JPH1171587A - Fuel oil containing middle distillate and copolymer of ethylene and unsaturated carboxylic acid ester as substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fuel oil containing a middle distillate and a copolymer of ethylene and an unsaturated carboxylic acid. SOLUTION: This fuel oil contains (A) a mineral oil, having <-8 deg.C cloud point, <120 deg.C boiling range (90-20%) and <10 deg.C difference between the cold filter plugging point(CFPP) and the pour point(PP) and (B) one or more copolymers containing (B1) a bivalent structural unit represented by formula (1) CH2 -CH2 and (B2) one or more bivalent structural units represented by formula (2) CH2 -CR<1> R<2> (R<1> is hydrogen or methyl; R<2> is COOR<3> , OR<3> or OCOR<3> ; R<3> is an alkyl group having at least 4 and 30 carbon atoms at the maximum) or (B2) a bivalent structural unit, represented by formula (2a) and derived from maleic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to fuel oils containing a middle distillate and a copolymer of an ester of ethylene and an unsaturated carboxylic acid and exhibiting improved cold flow properties.

[0002]

2. Description of the Related Art Crude oil and middle distillates obtained by distillation of crude oil, such as light oil, diesel oil or heating fuel oil, are crystallized as plate crystals when the temperature is lowered, depending on the place of production of the crude oil, and It contains various amounts of n-paraffins, which can be agglomerated with oil. As a result, the flow characteristics of these oils or fractions are degraded, for example, causing problems in the recovery, transportation, storage and / or use of mineral oils and mineral oil fractions. In the case of mineral oil, this crystallization phenomenon causes deposition on the pipe wall, especially during transport through the pipeline in winter, and in special cases, for example, when the pipeline is closed, when it becomes completely blocked. There is. Paraffin precipitation causes difficulties in storing and processing mineral oil. Therefore, it is necessary to store mineral oil in a heated tank in winter. In the case of mineral oil fractions, clogging of filters of diesel engines and furnaces due to crystallization occurs, which prevents reliable metering of the fuel and completely interrupts the fuel or heating medium supply flow .

Conventional methods for removing crystallizing paraffin, which are only relevant for the removal of already formed precipitates (thermally, mechanically or by using solvents)
In addition, chemical additives (so-called flow improvers or paraffin inhibitors) have recently been developed, which physically interact with the precipitated paraffin crystals and modify their shape, size and cohesive properties. This additive acts as an additional crystal seed and partially crystallizes with the paraffin, resulting in the formation of a large number of smaller paraffin crystals with altered crystal morphology. Some of the effects of this additive are:
This can also be explained by the dispersion of paraffin crystals. The modified paraffin crystals have a low tendency to agglomerate, so that the oil into which the additive has been introduced can be pumped, or at a temperature which is often more than 20 ° C. lower than in the case of oil without additives. Can be processed.

[0004] The flow and low temperature behavior of mineral oils and mineral oil fractions are determined by the pour point (measured according to ISO 3016) and the gas oil filter plugging point (measured according to CFPP: EN116).
Is defined by defining Both values are measured in ° C. Typical flow improvers for crude oils and middle distillates are copolymers of ethylene and carboxylic esters of vinyl alcohol. Therefore, German Patent Application Publication No.
According to A-11 47 799, the molecular weight is about 1,000-3,
An oil-soluble copolymer of ethylene and vinyl acetate of 000 is added to a mineral oil distillate fuel having a boiling point of about 120-400 ° C. Copolymers containing about 60-99% by weight ethylene and about 1-40% by weight vinyl acetate are preferred. These are in an inert solvent at a temperature of about 70-130 ° C and 35-2,100a
It is particularly effective when produced by free-radical polymerization at a pressure of tm (gauge pressure) (DE-A-19 14 756).

Other polymers used as flow improvers include, besides ethylene and vinyl acetate, for example, 1-hexene (EP-A-0 184 083), diisobutylene (European patent application Release No.A-0
203 554) or the following general formula

[0006]

Embedded image Wherein R 1 and R ′ are the same or different and represent hydrogen or a C ₁ -C ₄ -alkyl group (EP-A-0-099).
No. 646). Copolymers of ethylene, alkene carboxylate and / or vinyl ester and vinyl ketone are also used as pour point depressants and for improving the flow properties of crude oils and middle distillates of crude oils (European Patent Application Publication A-0-0). 111 888).

In addition, copolymers based on α, β-unsaturated compounds and maleic anhydride are also used as flow improvers. German Patent 196 45 603 describes that
Copolymers of structural units derived from 60 to 99 mol% of ethylene and 1 to 40 mol% of maleic acid, anhydrides or imides are described.

[0008] DE-A 1 162 630 discloses copolymers of ethylene and vinyl esters of straight-chain fatty acids having 4 to 18 carbon atoms in which distillate fuels having a medium boiling point, such as heating fuel oils or diesel oils As pour point depressants. European Patent Application Publication No.
A-0 217 602 discloses that ethylene copolymers with vinyl esters having C ₁ -C ₁₈ alkyl groups are used as flow improvers for mineral oil fractions having a boiling range below 90 ° C. (90-20%). Are listed.

EP-A-0 493 769 describes terpolymers prepared from ethylene, vinyl acetate and vinyl neononanoate or neodecanoate and their use as additives in mineral oil fractions. Have been. European Patent Application Publication No.A-0 746
No. 598 describes copolymers of ethylene and dialkyl fumarate as a mixture with a mineral oil having a cloud point below -10 ° C.

The effectiveness of known additives for improving the properties of mineral oil fractions is, inter alia, in their locality where mineral oil is obtained,
Therefore, it differs particularly depending on the composition. Thus, additives which are very suitable for establishing certain properties in one crude fraction will give completely unsatisfactory results in crude fractions of different origins. With increasing awareness of environmental protection, fuels with low environmental pollution during combustion have been produced in recent years. Suitable diesel fuels are less than 500 ppm, especially 10
It is characterized by a very low sulfur content of less than 0 ppm, a low aromatic content and a low density of less than 0.86 g / mL, especially less than 0.84 g / mL. These cannot or cannot be treated with conventional flow improvers. In particular, it is manufactured for use in extreme cold conditions and has extremely low temperature properties, e.g. a cloud point of less than -8C, especially less than -15C, and a boiling range of 20 to 90% by volume.
A very narrow cut below 120 ° C, especially below 100 ° C, and sometimes below 80 ° C, with a distillation volume of 95% by volume of 36%.
Winter quality diesel fuels at temperatures below 0 ° C., especially below 350 ° C., especially below 330 ° C., have problems. The low-temperature properties of such fractions can currently only be satisfactorily improved by adding low-boiling, low-paraffin components, such as kerosene.

[0011] Compositions due to narrow fractions and low final boiling point have problems with regard to the reaction behavior of flow improvers in these oils. These oils, up to about C ₁₂ -C
_It has a paraffin distribution of ₁₄ , crystallizes at normal quality, and contains only small amounts of n-paraffins with hydrocarbon chains longer than _C18 . The cloud point and CFPP values are very low, especially for winter grades, so that conventional flow improvers are useless and their low temperature properties must be set by dilution with kerosene.

[0012]

Therefore, there was a problem to develop a new fuel oil having improved low-temperature fluidity as compared with the prior art.

[0013]

Surprisingly, the main chain polymer of ethylene having side chains with more than 5 carbon atoms is suitable for lowering CFPP even in the above middle distillates. Was found. Ethylene / vinyl acetate copolymers with the corresponding comonomer content, on the other hand, are poorly soluble in hydrocarbons.

The present invention relates to a process comprising: A) a cloud point of less than -8 ° C., a boiling point range (90-20%) of less than 120 ° C. and CFPP and PP
Mineral difference is less than 10 ° C. and, and _{B) B1) -CH 2 -CH 2} - (1) bivalent structural units and B2 represented ^{_{by) -CH 2 -CR 1 R 2 -}} (2) Wherein R ¹ is hydrogen or methyl, and R ² is COOR ³ , OR ³ or OCOR ³ , wherein R ³ is an alkyl group having at least 4 and up to 30 carbon atoms. (2a) containing one or more divalent structural units of the formula (2a) or wherein component B2) is derived from maleic acid

[0015]

Embedded image The present invention relates to a fuel oil containing one or more copolymers which are divalent structural units represented by The sulfur content of the mineral oil as defined in A) is preferably less than 500 ppm, especially 300 p
less than pm, especially less than 100 ppm. These cloud points are preferably below -15 ° C. The boiling range of this fraction (90-
20%) is preferably less than 100 ° C, especially less than 80 ° C.
95% distillation point below 360 ° C, preferably below 350 ° C, especially
Preference is given to using mineral oils which are below 330 ° C.

R¹Is preferably hydrogen. R^ThreeIs preferred
Or linear or branched C_Five-C _{twenty four}Alkyl groups, especially
Preferably linear or branched C₈-C₁₈With an alkyl group
is there. Further, in a particularly preferred embodiment of the present invention, R is
Neoalkyl groups having 7 to 11 carbon atoms, particularly preferred
Neoa having preferably 8, 9 or 10 carbon atoms
Is a alkyl group. From which the above neoalkyl group is derived
Oalkanoic acid is represented by the following general formula (3)

[0017]

Embedded image (Wherein R ′ and R ″ are both preferably straight-chain alkyl groups having 5 to 9, particularly preferably 6, 7 or 8 carbon atoms). The vinyl ester used for the polymerization is represented by the following general formula (4)

[0018]

Embedded image It is represented by Other suitable comonomers are those that can be derived from acrylic acid:

[0019]

Embedded image Preferred R ³ groups such as butyl, tert-butyl, pentyl, neopentyl, octyl, 2-ethylhexyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl and behenyl. The fuel oil composition according to the invention preferably contains a copolymer in which comonomer B1) is contained in an amount of 85 to 97 mol% and comonomer B2) in an amount of 3 to 15 mol%. 4 to 10 mol% B2)
And from 90 to 96 mol% of B1) are particularly preferred.

The copolymers defined under B) can be prepared by customary copolymerization methods, for example by suspension polymerization, solution polymerization, gas-phase polymerization or high-pressure bulk polymerization. Preferably 50 to 400 MPa, particularly preferably 100 to 300 MPa
Preference is given to high-pressure bulk polymerization at a pressure and preferably at a temperature of from 50 to 300 ° C, particularly preferably from 100 to 250 ° C. The reaction of the monomers is initiated by an initiator that forms free radicals (free radical chain initiator). Substances of this class include, for example, oxygen, hydrogen peroxide, peroxides and azo compounds, such as cumyl hydroperoxide, tert-butyl hydroperoxide, dilauroyl peroxide, dibenzoyl peroxide, bis (2- Ethylhexyl) peroxocarbonate, tert-butyl perpivalate, tert-butyl permalate, tert-butyl perbenzoate, dicumyl peroxide, tert-butyl cumyl peroxide, di- (tert-butyl) peroxide, 2,
2'-azobis (2-methylpropanonitrile) and 2,2'-
Azobis (2-methylbutyronitrile). The initiator may be used alone or in a mixture of two or more substances in an amount of 0.001 based on the monomer mixture.
It is used in an amount of -20% by weight, preferably 0.01-10% by weight.

Preferably the copolymer defined in B) is
20 to 10,000 mPas at 140 ° C., particularly preferably 30 mPas.
~ 5000mPas, more preferably 50 ~ 2000mPas
Having a melt viscosity of The desired melt viscosities of these copolymers are established for a given composition of the monomer mixture by varying the reaction factors pressure and temperature and optionally by adding regulators. Hydrogen, saturated or unsaturated hydrocarbons such as propane, aldehydes such as propionaldehyde, n-butyraldehyde or isobutyraldehyde,
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone or alcohols such as butanol are useful as modifiers. Depending on the intended viscosity, the regulator is up to 20% by weight, preferably 0.05 to 10% by weight, based on the monomer mixture.
Used in quantity.

The copolymers defined under B) may contain up to 4% by weight of vinyl acetate or up to 5% by weight of other comonomers. Such comonomers can be, for example, vinyl esters, vinyl ethers, alkyl acrylates, alkyl methacrylates or higher olefins having at least 5 carbon atoms. Preferred higher olefins are hexene, 4-methylpentene, octene or diisobutylene.

In order to obtain a copolymer as defined in B),
A monomer mixture containing from 1 to 50% by weight, preferably from 3 to 40% by weight, of a comonomer in addition to ethylene and optionally a regulator is used. Because the composition of the monomer mixture differs from the composition of the copolymer, different polymerization rates of the monomers are taken into account. The polymer is obtained as a colorless melt which solidifies at room temperature into a waxy solid.

The high-temperature bulk polymerization is carried out in a known high-pressure reactor, such as an autoclave or a tubular reactor, in a batch or continuous manner, with the tubular reactor being particularly useful. Solvents, such as aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures, benzene or toluene, may be included in the reaction mixture. A technique using no solvent is preferred. In a preferred embodiment of the polymerization, a mixture of monomers, initiator and, optionally, modifier is introduced into the tubular reactor through the reactor inlet and one or more side wall inlets. The monomer streams may now have different compositions (EP-A-0 271 738
Specification).

The copolymers defined under B) are added to the mineral oil or mineral oil fraction defined under A) in the form of a solution or dispersion. These solutions or dispersions are preferably
It contains from 90 to 90% by weight, particularly preferably from 10 to 80% by weight, of the copolymer. Suitable solvents or dispersants are aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures,
For example, gasoline cuts, kerosene, decane, pentadecane, toluene, xylene, ethylbenzene or commercially available solvent mixtures such as Solvent Naphtha, Shellsol AB®, Solvesso 150®, Solvesso 200®, Exxsol® Trademarks), ISOPAR (registered trademark) and Shellsol D type (registered trademark). The fuel oil according to the invention is preferably from 0.001 to 2 on a distillate basis.
%, Particularly preferably 0.005 to 0.5% by weight of copolymer.

The fuel oil according to the invention may additionally contain an oil-soluble co-additive which itself improves the cold flow properties of the crude oil, lubricating oil or fuel oil. Examples of such co-additives are copolymers or terpolymers of ethylene containing vinyl acetate, polar compounds that disperse paraffins (paraffin dispersants) and comb-lik
e) It is a polymer.

Oil-soluble polar compounds having ionic or polar groups, such as aliphatic or aromatic amines, preferably long-chain aliphatic amines and aliphatic or aromatic mono-, di-,
Amine salts and / or amides obtained by reaction with tri- or tetracarboxylic acids or their anhydrides are useful as paraffin dispersants (U.S. Pat. No. 4,211,534).
Specification). Other paraffin dispersants are copolymers of maleic anhydride and an α, β-unsaturated compound which can optionally be reacted with a primary monoalkylamine and / or an aliphatic alcohol (EP-A-0 154). 177), the reaction products of alkenyl spirobislactones with amines (EP-A-0 413 279) and α, according to EP-A-0 606 055. It is a reaction product of a terpolymer based on β-unsaturated dicarboxylic anhydride, α, β-unsaturated compound and polyoxyalkenyl ether of lower unsaturated alcohol.

Comb polymers are polymers in which carbon groups having at least 8, and preferably at least 10, carbon atoms are attached to a polymer backbone. These are preferably homopolymers whose alkyl side chains contain at least 8, preferably at least 10, carbon atoms. In the case of a copolymer, at least 20
%, Preferably at least 30%, of the monomers have side chains (Comb-like Polymers-Structure and Properti
es; NA Plate and VP Shibaev, J. Polym. Sci. Mac
romolecular Revs. 1974, 8, 117). Examples of suitable comb polymers are fumarate / vinyl acetate copolymers (see EP-A-0 153 176), copolymers of C ₆ -C ₂₄ -α-olefins with NC ₆ -C ₂₂ -alkylmaleimides (European Patent Application Publication No. A-0
No. 320 766) and esterified olefin / maleic anhydride copolymers, polymers and copolymers of α-olefins and esterified styrene and maleic anhydride copolymers.

The novel fuel oils may contain other additives, such as dewaxing aids, corrosion inhibitors, antioxidants, lubricating aids and sludge inhibitors.

[0030]

EXAMPLES The following additives A1 to A5 were prepared: A1: imidized with coconut oil fatty alkylamine;
Ethylene MA copolymers containing MA of 30 wt% (8 mol%), A2: 7 containing VeoVa 10 mole%, ethylene -VeoVa copolymer having a V ₁₄₀ of 200 mPas, A3: 14 containing VeoVa 10 mole% and ethylene -VeoVa copolymer having a V ₁₄₀ of 270mPas, A4: 7 containing mol% of VeoVa 11, ethylene -VeoVa copolymer having a V ₁₄₀ of 84mPas, A5: ethylene and 8 mole% with V ₁₄₀ of 65mPas copolymers of stearyl acrylate, MA: maleic anhydride VeoVa 10/11: vinyl neodecanoate / Neo undecanoate V _140: plate and cone 140 ℃ (plate-and-con
e) Melt viscosity of the copolymer measured according to ISO 3219 using a measuring system Effect of additives Table 3 shows the results for different fractions from the Scandinavian refinery.
3 shows the effect of additives as flow improvers on mineral oil fractions based on the CFPP test (gas oil filter plugging test according to EN 116). The additives are used as 50% strength solutions in Solvent Naphtha. For comparison, it contained 13.3 mol% of vinyl acetate, commercially available ethylene having a melt viscosity V _{1 40} of 125MPas - vinyl acetate copolymer (EVA copolymer)
Effect of (V1) and 16 mol% of vinyl acetate and 1.2
9 shows the effect of a commercial ethylene-vinyl acetate-vinyl neodecanoate terpolymer (V2) containing mol% of vinyl neodecanoate and having a melt viscosity V140 of ₁₄₀ mPas. CFPP is measured according to EN 116, and PP is an automatic device (Her
Measure according to ISO 3016 using zog MC 852). Table 3: CFPP effect

[0031]

[Table 1] List of trade names used Solvent Naphtha Aromatic solvent mixture having a boiling range of 180-210 ° C. Shellsol AB® Solvesso 150® Solvesso 200® Aromatic having a boiling range of 230-287 ° C. Solvent Mixtures Exxsol® Dearomatized solvents with different boiling ranges, for example Exxsol D60®: 187-215
° C ISOPAR (Exxon) Isoparaffinic solvent mixtures with different boiling ranges, eg ISOPAR L: 190-210 ° C Shellsol D® Mainly aliphatic solvent mixtures with different boiling ranges

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Marx Kupets, Germany 46439 Dainsler Ken, Hohe Kamp, 1 (72) Inventor Valtraut Nagel Germany, 46147 Oberhausen, Drogner Strasse, 29 (72) Inventor Raimund Weiltwang, Germany, 46147 Oberhausen, Hans-Sachs-Strasse, 24

Claims (12)

[Claims] 1. A) a mineral oil having a cloud point of less than -8 ° C., a boiling range (90-20%) of less than 120 ° C. and a difference between CFPP and PP of less than 10 ° C. and B) B1) A divalent structural unit represented by —CH ₂ —CH ₂ — (1) and B2) —CH ₂ —CR ¹ R ² — (2) wherein R ¹ is hydrogen or methyl; ² is COOR ³ , OR ³ or OCOR ³ , wherein R ³ is an alkyl group having at least 4 and at most 30 carbon atoms) or one or more divalent structural units Wherein component B2) is derived from maleic acid A fuel oil containing one or more copolymers which are divalent structural units represented by the formula: 2. The fuel oil according to claim ¹ , wherein R ¹ is hydrogen. 3. The fuel oil according to claim 1, wherein R ³ is C ₅ -C ₂₄ -alkyl or a neoalkyl group having 7 to 11 carbon atoms. 4. The fuel oil according to claim 1, wherein R ³ is C ₈ -C ₁₈ -alkyl or a neoalkyl group having 8, 9, or 10 carbon atoms. 5. The process as claimed in claim 1, wherein the copolymer as defined in B) has a melt viscosity at 140 ° C. of from 20 to 10,000 mPas, preferably from 30 to 5,000 mPas, particularly preferably from 50 to 2,000 mPas. The described fuel oil. 6. The copolymer as defined in B) comprising 3 mol%
6. The fuel oil according to claim 1, comprising up to 5 mol% of vinyl acetate or up to 5 mol% of other comonomers. 7. The copolymer as defined in B) is a vinyl ester, vinyl ether, alkyl acrylate, alkyl methacrylate or higher olefin having at least 5 carbon atoms, preferably hexene, 4-methylpentene, octene or diisobutylene. The fuel oil according to any one of claims 1 to 6, which contains. 8. The mineral oil as defined in A) has a sulfur content of 500 p.
less than pm, preferably less than 300 ppm, particularly preferably 100 ppm
The fuel oil according to any one of claims 1 to 7, wherein the fuel oil is less than. 9. The fuel oil according to claim 1, wherein the cloud point of the mineral oil is less than -15 ° C. 10. The mineral oil has a boiling point range (90 to 20%) of 100 ° C.
Fuel oil according to any of the preceding claims, wherein the fuel oil has a temperature of less than 80C. 11. The fuel oil according to claim 1, wherein a 95% distillation point of the mineral oil is lower than 360 ° C. 12. A process as claimed in claim 1, comprising 85 to 97 mol% of comonomer B1) and 3 to 15 mol% of comonomer B2), preferably 4 to 10 mol% of comonomer B2). Fuel oil.