EP0531807B1 - Process for storing and transporting liquid hydrocarbons - Google Patents

Abstract

The present invention relates to the use of hydrocarbon-rich gels as a safe storage or transportation form for liquid hydrocarbons and to a process for the safe storage and safe transportion of liquid hydrocarbons, characterised in that a) the hydrocarbon is converted into a hydrocarbon-rich gel by addition of a surfactant and water and b) after storage or transportation has taken place, the hydrocarbon-rich gel is broken down again.

Description

The present invention relates to a method for the safe storage or transport of liquid hydrocarbons, the hydrocarbon being converted into a hydrocarbon-rich gel which is destroyed again after storage or transport, and a method for destroying a hydrocarbon-rich gel.

The storage or transport of liquid hydrocarbons, for example fuels, by road, rail and by water represents a considerable potential hazard. For example, the flammability and explosiveness in mixtures with air in the past have led to serious accidents, which have been considerable Have caused damage. In addition, fuel leaking from leaked storage or transport containers repeatedly causes serious ecological damage.

The object of the present invention is therefore to provide a method for the safe storage or transport of hydrocarbons.

This object is surprisingly achieved in that the hydrocarbons are stored or transported in the form of hydrocarbon-rich gels.

A hydrocarbon-rich gel is understood to mean a system consisting of polyhedra formed by surfactant and filled with hydrocarbon, water forming a continuous phase in the narrow spaces between the polyhedra. Systems of this type are known and in Angew. Chem. 100 933 (1988) and Ber. Bunsenges. Phys. Chem. 92 1158 (1988).

Hydrocarbon-rich gels are characterized by the appearance of a yield point. This flow limit is reached when the gel no longer withstands the stress (shear, deformation) and begins to flow. Below the yield point, the gel structures have solid properties and obey Hooke's law. Ideally, the system is equivalent to a Newtonian liquid above the yield point. This means that hydrocarbon-rich gels can be pumped in a simple manner, but cannot flow at rest due to their solid-state properties. This means that they cannot escape from defective storage or transport containers, and there is almost no risk to the environment.

The present invention relates to a method for the safe storage or transport of liquid hydrocarbons, which is described in claim 1. The present invention further relates to a method described in claim 2 for destroying a hydrocarbon-rich gel.

Surfactant and water are preferably added to the hydrocarbon in amounts such that a hydrocarbon-rich gel is formed from 70 to 99.5% by weight of hydrocarbon, 0.01 to 15% by weight of surfactant and 0.49 to 15% by weight of water.

Surfactant and water are particularly preferably added to the hydrocarbon in amounts such that a hydrocarbon-rich gel is formed from 80 to 99.5% by weight of hydrocarbon, 0.01 to 5% by weight of surfactant and 0.49 to 15% by weight of water.

Hydrocarbons which are particularly suitable for the process according to the invention are n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-dodecane, n-tetradecane, n-hexadecane, cyclohexane, Cyclooctane, benzene, toluene, kerosene, gasoline, unleaded gasoline, heating oil, diesel oil and crude oil.

Anionic, cationic, amphoteric or nonionic surfactants can be used to form the hydrocarbon-rich gels.

   worin R und R' Alkylreste mit zusammen 11 bis 17 C-Atomen bedeuten;
Alkylbenzolsulfonate bzw. -sulfate der Formel

   worin n = 0 oder 1 ist
   und R und R' Alkylreste mit zusammen 11 bis 13 C-Atomen bedeuten;
Olefinsulfonate der Formel R-CH₂-CH = CH-CH₂-SO₃^⊖Na^⊕
   worin R Alkyl mit 10 bis 14 C-Atomen bedeutet;
Fettalkoholsulfate der Formel R-CH₂-O-SO₃^⊖Y^⊕
   worin R Alkyl mit 11 bis 15 C-Atomen und
   Y^⊖ Na^⊕ oder Triethanolamin bedeuten;
Fettalkoholpolyglykolsulfate der Formel



        R-CH₂-O(C₂H₄O)_n-SO₃^⊖Na^⊕



   worin n = 2 bis 7 ist und
   R Alkyl mit 8 bis 15 C-Atomen bedeutet;
Sulfosuccinate der Formel

   worin n 2 bis 6 ist und
   R Alkyl mit 11 bis 13 C-Atomen bedeutet;
Fettalkoholpolyglykolphosphate der Formel



        R-CH₂-O(C₂H₄O)_nPO₃H^⊖Na^⊕



   worin n 2 bis 6 ist und
   R Alkyl mit 15 bis 17 C-Atomen bedeutet;
Alkanphosphonate der Formel



        R-PO₃H^⊖Na^⊕



   worin R Alkyl mit 12 bis 16 C-Atomen bedeutet;
oder Natriumsalze von Ölsäurederivaten wie Ölsäuresarkosid, Ölsäureisothionat oder Ölsäuremethyltaurid.Preferred anionic surfactants are
Soaps of the formula R-CH₂-COO ^⊖ Na ^⊕
wherein R represents a hydrocarbon radical having 10 to 20 carbon atoms;
Alkanesulfonates of the formula

wherein R and R 'are alkyl radicals with a total of 11 to 17 carbon atoms;
Alkylbenzenesulfonates or sulfates of the formula

where n = 0 or 1
and R and R 'are alkyl radicals with a total of 11 to 13 carbon atoms;
Olefin sulfonates of the formula R-CH₂-CH = CH-CH₂-SO₃ ^⊖ Na ^⊕
wherein R is alkyl having 10 to 14 carbon atoms;
Fatty alcohol sulfates of the formula R-CH₂-O-SO₃ ^⊖ Y ^⊕
wherein R is alkyl with 11 to 15 carbon atoms and
Y ^⊖ Na ^⊕ or triethanolamine;
Fatty alcohol polyglycol sulfates of the formula



R-CH₂-O (C₂H₄O) _n -SO₃ ^⊖ Na ^⊕



where n = 2 to 7 and
R represents alkyl having 8 to 15 carbon atoms;
Sulfosuccinates of the formula

wherein n is 2 to 6 and
R represents alkyl with 11 to 13 carbon atoms;
Fatty alcohol polyglycol phosphates of the formula



R-CH₂-O (C₂H₄O) _n PO₃H ^⊖ Na ^⊕



wherein n is 2 to 6 and
R represents alkyl with 15 to 17 carbon atoms;
Alkane phosphonates of the formula



R-PO₃H ^⊖ Na ^⊕



wherein R is alkyl with 12 to 16 carbon atoms;
or sodium salts of oleic acid derivatives such as oleic acid sarcoside, oleic acid isothionate or oleic acid methyl tauride.

   worin
   R¹ Alkyl mit 10 bis 22 C-Atomen,
   R² Alkyl mit 1 bis 12 C-Atomen oder Benzyl
   R³ und R⁴ unabhängig voneinander Wasserstoff oder Methyl und
   X^⊖ Cl^⊖, Br^⊖ oder CH₃SO₄^⊖ bedeuten;
Fettamine, wie beispielsweise Kokosfettamine, Laurylfettamin, Oleylfettamin, Stearylfettamin, Talgfettamin, Dimethylfettamine oder kettenreine primäre Alkylamine mit 8 bis 22 C-Atomen;
Ammoniumborat-Betain auf Basis Didecylamin;
Stearyl-N-acylamido-N-methyl-imidazolinium-chloride der Formel

Alkenylbernsteinsäurederivate der Formeln

   worin R jeweils iso-C₁₈H₃₅ oder Polybutenyl bedeuten.Preferred cationic surfactants are
Quaternary ammonium compounds of the formula

wherein
R¹ alkyl with 10 to 22 carbon atoms,
R² alkyl with 1 to 12 carbon atoms or benzyl
R³ and R⁴ independently of one another hydrogen or methyl and
X ^⊖ Cl ^⊖ , Br ^⊖ or CH₃SO₄ ^⊖ ;
Fatty amines, such as, for example, coconut fatty amines, lauryl fatty amine, oleyl fatty amine, stearyl fatty amine, tallow fatty amine, dimethyl fatty amines or chain-pure primary alkyl amines having 8 to 22 carbon atoms;
Ammonium borate betaine based on didecylamine;
Stearyl-N-acylamido-N-methyl-imidazolinium chloride of the formula

Alkenyl succinic acid derivatives of the formulas

where R is iso-C₁₈H₃₅ or polybutenyl.

   worin R Alkyl mit 12 bis 14 C-Atomen bedeutet;
N-Carboxyethyl-N-alkylamido-ethylglycinate der Formel

   worin R Alkyl mit 11 bis 13 C-Atomen bedeutet;
N-Alkylamido-propyl-N-dimethylaminoxide der Formel

   worin R Alkyl mit 11 bis 13 C-Atomen bedeutet;
Bevorzugte nichtionische Tenside sind beispielsweise
1,4-Sorbitanfettsäureester der Formel

   worin R Alkyl mit 11 bis 17 C-Atomen bedeutet;
Fettalkoholpolyglykolether der Formel



        R-O(CH₂-CH₂-O)_nH



   worin n = 3 bis 15 ist und R geradkettiges oder verzweigtes Alkyl mit 9 bis 19 C-Atomen bedeutet;
Alkylphenolpolyglykolether der Formel

   worin n = 3 bis 15 ist und R und R' Alkyl mit zusammen 7 bis 11 C-Atomen bedeuten.Preferred amphoteric surfactants are, for example
Alkyl betaines of the formula

wherein R is alkyl having 12 to 14 carbon atoms;
N-carboxyethyl-N-alkylamido-ethylglycinate of the formula

wherein R represents alkyl having 11 to 13 carbon atoms;
N-alkylamido-propyl-N-dimethylamine oxides of the formula

wherein R represents alkyl having 11 to 13 carbon atoms;
Preferred nonionic surfactants are, for example
1,4-sorbitan fatty acid esters of the formula

wherein R is alkyl with 11 to 17 carbon atoms;
Fatty alcohol polyglycol ether of the formula



RO (CH₂-CH₂-O) _n H



where n = 3 to 15 and R is straight-chain or branched alkyl having 9 to 19 carbon atoms;
Alkylphenol polyglycol ethers of the formula

where n = 3 to 15 and R and R 'are alkyl with a total of 7 to 11 carbon atoms.

After storage or transport, the liquid hydrocarbon must be recovered, ie the gel structure must be destroyed.

This is done by treatment with mechanical waves, by applying a vacuum or vacuum or, if the hydrocarbon-rich gel is formed with the aid of an ionic surfactant, by adding an oppositely charged substance.

Mechanical waves are understood to mean, in particular, pressure waves of high frequency, for example ultrasound. When the gel structure is destroyed by ultrasound, the hydrocarbon phase begins to emerge from the gel dressing after only a few seconds. The separation is complete when two thin phases coexist. This is usually the case after about 30 seconds.

When the gel structure is destroyed by applying a vacuum or vacuum, the preferred range is of course dependent on the boiling point of the hydrocarbon. A vacuum of up to 0.1 torr is usually advantageous.

In the destruction of gel structures formed with ionic surfactants, oppositely charged surfactants or polymers or copolymers are preferably used.

In the event that gel structures based on cationic surfactants are destroyed, the above-mentioned anionic surfactants are particularly preferably used.

Particularly preferred polymers with anionic groups are, for example

die auch vernetzt und/oder ganz oder teilweise neutralisiert sein können;
Poly-2-Acrylamido-2-methyl-propansulfonsäuren, bestehend aus Grundelementen der Formel

die auch vernetzt und/oder ganz oder teilweise neutralisiert sein können;
oder Poly-Vinylphosphonsäuren, bestehend aus Grundelementen der Formel

die auch vernetzt und/oder ganz oder teilweise neutralisiert sein können.Polyacrylates, consisting of basic elements of the formula

which can also be networked and / or completely or partially neutralized;
Poly-2-acrylamido-2-methyl-propanesulfonic acids, consisting of basic elements of the formula

which can also be networked and / or completely or partially neutralized;
or polyvinylphosphonic acids, consisting of basic elements of the formula

which can also be networked and / or completely or partially neutralized.

Mixtures of the polymers mentioned or polymers which contain several of the basic elements mentioned are also preferred. It is also possible to use polymers which consist, for example, of the above-mentioned basic elements with a negative charge and those with a positive charge.

Cross-linked, partially neutralized polyacrylic acid is very particularly preferred. This also has the advantage that, due to its enormous absorption capacity for water, it can bind the aqueous phase of the gel to be destroyed quantitatively. Because of this absorption capacity for water, crosslinked, partially neutralized polyacrylic acid can not only destroy gel structures based on cationic surfactants, but also those based on anionic, amphoteric or nonionic surfactants.

In the event of the destruction of gel structures based on anionic surfactants, the above-mentioned cationic surfactants are particularly preferably used.

die auch vernetzt und/oder ganz oder teilweise neutralisiert sein können.Particularly preferred polymers with cationic groups are, for example
Poly-diallyl-dimethyl-ammonium chloride, which can also be cross-linked and / or completely or partially neutralized, or poly-methacrylic acid-2-dimethylaminoethyl ester consisting of basic elements of the formula

which can also be networked and / or completely or partially neutralized.

Mixtures of the polymers mentioned or polymers which contain both of the basic elements mentioned are also preferred. It is also possible to use polymers which consist, for example, of the above-mentioned basic elements with a positive charge and those with a negative charge.

The destruction of the gel structure is carried out in a simple manner so that the surfactant or polymer as such or in a suitable solvent is added to the gel structure and briefly shaken. The gel disintegrates spontaneously and is faster the higher the counter ion concentration.

Depending on the system, sensible gel disintegration rates are achieved if 0.2 to 25 g, preferably 0.4 to 5 g, of oppositely charged surfactant or polymer are added per g of surfactant contained in the yellow.

Suitable solvents in which the surfactant or polymer used for gel destruction can be dissolved are, for example, xylene, water or alcohols.

The concentrations of the surfactants in the solvents are not critical, but are preferably from 30% by weight until the solution is saturated. If the hydrocarbon to be stored or transported is a fuel or lubricating oil, it is particularly advantageous if surfactants which can remain as an additive in the hydrocarbon are selected both for gel formation and for gel destruction. For example, sulfonates are known as detergent additives and alkenylsuccinic acid imidoamines are known as dispersant additives (J. Raddatz, WS Bartz, 5th International Coll. January 14-16, 1986, Esslingen Technical Academy "Additives for Lubricants and Working Fluids"). Succinimides are also known as oil and fuel additives (see, for example, EP 198 690, US 4,614,603, EP 119 675, DE 3 814 601 or EP 295 789).

example 1 a) Manufacturing

1 g of sodium dodecyl sulfate was dissolved in 9 g of water and placed in an Erlenmeyer wide-necked flask. 400 g of ligroin were added at room temperature with vigorous stirring using a magnetic stirrer. A gel system rich in hydrocarbons was formed.

b) pumping tests

Pump tests were carried out with this gel system using an Ika peristaltic pump. The diameter of the polyethylene hose used was 4 mm. The pumpability was recorded as an amount of gel which was pumped from vessel A to vessel B after a defined unit of time. The measurement results from a test duration of 5 minutes at different pump speeds are summarized below: Speed level Test duration amount of gel pumped 10th 5 min 3.8 g 10th 5 min 3.7 g 20th 5 min 4.4 g 20th 5 min 4.1 g 20th 5 min 2.9 g 20th 5 min 3.8 g 20th 5 min 3.9 g 20th 5 min 3.8 g 30th 5 min 4.4 g 30th 5 min 4.3 g 30th 5 min 4.3 g 30th 5 min 4.5 g 40 5 min 4.2 g 40 5 min 4.5 g 40 5 min 3.8 g

In summary, it can be said that the pumping power proves to be independent of the pumping speed due to the viscoelasticity of the gel systems.

c) Storage and transportation

No changes in the consistency or rheological behavior of the gel system could be found in an observation period of six months. Permanent shear or vigorous shaking during transport by rail and road has no effect on gel stability.

d) Gel destruction by ultrasound

In a series of experiments, 50 g of gel of the composition described under 1a were destroyed using the Sonifier Cell Disruptor B-30 ultrasound device using different energy levels. The time of complete structural destruction was recorded: Energy level Time to destruction Level 10 1 sec Level 8 10 sec Level 6 35 sec Level 4 197 sec level 3 390 sec

e) Gel destruction by applying a vacuum

50 g of the gel prepared according to Example 1a were connected to an oil pump in a 1 liter one-necked flask via vacuum regulator and cold trap. At a vacuum of 0.6 mm Hg, the gel disintegration started within 5 minutes when the flask was heated by means of a thermostat bath to a gel temperature of 30 to 40 ° C. and was over after a short time.

f) Gel destruction by adding a cationic surfactant

100 g of the gel prepared according to Example 1a were placed in a 500 ml Erlenmeyer flask and mixed with 600 ppm of a commercial surfactant based on coconut fatty amine. When mixed by simple mechanical movement, the gel disintegrated spontaneously. The result was a system consisting of two thin, immiscible phases.

g) Gel destruction by adding a polymer with cationic groups

100 g of the gel prepared according to Example 1a were placed in a 500 ml Erlenmeyer flask and 4000 ppm of poly-diallyl-dimethyl-ammonium chloride were added. When mixed by simple mechanical movement, the gel disintegrated spontaneously. The result was a system consisting of two thin, immiscible phases.

Example 2

A hydrocarbon-rich gel of 1.6 g of sodium dodecyl sulfate, 6.4 g of H₂O and 392 g of kerosene was prepared as described in Example 1a, the mixing being carried out using a Vortex Genie mixer.

Pumping tests analogous to Example 1b gave the following results: Speed level Test duration amount of gel pumped 10th 5 min 64.9 g 10th 5 min 60.2 g 10th 5 min 64.3 g

The gel decomposition was carried out analogously to Examples 1d to 1g.

Example 3

A hydrocarbon-rich gel made from 1.6 g of a commercially available nonionic surfactant based on a nonylphenol polyglycol ether, 6.4 g H₂O and 392 g kerosene was prepared as described in Example 1a.

Pumping tests analogous to Example 1b gave the following results: Speed level Test duration amount of gel pumped 10th 5 min 55.4 g 10th 5 min 58.5 g 10th 5 min 54.4 g

Gel destruction was carried out analogously to Examples 1d and 1e.

Example 4

A hydrocarbon-rich gel of 1.6 g of sodium dodeyl sulfate, 6.4 g of H₂O and 392 g of hexane was prepared as described in Example 1a.

Pumping tests analogous to Example 1b gave the following results: Speed level Test duration amount of gel pumped 10th 5 min 21.4 g 10th 5 min 22.2 g 10th 5 min 21.5 g

Gel destruction was carried out analogously to Examples 1d to 1g.

Example 5

A hydrocarbon-rich gel from 1.6 g of a commercial cationic surfactant based on a quaternary ammonium compound, 6.4 g H₂O and 392 g kerosene was prepared as described in Example 1a.

Pumping tests analogous to Example 1b gave the following results: Speed level Test duration amount of gel pumped 10th 5 min 283.0 g 10th 5 min 288.8 g 10th 5 min 248.8 g

Gel destruction was carried out analogously to Examples 1d to 1g, but in the case of 1g a crosslinked, partially neutralized polyacrylic acid was used.

As described in Examples 1 to 5, the hydrocarbon-rich gels of Examples 6 to 19 below were prepared from ligroin, anionic surfactant and water and 41 g each were destroyed with the stated amount of cationic surfactant. The following cationic surfactants were used:

As described in Examples 1 to 5, the hydrocarbon-rich gels of Examples 20 to 36 below were prepared from ligroin, cationic surfactant and water and 1 g each was destroyed with the stated amount of anionic surfactant.

As described in Examples 1 to 5, the hydrocarbon-rich gels of Examples 37 to 50 below were prepared from ligroin, surfactant and water and 1 g each was destroyed with the stated amount of an oppositely charged polymer.

Polymer 1:

Polyacrylat

Polymer 2:

Poly-Dialkyl-dimethyl-ammoniumchlorid

Polymer 3:

Poly-2-Acrylamido-2-methyl-propansulfonsäure

Polymer 4:

Poly-Vinylphosphonsäure

Polymer 5:

Poly-Methacrylsäure-2-dimethylaminoethylester

The following polymers were used:

Polymer 1:

Polyacrylate

Polymer 2:

Poly-dialkyl-dimethyl-ammonium chloride

Polymer 3:

Poly-2-acrylamido-2-methyl-propanesulfonic acid

Polymer 4:

Poly vinyl phosphonic acid

Polymer 5:

Poly-methacrylic acid 2-dimethylaminoethyl ester

Claims (6)

1. Process for the safe storage and the safe transportation of liquid hydrocarbons by

   a) converting the hydrocarbon into a hydrocarbon-rich gel by addition of a surfactant and water and

   b) breaking down the hydrocarbon-rich gel after storage or transportation has taken place, characterised in that the hydrocarbon-rich gel is broken down by treatment with mechanical waves, application of a reduced pressure or vacuum or, if the hydrocarbon-rich gel is formed with the aid of an ionic surfactant, by addition of oppositely charged surfactants or polymers or copolymers.
2. Process of breaking down a hydrocarbon-rich gel by treatment with mechanical waves, application of a reduced pressure or vacuum or, if the hydrocarbon-rich gel is formed with the aid of an ionic surfactant, by addition of oppositely charged surfactants or polymers or copolymers.
3. Process according to Claim 1 and/or 2, characterised in that the hydrocarbon-rich gel consists of 70 to 99.5 % by weight of hydrocarbon, 0.01 to 15 % by weight of surfactant and 0.49 to 15 % by weight of water.
4. Process according to one or more of Claims 1 to 3 characterised in that the hydrocarbon-rich gel consists of 80 to 99.5 by weight of hydrocarbon, 0.01 to 5 % by weight of surfactant and 0.49 to 15 % by weight of water.
5. Process according to one or more of Claims 1 to 4, characterised in that n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-dodecane, n-tetradecane, n-hexadecane, cyclohexane, cyclooctane, benzene, toluene, kerosene, petrol, lead-free petrol, heating oil, diesel oil or crude oil are employed as the hydrocarbons.
6. Process according to one or more of Claims 1 to 5, characterised in that anionic, cationic, amphoteric or non-ionic surfactants are employed as the surfactant.