NO127757B - - Google Patents

Description

Hydrocarbon composition containing

agent for improving buoyancy.

The present invention relates to agents for improving the buoyancy, and is particularly well suited for use in residual fuel

substances or crude oils.

Although certain polymers which have recently been used as flowability improvers for waxy fuels, such as residual fuels or crude oils, are good agents for improving pumpability, the pour point of the mixture of the fuel and the flowability improver is not good enough. Relatively surprisingly, it has now been found that the pour point can be improved to a significant extent by adding certain types of other agents to improve the flowability to the mixture.

According to the present invention, there is provided a hydrocarbon-containing composition comprising a major part by weight of a crude oil or a fuel comprising residues from the distillation of crude oil, or a flash distillate fuel, and this composition is characterized in that it comprises: at least one known per se polymer A with a series of substantially linear paraffinic side chains, each containing at least 18 carbon atoms, and where the polymer is derived directly or indirectly from a homo- or copolymerization of a compound containing an organic group that can be polymerized, and

at least one known per se polymer B which is a copolymer

of ethylene and one or more ethylenically unsaturated compounds, so that the copolymer contains at least 50 mole percent polymerized ethylene units, and where the remainder are ethylenically unsaturated compounds with a double bond, preferably a terminal bond, and where any essentially linear paraffin chains contain less than 18 carbon atoms. The side chains in the polymer preferably contain at least 22 carbon atoms.

Examples of organic groups which may be present in the polymerizable compound are carboxyl, anhydride, hydroxyl, amino and olefinic groups. At least 25 mole percent, preferably at least 50 mole percent, of the compounds from which the polymer is prepared, contains a substantially linear paraffinic side chain containing at least 18 carbon atoms.

Examples of type A polymers are the following:

1) Homopolymers or copolymers of compounds with an organic group (e.g. carboxyl, hydroxyl, amino or olefinic group) which can be polymerised, and where said organic group is adjacent to an essentially linear paraffinic chain containing at least 18 carbon atoms , preferably at least 22 carbon atoms.

Examples: Homo- or copolymers of long-chain acrylates, methacrylates, vinyl esters, allyl esters, fumarates, maleates, vinyl ethers, olefins, including block copolymers of olefins.

2) Copolymers of (I) with at least 25 mole percent, preferably more than 50 mole percent of compounds with an organic group (e.g. a carboxyl group, a hydroxyl, amino or olefinic group) which can be polymerized, and where said organic group adjoins an essentially linear paraffinic chain containing at least 18 carbon atoms, preferably at least 22 carbon atoms and (II) compounds which can be polymerized with compounds of type (I), and where the compounds (II) have an organic group (e.g. a carboxyl group, hydroxyl, amino or olefinic group) adjacent to a hydrocarbyl or a substituted hydrocarbon group with less than 18 carbon atoms, preferably

show less than 10 carbon atoms.

Examples: Copolymers of compounds specified under section (1) with short-chain compounds of the same type as in section (1), but where the side chain as specified in section (1) is absent, e.g. vinyl acetate/behenyl fumarate, methyl methacrylate/behenyl methacrylate, styrene/behenyl maleate.

3) Homopolymers of polymerizable compounds containing an organic group (e.g. a carboxyl group, a hydroxyl or amino group) reacted with a long-chain compound with an organic group (e.g. a carboxyl group, a hydroxyl - or amino group) which can react with the organic group present in the homopolymer, and where the organic group in the long-chain compound is close to an essentially linear paraffinic chain containing at least 18 carbon atoms, and preferably more than 22 carbon atoms. At least 25%, and preferably at least 50% of the organic groups in homopoly-

The mer is modified by a reaction with the organic group in the long-chain compound.

Examples? a. Polyacrylic acid, polymethacrylic acid, polymaleic anhydride, reacted with long-chain alcohols, e.g. behenyl alcohol or amines,

b. Polyallyl alcohol, reacted with long-chain acids, e.g. behenic acid.

(4) A copolymer X prepared by reacting a long-chain compound containing an organic group (e.g. a hydroxyl or amino group or a carboxyl group) adjacent to an essentially

lig linear paraffinic chain containing at least 18 carbon atoms, (preferably at least 22 carbon atoms), with a copolymer Y prepared by copolymerizing a mixture of monomers in which at least 25 mol percent, preferably more than 50 mol percent, contains an organic group which can react with the long-chain connection. Preferably, at least 50%, and more preferably at least 75%, of the organic groups in the copolymer Y should be modified by the reaction with the long-chain compound. Examples a. Copolymers of acrylate or methacrylate esters with acrylic or methacrylic acid reacted with long-chain alcohols, e.g. beheny lalcohol. b. Copolymers of allyl alcohol with styrene which are then reacted with behenic acid. c. Copolymers of olefins, such as ethylene, propylene, etc. with maleic anhydride, vinyl acetate/maleic anhydride, or styrene/maleic anhydride copolymers, and where each copolymer is then reacted with long-chain alcohols, e.g. behenyl alcohol. (5) Condensation polymers produced by a condensation reaction, e.g. an esterification involving the elimination of water. Suitable copolymers of this type can e.g. produced by . methods where a compound with one or more carboxyl groups is reacted with a compound with one or more alcoholic hydroxy groups and/or amino groups, and where at least one of the compounds has a substantially linear paraffinic chain adjacent to the ester-forming group (e.g. -OH or -COOH) containing at least 18 carbon atoms.

An example of a type A copolymer can be prepared by copolymerizing an ester of an ethylenically unsaturated alcohol with an ester of an ethylenically unsaturated carboxylic acid, provided that at least one of said esters has a substantially linear paraffinic chain containing at least 18 carbon atoms. Suitable esters of unsaturated alcohols include vinyl or allyl esters of C₁ to C₁₀ monocarboxylic acids, e.g. acetic acid, propionic acid, butyric acid, hexa-oic acid, dodecaoic acid, behenic acid or myristic acid. Particularly suitable esters are vinyl acetate, vinyl propionate or vinyl behenate. Suitable esters of unsaturated carboxylic acids include esters of monocarboxylic acids, such as acrylic acid, methacrylic acid, oleic acid or elaidic acid, esters of dicarboxylic acids, e.g. maleic acid, fumaric acid, mesaconic acid, citraconic acid, or itaconic acid, or esters of other ethyl polycarboxylic acids, e.g. cis- and trans-acotinic acid.

The molar ratio between the two types of esters can vary, but should preferably be from 25 to 75 mol-$ of an ester, and from 75

to 25 mol-$ of the second ester. Said esters can be copolymerized by developing free radicals by decomposing peroxides or azo compounds, such as benzoyl peroxide and azo-bis-isobutyronitrile or other similar compounds.

Particularly preferred copolymers of this type are copolymers of vinyl acetate with C 2 to C 3 alkyl fumarates or maleates, e.g. a copolymer of vinyl acetate and behenyl fumarate esters.

Type A copolymers preferably have a number average molecular weight of between 1000 and 100,000, preferably between 2000 and 20,000.

Another example of a type A polymer is an alkyl or acyl polystyrene, where the alkyl or acyl radical contains at least 18 and more preferably at least 22 carbon atoms. These polystyrenes should also preferably also contain 2 to 50 repeating styrene units, and at least half of the styrene units should be alkylated or acylated.

Very suitable acyl polystyrenes are those where the acyl group (CRO-) has from 22 to 30 carbon atoms, e.g. of the type derived from behenic acid CH^(CH2)2QC00H. These acyl polystyrenes can be prepared by dissolving styrene in a solvent, e.g. o-di-chlorobenzene, and add to the prepared solution from 0.5 to 1.0 mol per mol of styrene of an acyl halide/aluminum trihalide complex.

(The complex can be prepared by mixing equimolar amounts of aluminum trihalide, eg AlCl^, with the acyl halide dissolved in a solvent, eg o-dichlorobenzene, preferably at a temperature of 20° - 70°C). After all the acyl halide/aluminum halide complex has been added to the styrene solution, and hydrogen halide evolution has stopped, the aluminum catalyst can be destroyed by adding water or alcohol to the reaction mixture. The acylated polystyrene can then be taken up in a suitable solvent, e.g. heptane or kerosene.

The ratio of styrene units to acyl units in the polystyrene can vary, e.g. from 1:1 to 2:1 respectively. The average number molecular weight of the acyl polystyrenes should preferably be between 1000 and 25000, e.g. between 8000 and 15000.

Another suitable group of type A polymers are those prepared by condensing (1) a dicarboxylic acid (preferably with a C2~ to Cg connecting chain connecting the two carbonyl groups), an anhydride or an ester thereof (preferably with a C-, -Cc-aliphatic alcohol), where there is a C-^g- to C^-straight-chain hydrocarbyl group attached to the carbon chain connecting the two carbonyl groups of the acid, anhydride or ester, with (2) a alcohol, an amine, or a hydroxyamine, each having three to at least six hydroxy, primary amino, or secondary amino groups, and (3) a monocarboxylic acid (preferably ~C^g-hydrocarby 1)', provided that if only two or three carbon atoms in the carbon chain that connects the carbonyl groups in said dicarboxylic acid, anhydride or ester, then any amino group in component (2) must be a secondary amino group. Reactant (2) is conveniently a triol, secondary amine or hydroxyamine, each suitably C 1 to C 2 , preferably C 2 , or is a trialkanolamine, preferably C 2 to C 2 .

To prepare the polymer, the three components (1),

(2) and (3) are traded with each other. Preferably, the three components should be reacted in equimolar amounts, but minor deviations from equimolar amounts can also be used, e.g. 0.8 to 1.2 mol of (1) reacted with 0.8 to 1.2 mol of (2) and 0.8 to 1.2 mol of (3).

The molecular weight of the produced polyesters or polyester amides should preferably be more than 1000, e.g. between 1200 and 5000.

Suitable examples of such condensation polymers are described in British Patent No. 1.1^0.067, particularly those prepared by condensing a C₁O+-alkenyl-substituted succinic anhydride with diethanolamine and a mixture of C20-C22 fatty acids.

Other suitable type A polymers are the condensation polymers (described in Norwegian available patent application 1861/69. Such Dolymers can be prepared by a condensation reaction of (l) a dicarboxylic acid (preferably with a Cg- to C^-connecting chain), an anhydride or an ester thereof (preferably with a C^- to C^-aliphatic alcohol), where the number of carbon atoms in the chain connecting the two carbonyl groups is between 1 and 12, with (2) a polyol containing at least four, and up to at least six hydroxy groups, where all the carbon atoms in the beta position with respect to the hydroxy group must be tertiary carbon atoms, and (3) a monocarboxylic acid, provided that either reactant (1) or reactant (3) or both, has a carbon-

and hydrogen-containing group, which also contains at least 8 carbon atoms, either attached to one of the carbon atoms in that chain,

which connects the two carbonyl groups in (l) or linked to carbonyl group one in the acid (3).

To prepare the polymer, the three components (l),

(2) and (3) are traded with each other. In the preferred embodiment, ie when the polyol is a tetrol, the amounts of the three components should be two moles of (3) per mol of (l) and per mol of (2), but variations can be used, e.g. from 0.5 to 1.5 mol of (1) reacted with 0.5 to 1.5 mol of (2) and 1.0 to 3»0 mol of (3). The molecular weight of the polymers should preferably be more than 1000, suitable and appropriate between 1200 and 20,000.

Reactant (1) is preferably a hydrocarbyl"* (e.g. alkenyl- or alkyl-) substituted succinic acid or succinic anhydride. Reactant (2) is preferably a tetrol. This can e.g. be 1,2,4 ,5-tetramethylolbenzene or a polypentaerythritol, but is preferably pentaerythritol, or a halogenated pentaerythritol Reactant (3)

should preferably contain from 13 to 31 carbon atoms. To achieve optimal results, the carbon- and hydrogen-containing group should

substituent in the reactants (1) or (3) or in both, be a straight-chain radical, e.g. one with a chain length of between 18 and kk carbon atoms. The number average molecular weight for these condensation polymers is preferably more than 1000, e.g. between 1200 and 20,000..A particularly preferred condensation polymer can be prepared by condensing a <C>22-C2g-alkenyl or C,j0+-alkenyl-substituted succinic anhydride with pentaerythritol and a mixture of <C>20<->C22-f6ttAcids-

Type A copolymers are usually oil-soluble, and flowability-improving polymers, characterized by a hydrocarbon chain, or an ether- or ester-interrupted hydrocarbon chain, where at least 25 mol-$ of the monomer used for the production of said polymer has essentially straight alkyl side chains with 18 to kk, preferably from 22 to 30, carbon atoms, and where said side chains are linked to the main chain of the polymer, either directly or indirectly via ester, amide or ether bonds.

The second component in the polymer mixture according to the present invention is a type B polymer. Such polymers are defined as copolymers of ethylene and one or more ethylenically unsaturated compounds, so that the copolymer contains at least 50 mol-$, preferably 82 - 99 mol-%, e.g. from 86 - 97 mol-$, of polymerized ethylene units, where the remainder is ethylenically unsaturated compounds with a double bond, preferably a terminal bond, and if there is an essentially linear paraffin chain, then such a chain should contain less than 18 carbon atoms, preferably less than 5 carbon atoms. Examples of such ethylenically unsaturated compounds which can be copolymerized with ethylene are ethylenically unsaturated acids, anhydrides, esters, amines, hydroxy compounds, nitriles, amides, imides or halides. Also included is chlorinated polyethylene containing from 10 to 60% chlorine by weight based on the weight of the chlorinated polymer.

The preferred comonomers which can be used in compositions according to the present invention are those with the formula

I^RgC = CR^R^, where R1 and is hydrogen or C1 to C^Q-hydrocarbyl, preferably alkyl,

R 2 is -COOH, -COOR^, -OR,., -COR^, -SR,., -R^ or -R^, wherein

is hydrocarbyl, such as alkyl, or alkaryl, provided that an optionally present saturated linear side chain contains less than 18 carbon atoms,

R^ is R^ Rg, -CONRjRy -CHgOH, -CN, -CHgNR^R^> halogen or -NCO.

Suitable ethylenically unsaturated compounds with which ethylene can be copolymerized include the following: (1) Carboxylic acids, e.g. acyl, methacylic, vinylacetic, fumaric, maleic and itaconic acid, (2) C₁ to C₂ esters (especially alkyl) of unsaturated carboxylic acids, e.g. of the type mentioned above. Such esters include e.g. methyl, ethyl, butyl (both normal and iso), hexyl esters of acrylic acid, methacrylic acid, fumaric acid or maleic acid, (3) amides, imides and anhydrides, e.g. amides, imides and anhydrides (where these exist) of the above-mentioned acids. One can e.g. use maleic anhydride, acrylamide, maleimide or itaconamide, (4) unsaturated hydroxy compounds, e.g. alcohols, polyols and phenolic compounds. One can thus use allyl alcohol, but-1-en-l-ol, hydroxyethyl methacrylate, eicos-4-en-l-ol, but-2-en-l, 4-diol, para-allylphenol (chavicol), (5) unsaturated amines and nitriles, e.g. allylamine, allyl cyanide, 1-amino-but-2-ene, 1-amino-hex-5-ene, dimethylaminoethyl methacrylate, dimethylaminomethacrylate, or acrylonitrile, methacrylonitrile, (6) alkenyl alkyl ethers, styrenalkenyl halides, unsaturated aldehydes or ketones. One can thus e.g. use vinyl methyl ether, vinyl ethyl ether, allyl n-hexyl ether, styrene itself, a-methyl styrene, p-methyl styrene, vinyl chloride (equivalent to chlorinated polyethylene), allyl chloride, acrolein, methyl vinyl ketone, or cinnamaldehyde, (7) unsaturated esters of saturated carboxylic acids, e.g. vinyl or allyl esters of C₁ to C₁ monocarboxylic acids, e.g. vinyl acetate, allyl acetate, vinyl butyrate, or isopropenyl acetate, (8) olefins containing a saturated chain of less than 18 carbon atoms, preferably less than 9 carbon atoms. Suitable olefins include propene, butene-1, butene-2, hexene-1 and styrene. The ethylene/olefin copolymer can preferably be prepared by using Ziegler catalyst systems, e.g. aluminum triethyl and titanium trichloride.

Type B copolymers can usually be prepared by polymerization using a peroxide initiator, e.g. di-t-butyl peroxide, e.g. in the manner described in

• Norwegian patent no. 122 715 or by one Ziegler catalysis i

the case where one has ethylene and compounds of formula RjRgC = CR^Rj^ where R± to R^ are all hydrocarbyl.

The resulting polymer should contain 50 mol-$ of ethylene, especially 82 to 99 mol-#, especially 86 to 97 mol-# of ethylene, and 1-18 mol-$, e.g. from 3 to lh mol-$ of the substituted ethylene. Such copolymers preferably have a number average molecular weight from 1,000 to 60,000, e.g. between kOOO and 20.<300.

In the polymer mixture, the ratio type A to type B can vary, and variation with respect to this ratio will often substantially affect the pumpability of the oil or fuel to which the mixture is added. Generally, however, it has been found that a weight ratio between A and B of between 1:5 and 5:1" e.g. 1:2 and 2:1, will be effective.

Said polymers are particularly well suited for use in crude oils or relatively heavy fuels. The polymers can be added to the crude oil at any stage. They can thus be added at the bottom of the hole, i.e. to the upflowing crude oil, at a point very close to the bottom of the hole, thereby preventing or reducing paraffinic deposits on the walls of the pipe. The preferred heavier fuels are of two types. Firstly, there are the residua-containing fuels which are defined as a fuel containing residua from a distillation at atmospheric pressure of a crude oil or shale oil or mixtures thereof. Secondly, there are "flash distillate fuels", which are defined as distillate fuels obtained by a flash distillation at reduced pressure of the residues obtained by a distillation of a crude oil at atmospheric pressure.

Typically, the residue-containing fuel will contain from 35 to 100 wt% of residue, and will typically have kinematic viscosities in the range of from 10 to 3,500 cp at 37.7°C. However, the viscosity of certain waxy fuels can be very difficult to measure accurately at 37-7°C, and it is well known that the viscosity of such fuels can be measured at higher temperatures. The viscosity at 37-7°C can then be obtained by extrapolation, using a R.E.F.U.T.A.S. viscosity temperature chart. The extrapolated kinematic viscosity will then fall in the desired range at 37-7°C. The R.E.F.U.T.A.S, temp eratur vi sco site t sdiagramme t was designed by C.I. Kelly, M.Sc. (Tech.), F.I.C., M. Inst. Pet., A.M.I.A.E. copyright in Great Britain and the United States by Baird and Tatlock (London) Limited, lk- 17 Cross Street, Hatton Garden, London E.C.l,

It is preferred to use fuels with kinematic viscosities between 15 and 1500 cp at 37»7°C, and also fuels where at least 6o $ boils above 2é0°C at atmospheric pressure.

Fuels such as the present invention can be used

on, therefore includes light, medium, heavy and bunker fuels, with viscosities from 10 - 3500 cp at 37-7°C, but the maximum viscosity, however, will usually be approx. 1500 cp at 37.7°C. Examples of suitable fuels are described in Pt 3 Industrial

and Marine Fuels BS 2869 jl°57.

Crude oils from which the aforementioned fuels are derived can also be used.

The polymer mixture is added to the crude oil or the heavy fuel, preferably in amounts of from 0.0001% by weight and upwards, e.g. between 0.0001 and 10 #, preferably between 0.001 and 10 wt-$ o, more especially between 0.01 and 1.0 $, more especially between 0.02 and 0.4 *$>, e.g. about. 0.3 weight-$ based on the weight of the fuel.

In cases where the polymer mixture includes two or more polymers, these can be added separately to the oil or fuel, or they can be mixed in advance.

The oil or fuel may also contain other additives, e.g. salting-out chemicals or combustion-improving additives etc.

Example 1.

Two copolymers were prepared:

Type A - a copolymer of (1) a C^Q+-alkenylsuccinic anhydride (ASA), (2) pentaerythritol and (3) a mixture of C20"<C>22~ fatty acids. This copolymer had a number average molecular weight of about 2500, and was produced by converting raw materials at approx.

200°C for 6 hours during distillation of eliminated water. The molar ratio (1):(2):(3) was 1.45:1.0:1.9* Said alkenyl succinic anhydride was prepared by reacting maleic anhydride with an -olefin with a molecular weight of approx. 650 (C.jq+) produced by a polymerization of ethylene.

Type B - a random copolymer of 72" wt-$ ethylene and

28 weight-$ vinyl acetate with a number average molecular weight of approx. 20,000. This was produced by copolymerizing ethylene and vinyl acetate at a pressure of approx. l430 kg/cm , using oxygen as the starting compound. The technique used is of the type known for an ethylene/vinyl acetate copolymerization.

The two copolymers A and B were mixed together and added

in a concentration of 0.10 and 0.05 wt-# to a residual fuel, a Libyan residuum, with the following characteristics:

Upper pour point 40.1°C

F.V.T. 376 °C

,0 n

Kinematic viscosity 60 C 118.3 cp

98.8°C 24.03 cp

As a comparison, copolymer A alone and copolymer B alone were added to said fuel, in each case at a concentration of 0.15% by weight.

The following table I shows the results obtained:

(1) The upper pour point was determined by the Institute of Petroleum

Method 15/67.

(2) Said 25 Poise Ferranti viscosity limit was determined by the method described in J.Inst. Pet., March I966. The limit was measured in °C, and is the temperature at which the sample

viscosity is 25 Poise, The viscosity is the Institute of Petroleum's pumpability - "I.P. Pumpability".

Example 2.

In this example, copolymers A and B were prepared as described in example 1, used together with two other copolymers A<1> and

A".

A' - is a type A copolymer with equimolar amounts

of vinyl acetate and behenyl fumarate, and with a number average molecular weight of approx. 20,000. This was produced by a polymerization where a benzoyl peroxide starting compound was used.

A" - is a type A copolymer, i.e. an acrylated polystyrene with a number average molecular weight of approximately 10,000, and which was prepared from behenic acid in the manner described above.

Mixtures of B either with A, A' or A" were added to the same Libyan residue as indicated in Example 1. For comparative purposes, the four copolymers A, B, A' and A" were added separately.

The results obtained are indicated in the following table:

It appears that optimal properties are achieved with minimal amounts of additive when copolymer B is combined with one of the polymers A, A<1> or A". This can, for example, be illustrated with regard to B and A' in a weight ratio of 1:1 , on the two attached diagrams. (Fig.

1 and fig. 2).

Example 3.

Mixtures those indicated in Example 2 were prepared

by using copolymers A, B and A'. These mixtures were added to North African heavy residual fuel with the following characteristics:

It can again be seen that optimal results are generally achieved with minimal amounts of additive, when copolymer B is combined either with polymer A or A<1>.

A combination of the two polymer types used is achieved

a synergistic effect. From example 1, it thus appears that the combination of 0.10 weight percent A and 0.05 weight percent B, which gave a pour point of 13.8°C, was more effective than could be expected from the sum of the improvement achieved for this amount of A polymer and B polymer. Thus, 0.15 weight percent A reduced the pour point from 40.1° to 15.5°C, or an improvement of 2i».6°C. It would thus be expected that 0.10% would give 2/3 of the improvement, or an improvement of 16.4° (ie 2/3 of 24.6°). Furthermore, if 0.15 weight percent B reduced the pour point of the oil from 40.1° to 32.2°C, or an improvement of 7-9°, one would expect that 0.05 weight percent B would lower the pour point by 2.6°C. One would therefore expect that 0.10 weight percent A would reduce the pour point by 16.4°, while 0.05 weight percent B would reduce the pour point by 2.6°, or a total reduction of 19°C. In reality, the reduction was 40.1° 13.8° or an improvement of 26.3°C, or an improvement that is 7.3° more than what would be expected.

By choosing the indicated polymeric compounds, one can thus achieve more than just a purely additive effect. Table II shows, for example, that the combination of the A and B copolymers has reduced the pour point to an extent that is greater than would have been achieved through the additive effects of the copolymers A and B alone. From fig. 1 further shows that the 1:1 weight combination of A' + B gave a much lower upper pour point at any particular concentration than would have been obtained by averaging the pour points at A' and B in fig. 1. At a concentration of 0.05 percent by weight, additive A' alone would thus give a pour point of approx. 16°, while B alone would give a tipping point of approx. 32°. It would thus be expected that a 1:1 combination would give a pour point of approx. 24°. As can be seen from fig. 1, however, the 1:1 combination of A' + B gave a pour point of approx. 18°C.

Fig. 2 shows that additive A', which gave lower pour points

(Fig. 1), was more viscous, requiring a higher temperature to produce a viscosity of 25 poise in the pumpability test. Additive B, which gave the best results in terms of pumpability (Fig. 2), was less effective in terms of pour point (Fig. 1). The combination of A' + B resul-

however, in approximately the average of the viscosity temperature results in fig. 2, but as pointed out in connection with fig. 1, this combination gave a synergistic improvement with respect to the pour point. Thus, while fig. 1 shows that A' alone would be more desirable than the combination at concentrations of 0.05, fig. 2 that A' alone gives the highest temperature-pumpability limit and that the total improvement is achieved using the combination of A' + B.

From Table II it appears that the combination of B + A" consistently gave pour point and viscosity-temperature values, i.e. the temperature at which the 25 poise viscosity is reached, which is much more advantageous than the values of each of the materials alone. 0.025 weight percent of 1:4 the combination of B + A" gave e.g. a pouring point of 22.6 combined, compared to 32.7 for A" alone and 33-3 for B alone. At the ratio 1:2

for B + A" even better results were obtained, as the combination gave a tipping point of 2.2°. As for the combination A + B, the ratio 1:1 at 0.16% by weight gave a tipping point of 5.5°C, while 0.15%

of B alone gave a slope of 32.2 and 0.15% of A alone gave a slope of 15.5°. Even if the amounts cannot be directly compared, it should still be clear that the combination gave better results than each component alone. For the 4:1 ratio of A + B, it appears from the table that an even greater effect is achieved, as at a level of 0.075% a tilt point of 12.2° was achieved, while B alone at 0.05% gave a tilt point of 32.2° and A alone at 0.15% gave a tipping point of 15-5° (see

table II). Similar results appear from the table in example 3, where the combination of A' + B is consistently better than the results obtained with each material alone. By e.g. the concentration of 0.02 gave A' alone a pour point of 29.3°; B alone gave a pour point of 32.2°, while the combination gave a pour point of 6.0°. Likewise, the combination B + A gave a tipping point of 27.7° compared to a tipping point of 32.2° for 0.02% B and a tipping point of 27.7° for 0.05% A.

Claims (34)

1. Hydrocarbon-containing composition comprising a major part by weight of a crude oil or a fuel, comprising residues from the distillation of crude oil, or a flash distillate fuel, character characterized in that it comprises: at least one known per se polymer A with a number of substantially linear paraffinic side chains, each containing at least 18 carbon atoms, and where the polymer is derived directly or indirectly from a homo- or copolymerization of a compound containing an organic group that can be polymerized, and at least one known per se polymer B which is a copolymer of ethylene and one or more ethylenically unsaturated compounds, so that the copolymer contains at least 50 mole percent polymerized ethylene units, and where the rest are ethylenically unsaturated compounds with a double bond, preferably a terminal bond, and where any substantially linear paraffin chains contain less than 18 carbon atoms. 2. Composition according to claim 1, characterized in that each of the mentioned side chains in polymer A contains at least 22 C atoms. 3. Composition according to claim 1 or 2, characterized in that polymer A is a homo- or copolymer of a compound where said organic group is adjacent to an essentially linear paraffinic chain containing at least 18 C atoms. 4. Composition according to claim 3, characterized in that polymer A is a homo- or copolymer of long-chain acrylates, methacrylates, fumarates or maleates. 5. Composition according to claim 1 or 2, characterized in that polymer Å is a copolymer of vinyl acetate and behenyl fumarate. 6. Composition according to claim 1 or 2, characterized in that polymer A is a reaction product of (I) said directly or indirectly derived homopolymer and (II) a long-chain compound with an organic group which can react with the organic group in the homopolymer, and where the organic group in the long-chain compound is adjacent to an essentially linear, paraffinic chain containing at least 18 C atoms. 7. Composition according to claim 6, characterized in that polymer A is the reaction product of polyacrylic acid, polymethacrylic acid or polymaleic anhydride with behenyl alcohol. 8. Composition according to claim 1 or 2, characterized in that polymer A is the reaction product of (I) a long-chain compound containing an organic group adjacent to an essentially linear paraffinic chain containing at least 18 C atoms with (II) a copolymer of a mixture of monomers where at least 25 mole percent contain an organic group that is reactive with the long-chain compound. 9.. Composition according to claim 8, characterized in that polymer A is the reaction product of a long-chain alcohol with a copolymer of (I) an acrylate ester and acrylic acid or (II) an α-olefin and maleic anhydride or (III) styrene and maleic anhydride. 10. Composition according to claim 9, characterized in that said long-chain alcohol is behenyl alcohol. 11. Composition according to claim 1 or 2, characterized in that polymer A is a condensation polymer. 12. Composition according to claim 11, characterized in that polymer A is a condensation polymer of an ester <*> of an ethylenically unsaturated alcohol and an ester of an ethylenically unsaturated carboxylic acid, and where at least one of the mentioned esters has an essentially linear paraffinic chain with at least 18 carbon atoms. 13. Composition according to claim 12, characterized in that polymer A is a copolymer of vinyl acetate and a C-4 to C4-alkyl fumarate or maleate. 14. Composition according to claim 13, characterized in that polymer A is a copolymer of vinyl acetate and behenyl fumarate. 15. Composition according to any one of the aforementioned claims, characterized in that polymer A has a number average molecular weight of between 1,000 and 100,000. 16. Composition according to claim 1 or 2, characterized in that polymer A is an acyl or alkyl polystyrene, where the acyl or alkyl radical contains at least 18 C atoms. 17. Composition according to claim 16, characterized in that polymer A is a C22-^0-acylpolystyrene. 18. Composition according to claim 17, characterized in that polymer A has a number average molecular weight between 1,000 and 25,000. 19. Composition according to claim 11, characterized in that polymer A is the condensation product of (I) a dicarboxylic acid, an anhydride or ester thereof, where there is a C^g- to C^-hydrocarbyl group attached to the carbon chain that connects the two carbonyl groups in the acid, anhydride or ester, and (II) an alcohol, an amine or a hydroxyamine, each having three or more hydroxy, primary amino or secondary amino groups, and (III) a monocarboxylic acid, provided that if there are only two or three bon atoms in the carbon chain 3om connecting the carbonyl groups in the dicarboxylic acid, the anhydride or the ester, then any amino group in component (II) must be a secondary amino group. 20. Composition according to claim 19, characterized in that polymer A is the condensation product of C₂Q+-alkenylsuccinic anhydride with diethanolamine and a mixture of C₂₂₂₂ fatty acids. 21. Composition according to claim 19 or 20, characterized in that polymer A has a number average molecular weight of between 1000 and 5000. 22. Composition according to claim 11, characterized in that polymer A is the condensation product of (1) a dicarboxylic acid, anhydride or esters thereof, and where the number of carbon atoms in the chain connecting the two carbonyl groups is from 1 to 12, and (2) a polyol containing at least four hydroxy groups, where all the carbon atoms in the beta position with respect to a hydroxy group must be tertiary carbon atoms, and (3) a monocarboxylic acid, provided that either reactant (1) or reactant (3) or both, has a carbon and hydrogen-inclusive group containing at least 8 carbon atoms, and which is either attached to one of the carbon atoms in the carbon chain, which connects the two carbonyl groups in (1) or is linked to the carbonyl group in the acid (3). 23. Composition according to claim 22, characterized in that polymer A is the condensation product of a C22 2g-alkenyl or C^Q+-alkenylsuccinic anhydride and pentaerythritol and a mixture of <C>2Q-C22<->fatty acids. 24. Composition according to claim 22 or 23, characterized in that polymer A has a number average molecular weight of between 1,000 and 20,000. 25. Composition according to any of the aforementioned claims, characterized in that. polymer B is a copolymer containing 82 - 99 mole percent of polymerized ethylene units. 26. Composition according to claim 25, characterized in that polymer B is a copolymer of ethylene and a comonomer with the formula: R1R2C = CR^R^, where R^ and R^ are hydrogen or C, to C1Q hydrocarbyl, preferably alkyl, R2 is -COOH, -C00R5, -OR5, -C0R5> -SR5> -R^ or -R5> where R^ is hydrocarbyl, such as alkyl, or alkaryl, provided that an optionally present linear side chain contains less than 18 carbon atoms, R^ is R^ R 2 , -CONR-jR^, -CH 2 OH, -CN, -Ch^NR^, halogen or -NCO. 27. Composition according to claim 25 or 26, characterized in that polymer B is a copolymer of ethylene and acrylic acid, methacrylic acid, fumaric acid or maleic acid, or their - C 1 -alkyl esters or anhydrides. 28. Composition according to claim 25 or 26, characterized in that polymer B is a copolymer of ethylene and styrene or an alkylstyrene. 29. Composition according to claim 25 or 26, characterized in that polymer B is a halogenated polyethylene. 30. Composition according to claim 25 or 26, characterized in that polymer B is an ethylene/vinyl acetate copolymer. 31. Composition according to claim 30, characterized in that polymer B has a number average molecular weight of between 1,000 and 60,000. 32. Composition according to any of the aforementioned claims, characterized in that the weight ratio polymer A to polymer B is from 1:5 to 5:1. 33. Composition according to any one of claims 1-32, characterized by containing a total of from 0.0001 weight percent to 10 weight percent of polymers based on the weight of the crude oil or fuel. 34. Composition according to claim 33> characterized by containing from 0.01 to 1.0 weight percent polymers based on the weight of crude oil or the fuel.