EP1658356A1

EP1658356A1 - Alkoxylated, cross-linked polyglycerols and use thereof as biodegradable demulsifier

Info

Publication number: EP1658356A1
Application number: EP04734666A
Authority: EP
Inventors: Dirk Leinweber; Franz Xaver Scherl; Elisabeth Wasmund; Heidi Grundner
Original assignee: Clariant Produkte Deutschland GmbH
Current assignee: Clariant Produkte Deutschland GmbH
Priority date: 2003-06-04
Filing date: 2004-05-25
Publication date: 2006-05-24
Anticipated expiration: 2024-05-25
Also published as: US20060281931A1; US7671098B2; WO2004108863A1; DE502004004384D1; EP1658356B1; NO336950B1; DE10325198A1; DE10325198B4; NO20056114L

Abstract

The invention relates to the use of alkoxylated cross-linked polyglycerols having multifunctional electrophilic compounds. Said polyglycerols have a molecular weight of between 1000 - 100.000 units and have between 5 - 100 glycerol units which are alkoxylated by C2-C4-alkylen oxide groups or a mixture of said type of alkylen oxide groups such that the cross-linked, alkoxylated polyglycerol has an alkoxylation degree of between 1 - 100 alkylen oxide units per free OH group. The invention also relates to the use of said polyglycerols for the demulsification of oil/water emulsions in amounts ranging from 0.0001 5 wt.- %, in relation to the oil content of the emulsion which is to be demulsified.

Description

description

Alkoxylated cross-linked polyglycerols and their use as biodegradable emulsion breakers

The present invention relates to the use of alkoxylated crosslinked polyglycerols for splitting water-oil emulsions, in particular in the production of crude oil.

Crude oil is produced as an emulsion with water. Before the

For further processing of the crude oil, these crude oil emulsions have to be split into the oil and water components. This is generally done using so-called petroleum splitters. Petroleum splitters are surface-active polymeric compounds which are able to bring about the required separation of the emulsion components within a short time.

US 4,321,146 alkylene oxide block copolymers and US 5,445,765 alkoxylated polyethyleneimines are disclosed as petroleum splitters. These can be used as individual components, in mixtures with other emulsion splitters, or as cross-linked products. Crosslinks are carried out, for example, by reacting alkoxylated low molecular weight alcohols (such as glycerol or pentaerythrol) or alkoxylated alkylphenol formaldehyde resins with bifunctional compounds such as diepoxides or diisocyanates. Such cross-linked compounds are disclosed in US 5,759,409 and US 5,981,687.

The use of alkoxylated glycerol as a demulsifying component in lubricating oils has been described in DD-229 006. Here, glycerin is reacted with alkylene oxides either to form a block copolymer or a statistical copolymer.

The use of alkoxylated di- and triglycerols as petroleum emulsion breakers has also been described (US-3,110,737, US-2,944,982 and U.S. 4,342,657).

Alkoxylated polyglycerols are known per se. They are described in the prior art for various applications. For example, in US 5 502 219 alkoxylated polyglycerols have been esterified to be a low calorie substitute for

To produce vegetable oils. In US 4,061,684 the alkoxylated polyglycerols were esterified and used as water-swelling gels. Alkoxylated polyglycerols which have been reacted with alpha-olefin epoxides act as defoamers according to WO-98/03243. Sulfation of alkoxylated polyglycerols leads to substances which are used in hair shampoos, as disclosed in US Pat. No. 4,263,178.

Alkoxylated polyglycerols have been disclosed in DE 101 07880 A1 as effective emulsion breakers.

The different properties (e.g. asphaltene, paraffin and salt content, chemical composition of the natural emulsifiers) and water content of different crude oils make it essential to further develop the existing oil splitter. In particular, the focus is on a low dosing rate and wide applicability of the petroleum splitter to be used, in addition to the desired higher effectiveness from an economic and ecological point of view. Emulsion splitters with good biodegradability and low bioaccumulation are also increasingly required to replace the alkylphenol-based products under discussion.

The task thus arose to develop new petroleum splitters which are superior in their action to the already known alkoxylated polyglycerols, can be used in even lower doses and have better biodegradability.

It was surprisingly found that alkoxylated crosslinked polyglycerols show an excellent effect as a petroleum splitter even at very low doses. In addition, they showed significantly better biological Degradability (according to OECD 306) compared to conventional commercial emulsion splitters and alkoxylated non-crosslinked polyglycerols.

The invention therefore relates to the use of alkoxylated polyglycerols crosslinked with multifunctional electrophilic compounds and having a molecular weight of 1000 to 100,000 units, which comprise 5 to 100 glycerol units which are alkoxylated with C ₂ -C ₄ -alkylene oxide groups or a mixture of such alkylene oxide groups, so that the crosslinked, alkoxylated polyglycerol has a degree of alkoxylation of 1 to 100 alkylene oxide units per free OH group, for splitting oil / water emulsions in amounts of 0.0001 to 5% by weight, based on the oil content of the emulsion to be split.

These alkoxylated crosslinked polyglycerols can be obtained from crosslinked polyglycerols having 5 to 100 glycerol units by alkoxylating the free OH groups with a C ₂ -C ₄ alkylene oxide or a mixture of such alkylene oxides in a molar excess, so that the alkoxylated crosslinked polyglycerol has the degree of alkoxylation mentioned.

The production of the polyglycerol is known in the prior art and is generally carried out by acidic or alkaline-catalyzed condensation of glycerol. The reaction temperature is generally between 150 and 300 ° C, preferably 200 to 250 ° C. The reaction is usually carried out at atmospheric pressure. HCl, H2SO4, sulfonic acids or H3PO _{4 may} be mentioned as catalyzing acids, and NaOH or KOH as bases, which are used in amounts of 0.1 to 50% by weight, based on the weight of the reaction mixture. The condensation generally takes 3 to 10 hours. Polyglycerols can be represented by Formula 1.

In Formula 1, n stands for the degree of condensation, i.e. the number of glycerol units. n increases with increasing reaction time and is determined using the OH number.

In the next step, the polyglycerols produced in this way are crosslinked with di- or multifunctional, electrophilic compounds. In this way, a very easily controllable increase in the molecular weight of the polyglycerols is achieved. Among others, di- or polyglycidyl ethers, di- or polyepoxides, di- or polycarboxylic acids, carboxylic acid anhydrides, di- or polyisocyanates, dialkoxy dialkylsilanes, trialkoxyalkylsilanes and tetraalkoxysilanes are used as crosslinkers. The crosslinking is carried out as is known in the prior art.

The following crosslinkers are particularly preferred:

Bisphenol-A diglycidyl ether, butane-1, 4-diol diglycidyl ether, hexane-1, 6-diol diglycidyl ether, ethylene glycol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, resorcinol diglycidyl ether,

Glycerol diglycidyl ether, glycerol triglycidyl ether, glycerol propoxylate triglycidyl ether,

Polyglycerol polyglycidyl ether, p-aminophenol triglycidyl ether,

Polypropylene glycol diglycidyl ether, pentaerythritol tetraglycidyl ether,

Sorbitol polyglycidyl ether, trimethylolpropane triglycidyl ether, castor oil triglycidyl ether, diaminobiphenyltetraglycidyl ether, soybean oil epoxide,

Adipic acid, maleic acid, phthalic acid, maleic anhydride,

Succinic anhydride, dodecyl succinic anhydride, phthalic anhydride,

Trimellitic anhydride, pyromellitic anhydride, dimethoxydimethylsilane,

Diethoxydimethylsilane, tetraalkoxysilanes, toluene diisocyanate, diphenylmethane diisocyanate.

The crosslinking agents or chemically related compounds mentioned are preferably used in the range of 0.1-10, particularly preferably 0.5-5 and especially 1.0-2.5% by weight, based on the polyglycerol.

As a rule and particularly preferably, the crosslinking step is carried out after the glycerol condensation and before the alkoxylation. Crosslinking after glycerol condensation and subsequent alkoxylation can can also be carried out according to the invention.

The crosslinked polyglycerols obtained from glycerol condensation and subsequent crosslinking are then alkoxylated with one or more C ₂ -C ₄ alkylene oxides, preferably ethylene oxide (EO) or propylene oxide (PO). The alkoxylating agent is used in a molar excess. The

As is known in the prior art, alkoxylation is carried out by reacting the polyglycerols with an alkylene oxide under elevated pressure, generally from 1.1 to 20 bar, at from 50 to 200.degree. The alkoxylation takes place on the free OH groups of the polyglycerols. So much alkylene oxide is used that the average degree of alkoxylation is between 1 and 100 alkylene oxide units per free OH group. The average degree of alkoxylation here means the average number of alkoxy units which are attached to each free OH group. It is preferably 2 to 70, in particular 5 to 50, especially 20 to 40.

The alkoxylation is preferably carried out first with PO and then with EO. The ratio of EO to PO in the alkoxylated polyglycerol is preferably between 1: 1 and 1:10. According to the invention, however, the alkoxylation can also take place in the reverse order, first EO then PO or with a mixture of PO and EO.

The polyglycerol obtained after condensation, subsequent crosslinking and alkoxylation preferably has a molecular weight of 3,000 to 50,000 units, in particular 5,000 to 30,000 units, especially 8,000 to 25,000.

The alkoxylated, crosslinked polyglycerols prepared by the process described are exemplified for the case of the crosslinking agent phthalic anhydride by the following structure (Formula 2):

(2)

(AO) k, i, mO stand for the alkoxylated OH radicals, in which AO is a C ₂ -C 4

Alkylene oxide unit and k, I, m represent the degrees of alkoxylation, n stands for

Degree of condensation of glycerin. n is preferably a number from 5 to 50, particularly preferably 8 to 30, especially 10 to 20.

A preferred subject of the present invention is the use of the alkoxylated polyglycerols as splitters for oil / water emulsions in the

Oil production.

For use as an oil splitter, the crosslinked alkoxylated polyglycerols are added to the water-oil emulsions, which is preferably done in solution. Paraffinic or aromatic solvents are preferred as solvents for the crosslinked alkoxylated polyglycerols. The crosslinked alkoxylated polyglycerols are used in amounts of 0.0001 to 5, preferably 0.0005 to 2, in particular 0.0008 to 1 and especially 0.001 to 0.1% by weight, based on the oil content of the emulsion to be split.

Examples

example 1

Production of pentadecaglycerin

100.0 g glycerol and 3.7 g NaOH (18%) were mixed in a 250 ml three-necked flask equipped with a contact thermometer, stirrer and water separator. The reaction mixture was quickly heated to 240 ° C. while stirring and flushing with nitrogen. At this temperature, the water of reaction was distilled off over 8 h. The product was evaporated to dryness on a rotary evaporator (Yield: 67.3 g) and the molar mass analyzed by GPC (M ^* «1100 g / mol, standard polyethylene glycol). The chain length n was determined by the OH number.

Example 2 Cross-linking of pentadecaglycerin with bisphenol A diglycidyl ether

In a 500 ml three-necked flask with a contact thermometer, stirrer and reflux condenser, 250.0 g of pentadecaglycerol were heated to 80 ° C. with a gentle nitrogen purge. At this temperature, 13.2 g of bisphenol A diglycidyl ether (80% solution in an aromatic solvent) were rapidly added dropwise. The reaction temperature was then raised to 120 ° C. and the reaction mixture was allowed to stir for 8 h until no unreacted diglycidyl ether could be detected by titration of the epoxy number. The product was evaporated to dryness on a rotary evaporator (yield: 260.0 g) and the molar mass was analyzed by GPC (M ^* »2600 g / mol, standard polyethylene glycol).

Example 3

Crosslinking of pentadecaglycerin with dodecylsuccinic anhydride

100.0 g of pentadecaglycerol, 1.5 g of alkylbenzenesulfonic acid and 2.7 g of dodecylsuccinic anhydride were placed in a 250 ml three-necked flask with a contact thermometer, stirrer and water separator at room temperature. The reaction mixture was then heated to 165 ° C. and the mixture was left to stir at this temperature for a further 8 hours until no more water of reaction formed in the water separator (reaction control: acid number). The product was evaporated to dryness on a rotary evaporator (yield: 102.0 g) and the molar mass was analyzed by GPC (M ^* »2450 g / mol, standard polyethylene glycol). Example 4

Crosslinking of pentadecaglycerin with toluene-2,4-diisocyanate

In a 250 ml three-necked flask with a contact thermometer, stirrer and reflux condenser, 100.0 g of pentadecaglycerol were heated to 60 ° C. with a gentle nitrogen purge. Then 2.4 g of toluene-2,4-diisocyanate were slowly added dropwise at this temperature. The reaction temperature was raised to 100 ° C. and the reaction mixture was stirred at this temperature for a further 8 h (reaction control: isocyanate number). The product was evaporated to dryness on a rotary evaporator (yield: 102.2 g) and the

Molecular mass analyzed by GPC (M ^* 2380 g / mol, standard polyethylene glycol).

Example 5

Production of decaglycerin

In a 250 ml three-necked flask with contact thermometer, stirrer and

Water separators were mixed with 100.0 g glycerol and 3.7 g NaOH (18%).

The reaction mixture quickly opened with stirring and nitrogen flushing

Heated at 240 ° C. At this temperature, the water of reaction was distilled off over 5 h. The product was evaporated to dryness on a rotary evaporator

(Yield: 74.9 g) and analyzed by GPC (M ^* «730 g / mol). The chain length n was determined by the OH number.

Example 6 Cross-linking of decaglycerin with bisphenol A diglycidyl ether

In a 250 ml three-necked flask with a contact thermometer, stirrer and reflux condenser, 100.0 g of decaglycerin were heated to 80 ° C. with a gentle nitrogen purge. 3.0 g of bisphenol A diglycidyl ether (80% solution in an aromatic solvent) were rapidly added dropwise at this temperature. The reaction temperature was then raised to 120 ° C. and the reaction mixture was allowed to stir for 8 h until no unreacted diglycidyl ether could be detected by titration of the epoxy number. The product was evaporated to dryness on a rotary evaporator (yield: 102.3 g) and the molar mass was analyzed by GPC (M ^* »1530 g / mol, standard polyethylene glycol).

Example 7 Cross-linking of decaglycerin with dodecylsuccinic anhydride

100.0 g of decaglycerol, 1.5 g of alkylbenzenesulfonic acid and 2.5 g of dodecylsuccinic anhydride were placed in a 250 ml three-necked flask with a contact thermometer, stirrer and water separator at room temperature. The reaction mixture was then heated to 165 ° C. and the mixture was left to stir at this temperature for a further 8 hours until no more water of reaction formed in the water separator (reaction control: acid number). The product was evaporated to dryness on a rotary evaporator (yield: 101.8 g) and the molar mass was analyzed by GPC (M ^* 1420 g / mol, standard polyethylene glycol).

Example 8

Cross-linking of decaglycerin with toluene-2,4-diisocyanate

In a 250 ml three-necked flask with a contact thermometer, stirrer and reflux condenser, 100.0 g of decaglycerin were heated to 60 ° C. with a gentle nitrogen purge. Then 2.4 g of toluene-2,4-diisocyanate were slowly added dropwise at this temperature. The reaction temperature was raised to 100 ° C. and the reaction mixture was stirred at this temperature for a further 8 h (reaction control: isocyanate number). The product was evaporated to dryness on a rotary evaporator (yield: 102.1 g) and the molar mass was analyzed by GPC (M ^* 1650 g / mol, standard polyethylene glycol).

Oxalkylation of the cross-linked polyglycerols

ethylene oxide

The cross-linked polyglycerols described above were converted into one

1 l glass autoclave introduced and the pressure in the autoclave with nitrogen to approx. 0.2 bar overpressure set. The mixture was slowly heated to 140 ° C. and, after this temperature had been reached, the pressure was again set to 0.2 bar gauge pressure. The desired amount of EO (see Table 1) was then metered in at 140 ° C., the pressure should not exceed 4.5 bar. After the addition of EO was allowed to react at 140 ° C for 30 minutes.

propylene oxide

The crosslinked polyglycerols described above were introduced into a 1 liter glass autoclave and the pressure in the autoclave was adjusted to about 0.2 bar excess pressure with nitrogen. The mixture was slowly heated to 130 ° C. and, after this temperature had been reached, the pressure was again set to 0.2 bar gauge pressure. The desired amount of PO was then metered in at 130 ° C. (see Table 1), the pressure should not exceed 4.0 bar. After the PO addition had ended, the mixture was left to react at 130 ° C. for a further 30 minutes.

The degree of alkoxylation was determined by means of ¹³ C-NMR.

Determination of the splitting effectiveness of petroleum emulsion splitters

To determine the effectiveness of an emulsion splitter, the water separation from a crude oil emulsion per time and the dewatering and desalination of the oil were determined. For this purpose, 100 ml of the crude oil emulsion were poured into splitter glasses (tapered, screwable, graduated glass bottles), a defined amount of the emulsion splitter was added with a micropipette just below the surface of the oil emulsion and the splitter was mixed into the emulsion by intensive shaking. The split glasses were then placed in a tempering bath (30 ° C and 50 ° C) and the water separation was monitored.

During and after the end of the emulsion splitting, samples of the oil were taken from the upper part of the splitter glass (so-called top oil) and the water content according to Karl Fischer and the salt content were determined by conductometry. In this way, the new splitters could be assessed after water separation, drainage and desalination of the oil.

Splitting effect of the splitters described

Origin of the crude oil emulsion: Holzkirchen Sonde 3, Germany Water content of the emulsion: 46% Salt content of the emulsion: 5%

Demulsification temperature: 50 ° C

Table 1:

Effectiveness of alkoxylated cross-linked polyglycerols as an emulsion splitter in comparison to the corresponding alkoxylated uncross-linked polyglycerol and Dissolvan 4738 (dosing rate 20 ppm)

Table 2:

Biodegradability of alkoxylated, crosslinked polyglycerols (closed bottle test according to OECD 306) compared to the corresponding alkoxylated, uncrosslinked polyglycerol and Dissolvan 4738

Claims

claims

1. Use of alkoxylated polyglycerols crosslinked with multifunctional electrophilic compounds and having a molecular weight of 1000 to 100,000 units, which comprise 5 to 100 glycerol units which are substituted with C ₂ -C ₄ -

Alkylene oxide groups or a mixture of such alkylene oxide groups are alkoxylated, so that the crosslinked, alkoxylated polyglycerol has a degree of alkoxylation of 1 to 100 alkylene oxide units per free OH group, for splitting oil / water emulsions in amounts of 0.0001 to 5% by weight. , based on the oil content of the emulsion to be split.

2. Use according to claim 1, wherein the number of glycerol units is between 5 and 50.

3. Use according to claim 1 and / or 2, wherein the alkoxylated crosslinked polyglycerols have a molecular weight of 3000 to 50,000 units.

4. Use according to one or more of claims 1 to 3, in which the average degree of alkoxylation is between 1 and 70 alkylene oxide units per free OH group.

5. Use according to one or more of claims 1 to 4, wherein the alkylene oxide is ethylene oxide or propylene oxide.

6. Use according to one or more of claims 1 to 5, wherein a mixed alkoxylation with ethylene oxide and propylene oxide is present in a ratio of 1: 2 to 1:10.

7. Use according to one or more of claims 1 to 6, wherein the crosslinking of the polyglycerols by means of bisphenol-A diglycidyl ether, butane-1,4-diol diglycidyl ether, hexane-1, 6-diol diglycidyl ether, ethylene glycol diglycidyl ether, cyclohexane dimethanol diglycidyl ether, resorcinol diglycidyl ether, Glycenndiglycidylether, glycerol triglycidyl ether, Glycerinpropoxylattriglycidylether, polyglycerol polyglycidyl ether, p-Aminophenoltriglycidylether, polypropylene glycol diglycidyl ether, pentaerythritol tetraglycidyl ether, sorbitol polyglycidyl ether, trimethylolpropane triglycidyl ether, Castoröltriglycidylether, Diaminobiphenyltetraglycidylether, soybean oil epoxide, adipic acid, maleic acid, phthalic acid, maleic anhydride, succinic anhydride, dodecyl succinic anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, dimethoxydimethylsilane, diethoxydimethylsilane, Toluoldiisoyanat, Diphenylmethane diisocyanate takes place.

8. Use according to one or more of claims 1 to 7, wherein the crosslinking step is carried out after the alkoxylation of the polyglycerols.