EP0549918A1 - Demulsifier based on an alkoxylate and process for the preparation of the alkoxylate - Google Patents

Abstract

Petroleum de-emulsifier based on an alkoxylate having a polydispersity of at least 1.7, and a process for preparing the alkoxylates, using a metal alcoholate as catalyst.

Description

The present invention relates to petroleum emulsion breakers containing an alkoxylate of an alkylphenol-formaldehyde resin, an alcohol, a bisphenol or an amine and a process for the preparation of the alkoxylates using a special catalyst.

When crude oils are extracted, an increasing proportion of water is also extracted with increasing exploitation of the deposits. Surface-active substances contained in the crude oils emulsify most of the water, forming stable water-in-oil emulsions. The emulsified water can make up 0.1 to over 50% by weight of the total emulsion. Salts can be dissolved in the emulsion water, which lead to corrosion problems when the crude oil is further processed in the refinery. The emulsion water must therefore be separated off before transport or reduced to an acceptable concentration. This is usually done by adding so-called petroleum emulsion splitters, whereby heating the crude oil facilitates and accelerates the separation.

The crude oils differ greatly in their composition depending on their provenance. The natural emulsifiers contained in the crude oils also have a complicated chemical structure, so that in order to overcome their effects, oil demulsifiers (demulsifiers) have to be selectively developed. By opening up new crude oil fields and changing production conditions in older fields, new demulsifiers are constantly needed, which cause faster separation into water and oil and the lowest possible residual water and residual salt quantities.

The most frequently used demulsifiers are ethylene oxide / propylene oxide block copolymers, alkoxylated alkylphenyl-formaldehyde resins, as described, for example, in DE-PS 27 19 978, alkoxylated polyamines (see, for example, US 3 907 701 and DE-OS 24 35 713) and Crosslinking products of the above basic classes with multifunctional reagents, such as diisocyanates, dicarboxylic acids, bisglycidyl ethers, di- and trimethylolphenols.

However, the known petroleum emulsion splitters often do not quite meet the requirements, since the separation of the emulsion into specification-compliant oil and water with the lowest possible residual oil content either takes too long a time or requires excessive dosages of the splitter.

The object of the present invention was therefore to provide petroleum emulsion splitters which allow the emulsion to be separated as quantitatively as possible into oil and water in the shortest possible time, i.e. which show good effectiveness even in low doses.

Since the exploitation of the crude oil fields as far as possible and the complete separation of the residual oil from the water are becoming increasingly important for economic and ecological reasons, the solution to this task is of additional importance.

in der A für einen Ethylen-, Propylen- und/oder Butylen-Rest steht und n = 3-100 ist und in der R für den Rest

• eines Alkylphenol-Formaldehyd-Harzes der Formel II
  
  worin R¹ ein verzweigtkettiger C₃-C₁₈-Alkylrest und y = 3 bis 30 ist;
• eines Alkohols der Formel III
  
  worin R² entweder ein C₁-C₂₀-Alkylrest mit x = 1 und z = 0 ist,
  oder R² ein C₂-C₁₀-Alkylenrest mit x = 2 und z = 0 oder mit x = 1, z = 1 und R³ = C₁-C₆-Alkyl- oder C₁-C₂₀-Acylrest ist,
  oder R² ein C₆-C₁₀-Arylrest ist, der mit bis zu 2 C₃-C₁₈-Alkylresten substituiert sein kann, wobei x = 1 und z = 0 ist;
• eines Amins der Formel IV
  
  
  
          R⁴-NH₂    IV
  
  
  
  worin R⁴ ein linearer oder verzweigter C₁-C₆-Alkyl- oder C₁-C₁₀-Hydroxyalkyl-Rest ist oder einem Rest der folgenden Formel V entspricht
  
  mit R⁵ = H oder C₁-C₃-Alkyl, m = 2 bis 4, r = 2 bis 10 und q = 0 bis 5,
• eines Bisphenols der Formel VI
  
  worin k = 0 bis 3 sowie R⁶ und R⁷ unabhängig voneinander H und C₁-C₃-Alkyl sein kann; oder
• eines Polyethylenimins mit dem Molekulargewicht M_w von 2000 bis 50 000

steht;
wobei die

Reste jeweils anstelle der am Sauerstoff oder Stickstoff stehenden Wasserstoffe der Alkylphenol-Formaldehyd-Harze, der Alkohole, Bisphenole, Amine oder Polyethylenimine stehen und p der Anzahl der zu alkoxilierenden Wasserstoffe entspricht, dadurch gekennzeichnet, daß das Alkoxilat der Formel I eine Polydispersität Q = $\overline{\text{M}}$

_w/ $\overline{\text{M}}$

_n von mindestens 1,7 aufweist.It has now been found that this object can be achieved using petroleum emulsion splitters based on an alkoxylate of the general formula I

in which A represents an ethylene, propylene and / or butylene radical and n = 3-100 and in R represents the rest

• an alkylphenol-formaldehyde resin of the formula II
  
  wherein R¹ is a branched chain C₃-C₁₈ alkyl group and y = 3 to 30;
• an alcohol of formula III
  
  wherein R² is either a C₁-C₂₀ alkyl group with x = 1 and z = 0,
  or R² is a C₂-C₁₀ alkylene radical with x = 2 and z = 0 or with x = 1, z = 1 and R³ = C₁-C₆-alkyl or C₁-C₂₀-acyl radical,
  or R² is a C₆-C₁₀ aryl radical which can be substituted with up to 2 C₃-C₁₈ alkyl radicals, where x = 1 and z = 0;
• an amine of formula IV
  
  
  
  R⁴-NH₂ IV
  
  
  
  wherein R⁴ is a linear or branched C₁-C₆-alkyl or C₁-C₁ Hydrox-hydroxyalkyl radical or corresponds to a radical of the following formula V.
  
  with R⁵ = H or C₁-C₃-alkyl, m = 2 to 4, r = 2 to 10 and q = 0 to 5,
• a bisphenol of formula VI
  
  wherein k = 0 to 3 and R⁶ and R⁷ can independently be H and C₁-C₃-alkyl; or
• a polyethyleneimine with a molecular weight M _w of 2000 to 50,000

stands;
being the

In each case, radicals are substituted for the hydrogens of the alkylphenol-formaldehyde resins, the alcohols, bisphenols, amines or polyethyleneimines and p corresponds to the number of hydrogens to be alkoxylated, characterized in that the alkoxylate of the formula I has a polydispersity Q = $\overline{\text{M}}$

_w / $\overline{\text{M}}$

_n of at least 1.7.

It is essential for the desired properties of the petroleum emulsion splitters according to the invention that the alkoxylate shows the stated polydispersity. This polydispersity is achieved by producing the alkoxylate using a special catalyst.

_w von 2000 bis 50 000 mit Ethylenoxid, Propylenoxid und/oder Butylenoxid umsetzt in Gegenwart eines, gegebenenfalls teilhydrolisierten, Metall-Alkoholats als Katalysator, wobei das Metall aus den Metallen der Gruppen IIA, IIIA, IVB, sowie Zn, Ce und La ausgewählt ist und die Alkoholat-Gruppe 1 bis 8 C-Atome aufweist.The present invention therefore also relates to a process for the preparation of alkoxylates of the above general formula I, which is characterized in that alkylphenol-formaldehyde resins of the above formula II, bisphenols of the above formula VI, alcohols of the above formula III , Amines of formula IV given above or polyethyleneimines with a molecular weight $\overline{\text{M}}$

_w reacted from 2000 to 50,000 with ethylene oxide, propylene oxide and / or butylene oxide in the presence of an optionally partially hydrolyzed metal alcoholate as a catalyst, the metal being selected from the metals from Groups IIA, IIIA, IVB, and Zn, Ce and La and the alcoholate group has 1 to 8 carbon atoms.

In the petroleum emulsion splitters based on alkoxylated compounds known from the prior art, hydroxides of the alkali metals are used as catalysts for the alkoxylation (see e.g. DE-PS 20 13 820, column 5, AII). With these catalysts, as was found in comparative experiments, only polydispersities up to 1.6 are achieved.

It has now surprisingly been found that the crude oil emulsions according to the invention achieve a significantly faster splitting of the crude oil emulsions, and the splitters according to the invention can be dosed correspondingly lower.

_w/ $\overline{\text{M}}$

_n ist bekanntlich ein Maß für die Molekulargewichtsverteilung von polymeren Verbindungen (siehe z.B. Encyclopedia of Polymer Sci. and Engineering, Vol. 10, S. 4, J. Wiley 1987). Je größer der Wert von Q, desto breiter die Molekulargewichtsverteilung. Für die erfindungsgemäß hergestellten Alkoxilate heißt dies, daß sie eine breitere Molekulargewichtsverteilung zeigen als die bekannten, mit Alkalihydroxid als Katalysator hergestellten Verbindungen.The polydispersity Q = $\overline{\text{M}}$

_w / $\overline{\text{M}}$

_As is known, _n is a measure of the molecular weight distribution of polymeric compounds (see, for example, Encyclopedia of Polymer Sci. and Engineering, Vol. 10, p. 4, J. Wiley 1987). The larger the value of Q, the wider the molecular weight distribution. For the alkoxylates prepared according to the invention, this means that they have a broader molecular weight distribution than the known compounds prepared with alkali metal hydroxide as a catalyst.

For the alkylphenol-formaldehyde resins, this can also be expressed by the hydroxyl number: while the known alkoxylates have hydroxyl numbers from 130 to 170, the alkoxylates prepared according to the invention have hydroxyl numbers above 170, preferably between 180 and 300.

_w von 2000 bis 50 000, insbesondere von 5000 bis 25 000 eingesetzt.The starting compounds for the preparation of the alkoxylates are alkylphenol-formaldehyde resins of the formula II, alcohols of the formula III, amines of the formula IV, bisphenols of the formula VI or polyethyleneimines with a molecular weight $\overline{\text{M}}$

_w from 2,000 to 50,000, in particular from 5,000 to 25,000.

Alkylphenol-formaldehyde resins, alcohols and polyethyleneimines are preferred.

As alkylphenol-formaldehyde resins which can be prepared by known processes, in particular those are used which carry an iso-C₄-C₁₂ alkyl radical and in which y = 5 to 11. An iso-C₈-C₁₂ alkyl radical is particularly preferred.

In particular, diols such as e.g. Ethylene glycol, diethylene glycol or butylene glycol, or glycol monoesters such as e.g. Ethylene glycol monoacetate used.

The amines to be used include, in particular, the polyalkylene polyamines, such as Diethylene triamine, triethylene tetramine or tetraethylene pentamine. Alkanolamines are also suitable.

The polyethyleneimines are preferably branched and contain primary, secondary and tertiary amine groups.

Bisphenol A should be mentioned in particular as bisphenol.

All of these compounds are known per se and have been described many times in the literature.

The alkoxylation of the alkylphenol-formaldehyde resins, the alcohols, bisphenols, amines and polyethyleneimines takes place with ethylene oxide, propylene oxide and / or butylene oxide. Ethylene oxide and / or propylene oxide are preferably used.

The reaction is carried out in an inert solvent such as e.g. Toluene or xylene, usually at 100 to 180 ° C. The required moles of alkylene oxide are introduced per unit to be alkoxylated or OH or H₂N group, so that n = 3-100, preferably 3 -50, particularly preferably 4-12. In the case of the amines, there is a two-stage reaction, as is e.g. is described in DE-OS 24 35 713, advantageous. The amount of starting compound and alkylene oxide in relation to the solvent is e.g. chosen so that an 80 wt .-% solution results.

The metal alcoholates according to the invention, which can be represented by the following formula VII, are used as catalysts:



Me (OH) _d (OR) _e VII



in which Me stands for metals of group IIA, in particular Mg, Ca and Ba, of group IIIA, in particular Al, of group IVB, in particular Ti (group name corresponding to CAS up to 1986), and Zn, Ce or La, d = 0 and the upper limits of d and e depend on the valence of the metal. Aluminum tri or titanium tetra alcoholates are preferably used, in particular aluminum tri (isopropylate).

The metal alcoholates can also be used in conjunction with Zn-alkylene and small amounts of H₂O in hexane (see US 3,384,603).

The amount of the catalyst used, based on the end products, is 0.05 to 5% by weight.

The starting compounds can also be used in a conventional manner, i.e. catalyzed with alkali metal hydroxides, prepared, partially oxyalkylated compounds are used. It is only essential that the required polydispersity is obtained by subsequent alkoxylation using the above-mentioned metal alcoholates according to the invention.

The polydispersity Q must be at least 1.7 in order to achieve the desired effect. Q is preferably 1.7-5, particularly preferably 1.8 to 3.0, in particular 1.8 to 2.8. It can be observed that the differences in the Q values between alkoxylates prepared with conventional catalysts and alkoxylates prepared with the catalysts to be used according to the invention are different, depending on which compound RH one starts from. However, the difference between these Q values, based on the same starting compound RH, should be 0.3 or more.

_w- und $\overline{\text{M}}$

_n-Werte wurden gelpermeationschromatographisch bestimmt.The ones required to calculate Q. $\overline{\text{M}}$

_w - and $\overline{\text{M}}$

_n values were determined by gel permeation chromatography.

The conditions for the GPC analysis were as follows:
Column material: PL gel with 5 µm particle size
Column length: 300 cm, diameter 7.5 mm.

A column combination of guard column, a column with 100 Å material, 2 columns with 500 Å material and another column with 1000 Å material was used. The internal standard was toluene, the flow was 1 ml / min, the temperature 70 ° C.
Detector: RI + UV (254 nm).

The feed volume was 20 ul of a 1 wt .-% solutions, solvent THF.

_n- und $\overline{\text{M}}$

_w-Werte wurden mit Hilfe von Eichsubstanzen (Ethoxilate) mittels eines üblichen Rechenprogramms aus dem Chromatogramm ermittelt.The $\overline{\text{M}}$

_n - and $\overline{\text{M}}$

_w values were determined using calibration substances (ethoxylates) from the chromatogram using a standard computer program.

In addition to the alkoxylate A of the general formula I, the petroleum emulsion splitter according to the invention can contain, as further component B, a different alkoxylated polyalkylene polyamine which does not have the Q values according to the invention. Such additional components are known and e.g. described in more detail in DE-PS 27 19 978, for which reference is made in this patent specification in particular to column 4, B. This additional mixture component is also disclosed in DE-OS 22 27 546.

The weight ratio A to B is preferably 60:40 to 40:60% by weight.

The splitters are advantageously added to the crude oil emulsions in amounts of 1 to 1000 ppm, preferably 10 to 100 ppm, based on the weight of the emulsion to be split, at temperatures between 20 and 80 ° C.

The splitters can be used as solutions because of their better meterability. Mixtures of organic solvents (eg methanol) with water or organic solvents with boiling points between 50 and 200 ° C. can be used as solvents serve, for example toluene, xylenes, tetrahydrofuran, dioxane, lower alcohols and light petroleum fractions of the boiling point mentioned.

If solutions are used, these are expediently adjusted to an active substance content (splitter content) of 0.5 to 50% by weight. During the cleavage, the solutions are preferably added to the crude oils at the probes (in the field). The cleavage then already takes place at the temperature of the freshly pumped water-in-oil emulsion at such a rate that the emulsion can be broken on the way to the processing plant. There it is separated in a possibly heated separator and possibly with the help of an electric field without difficulty into pure oil and salt water.

Examples A) Preparation examples of alkoxylates

• 1. The starting compounds given in Table 1 were reacted with the moles of alkylene oxide also given using the respective catalyst in toluene at the given temperatures. The polydispersities Q obtained are also given in Table 1.
  
  
• 2. According to the prior art (see DE-PS 27 19 978) about 78 g (0.0191 mol) of a polyethyleneimine with a molecular weight of about 18,000 (44% solution in H₂O) about 500 g of propylene oxide ( PO) in a 2 l stirred autoclave with nitrogen at 90 to 100 ° C for 600 min at 6.5 bar. The water was then removed in vacuo. 852 g of product were obtained, ie the actual PO uptake was 1.1 mol per ethyleneimine unit in the polyethyleneimine.
  In a second stage, 667 g of propylene oxide were added to 53.4 g of product from stage 1 in the presence of 0.53 g (1% by weight) of K-tert-butoxide in the stirred autoclave at 130 to 140 ° C. for 36 hours 7.4 bar pressed. The excess propylene oxide PO was then removed. 715 g of product were obtained, ie 22.8 mol of PO per ethyleneimine unit were taken up in the polyethyleneimine.
  In a third stage, 132 g of ethylene oxide (EO) were finally injected onto 214.4 g of product from stage 2 in the presence of 2.14 g of K-tert-butoxide at 120 to 130 ° C. for 150 min at 6.8 bar and the excess EO deducted. You got 361 g of product, ie the actual uptake of EO was 21.9 mol per ethyleneimine unit in the polymer.
  The end product had a Q value of 1.4.
• 3. In the preparation of the alkoxylate according to the invention, stages 1 and 2 were first carried out as indicated under 2. and then the K-tert-butoxide was separated off.
  214.4 g of the product thus obtained were 132 g EO in the presence of 6.43 g aluminum tri-isopropylate (≙ 3 wt .-%) in a stirred autoclave with nitrogen at 120 to 130 ° C for 870 min at 9.4 pressed on bar and then removed excess EO. 365 g of product were obtained, ie the actual uptake of EO was 21.8 mol per ethyleneimine unit in the polyethyleneimine.
  This product had a Q value of 1.7.

B) Application engineering examples

According to A) 1. The alkoxylates obtained were mixed with an oxalkylated polyalkylene polyamine B, prepared according to DE-PS 27 19 978, column 4, B, in a ratio of 1: 1 and tested for their effectiveness as a petroleum emulsion breaker.

Then the amounts of the corresponding alkoxylate given in each case were added to 100 g of one of the crude oil emulsions shown in Table 2. The mixtures were each stirred in a glass flask with a mechanical stirrer at 55 ° C. for 10 minutes at a stirring speed of 500 rpm and poured into a 100 ml standing cylinder. The standing cylinder was placed in a water bath at the specified test temperature and the water separation was observed and recorded over a period of 4 hours.

In the following test, the alkoxylates were tested under conditions which are otherwise the same as those given in Table 2, without the additional component B:

The results are shown in Table 3. Table 3 No. from Tab. 2 Formation water (ml) separated from 100 g emulsion according to: Minutes Hours 10th 20th 30th 45 60 2nd 4th 16 1 0 0 3rd 5 8th 20th 25th 2nd 0 0 1 3rd 5 18th 22 3rd 0 0 4th 24th 28 35 39 4th 0 0 4th 9 15 31 33 5 0 0 1 3rd 9 17th 20th No. from Tab. 2 Formation water (ml) separated from 100 g emulsion according to: Minutes Hours 10th 20th 30th 45 60 2nd 4th 16 6 0 0 0 0 0 2nd 4th 7 0 0 2nd 7 13 21 30th 8th 0 0 0 0 4th 12th 19th 9 0 1 2nd 8th 15 17th 23 10th 0 0 0 2nd 2nd 9 15 11 0 0 2nd 8th 12th 17th 19th 12th 0 0 0 4th 7 10th 13 13 0 0 0 0 3rd 10th 16 24th 14 0 0 0 0 0 1 3rd 7

The even numbered examples are the comparative examples
The results show that the petroleum emulsion splitters according to the invention result in significant improvements in the splitting speed with a large number of different crude oil emulsions.

Claims (8)

Petroleum emulsion splitter based on an alkoxylate of the general formula I

in which A represents an ethylene, propylene and / or butylene radical and n = 3-100 and
in the row for the rest - An alkylphenol-formaldehyde resin of the formula II

wherein R¹ is a branched chain C₃-C₁₈ alkyl group and y = 3 to 30; - An alcohol of formula III

wherein R² is either a C₁-C₂₀ alkyl group with x = 1 and z = 0, or R² is a C₂-C₂₀ alkylene group with x = 2 and z = 0 or with x = 1, z = 1 and R³ = C₁-C₆- Is alkyl or C₁-C₂₀ acyl or R² is a C₆-C₁₀ aryl which may be substituted with up to 2 C₃-C₁₈ alkyl, where x = 1 and z = 0; an amine of the formula IV



R⁴-NH₂ IV



wherein R⁴ is a linear or branched C₁-C₆-alkyl or C₁-C₁ Hydrox-hydroxyalkyl radical or corresponds to a radical of the following formula V.

with R⁵ = H or C₁-C₃-alkyl, m = 2 to 4, r = 2 to 10 and q = 0 to 5; - a bisphenol of the formula VI

wherein k = 0 to 3 and R⁶ and R⁷ can independently be H and C₁-C₃-alkyl; or - A polyethyleneimine with the molecular weight $\overline{\text{M}}$

_w from 2000 to 50,000 stands;
being the

In each case, radicals are substituted for the hydrogens of the alkylphenol-formaldehyde resins, the alcohols, bisphenols, amines or polyethyleneimines and p corresponds to the number of hydrogens to be alkoxylated, characterized in that the alkoxylate of the formula I has a polydispersity Q = $\overline{\text{M}}$

_w / $\overline{\text{M}}$

_n of at least 1.7. Petroleum emulsion splitter according to Claim 1, characterized in that R represents the residue of an alkylphenol-formaldehyde resin of the formula II, in which R¹ is an iso-C₄-C₁₂ alkyl residue and y = 5 to 11, and / or n = 3 to 50 , is preferably 4 to 12. Petroleum emulsion splitter according to Claim 1, characterized in that R represents an alcohol of the formula III in which x = 2 and z = 0 or x = 1, z = 1 and R³ is a C₁-C₃ acyl radical. Petroleum emulsion splitter according to claim 1, characterized in that Q = 1.7 to 5.0, preferably 1.8 to 3.0. Petroleum emulsion splitter according to Claim 1, characterized in that it contains, in addition to the alkoxylate of the formula I, a different alkoxylated polyalkylene polyamine. Petroleum emulsion splitter according to claim 1, characterized in that A stands for an ethylene and / or propylene radical. A process for the preparation of alkoxylates of the general formula I according to claim 1, characterized in that alkylphenol-formaldehyde resins of the formula II according to claim 1, bisphenols of the formula VI according to claim 1, alcohols of the formula III according to claim 1, amines of the formula IV according to claim 1 or polyethyleneimines with a molecular weight $\overline{\text{M}}$

_w reacted from 2000 to 50,000 with ethylene oxide, propylene oxide and / or butylene oxide in the presence of an optionally partially hydrolyzed metal alcoholate as a catalyst, the metal being selected from the metals from Groups IIA, IIIA, IVB, and Zn, Ce and La and the alcoholate group has 1 to 8 carbon atoms. Process according to claim 7, characterized in that the metal is Al or Ti and the alcoholate group is a C₂, n or iso-C₃, n or iso-C₄ or tert.-C₄ group.