WO1994020421A1

WO1994020421A1 - Silicone based polymers as spill treating agent

Info

Publication number: WO1994020421A1
Application number: PCT/CA1994/000117
Authority: WO
Inventors: Emilien Pelletier; Robert Siron
Original assignee: Institut National de La Recherche Scientifique INRS
Current assignee: Institut National de La Recherche Scientifique INRS
Priority date: 1993-03-02
Filing date: 1994-03-01
Publication date: 1994-09-15
Anticipated expiration: 1995-09-02
Also published as: AU6152494A

Abstract

In accordance with the present invention, there is now provided a method of recovering hydrocarbons such as crude oil, oil processing products, oil residues and the like, spilled on a watery environment, which comprises contacting the hydrocarbon slick with a composition comprising the reaction products of at least one hydrolysable silane derivative reacted with a polyoxyethylenic surfactant, an aliphatic carboxylic acid, an aliphatic alcohol, or mixtures thereof. The reaction products of the composition further react in the presence of water to form an anti-adhesive polysiloxane matrix, thus trapping the hydrocarbon into the matrix. The removal of the resulting silicone/hydrocarbon solid residues from the water surface is performed by simple netting or conventional mechanical means. The residues are washed with hydrocarbon solvents leaving inert silicone polymers to de discarded and a hydrocarbon solution to be recycled.

Description

TITLE

Silicone based polymers as spill treating agent

BACKGROUND OF THE INVENTION

Crude oil, oil processing products and hydrocarbon residues are a major cause of severe environmental damage when spilled in the aquatic environment. Among the impacts of oil spills are the loss of shoreline habitat mainly for birds and aquatic mammals, the contamination of water and interstitial sediments with toxic hydrocarbons and, in some cases, major economic loss from the reduction of recreational and fisheries activities. Only large oil spills capture public attention but small spills occurring daily in harbours, seaports and marinas or along navigation channels and waterways are very common and represent over 90% of the spilled oil products every year.

Several techniques have been proposed to remove oil slicks from watery environments. However, the effectiveness of these methods varies significantly depending on the size of the spill and the environmental conditions present at that time on the site. Oil spill recovering technologies can be divided in three major groups: 1) mechanical containment; 2) controlled burning and 3) spill- treating agents. The latter includes the use of solid adsorbents and dispersants.

Mechanical containment and eventual complete cleaning of the site involves the use of booms and skimmers to block the oil spread, concentrate it, and pump it from the water. A large number of systems exist but the current technology still has many limitations and experts agree that at best, recovery capabilities for large ocean spills do not exceed 20%, provided that the conditions are favourable and the most advanced technology is available on the site.

Burning spilled oil from the surface of water is not currently a major spill recovering method, but could eventually be considered if the oil slick could be contained and thickened using fireproof booms. Igniting and keeping a slick ablaze can be contemplated, for example, if the oil is freshly spilled and the slick is at least >

3 mm thick. However, a serious drawback to this method is that it transfers pollution to the air, and the oil residues remaining on the water after burning constitute a further pollution problem that also must be addressed.

5 In the past two decades, approximately 600 chemical agents for treating oil spills have been developed worldwide but only few of them are presently utilized commercially. Oil treating agents can be divided in four groups: dispersants, surface-washing agents, emulsion breakers or demulsifiers, and gelling agents or solidifiers.

10

Dispersants are chemical formulations of ionic and neutral surfactants usually dissolved in hydrocarbon-based solvents, and have the capability of decreasing the water/oil interfacial tension and promote the dispersion of tiny oil droplets into the underlying water mass. The major drawbacks associated with

15 dispersants are their unfavourable acceptance by the public as well as the relative toxicity of the oil-in-water dispersion. Furthermore, the effectiveness of dispersants significantly depend on environmental conditions, application techniques and chemical nature of spilled oiL

20 Surface-washing agents are surfactants mixtures which remove oil from solid surfaces such as beaches, rocks or boat hulls, by a "detergent" effect. The efficiency of recuperation of most commercial surface-washing agents is below 50% and some of them exhibit an important dispersant effect.

25 Emulsion breakers or demulsifiers are chemical agents which can prevent the formation or break down water-in-oil emulsions. The majority of these agents are hydrophillic surfactants which tend to leave quickly the oil and cannot be used on open water. Recent oil spilled treating compositions using polymers instead of surfactants have been reported to treat emulsified oil successfully. US 5,004,559

30 teaches the use of polyoxyalkylene-polysiloxane block copolymers to demulsify water- containing crude oil but such a process does not solidify the oil residues and does not improve its recovery by mechanical means. This process is used for removing water intimately associated with crude oil when extracted from underground wells. The process consists in mixing the demulsifying agent with the emulsified oil/water blend under vigorous agitation at a temperature of from 40 to 80°C. Such process is applicable in plants involved in the treatment of crude oil prior to its refinery.

Yet another approach to the treatment of oil slicks is the use of gelling agents or solidifiers which facilitate the recuperation of the spilled oil from the water surface by lifting off. These agents often consist of polymerization catalysts and cross-linking agents. For example, US 4,980,072 teaches that polyether containing isocyanate end groups added to hydrocarbons form a gel containing hydrocarbons which can be removed from seawater surface mechanically. However, gelling agents usually suffer from a major field application restriction: the formation of the gel is not an instantaneous process and it requires vigorous and thorough agitation at the oil/water interface. Furthermore, gelling agents historically have not been used or stored for use during oil spill recovery because of the large amount required, which is very often over 40% of the actual volume of the oil, to solidify the slick.

US 5,076,938 discloses a method for the encapsulation of hydrocarbons to produce a solid material which is easily removed from a spillage site. The method involves the treatment of oil with a concentrated solution of surfactants to emulsify the oil followed by the addition of a silicate solution which immobilizes the resulting acidic mixture and produces a gel-like precipitate which can be dried, thus leading to a grey powder. However, the method can be used on solid surfaces only since the application of emulsifying solution on oil floating on water would result in a dispersion of the oil in the water mass and subsequently the dilution of the silicate solution without any gelling effect.

It would therefore be highly desirable to obtain an effective method of removing spilled hydrocarbons, or any derivatives thereof, from watery environment. The method would be applicable to both damp surfaces and water surface and the treated hydrocarbon slick would be recovered by simple mechanical means. Such method would preferably trap and solidify the crude hydrocarbon, which could be easily recovered. The hydrocarbon treating composition could also be used to prevent the contamination of the shores neighbouring the spill. The hydrocarbon would preferably be easily extracted from the recovered hydrocarbon/hydrocarbon-treating composition residues. Finally, the action of the hydrocarbon-treating composition would be independent from environmental conditions such as the ambient temperature, the nature of the hydrocarbon and the salinity of water, and would not further pollute the environment.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is now provided a method of recovering hydrocarbons such as crude oil, oil processing products, oil residues and the like, spilled on a watery environment, which comprises contacting the hydrocarbon slick with a composition comprising the reaction products of at least one hydrolysable silane derivative reacted with a polyoxyethylenic surfactant, an aliphatic carboxylic acid, an aliphatic alcohol, or mixtures thereof. The silane derivative reacts with the other components of the composition, and in the presence of water, a further reaction takes place to form an anti-adhesive polysiloxane matrix, thus trapping the hydrocarbon into the matrix. The removal of the resulting silicone/hydrocarbon solid residues from the water or damp surface is performed by simple netting or conventional mechanical means. The residues are washed with hydrocarbon solvents leaving inert silicone polymers to be discarded and hydrocarbon solution to be recycled.

In an aspect of the invention, there is also provided a method for protecting a damp surface against hydrocarbon spills, which comprises contacting the surface with a composition comprising the reaction products of at least one hydrolysable silane derivative reacted with a polyoxyethylenic surfactant, an aliphatic carboxylic acid, an aliphatic alcohol, or mixtures thereof, to form an anti-adhesive polysiloxane matrix on the surface to prevent the adherence of the spilled hydrocarbon on the surface and facilitate the recuperation of the hydrocarbon.

In a further aspect of the present invention, there is also provided a composition for recovering spilled hydrocarbons such as crude oil, oil processing ϋ

products, oil residues and the like, or for protecting a damp surface against hydrocarbon spills, which comprises the reaction products of at least one hydrolysable silane derivative reacted with a polyoxyethylenic surfactant, an aliphatic carboxylic acid, an aliphatic alcohol, or mixtures thereof. 5

DETAILED DESCRIPTION OF THE INVENTION

As used in the present application, the expression "watery environment" is meant to include water or damp surface such as rocks, sand, shells, 10 wharfs, dams, river banks, cement, asphalt or any other material or surface susceptible of being contaminated by oil spills.

The method to prepare a preferred reactive composition is first to react a polyoxyethylenic surfactant of the general formula

15

CH₃-(CH₂)_n(C₂H₅O)_m-H

wherein n = 11-17 and m = 2-21; or an aliphatic carboxylic acid of general formula

20

CH₃(CH₂)_pCOOH wherein p = 11-17; or an aliphatic alcohol of general formula

25 CH₃(CH2)_qCH₂OH

wherein q is 11-17; or mixtures thereof, with an excess of at least one silane derivative of general formula

30 X₃SiR

wherein R = H, or C_{1 2a} alkyl and X = halogen or a lower alkoxy group, preferably chlorine or OCH₃ in suitable non-aromatic hydrocarbon solvents such as pentane, hexanes or petroleum ether as well as a mixture of light hydrocarbons. When this composition is placed in the presence of water or humidity, the reaction pioducts further react to form a polysiloxane matrix of the silicone type.

The term "silicone" is defined in the present application as a synthetic polymer containing a repeating silicon-oxygen backbone and various organic groups, R and OR, attached to silicon atoms. The Si-halogen bond is important in silicon chemistry and the hydrolysis of organochlorosilanes, for example, gives siloxane structures which are the basis of silicone products. Halosilanes are reactive towards polar reagents and the first step of the reaction involves the displacement of one or more halogen atoms by a nucleophilic attack:

Si-halogen + R-OH Si-OR + H-halogen

Depending on reagents and reaction conditions used, reactions of halosilanes with protic materials provide a number of intermediates (silanols, alkoxysilanes, siloxanes) that can be used as starting materials for polymer synthesis.

In one preferred embodiment of the method of the present invention, the first step usually involves the reaction of an excess of a trichlorosilane, thus containing 3 Si-Cl hydrolysable bonds, with a polyoxyethylenic surfactant such as polyoxyethylene stearyl ether, in a hydrocarbon solvent. When conducted under proper conditions of temperature and pressure well known to the man of ordinary skill in the art, this reaction leads to the formation of a solution of alkoxychlorosilanes 1 and 2 and alkoxysilanes 3, as illustrated in Scheme 1.

SCHEME 1

CI R — Si -0-tCH₂CH₂O^C_1$H₃₇

CI

CI R— Si -0-f CH₂CH₂O^ Cι₈H_j7

0-t CH₂CH₂O^C„iH₃₇

The completeness of this reaction is monitored by infrared spectrometry. Polyoxyethylenic surfactants show a large primary alcohol (R-OH) absorption band in the spectral region of 3500 cm"¹. Silane derivatives show the very characteristic Si-H stretching band at 2230 cm^"1 when R = H. The spectrum of the reactive composition shows, after the addition of the silane derivative to the surfactant, the complete disappearance of the R-OH absorption band in the spectral region of 3500 cm'¹. The non-reactive Si-H band is observed at a higher wave number (2250 cm^"1) due to the substitution of the halogen atoms by one or more alkoxy groups at the silicon centre. The 1400-1000 cm"¹ region of the spectra of the polyoxyethylenic surfactant and the reactive composition are very similar. This is attributed to the superposition of stretching and bending modes of polyoxyethylenic groups which are not modified by the reaction. The reactivity of this mixture can be adjusted according to the requirements of the application procedure by varying the molar ratio and the nature of the silane derivatives towards the surfactant. These adjustments can be easily determined by any man skilled in the art. The reactive alkoxysilanes and siloxanes derivatives are readily obtained by stirring under c

nitrogen atmosphere the polyoxyethylenic surfactant with the silane derivative(s) at room temperature for a few minutes.

In a second embodiment of the method of the present invention, the 5 polyoxyethylenic surfactant is replaced by an aliphatic alcohol as defined above, such as dodecyl alcohol, under similar conditions. The progress of the reaction and its completeness is monitored by the disappearance of 2 R-OH infrared absorption bands at 3630 and 1050 cm"¹, and the formation of a new peak at 1100 cm"¹ corresponding to the vibration of the C-O-Si created. As mentioned above for the 10 polyoxyethylenic surfactant, the reactive alkoxysilanes and siloxanes derivatives are readily obtained by stirring under nitrogen atmosphere the aliphatic alcohol with the silane derivative(s) at room temperature for a few minutes.

In a third embodiment of the method of the present invention, the 15 polyoxyethylenic surfactant is replaced by an aliphatic carboxylic acid as defined above, such as stearic acid, under similar conditions. The progress of the reaction and its completeness is monitored by the disappearance of the carbonyl (acid) infrared absorption band at 1705 cm"¹, and the formation of a new peak at 1740 cm"¹ corresponding to the vibration of a carbonyl (ester) the CO-O-Si created. In this 20 case, in order to obtain the reactive alkoxysilanes and siloxanes derivatives, it is necessary to heat the mixture of the carboxylic acid aliphatic alcohol with the silane derivative(s) under reflux and nitrogen atmosphere for about 1 hour, preferably in CC1₄.

25 A second optional step of the preparation procedure is the addition to the reactive solution of a variable amount of an alkylhalosilane or a mixture of alkyltrihalosilanes as a hydrophobic cross-linking polymerization reagent responsible for the three dimensional structure of the silicone polymer in contact with the hydrocarbon/water interface. A preferred embodiment comprises the incorporation

30 of a given amount of a polydimethylsiloxane fluid of intermediate viscosity in the reactive composition to improve the plasticity and flexibility of the final hydrorysed product. Since a hydrocarbon spill-treating composition prepared as above contains a number of hydrolysable units (Si-X), its contact with water, seawater or any wet surface provokes a rapid but non violent hydrolysis of the reactive species in the composition, thus trapping the floating hydrocarbon and hydrocarbon residues into a semi-solid cross-linked silicone polymer.

To obtain satisfactory results, it is most preferred that the polyoxyethylenic surfactant, the carboxylic acid and the aliphatic alcohol possess a long hydrocarbon chain, which incidentally may be substituted. This is explained by the fact that compounds of these families having a shorter hydrocarbon chain are water-soluble and almost insoluble in hydrocarbon solvents. They are therefore undesirable for the purposes of the present invention.

The hydrocarbon spill-treating compositions of the present invention must obviously be stored under dry conditions to avoid undesirable hydrolysis. The field application of these compositions to water or damp surfaces can be done by means of a slightly pressurized container equipped with a spray nozzle. The composition is sprayed over and around the hydrocarbon slick and the silicone polymerization takes place within seconds to a few minutes. When the hydrolysis is completed, a white flexible solid coating has been formed over the treated surface, which "envelops" the slick. Hydrocarbon/silicone residues can be collected easily from the surface of water using a landing net having a small mesh size (1/16 to 1/8 inch), or any other mechanical means suitable for separating floating solids from water. When applied to damp surfaces, the compositions also form a white solid coating "enveloping" the hydrocarbon and hydrocarbon residues easily collected with scrapers or any other appropriate mechanical means.

If X is a halogen in the silane derivatives used in the composition, the hydrolysis reaction generates small concentrations of acid (hydrochloric, hydrofluoric etc.). Caution must therefore be taken up to that point, and neutralisation with a base such as calcium carbonate or any other neutralizing agent not causing damage to the environment, is recommended. This minor inconvenience is however minimized significantly in seawater due to the strong buffer capacity of the latter. The alternative is to used silane derivatives wherein X is an alkoxy group to avoid the formation of such acid. After the collecting of hydrocarbon/silicone residues from the water surface or wet substrates, they are treated to recover the hydrocarbon. Since the silicone cross-linked polymer formed during the hydrolysis of the hydrocarbon-treating composition is insoluble in the majority of commonly used organic solvents, the recovery of hydrocarbons can be done by washing or extracting the hydrocarbon/silicone residues with methylene chloride or a mixture of methylene chloride and a light non-aromatic hydrocarbon. Methods of hydrocarbon recovery can vary from a simple agitation of residues into a large volume of solvent followed by centrifugation or decantation, to ultrasonic or soxhlet extractions. In all cases, unaltered hydrocarbons are quantitatively recovered and white-grey flaky silicone residues no longer showed any chemical reactivity.

Numerous silicone based hydrocarbon spill- treating compositions have been prepared and used on floating hydrocarbon slicks and hydrocarbon residues lying on wet solid surfaces. To demonstrate the potential uses for the method of the present invention, a number of examples are described hereafter. These examples are provided to illustrate the present invention and should not be construed as limiting its scope.

Example 1

An inert white plastic recipient was used to simulate the contact of a floating oil slick with solid substrates such as those found on a beach front. Small rocks of various sizes and calcareous shells from different marine bivalves were placed on a rough flat surface tilted in the back and the box was filled with seawater so that all the rocks and the shells are covered with the seawater. 50 mL of (Forties) crude oil was slowly poured until about 2/3 of the water surface was covered. After a few minutes, the oil slick was treated with a silicone oil spill- treating composition by spraying around and over the slick about 20 mL of a reactive solution prepared as indicated above and containing the following reagents in 15 ml of petroleum ether:

- Polyoxyethylene (2) stearyl ether: 2 mmoles (0.72 g);

- Trichlorosilane: 2.2 mmoles (031 g); &

- Octadodecyltrichlorosilane: 10 mmoles (3.83 g);

- Trimethoxysilane: 10 mmoles (1.23 g); and

- Silicone fluid: 0.10 g.

5 A strong herding effect was observed at the moment of the contact of the solution with the surface of the water, that is, the composition reduced the size of the slick by at least three times its original dimension. Within one minute after the application of the treating composition around and over the slick, a white coating was formed. A vigorous stirring of the treated slick with a small paddle

10 showed that no more oil was free to spread over the water surface. No residue was visible beneath the surface of the water. Seawater was slowly drained and oil residues/silicone stuck to the rough surface and covered rocks and bivalve shells. Using a simple plant sprayer filled with seawater, it was easy to remove and wash out all oil residues/silicone from rocks and shell surfaces leaving no apparent traces

15 of oil and oil residues/silicone. The usual strong adherence of crude oil to solid surface was eliminated by the action of the silicone oil spill-treating composition which entrapped oil molecules into its polymeric network and modified completely the solid wetting and adherence properties of the oil. Using a water jet sprayer, residues were quantitatively returned to the surface of seawater lying in the bottom

20 of the recipient and residues were easily collected using a small square net.

As a comparative example, crude oil was spilled in similar conditions on rocks and shells without any treatment of the slick. It was impossible to remove all the oil from solid substrates with the plant sprayer. In fact, only about 50 % of 25 the oil originally spilled was recovered.

Example 2

In order to assess the anti-adhering properties of silicone oil treating composition on sand, a round container was filled with fine beach sand and placed 30 in a plastic recipient. The recipient was filled with seawater in order to wet the sand and cover its surface. Before any oil addition, the water surface just above the sand was sprayed with about 20 mL of the silicone oil-treating composition prepared in example 1. After the formation of the white coating on the water surface, water was drained slowly and the polymer film was allowed to stick to the sand surface. About 5 mL of crude oil was slowly poured over the white film. After about 5 minutes, tne recipient was filled again with seawater. When the water level reached the sand surface level, the white film and the incorporated crude oil was lifted from the sand surface and began to float on the water surface. The sand below the silicone film was completely protected from the oil leaving no apparent traces of oil and oil residues/silicone. The protective effect of silicone oil spill-treating composition is remarkable, and this simple experiment shows that it is possible to use the invention as a chemical barrier in front of or around a drifting oil slick. The silicone film will reach first the solid substrate and coat it, and the adherence of the untreated oil coming later will be reduced by the inclusion properties of the silicone film.

Example 3

In order to assess the containment effect of the spill-treating agent of the present invention, about 10 mL of hydraulic fluid (viscosity = 77 cps) is poured on the top of a flat concrete surface dried and tilted at an angle of about 5 to 10° in a plastic container. The oil slowly glided towards the bottom of the container. About 2 mL of the composition prepared in Example 1, but activated with a higher proportion of trichlorosilane, is then applied on the slick and on the front of the slick to form a chemical barrier. The oil slick was rapidly stopped on the middle of the concrete surface, as a result of the reaction of the composition with the humidity present in the air. After the recovery of the oil spill, the experiment was repeated without treating the oil, which ultimately made it through the bottom of the plastic container.

This simple experiment illustrates the potential of the composition of the present invention, since the sole humidity of air was sufficient to activate the polymerisation reaction necessary to form the desired protective film around the oil spilled. c

Example 4

To illustrate the ability of the composition of the present invention to clear oil from water surface and contribute to a rapid cleaning, a thin oil sheen was formed over the surface of a large cylindrical jar filled with seawater, by

5 contacting the water surface with light crude oil. The oil-treating agent used has the following composition dissolved in 15 mL of n-pentane:

- dodecyl alcohol: 2 mmoles;

- trichlorosilane: 2 mmoles;

- octadecyltrichlorosilane: 10 mmoles; 10 - trimethoxysilane: 10 mmoles; and

- silicone fluid: 0.1 g.

After spreading the oil over the water surface, one drop of the composition is placed in the center of the oiled surface. The repulsion effect is

15 instantaneous and the oil is herded along the wall of the jar. Such an effect can also be obverse using compounds exhibiting some surface-active properties. However, in the present example, the oil was permanently cleared from the surface because a tiny white layer of reacted silicon was formed and contributed to avoid any return of the oil on the water surface. This semi-solid protective layer was found very

20 resistant to environmental factors such as the wave actions. Only a vigorous and prolonged mechanical stirring can partly destroy it. Many oil drops applied at the center of the treated surface were trapped by the silicon film and did not spread over the surface of water.

25 Among expected applications for this particular formulation using a non-toxic alcohol and carboxylic acid as a basic component is the quick removal of an oil sheen over the surface of water reservoirs and wells used for community water supplies or irrigation, and also in marinas or recreational aquatic areas.

30 Example 5

An experiment similar to that described in Example 4 was realized except that the treating composition was replaced with the following composition dissolved in 15 ml of petroleum ether: c-

- stearic acid: 2 mmoles (0.56 g)

- trichiorosilane: 4 mmoles (0.56);

- trimethoxysilane: 10 mmoles (1.23 g); and

- silicon fluid: 0.1 g.

5 The results obtained were comparable to those described in Example 4.

While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses or adaptations of the 10 invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains, and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A method for recovering hydrocarbon spilled on a watery environment, which comprises - contacting the hydrocarbon slick with an effective amount of a composition comprising the reacted products of at least one hydrolysable silane derivative reacted with a polyoxyethylenic surfactant, an aliphatic carboxylic acid, an aliphatic alcohol or mixtures thereof, to form an anti-adhesive polysiloxane matrix, whereby the hydrocarbon is confined in the matrix; - collecting the resulting matrix and treating it to separate the hydrocarbon from the matrix.

2. A method according to claim 1, wherein the silane derivative is of formula X₃SiR wherein X is halogen or a lower alkoxy group, and R is C^ alkyl or a hydrogen atom.

3. A method according to claim 1 wherein the polyoxyethylenic surfactant is of the general formula:

CH₃-(CH₂)_n(C₂H₅O)_m-H wherein n = 11-17 and m = 2-21; the aliphatic carboxylic acid is of general formula:

CH₃(CH2)_pCOOH wherein p = 11-17; and the aliphatic alcohol of general formula: CH₃(CH₂)_qCH₂OH wherein q is 11-17.

4. A method according to claim 1, wherein the watery environment is water or a damp surface.

5. A method according to claim 1, wherein the collecting is realized by mechanical means or netting.

6. A method according to claim 1, wherein the hydrocarbon is crude oil, oil processing products and oil residues.

7. A method according to claim 1, wherein the hydrocarbon is recovered by placing the matrix containing the hydrocarbon confined therein in a hydrocarbon-dissolving solvent, the resulting suspension being treated to separate the polysiloxane matrix from the oil.

8. A method according to claim 1, wherein a polydialkylsiloxane fluid is incorporated in the composition before it is applied on the hydrocarbon slick.

9. A method for protecting a damp surface against hydrocarbon spills, which comprises contacting the surface with a composition comprising the reaction products of at least one hydrolysable silane derivative reacted with a polyoxyethylenic surfactant, an aliphatic carboxylic acid, an aliphatic alcohol or mixtures thereof, to form an anti-adhesive polysiloxane matrix to prevent the adherence of the hydrocarbon on the surface and facilitate the recuperation of the hydrocarbon.

10. A method according to claim 9, wherein the silane derivative is of formula X₃SiR wherein X is halogen or a lower alkoxy group, and R is C^ alkyl or a hydrogen atom.

11. A method according to claim 9 wherein the polyoxyethylenic surfactant is of the general formula:

(^-(CH^C^O^-H wherein n = 11-17 and m = 2-21; the aliphatic carboxylic acid is of general formula:

CH₃(CH2)_pCOOH wherein p = 11-17; and the aliphatic alcohol of general formula:

wherein q is 11-17.

12. A method according to claim 9, wherein the hydrocarbon is crude oil, oil processing products and oil residues.

13. A composition for recovering hydrocarbon spilled on a watery environment, or for protecting a damp surface against hydrocarbon spills, which comprises the reaction products of at least one hydrolysable silane derivative reacted with a polyoxyethylenic surfactant, an aliphatic carboxylic acid, an aliphatic alcohol or mixtures thereof.

14. A composition according to claim 13, wherein the silane derivative is of formula X₃SiR wherein X is halogen or a lower alkoxy group, and R is C_j.₂₀ alkyl or a hydrogen atom.

15. A composition according to claim 13 wherein the polyoxyethylenic surfactant is of the general formula:

wherein n = 11-17 and m = 2-21; the aliphatic carboxylic acid is of general formula:

CH₃(CH₂)_pCOOH wherein p = 11-17; and the aliphatic alcohol of general formula:

CH₃(CH₂)_qCH₂OH wherein q is 11-17.

16. A composition according to claim 13 further comprising a polydialkylsiloxane fluid.