the formation from which crude oil is to be extracted to form an injectable fluid, wherein the alcohols and surfactant compounds comprises in the range of from 0.05 to 1.0 wt%, preferably in the range of from 0.1 to 0.8 wt% of the injectable fluid, and then injecting the injectable fluid into the formation.

The interactions between the alcohols and surfactant compounds and the hydrocarbons in the hydrocarbon containing formation have been described in for instance WO2011/100301, which is incorporated herein by reference.

WO2011/100301 describes methods to determine the suitability of different internal olefin sulfonates composition for a particular hydrocarbon containing formation.

In an embodiment of a method to treat a hydrocarbon, preferably crude oil, containing formation, an internal olefin sulfonate composition may be provided (e.g. by injecting a fluid comprising the internal olefin sulfonate composition) into a hydrocarbon containing formation through an injection well.

In an embodiment, an alcohols and/or surfactant compounds composition is provided to the formation containing crude oil with heavy components by admixing it with brine from the formation from which hydrocarbons are to be extracted or with fresh water. The mixture, i.e. the injectable fluid, is then injected into the hydrocarbon containing formation.

In an embodiment, an alcohols and/or surfactant compounds composition may interact with at least a portion of hydrocarbons and at least a portion of one or more other fluids in the formation to reduce at least a portion of the interfacial tension between the hydrocarbons and one or more fluids. Reduction of the interfacial tension may allow at least a portion of the hydrocarbons to form an emulsion with at least a portion of one or more fluids in the formation. An interfacial tension value between the hydrocarbons and one or more fluids may be altered by the internal olefin sulfonate composition to a value of less than 0.1 dyne/cm. In some embodiments, an interfacial tension value between the hydrocarbons and other fluids in a formation may be reduced by the hydrocarbon recovery composition to be less than 0.05 dyne/cm. An interfacial tension value between hydrocarbons and other fluids in a formation may be lowered by the internal olefin sulfonate composition to less than 0.001 dyne/cm, in other embodiments.

At least a portion of the alcohols and/or surfactant compounds

composition/hydrocarbon/fluids mixture may be mobilized to a production well.

An increased hydrocarbon mobility and consequently increased hydrocarbon production may increase the economic viability of the hydrocarbon containing formation.

The process according to the present invention could also be described as: a process for preparing C10 to C30 alcohols, comprising the following steps:

(a) providing a liquid olefin feed comprising aliphatic, non-cyclic C10 to

C30 olefins;

(b) providing an oxidant feed comprising at least 5% by volume of N₂O, based on the total oxidant feed;

(c) reacting the liquid olefin feed with the oxidant feed to obtain an

oxidation reaction product comprising C10 to C30 carbonyls, wherein the liquid olefin feed and the oxidant feed are contacted in a reactor at temperatures in the range of from 150 to 500° C and pressures in the range of from 10 to 300 bar; (d) reducing at least part of the C10 to C30 carbonyls to the corresponding

C10 to C30 alcohols.

Step (a) herein is equivalent to step (i-a), step (b) herein is equivalent to step (1-b), step (c) is equivalent to step (i) and step (d) herein si equivalent to step (ii).

EXAMPLES

The invention is further illustrated by the following non-limiting examples.

EXPERIMENTAL SET-UP AND PROCEDURE: A 100 cc stainless steel autoclave is loaded with 15 g of olefin and sealed. The reactor is purged with nitrogen, pressured up with additional nitrogen to do an overnight safety leak test and then de-pressured. Nitrous oxide (N₂O) is then added at ambient or 40 °C, and then additional nitrogen is added to the vessel and sealed. The temperature is slowly ramped to the reaction temperature in an hour while being stirred with a gas-dispersion stirrer. The reaction is stirred at the set temperature for the duration of the run, then cooled down, depressurized and purged with nitrogen. The product is collected and analyzed via gas chromatography (GC) or nuclear magnetic resonance (NMR). Conversion and selectivity are defined as:

Conversion (wt %) = olefin concentration in the feed (wt%) - olefin concentration in product (wt%).

Selectivity (wt%) = carbonyl concentration in product (wt%)/ conversion (wt %)

EXAMPLE la: 15g of 1-dodecene as a representative olefin for the detergent range was loaded with 18.96 bar (275 psig) of N₂O and 4.14 bar (60 psig) of N₂, heated to 250 °C while being stirred at 750 rpm and held at temperature for 7 hours. At the end of the run the liquid product was analyzed via GC and the results are provided in Table 1.

EXAMPLE lb: 1-Dodecene was isomerised to provide predominantly internal or secondary dodecene. 15g of internal dodecene was loaded with 18.96 bar (275 psig) of N₂O and 4.14 bar (60 psig) of N₂, heated to 250 °C while being stirred at 750 rpm and held at temperature for 7 hours. At the end of the run the liquid product was analyzed via GC and the results are provided in Table 1. As can be seen from the comparison of Example la and lb, a significant improvement of the selectivity to ketones (secondary carbonyls) may be achieved by using a liquid olefin feed that comprises predominantly secondary olefins.

EXAMPLE 2a: A further 15g of the internal dodecene as used in Example lb was loaded with 36.20 bar (525 psig) of N₂O and 4.14 (60 psig) of N₂, heated to 250

°C while being stirred at 750 rpm and held at temperature for 13 hours. At the end of the run the liquid product was analyzed via GC and the results are provided in Table 1.

EXAMPLE 2b: A further 15g of the internal dodecene as used in Example lb was loaded with 36.20 bar (525 psig) of N₂O and 4.14 (60 psig) of N₂, heated to 260 °C while being stirred at 750 rpm and held at temperature for 7 hours. At the end of the run the liquid product was analyzed via GC and the results are provided in Table 1.

EXAMPLE 2c: further 15g of the internal dodecene as used in Example lb was loaded with 36.20 bar (525 psig) of N₂O and 4.14 (60 psig) of N₂, heated to 260

As can be seen from the comparison of Example lb and 2a, b and c, a significant improvement of the conversion of secondary olefins may be obtained by increasing the temperature and/or the reaction time, while maintaining a high selectivity toward secondary carbonyls. In Example 3c both the temperature and the reaction time were increased to give a conversion over 96wt%.

EXAMPLE 3: A mixture of C20 to C24 (C2024) alpha olefins (primary olefins) was isomerised to a mixture comprising predominantly internal, or secondary,

C2024 olefins. The mixture, comprising approximately 2mol% of C18 olefins, 60mol% of C20 olefins; 30mol% of C22 olefins and 8mol% of C24 olefins was used to represent a olefin feedstock used to prepare surfactant suitable for chemically enhanced oil recovery. 15 g of the internal C2024 olefin mixture was loaded with 34.47 bar (500 psig) of N₂O and 4.14 bar (60 psig) of N₂, heated to 250 °C while being stirred at 750 rpm and held at temperature for 15 hours. In this Exampe 3, conversion and selectivity are defined as:

Conversion (mol %) = olefin concentration in the feed (mol%) - olefin

concentration in product (mol%).

Selectivity (mol%) = carbonyl concentration in product (mol%)/conversion (mol %)

At the end of the run the solid product was analyzed via NMR. It was observed that 98mol% of olefins were converted, and that 96mol% of the product contained carbonyl compounds.

As can be seen from the comparison of Example 3, the process according to the invention may be suitably be used to convert olefins in the range of C20 to C30 olefins, in particular secondary olefins, at high conversion and selectivity.

Claims

C L A I M S

1. A process for preparing C10 to C30 alcohols, comprising the following steps:

(i) reacting aliphatic, non-cyclic C10 to C30 olefins with N₂O to obtain an oxidation reaction product comprising a C10 to C30 carbonyl;

(ii) reducing at least part of the C10 to C30 carbonyls in the oxidation reaction product to the corresponding C10 to C30 alcohols, wherein the aliphatic, non-cyclic C10 to C30 olefins are reacted with the N₂O by in step (i):

2. A process according to claim 1, wherein the liquid olefin feed comprises aliphatic, non-cyclic secondary CIO to C30 olefins.

3. A process according to claim 2, wherein the liquid olefin feed comprises in the range of from 90 to 100wt% of aliphatic, non-cyclic secondary C10 to C30 olefins, based on the olefins in the liquid feed.

4. The process according to any one of claims 1 to 3, wherein the liquid olefin feed further comprises at least one hydrocarbonaceous diluent which is inert toward N₂O under the conditions of step (i-c).

5. A process according to claim 4, wherein the liquid olefin feed comprises in the range of from 10 to 80wt% of aliphatic, non-cyclic C10 to C30 olefins, based on the liquid olefin feed.

6. A process according to claim 4 or 5, wherein the diluent is a non-cyclic paraffinic diluent.

7. A process according to any one of claims 1 to 6, wherein the liquid olefin feed is maintained in a liquid phase during step (i-c).

8. A process according to any one of claims 1 to 7, wherein the liquid olefin feed

comprises one or more aliphatic, non-cyclic secondary C12 to C18 olefins.

9. A process according to any one of claims 1 to 8, wherein the C10 to C30 carbonyls are reduced in step (ii) in the presence of H₂ and a hydrogenation catalyst.

10. A process according to any one of claims 1 to 9, wherein the aliphatic, non-cyclic C10 to C30 olefins are produced by a paraffin dehydrogenation process.

11. A process according to any one of claims 1 to 9, wherein the aliphatic, non-cyclic C10 to C30 olefins are produced by an ethylene oligomerization process to produce primary olefins followed by an isomerization of at least part of the primary olefins to secondary olefins.

12. A process for producing surfactant compounds, comprising:

a) producing C10 to C30 alcohols according to any one of claims 1 to 11;

b) reacting the alcohols with ethylene oxide or propylene oxide at temperature above 100°C and in the presence of a catalyst to produce alkoxylated alcohol surfactant compounds.

13. A process according to claim 12, wherein the ethoxylated or propoxylated alcohols are sulfated or sulfonated to at least one surfactant component selected from alcohol alkoxysulfate and alcohol alkoxysufonate.

14. A process according to claim 12, wherein the ethoxylated or propoxylated alcohols are carboxylated to alcohol alkoxycarboxylates.

15. A method of treating a crude oil containing formation, comprising admixing at least one of:

a) a C10 to C30 alcohol prepared according to any one of claims 1 to 11; and

b) a surfactant compound prepared according to any one of claim 12 to 14,

with water and/or brine to form an injectable fluid and then injecting the injectable fluid into the formation.