JPH0345693A - Additive for diesel fuel - Google Patents

Abstract

The invention relates to additives which have a deposition-preventing action on paraffin crystals and a flow-improving action in the case of middle distillates and which are based on ethylene/vinyl acetate copolymers built up from the components A) 20 - 95 parts by weight of an ethylene/vinyl acetate copolymer or an ethylene/vinyl acetate terpolymer having a specific viscosity of eta sp/c = 5 - 50 ml/g (measured at 25 degrees C in xylene), a vinyl acetate content of 25 -35 % by weight and a degree of branching of from 3 to 15 CH3 groups per 100 CH2 groups and B) 1 - 80 parts by weight of an ethylene/vinyl acetate copolymer having a melt viscosity index of from 20 to 1 000 g/10 mm and a vinyl acetate content of 15 -35 % by weight and C) 0 - 75 parts by weight of a polyalkyl (meth)acrylate having 6 to 26 carbon atoms in the alkyl radical. h

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an additive, in particular for medium distillates, which has an anti-deposition effect on paraffin crystals and a flow-improving effect.

BACKGROUND OF THE INVENTION The reversion of the oil extraction industry to partially lower quality reserves has intensified and for the first time recognized the problems encountered with petroleum products. In this connection, the paraffin content of petroleum and petroleum products should also be noted. Paraffin crystallizes when cooled,
As a result, the fluidity of petroleum or petroleum products is low, decreasing at 1A degrees and can stop altogether at sufficiently low temperatures. Upon heating, the crystallized nokurafuin generally dissolves again in the oil matrix. Technology has developed additives, so-called "pour point" reducers (the pour point temperature is the temperature at which petroleum just flows, see DIN 51597), which reduce the pour point already from 0.05 to 1. % concentration by weight (Ullmans Encyclop)
Lie der Lech-nischen Chem
ie, 4. Auflage, Band 20. Ve
rlagChemie 1981).

In practice, mainly ethylene-vinyl acetate copolymers (EVA-copolymers) were used as flow improvers for middle distillates. European Patent Publication No. 1135.81
The specification describes an additive based on a copolymer of ethylene and a vinyl ester of a carboxylic acid having 1 to 4 carbon atoms, having a molecular weight (number average) of 100 to 6000, with 20% and 90% distillation thereof. Score is 65-10
As a flow improver for petroleum fuels that differ within the temperature range of 0°C and/or as a flow improver for petroleum fuels, the 90% distillation point and the boiling point differ between 10 and 20°C, i.e. the so-called "Narrow Boiling Desthiolates".
The additive is again a mixture of two copolymers.

This patent application is based on the description in U.S. Pat. No. 3,048,479, in which one copolymer promotes the formation of paraffin wax (FR ) select the principle to be followed. Specifically, according to said European Patent Application, ethylene-vinyl acetate copolymers are used in both cases.

EP 254 284 relates to mineral oils and a method for improving the flow properties of mineral oils by adding mixtures of ethylene-vinyl acetate-diisobutylene terpolymers and ethylene-vinyl acetate copolymers. The terpolymer advantageously has a molecular weight Mn=500 to 1
0000 and preferably contains 6 to 20 CH3 groups per 100 CH2 groups in the side chain not derived from acetate groups.
have a number of individuals. The EVA copolymer advantageously has a molecular weight M
n = 500 to l 0000 and CH2 groups 10
Contains 2 to 10 CH3 groups per 0 CH3 groups.

Also, from German patent application no.
5-35% by weight and viscosity 200-l 500mPa-5
Ethylene-vinyl acetate (at 140°C)
Flow improvers for mineral oils or mineral oil distillates are known which contain copolymers and likewise ethylene-propylene vinyl acetate copolymers with 25-35% by weight of vinyl acetate and a viscosity of 200=l 500 mPa. .

JP-A-62-119296 (Chew.

Abstract;
It consists of ethylene and carboxylic acid vinyl ester having a molecular weight of 0 to 10,000.

Additives with pour point improving effects for EVA-based gasoline, kerosene and fuel mixtures are also disclosed in Japanese Patent Application Laid-Open No. 58-19498.
No. 8 (Chew. Abstr.

100, 177 634u). The additive is ethylene-vinyl ester-copolymer 2-98
%, and the remainder consists of ethylene-vinyl acetate copolymer, acrylic acid ester-ethylene copolymer, etc. Another earlier publication (West German Patent Application No. 2048308) describes, for example,
An additive of an ethylene-vinyl acetate copolymer in the form of a mixture consisting of a copolymer part with a molecular weight of 00 and a copolymer 3s with a molecular weight of 9000 is recommended.

Gra7 polymers of long-chain esters of (meth)acrylic acid to ethylene-vinyl acetate copolymers are recommended as flow improvers for middle distillates in DE 37 25 059 [Invention As is clear from the publications of the state of the art, mixtures of various types of ethylene-vinyl acetate copolymers are recommended as oil additives, in particular their fluidity. action is triggered. The idea of using a mixture is of course insufficient to derive concrete laws from it into technical means. Obviously, the type and type of oil or oil product or the place of production plays a decisive role. On the other hand, not only the composition but also the molecular weight of the polymer additive has a certain influence on its special effects.

The object of the invention was to provide additives for middle distillates of the petroleum industry. In particular, this issue has a special emphasis on “
High Final
The object of the present invention was to provide an additive which prevents the deposition of paraffin crystals, especially at low temperatures, and which improves the filterability of petroleum products.

Middle distillates are defined as conventional gas oils (boiling point range 170-350°C, especially 225-35°C), as is customary in the petroleum industry.
0°C, <TBP according to ASTM 2892), is to be understood as a fraction that includes diesel fuel, aircraft turbine fuel and fuel oil. Generally, among these, boiling ranges above 170°C, advantageously 2
Fractions with temperatures above 25 °C are used (W
innercker-Ktlchler, 4th edition, Ka
RL Hansar Verlag, Munich 1981). In particular, the use of the additive according to the invention is directed to high final boiling diesel fuels. Among these, those skilled in the art generally know that the end point is >380°C;
It should be understood that diesel fuel has a distillation point >30°C.

In particular, the additive according to the invention is suitable for medium distillates containing more than 0.5% by weight of n-alkanes with a chain length of more than 25 carbon atoms, in particular with a boiling point (at pressure cuff 60 m+w) of 360
It is used as a flow improver for middle distillates at temperatures exceeding ℃.

Means for Solving the Problem J The additive according to the invention has: A) specific viscosity +751)/C-6 to 50112/g (measured in xylene at 25°C), vinyl acetate content 25
~35% by weight and degree of branching CH2 groups per 10OS CH3
20 to 95 parts by weight of ethylene-vinyl acetate terpolymer having 3 to 15 groups / V M +1-A-1-I+-1 and B) Melt viscosity index 20 to 1 O009 / l Onam
and C) polyalkyl having 6 to 26, preferably 8 to 24 carbon atoms in the alkyl group. (Meta)acrylate 0~
75, preferably 1 to 70, especially 5 to 66 parts by weight.

If component A) is present as a terpolymer, it contains 20-35% by weight of vinyl acetate, 50-70% by weight of ethylene, and olefins, in particular represented by diisobutylene, imbutylene (which may not be used as a comonomer in its own right). a third 7-mer selected from the group of alkenes with more than 2 carbon atoms represented by alkyl-dienes or propane;
The production of the side components consisting of ethylene-vinyl acetate copolymer and terpolymer according to A) and B) above is based on the known state of the art as already mentioned. (West German Patent Application No. 36160)
56, European Patent Application No. 99646 or West German Patent Application No. 1914756).

Advantageously, the preparation is carried out in an autoclave at a temperature of 80-150° C. and a pressure of 5-16 II Pa-8 in the presence of a radical initiator, a peroxide, and in a suitable organic solvent. (Winnacker-K
uchler, 4th edition, volume 6 + 570+ Karl
Hanser Verlag, Munich 1982).

Representative materials of the type that can be used in the present invention are, for example, commercially available. Measured viscosity +ysp/c-6-50m
ffi/g is approximately the molecular weight Mw - approximately 1000-10000
corresponds to

Melt viscosity index MFI-20 to 1000 is approximately molecular weight M
In this case, corresponding to w = 20000-10000,
The last high molecular weight ethylene vinyl acetate
The copolymer corresponds to a type of commercially available hot melt adhesive.

Analytical measurements (molecular weight, etc.) on ethylene-vinyl acetate-copolymers are carried out by Brauer eLal, C
hew, Techn, 24.630=635 (1
977). Measurement of viscosity ηsp/c is as follows:
DINI342, DIN51562 and DIN7745
The production of polyalkyl (meth)acrylate C) carried out based on the method known per se is carried out using the formula I: (1), in which R1 represents a hydrogen atom or a methyl group, and R2
represents an optionally branched alkyl group having 6 to 26, preferably 8 to 24, in particular 12 to 20 carbon atoms. be able to.

Advantageously, the polyalkyl (meth)acrylates are produced using solution polymerization and in a particular embodiment in the presence of components A) and B). Suitable solvents LM include, for example, those described in the 1st field of technology that can dissolve sulfur and can be polymerized at high temperatures. Standard values include a boiling point of at least 50°C at 760a+*.

Therefore, the solvent LM is, for example, kerosene (boiling point range 180
~210°C), paraffin-based oils or gas oils.

Generally the ratio is between 80:20 and 20:80 by weight of polymer product formed to solvent LM. 60 advantageously:
40-25: Select so that 75 occurs. As a rule of thumb, the weight ratio of solvent LM to polymer is l
:1 may be sufficient.

When carrying out the polymerization of monomers of formula I, the procedure can be carried out as follows: In a suitable polymerization vessel equipped with a stirrer, a reflux condenser and a thermometer, a monomer of formula I is added in a solvent. Heat to a temperature above 50°C. Advantageously, a protective gas, such as nitrogen or a noble gas, such as argon or helium, is first introduced for a fixed period of time, for example for 1 hour, and the work is further carried out under protective gas. The polymerization is initiated by radical initiators known per se, preferably of the lipophilic type, in particular percompounds such as butyl perpivalate, tert-butyl peroctoate. The amount of initiator added is generally in the range 0.1-2% by weight relative to the monomers (H, Rauch-Puntiga@
, Th, V61ker.

Acryl-und Methacrylverbin
dungen, Springer Publishers 1967).

To adjust the molecular weight, regulators such as known sulfur-based*
*Agents, especially mercaptans such as dodecyl mercaptan, can be added in customary amounts of 0.5 to 5% by weight, based on the amount of mercaptan.

The total polymerization time can generally be about 4 to 16 hours. The polymer product can be isolated in a manner known per se, for example by precipitation, but it is particularly advantageous to be able to process it further in solution.

The polymerization of heptamers of the formula (1) in the presence of ethylene-vinyl acetate copolymers or terpolymers can also be carried out in principle in the same way: Preparation of polymers a) and b) in the solvent LM Dissolution is advantageously assisted by heating to a temperature within the range of 90±10° C., for example while stirring. Furthermore, taking into account the decomposition temperature of the initiator used, the monomers of the formula (II) are added at elevated temperatures, for example up to 90° C., and under protective gas, preferably using a metering pump and at a constant rate. Within the time period, for example 2±
Dispense within 1/2 hour. Preferably, after the end of the monomer feed, the initiator is added again, usually at about 5 to 15% of the amount already added. The total polymerization time can generally be about 4 to 16 hours.

Additives Additives according to the present invention are generally provided as relatively concentrated polymer solutions in solvent LM. Generally, the content of polymer in the concentrate is 20-80% by weight.

Advantageously, the additive is such that the oil or fraction whose flowability or filterability is to be improved contains 10 to 1 Q 00 ppm, preferably 50 to 500 ppll, of the polymeric additive according to the invention. Add in appropriate amount.

The advantageous effect of the additive according to the invention is that the middle distillate, in particular 2
Long-chain n-alkanes with 5 or more carbon atoms 0.5
This is particularly true when used with middle distillates containing more than % by weight, especially those whose boiling point exceeds 230° C. at a pressure cuff of 60 a+m. In particular, the surprising wax build-up inhibiting properties of the polymer mixtures according to the invention are only evident in diesel fuels having such a high proportion of long-chain n-alkanes. In this case, high final boiling diesel fuels, diesel fuels with partially but also general boiling point characteristics are relevant. In contrast, many diesel fuels with a small proportion of long-chain alkanes have flow-improving properties that outweigh wax build-up prevention properties.

[Effect of the invention] One of the objects that the invention sought to achieve is that wax build-up inhibiting action and also flow-improving properties are present in the entire range of middle distillates, if not mutually important segments. It was to provide additives. This object was surprisingly able to be achieved with the polymer combination according to the invention consisting of components A), B) and optionally C). It should also be noted that, in particular, the presence of component C) provides an excellent storage stability of the concentrate form of the additive according to the invention. In this connection, it should be noted that improved storage stability is not compromised by a general reduction in effectiveness.

【Example] Next, the present invention will be explained in detail with reference to Examples.

Viscosity +75 pec/c is DIN1342. DIN5
1562 and DIN 7745. Measurement of melt viscosity according to DIN 53735 and ASTM 1268-6
Based on 7.

■ Manufacture of the additive according to the invention consisting of components A), B) and optionally C) General specifications: The ethylene-vinyl acetate copolymer and optionally the polyalkyl (meth)acrylate are The mixing ratio is kerosene (boiling point 180-220℃
) in i, = 89'c - c Dissolved by stirring for 2 hours. The amount of kerosene was chosen to give a 50% solution in every case.

The following Examples I-8 were prepared using the following ethylene-vinyl acetate-copolymer or -terpolymer: EVA-AI-ethylene-vinyl acetate-diisobutylene-terpolymer (61:28:11 ηSl)+3
0/C (xylene, 25℃) -1611Q/g)EV
A-A2-ethylene-vinyl acetate-copolymer (
VA content -32% by weight+? 5 pec/c (xylene, 25°C) -1911<1/g) EVA-83-ethylene-vinyl acetate Copo 150) Tocobo 00) Tocobo 800) Tocobo 12) Tocobo 150) Limer (VA content = 28% by weight, MFI-EVA-B
4-Ethylene-vinyl acetate-IJ mama-VA content-2
8% by weight, MFI-4EVA-85-ethylene-vinyl acetyl mer (VA content - 28% by weight, MFI-EV
A-B6-Nythylene-vinyl acetyl mer (VA content - 19% by weight, MFI-EVA-B7 = Ethylene-vinyl acetyl mer (VA content - 18% by weight, MFI-
Stream side composition (placement) l EV
A-AI 50 copies 10 EVA-8350 copies 2 EV
A-A266 part 10 EVA-8434 part 3 EV
A-Al 50 parts + EVA-8550 parts 4 EV
A-Al 80fi+EVA-B320 part 5 EV
A-A250 parts + EVA-8350 parts 6 EV
A-AI 95 copies + EVA-865 copies 7 EVA
-At 90 copies + EVA-8710 copies aEVA-AI
70 parts EVA-85 20 parts PAMA-C 110 parts Example 9 EVA-A 1712.59 and EVA-B 637.5 in a round flask equipped with a saber stirrer and a reflux condenser.
Kerosene (18
(0-210°C) dissolved in 7509. Subsequently, isoCtO-methacrylate 15009 and (-butyl peroctoate 22.5
90 g of the mixture within 2 hours using a metering pump.
Add at °C. After the end of the feed, a further 1.5 g of t-butyl peroctoate was added. Total polymerization time was 16 hours. The product contains a total of 75% polymerized raw material and is fluid at room temperature (act (40°C) = 450 On+
Pa, s) and cloudy. The solidification point was +5°C. The polymerization product contained 147.5 parts of EVA-A, EVA-
862.5 parts and 50 parts of U-polyisodecyl methacrylate.

Example 10 below describes the preparation of component C).

Example IO Preparation of poly16-18-alkyl methacrylate 1 - In a four-necked flask, 600 g of tallow methacrylate,
A naphthene-based oil 6009 with a viscosity of 1,2 mm2/s at 100°C was heated to 75°C. N2 was introduced for 1 hour, then 15 g of dodecyl mercaptan and 4.8 g of t-butylperbi/(rate) were added. After 4 hours,
Another 1.29 g of 1-butyl perpivalate was added. 1
After 2 hours, the polymerization was complete.

+7 sp/c (20℃, CHCQ3) -10
+mQ/9 Reaction rate: 9g, 7% (1) Flowability improving effect of additives The flowability improvers described in Examples 1 to 8 were added to a series of products consisting of the middle distillate area. The products designated DKI to DK7 originate from the following production areas: DKI: Diesel fuel from a British refinery DK2: Diesel fuel from a German refinery DK3: Diesel fuel from a German refinery DK4: French oil Diesel fuel from Greek refinery DK5: Diesel fuel from Greek refinery DK6: Diesel fuel from German refinery DK7: Diesel fuel from German refinery.
the In5 position of Petroleu
+++lO)] is written.

DK Content of n-alkanes 17% 22% 14% 14% 24% 17% 15% Content of n-alkanes (C>25) 0.8% 0.9% 0.6% 0.9% 1.8% 0.9% 0.7% One Zel Fuel One Zel Fuel 42.8 or J Vol. 52, (5 EPP Boiling point 90 77 70 82 95 00 91 The composition of the additives is as follows. Examples 1 to 1 heated before addition.
8 and a 75% solution of Example 1O.

DKI Example 00 9 Group (ppm) 20〇12 13 -1? 00 13 15 4 9 Comparative EVA-AI Comparative EVA-A2 7 7 9 9 12 10 =lO DK2 Example 戊 (ppm) Comparative EVA-AI 1 9 7 10 11 9 DK3 Example t, (ppn+) 15 15 16 DK4 5 10 +3 9 11 11 12 9 2 14 DK5 Example 00 Composition (ppm) 00 Comparative EVA-At Comparative EVA-A2 4 DK6 Example set 00 Comparative EVA-AI Comparative EVA-A2 12 Or (ppm) 00 2 3 14 2 1 DK7 Comparison of Example EVA-AI Comparison EVA-A2 Group 00 16 14 15 8 10 Composition (pp+m) 50 ta 7 12 13 Fill a sample of DK with added wax precipitation prevention effect into a tilted 20rxQ measuring cylinder. And it was cooled to a temperature 5° C. below the cloud point (cp). Subsequently, the sedimentation of the paraffin crystals is observed as a function of time and the sedimentation rate is expressed in %. cloud point (CP
) measurements were carried out according to DIN 51597.

DKI: Addition amount 500 ppm, T--1'o, cp-+
4℃ Example Sedimentation rate 15% after 100 hours Comparison EVA-At Comparison EVA-A2 DK2: Addition amount 2 Example 6% 5% 7% 40% 80% 0ppffls Tz -3℃, Sedimentation rate CP=+2℃ Comparison EVA-AI DK3: Addition amount 20 Example 52% 53% 51% 72% 64% 68% 63% 80% 01) l) II 1% T--8℃, CP=-3℃ Sedimentation rate after 0 hours 80 After time 1 2% 2 4% Comparison EVA-A168% 7% 10% 74% DK4+ addition amount 1100pp, T--3℃, Example C
Sedimentation rate after 50 hours 12% after 100 hours 5% 3I% 3% 94% 7% Comparison EVA-AI 11% 35%P - 1,0002°C 7% after 140 hours 4% 10% 65% DK6: Addition amount 500 ppm , T--1'o, CP-
+4℃ Example Sedimentation rate after 60 hours 82% after 170 hours 11%

Claims (1)

[Scope of Claims] 1. An additive having a deposition inhibiting effect on paraffin crystals and a flow improving effect in a middle distillate based on an ethylene-vinyl acetate copolymer, the additive having a component: A) specific viscosity η sp /c=5-50ml/g
(measured in xylene at 25° C.), ethylene-vinyl acetate copolymers or ethylene-vinyl acetate terpolymers with a vinyl acetate content of 25 to 35% by weight and a degree of branching of 3 to 15 CH_3 groups per 100 CH_2 groups. 95% by weight and B) ethylene with a melt viscosity index of 20-1000 g/10mm and a vinyl acetate content of 15-35% by weight.
An additive for diesel fuel, characterized in that it is composed of 1 to 80% by weight of a vinyl acetate copolymer and C) 0 to 75% by weight of a polyalkyl (meth)acrylate having 6 to 26 carbon atoms in the alkyl group. thing. 2. Additive according to claim 1, wherein the additive contains as component C) from 1 to 70% by weight of a polyalkyl (meth)acrylate having 6 to 26 carbon atoms in the alkyl group. 3. Component C) is the formula I: ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) [In the formula, R^1 represents a hydrogen atom or a methyl group, and R^
2 represents an optionally branched alkyl group having 2 to 26 carbon atoms] in the presence of components A) and B). Or the additive described in 2.