Patent Description:
The present invention relates to a method of demulsification of water-in-oil emulsions, particularly of water-in-oil emulsions caused by mixing of wash water and crude oil, more particularly of water-in-oil emulsions caused by mixing of wash water and crude oil in the desalter unit of the refinery by employing the demulsification additive composition according to claim <NUM>.

The water-in-oil emulsions are formed in various industrial operations, and are responsible for substantial loss of various industrial ingredients including difficulties in separation of oil. Therefore, breaking of water-in-oil emulsions during the processing of oil is the requirement of the industry, particularly of the crude oil refinery industry wherein the wash water gets mixed with crude oil in the desalter unit of the refinery and forms water-in-oil emulsion.

Presently, the water-in-oil emulsion caused by mixing of wash water and crude oil is broken by addition of demulsifier to the wash water.

Several demulsification compositions have been disclosed so far such as those from <CIT>, <CIT>, <CIT> or <CIT>.

The main problem of using the demulsifiers is that these are to be used in higher amounts and required continuously through the processing of crude oil, which results in substantial increase in cost of processing of crude oil.

Another problem of using the demulsifiers is that these are expensive, which also results in substantial increase in cost of processing of crude oil.

More importantly, the presently used demulsifiers are condensation product of nonyl phenols, and presently, there is a need to reduce consumption of nonyl phenols in view of their cost and environmental adverse effects.

Therefore, there is a need to reduce, if total elimination is not possible, the requirement of demulsifiers so that above-discussed problems of use of demulsifiers may, at least, be minimized without loss of or sacrificing the industrial output of the crude oil processing units.

Therefore, the present invention aims at providing a solution to above-described existing industrial problems by providing a method for demulsification of water-in-oil emulsions by employing the demulsification additive composition according to claim <NUM>.

Accordingly, the object of the present invention is to provide
ii) a method of demulsification of water-in-oil emulsions, particularly of water-in-oil emulsions caused by mixing of wash water and crude oil, more particularly of water-in-oil emulsions caused by mixing of wash water and crude oil in the desalter unit of the refinery by employing the demulsification additive composition of the present invention.

Accordingly, another object is to provide:
iii) a method of using the demulsification additive composition of the present invention for demulsification of water-in-oil emulsions, particularly of water-in-oil emulsions caused by mixing of wash water and crude oil, more particularly of water-in-oil emulsions caused by mixing of wash water and crude oil in the desalter unit of the refinery.

Accordingly, an object is to provide a demulsification additive composition for demulsification of water-in-oil emulsions, which is preferably caused by mixing of wash water and crude oil, more preferably for demulsification of the water-in-oil emulsions caused by mixing of wash water and crude oil in the desalter unit of the refinery so as to reduce the amount of the presently used demulsifiers, which are condensation product of nonyl phenols, and hence, to reduce consumption of nonyl phenols or condensation product of nonyl phenols, and thereby to reduce cost of processing and associated environmental adverse effects.

Other objects and advantages of present invention will become more apparent from the following description when read in conjunction with examples, which are not intended to limit scope of present invention.

With aim to overcome above-described industrial problems of the prior art and to achieve above-described objects of the present invention, the inventor has found that a composition according to claim <NUM>
surprisingly and unexpectedly, substantially improves demulsification efficiency of the demulsifier (the component (a)), and thereby, results in substantial reduction of requirement of amount of the demulsifier, which results in substantial decrease in cost of processing of crude oil, and associated environmental adverse effects.

The inventor has also found that the composition comprising a combination of the component (a), the component (b), and the component (c), surprisingly and unexpectedly, also substantially improves demulsification efficiency:.

Further, as the glyoxal and neutralized glyoxal are less expensive than the demulsifiers, it further results in substantial decrease in cost of processing of the crude oil.

The inventor has further found that the composition comprising a combination of the component (a) and the component (b), or comprising a combination of the component (a) and the component (b), and the component (c), wherein
the component (b) comprises one or more of the following:.

Therefore, the present composition does not comprise one or more of the following:.

In accordance with the present invention, the neutralized glyoxal is glyoxal having pH neutral to basic. The inventor has observed that the glyoxal is very acidic, and therefore, it may cause corrosion. Accordingly, neutralizing the glyoxal till its pH is neutral to basic avoids corrosion of crude oil processing unit, and still improves demulsification efficiency of the demulsifier.

In accordance with the present invention, the neutralized glyoxal is obtained by neutralizing the glyoxal with an amine or alkaline medium.

As per the present invention, the amine may include (or comprises) triethanol amine (TEA).

As per the present invention, the alkaline medium may include (or comprises) sodium hydroxide aqueous solution.

In accordance with the present invention, the neutralized glyoxal may also include (or comprise) neutralized derivative of glyoxal. Therefore, in the present invention, the term "neutralized glyoxal" or the term "neutralized derivative of glyoxal" have one and same meaning unless otherwise explicitly described.

In accordance with the present invention, the pH neutral to basic includes a pH varying from about <NUM> to about <NUM>.

In accordance with the present invention, the glyoxal derivative may comprise (or include) methanol, ethanol, butanol, or ethylene glycol derivative of glyoxal, or a mixture thereof.

In accordance with one of the preferred embodiments of the present invention, the demulsifier is selected from the group comprising oxyalkylated condensation product of:.

In accordance with another preferred embodiment of the present invention, the demulsifier is selected from the group comprising oxyalkylated condensation product of:.

In accordance with one of the preferred embodiments of the present invention, the demulsifier is selected from the group comprising:.

In accordance with one of the preferred embodiments of the present invention, the demulsifier may be selected from a group comprising:.

In accordance with one of the preferred embodiments of the present invention, the oxyalkylated product is an ethylene oxide derivative, propylene oxide derivative, butylene oxide derivative or a mixture thereof. In accordance with one of the preferred embodiments of the present invention, the oxyalkylated product is an oxyalkylated copolymer or an oxyalkylated polymer or an oxyalkylated resin. In accordance with one of the preferred embodiments of the present invention, the oxyalkylated product is a base catalyzed oxyalkylated copolymer or a base catalyzed oxyalkylated polymer or a base catalyzed oxyalkylated resin of one or more of the said phenolic compound (i.e. cardanol, nonyl phenol, butyl phenol, amyl phenol, alkyl phenol) and formaldehyde. In accordance with one of the preferred embodiments of the present invention, the oxyalkylated product is the oxyalkylated phenol formaldehyde resin, oxyalkylated phenol formaldehyde polymer, or oxyalkylated phenol formaldehyde copolymer.

In accordance with one of the embodiments of the present invention, the phenolic reactants includes alkyl phenols comprising alkyl group. In accordance with one of the embodiments of the present invention, the alkyl group comprises from about <NUM> to about <NUM> carbon atoms. In accordance with one of the embodiments of the present invention, the substitution may be of butyl, amyl, nonyl, hexyl, octyl, isooctyl, decyl, or dodecyl group.

It may be noted that term "copolymer" means a polymer made from two different phenols and the term "polymer" means a polymer made from one phenol, and resin is intended to include the polymers and copolymers.

In accordance with the one of the embodiments of the present invention, the reaction of alkyl phenol formaldehyde resin with alkylene oxide forms a high molecular weight oxyalkylated alkyl phenol formaldehyde resin.

In accordance with the one of the embodiments of the present invention, the alkylene oxide comprises ethylene oxide, propylene oxide, butylene oxide or a mixture thereof, preferably the alkylene oxide comprises ethylene oxide, propylene oxide, or a mixture thereof.

In accordance with the one of the preferred embodiments of the present invention, the molecular weight of the demulsifier may vary from about <NUM> to about <NUM> daltons, preferably from about <NUM> to about <NUM> daltons, more preferably from about <NUM> to about <NUM> daltons as measured by Gel Permeation Chromatography (GPC) using the tetrahydro furan (THF) as solvent.

In accordance with the one of the embodiments of the present invention, the average molecular weight of the demulsifier may vary from about <NUM> to about <NUM> daltons, preferably from about <NUM> to about <NUM> daltons, more preferably from about <NUM> to about <NUM> daltons as measured by Gel Permeation Chromatography (GPC) using the tetrahydro furan (THF) as solvent.

In accordance with the present invention, the composition comprises:.

depending upon the nature of the water-in-oil emulsion to be treated.

It may be noted that as per present invention, the additive composition may be added to the crude oil phase or to the desalter wherein wash water is mixed with crude oil and forms a water-in-oil emulsion.

It may also be noted that the scope of the present invention is not limited by the crude oil or the wash water.

The present invention relates to a method of demulsification of water-in-oil emulsions, particularly of water-in-oil emulsions formed by mixing of wash water and crude oil, more particularly of water-in-oil emulsions formed by mixing of wash water and crude oil in the desalter unit of the refinery, wherein the water-in-oil emulsion formed due to mixing of wash water in the crude oil is treated with the presently provided demulsification additive composition.

The present invention is now described with the help of following examples, which are not intended to limit scope of the present invention, but have been incorporated for the sake of illustrating the advantages of the present invention over the prior art.

The following examples were carried out under the following conditions:
PED No <NUM>.

In the following examples, the following compositions have been tested for their demulsification efficiency.

In above Table - I, dosage '<NUM>+<NUM>' indicates that the additive comprises <NUM> ppm of Component (a) and <NUM> ppm of Comparative component (b1), and so on.

However, in above Table - I, the 'Present Composition' comprises <NUM> ppm of Component (a) and <NUM> ppm of [Component (b) + Component (c)], wherein the [Component (b) + Component (c)] comprises the Component (b) which is glyoxal (<NUM>%) and the Component (c) which is H<NUM>PO<NUM> (<NUM>%) in DM (demineralized water) water in a weight ratio of <NUM>/<NUM>/<NUM>.

As can be observed from above Table I, the composition of the present invention demonstrates <NUM>% efficiency as against <NUM>% or <NUM>% efficiency of the comparative compositions.

In above Table - II, dosage '<NUM>+<NUM>' indicates that the additive comprise <NUM> ppm of Component (a) and <NUM> ppm of second component, i.e. Comparative component (b1), Comparative composition (B), Comparative component (b2), Comparative composition (C), Comparative component (b3), Comparative composition (D), Comparative component (b4), Comparative composition (E).

In above Tables I and II, the various components have following composition:.

As can be observed from above Table II, all of the comparative compositions only demonstrate <NUM>% or <NUM>% efficiency.

In Table III, the mixing time was <NUM> and mixing temperature was <NUM>, and the component (b) is <NUM> ppm of glyoxal (<NUM>%) in DM water, and the <NUM> ppm of component (c) comprises <NUM> ppm of glyoxal (<NUM>%) and <NUM> ppm of H<NUM>PO<NUM> (<NUM>%) in DM [i.e. <NUM>% by weight of glyoxal (<NUM>%) and <NUM>% by weight of H3PO4 (<NUM>%) in DM]; and the component (a) is <NUM>% active ethoxylated nonyl phenol cardanol formaldehyde resin, which is ethoxylated condensation product of <NUM>% by weight of nonyl phenol and <NUM>% by weight of cardanol.

As can be observed from above Table III, the composition of the present invention demonstrates <NUM>% efficiency as against <NUM>% or <NUM>% efficiency of the comparative compositions.

In Table IV, the mixing time was again <NUM> and mixing temperature was again <NUM><NUM>C, and the component (b) is <NUM> ppm of glyoxal (<NUM>%) in DM water, and the <NUM> ppm of component (c) comprises <NUM> ppm of glyoxal (<NUM>%) and <NUM> ppm of H<NUM>PO<NUM> (<NUM>%) in DM [i.e. <NUM>% by weight of glyoxal (<NUM>%) and <NUM>% by weight of H3PO4 (<NUM>%) in DM]; and the component (a) is <NUM>% active ethoxylated nonyl phenol para tertiary amyl phenol formaldehyde resin, which is ethoxylated condensation product of <NUM>% by weight of nonyl phenol and <NUM>% by weight of para tertiary amyl phenol.

As can be observed from above Table IV, the composition of the present invention demonstrates <NUM>% efficiency as against <NUM>% or <NUM>% efficiency of the comparative compositions.

In Table V, the mixing time was again <NUM> and mixing temperature was again <NUM><NUM>C, and the component (b) is <NUM> ppm of glyoxal (<NUM>%) in DM water, and the <NUM> ppm of component (c) comprises <NUM> ppm of glyoxal (<NUM>%) and <NUM> ppm of H<NUM>PO<NUM> (<NUM>%) in DM [i.e. <NUM>% by weight of glyoxal (<NUM>%) and <NUM>% by weight of H3PO4 (<NUM>%) in DM]; and the component (a) is <NUM>% active ethoxylated nonyl phenol para tertiary butyl phenol formaldehyde resin, which is ethoxylated condensation product of <NUM>% by weight of nonyl phenol and <NUM>% by weight of para tertiary butyl phenol.

In the foregoing examples, the present additive composition and the prior art or comparative additive composition was added to the water-in-oil emulsion of water and crude oil formed after mixing of water and crude oil.

The above experimental results confirm the above-discussed surprising and unexpected technical advantages of the present invention. Particularly these experiments confirm that the present additive composition comprising the Component (a), the Component (b) of the present invention and the Component (c) of the present invention demonstrates surprising and unexpected technical advantages.

Claim 1:
A method of demulsification of water-in-oil emulsions comprising a step of treating the water-in-oil emulsion with a demulsification additive composition, wherein the demulsification additive composition comprises:
(a) at least one demulsifier (the component (a)) comprising oxyalkylated alkyl phenol formaldehyde polymer, or a co-polymer, or an oxyalkylated condensation product of at least one alkyl phenol and formaldehyde; and
(b) a compound comprising glyoxal, neutralized glyoxal, ethylene glycol derivative of glyoxal, or a mixture thereof (the component (b)); and
(c) a phosphoric acid (the component (c)).