DE2338727A1 - HEATING OIL WITH REDUCED STOCK POINT - Google Patents

Description

Patent assessor Hamburg, July 20, 1973

Dr. G. Schupfner 726 / ik

Deutsche.Texaco AG

2000 Hamburg 76 Q? 73 077 (D 73,260-i ¹ )

Sextuple gate 2

TEXACO DEVELOPMENT CORPORATION 135 East 42nd Street New York, N.Y. 10017 UNITED STATES.

Heating oil with a reduced pour point

The invention relates to heating oils containing heavy vacuum gas oils as the main constituent, due to their considerably reduced pour point for transport in pipelines (pipelines) are particularly suitable.

In the petroleum industry, gas oils are crude oil fractions between kerosene and lubricating oil, however, there is one over the length of the boundaries can. The heavier, i.e. higher-boiling gas oils that are available under reduced gas oil are referred to as vacuum gas oils Pressure, i.e. at 0.05-0.2 atm., Is maintained.

Mineral oils that are exposed to low temperatures require, in order to maintain their fluidity, for example for transport in pipelines, or to meet the pour point specifications usually the addition of a pour point depressants, many classes of which are known.

These agents or additives, which lower the pour point, are mostly high molecular weight substances that can be obtained by alkylation of benzene, naphthalene and their derivatives, by polymerization of low molecular weight methacrylates or by Interpolymerization of such compounds produces.

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Many of these known additives are for pour point depression of vacuum gas oils because they are either expensive, require high concentrations or do not sufficiently lower the pour point of vacuum gas oils containing higher molecular weight paraffins.

Many of these pour point depressants are in heating oils, Diesel oils and similar mineral oils can be used, but not very effective for vacuum gas oils, the higher molecular weight paraffins contain. The poor effect of such additives may be explained by structural and / or molecular weight differences the paraffins contained in the various mineral oil fractions.

Attempts have been made so far in two ways, the pour point properties of paraffin-containing vacuum gas oils, namely by means of dewaxing Solvent extraction and centrifugation.

The first of these modes of operation requires the use and recovery of large quantities, which are relatively more expensive Solvent, which is necessarily expensive. In the case of dewaxing by centrifugation, the first step is a diluent, such as heavy gasoline, is added and then the mixture is brought to a low temperature, about -32 C, cooled, but this is time-consuming and also expensive. Another V / eg sees the Thermoeracken the paraffin-containing vacuum gas oils. The thermal cracking process leads to a lowering of the pour point from about -12 to -7 ° C, but also to a loss of considerable parts of the volume of the vacuum gas oil. It therefore exists The need for an economical method of lowering the pour point of paraffinic gas oils, the is around 15 - 38 ° C.

The invention is based on the problem of the flow properties of heating oil, the paraffin-containing vacuum gas oils Contains as the main ingredient, without dewaxing

233872?

to improve by adding suitable pour point depressants.

Another object of the invention is on paraffin-containing Gas oils create built-up fuel oils that can be found in pipelines at temperatures close to their pour points can be transported more easily.

The invention relates to a heating oil with a reduced pour point, characterized by the following composition:

a) a vacuum gas oil with a boiling range of about 232 - 566 ° C and a paraffin content of about 0.5-20 % by weight as the main component,

b) a petroleum distillation residue with an asphalt content of about 4-15% by weight, a density of about 5-20 ° API and a coke residue of about 5-25 % by weight in a proportion of about 1-20% by weight. -% and

c) a proportion of about 0.002-3% by weight of a poly (n-alkyl acrylate) copolymer which lowers the pour point and has a molecular weight of about 3,000-100,000 and in which the n-alkyl groups have at least about 18 carbon atoms !, at least about 70% of η-alkylene groups 20 - having 24 carbon atoms to about 2 - 65 wt .-% of C ^ Q-alkyl groups, to about 18 - 65 wt .-% of Cpo-alkyl groups and from about 8 -35 wt .-% consist of Cp ^ -alkyl groups, and the copolymer was incorporated into the mineral oil mixture at a temperature above the dissolution point of the paraffin content.

As has surprisingly been found, the pour point of a vacuum gas oil is considerably reduced if a small proportion of a distillation residue rich in asphalt is given to it together with a small proportion of an oil-soluble poly (n-alkyl acrylate) copolymer. clogs. If you contrast ÖE ^ vacuum gas oil is added only Hüekstand or only poly-acrylate, is to reduce the pour point of the

Α098Ί9 / 0635

Fuel oil mixture substantially, less, so that both additives apparently act synergistically

As a main component of the fuel oils according to the invention Vakurnngasöle are suitable which a paraffin content of about 0.5 - 20 wt .-%, a ASTH-Stοckpunkt of about 15 - 38 ⁰ C, a boiling range (at atmospheric pressure) of about 232 - 56G ⁰ C and have a density of about 20-35 ° API and usually in the distillation of Koherdclen, such as Arabian light crude oil (Arabian Light) at reduced pressure of about 0.05-0.2 atm. Typical vacuum gas oils that can be used are desulfurized Arabian Light vacuum gas oil (DS Arabian Lt. VGO), desulfurized lago Hedio Vakmimgasöl (DS Lago Medio VGO), Arabian Light vacuum gas oil (Arabian Lt. VGO), Lago Medio Vacuum gas oil (Lago Medio VGO) and Amna vacuum gas oil, the properties of which are shown in Table I below:

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σ> to crt

GoFÖl

Boiling range, ⁰ C pour point, ⁰ C (ASTM-D-97) sulfur, 96% paraffins by weight, 96% by weight Kinera. Viscous, at 50 ⁰ C,

cSt.

Kinem. Viscous, at

API density, 15.6 ^° C

cSt.

Tabel I. LaRO Medio Arab. Lt. Amna-Vak. D.S. Lt. D.S. Lapjo VGO VGO Gas oil Arab. VGO Medio VGO 232-566 343-566 343-482 343-566 343-566 32.2 35 35 32.2 32.2 1.4 2.6 0.30 0.23 0.16 <-Ί0 17.3 ~ 11 "-" 10

11.5

32.6

Gas oil distillation,% by volume at_ ° _C

SB *) - 5% by volume

10-20 "

30-40 "

50 "

6Ο-7Ο "

60-90 "95 - SE **)

308.2

335.6-370

375.8-390

399

410.6-424.6 439.5-458.2 469 -481.5

37.2

25.5

27.0

28.1

16.2 27.0

233.9-281 307.8-339 365 -395 414.8
432-457 472.2 +

58.0 20.0

360.6-398.4

411.7-429

440.5-453

464.8 +

'SB = start of boiling

= End of boiling point

Among the asphalthenreichen residual oils that are suitable for the novel fuel oils, are maintained at a temperature of 343 C or higher leave-distillation residues of Arabian Light - Lago Medio crude oil, a thermally cracked heavy fraction of Amna crude oil (34J ⁰ C or higher ), sulfur-containing residue (343 ° C or higher) from West Texas crude oil, and thermal cycle heating oils made from various crude oils. These distillation residues should preferably have an asphaltene content of approximately 4-15% by weight and a coke residue of approximately 5-25% by weight. The density of these residual oils is about 5-20 ° API (at 15.6 ⁰ C). The proportion of these residual oils in the heating oils according to the invention can be varied within wide limits and should be at most about 20% by weight, preferably about 1% by weight.

It should be noted that these residual oils not only reduce the pour point-lowering effect of the poly (n-alkyl acrylates) synergistically increase, but also increase the calorific value of the heating oil. The properties of typical residue fractions, which are suitable for the heating oils according to the invention are listed in Table 2:

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Setting point, ⁰ O (at 50 °
cSt » Weight% Table 2 48.9 + Amna
Back
(482 hours.
⁰ C) Arab.Lt.
Residual
(566 ⁰ C) * Cracked things
Amna-Rohol
(510 c) I. (at 98,
cSt. 2.8 48 , 9 + 48.9+ 21.1 I. API density, at 15.6 ⁰ O - 0, 31 3.2 0.29 Coke residue, Properties of the still bottoms 1700. - - - O
CD Therm. Circulatory Lake Medio
heating oil return 9.8 , 9 149 ⁰ C) 469 OO
CD Sulfur, wt. ~% 1.67 20.4 14, 8th 9.2 / 063 Kinem. Viscous. 0.87 17 » 17.1 cn Kinem. Viscous. 392 9 ⁰ C),
46.2 8.0

Asphalthene (in eC, - * ·
Insolubles), wt .-%

12th

The fritted component of the heating oil according to the invention is formed by a poly (n-alkyl acrylate) copolymer which is soluble in gas oil and has a molecular weight of about 3,000-100,000, preferably about 4,000-52,000, particularly preferably about 15,000-35,000, in in which the alkyl groups contain at least about 18 carbon atoms and at least 70% by weight of the alkyl groups contain 20-24 carbon atoms, with about 2-65% by weight of the C 1 -C 4 -alkyl groups from CpQ-alkylene, about 18 - 65% by weight of C _O p -alkylene and about 8 - 35% by weight? » consist of Cp ,, - alkylene. These copolymers can be prepared by a customary esterification of acrylic acid with an alcohol mixture and polymerization of the alkyl acrylate ilor.oraeren in the presence of a catalyst such as azobisisobutyionitrile, which is described in US Pat. No. 2,471,959, or known peroxide catalysts such as benzoyl or Lauroyl peroxide, produce using about 0.1-5 wt .-% of these catalysts. The polymerization is usually carried out at about 10 66, preferably about 26-38 C under a nitrogen blanket. During the polymerization, a sample is taken periodically to determine the refractive index. The polymerization reaction continues until the refractive index remains constant. Usually the polymerization time is about 1-10 hours.

The n-alkyl acrylate monomers for this copolymerization can be prepared in the usual way by reacting acrylic acid with n-alkanol mixtures in which the reactive n-alkanols have at least about 18 carbon atoms and 70% by weight of 20-24 N-alkanols containing carbon atoms, which contain about 2-65% by weight of eicosanol, about 18-65% by weight of docosanol and about 8-35% by weight of tetracosanol. A suitable alcohol mixture is sold by Continental t) il Co. under the registered trade name "Alfole". "Alfols" are raw n-Alksnol-genic with various ICettenläiigen, and also contain minor amounts of hydrocarbons. *;, Ketones and s ^1; erisch hindered non-reactive alcohols.

409819 / U6 35

BATH ORIGINAL

A typical analysis of two suitable "Alfol" alcohols is the-following:

Properties of C number distribution of alcohols ^C 18 ^C 20 ^C 22

Alfol 20 + R Alfol 22 + E 2 1 60 5 20th 60 10 21 5 9 3 4th 70 60 123 . 90 176 150 3 6th 12th 13th 0.2 0.3 45-57.2 45-57.8 12th 18th

^C 26

^C 28+ alcohol content,% by weight hydroxyl number hydroxyl number

(for 100 % alcohol content) saponification number iodine number

CO groups,% melting range, ⁰ C color (Gardner scale)

A common method for preparing the acrylate monomer consists in esterifying the alcohol mixture with acrylic acid in the presence of an esterification catalyst such as p-toluenesulfonic acid and an inhibitor such as hydroquinone, expediently in the presence of an azeotropic agent for removing the water formed, such as benzene. The esterification can be for example at about 87-93 ^U C perform and is continued until the amount of the aborted V / ater indicates that the esterification is substantially complete.

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BATH ORIGINAL

The heating oil according to the invention can be produced in various ways from these constituents. For example, the residual oil can be mixed with the vacuum gas oil or a gas oil mixture and the polyacrylate mixed in as a solution in toluene, xylene, light lubricating oil or in the vacuum gas oil itself. A preferred solvent that facilitates the incorporation of the polyacrylate in the vacuum gas oil is a light lubricating oil preparing lubricating oil concentrate containing 50 wt .-% polyacrylate - having a kinematic viscosity of about 2-4 cSt at 37.8 ⁰ C, with one an about 10..

To the residual oil and the vacuum gas oil to about 80 prior to the addition of the polyacrylate - 150 °, preferably about 80 to 121 ⁰ C are heated, after the addition of the resulting mixture for about 0.2 to - 1.5 hours or more at this temperature be held so that the complete dissolution of the copolymer is guaranteed. It is important that the polyacrylate be incorporated at a temperature above the solution point of the paraffin component. If the polyacrylate is mixed with a vacuum gas oil at a temperature which is considerably below the solution point of the paraffin contained, the polyacrylate / residual oil combination causes little or no lowering of the pour point.

The following examples are intended to explain the invention further:

example 1

This example describes two poly (n-alkyl acrylates), namely polyacrylate A and B, and their preparation.

The monomeric acrylates A and B were made from the following Alcohols A and B produced:

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Typical properties Alcohol A Alcohol 3

C number distribution,% by weight (for 100% alcohol content)

^C 18 5 0 ^C 20 39 12th C ₂₂ 27 47 C ₂₄ 14th 2 ^C 26 7th 10 ^C 28 3 5 ^c 30 ⁽⁺⁾ 5 5 ^C 32 ^ - _ Alcohol content, approx.% 70 60 Hydroxyl number 123 90 Saponification number 3 6th Iodine number 12th 13th CO groups, % 0.2 0.3 Melting range, ⁰ C 45-57.2 45-57.8 Color (Gardner scale ") 12th 18th

These alcohols A and B became the mono-aerylates A and B manufactured using the following approaches:

link Weight ν Κ Mole Hydroquinone 2 0.02 p-toluenesulfonic acid 5.6 0.036 Alcohol A 952 2 Alcohol B 1245 2 Acrylic acid, anhydrous 144 2 benzene 536 mm

'· 0 3 8 Ί 9 ■ / 0 6 3 5

The entire batch, with the exception of the acrylic acid, was added together at about 60 ° C. under nitrogen. Then, the acrylic acid was added with stirring and the mixture is brought to a liquid temperature of about 90 ⁰ C to reflux. Nitrogen was passed beneath the surface of the liquid reaction mixture at about 40-45 ml / min as the water of reaction was azeotropically driven off at a reflux rate of 4 ml / min. After 12 hours about 96% was and after 21 hours all of the theoretical amount of water had been removed. Then, the benzene was removed by stripping at 15 torr and a Flüssigkeitsteiiiperatur of about 60 ⁰ C. The monomeric product had the following properties:

Physics. Properties of the monomer mono-
Acrylate A Mon no-
Acrylate B Saponification number 115 95 Neutralization number 1.3 1.1 Hydroxyl number 8th 14th Specific gravity, 65.6 / 15.6 ^° C 0.8316 0.8310 The break is ex 1.4450 1.4465 Kinem. Viscous., CSt.
at 65.6 ⁰ C
at 98.9 ⁰ C 7.39
3.9 8.84
4.50 Dialysis residue, % <3 <3 Melting point, ⁰ C 36 38

Polymer synthesis

These monomers were polymerized as follows:

In separate tests, 200 g each of the mono-acrylates A uüd B heated to 85 ° C for 20 minutes and pre-cleaned in the process Nitrogen at 120 ml / min. The nitrogen flow was then reduced to 40 ml / min and 4 g Azobisisobutyronitrile added. The reaction mixture was stirred, its refractive index decreased every 1/2 hour.

409819/0635

read and the reaction continued until the refractive index remained constant, i.e., fluctuated of ± 3 units to the fourth decimal. A total reaction time of about 1.5 hours was required.

The product was cooled and when analyzed gave the following values:

Refractive index Spec. Wt. (65, melting point, C.

Kinem. Viscous., CSt. at 65.6 ⁰ C at 98.9 ° C

Dialysis Residue,% Mol wt., Of the residue

Example 2

This example illustrates the composition of the invention Heating oil as well as the effect of polyacrylate and residual oil alone and together on the pour point of the heating oil mixture.

Some blends were made of desulfurized heavy vacuum gas oil as the main ingredient and a 566 C + -Residue of Arabian Light crude oil by mixing the two ingredients, $ 0 minutes at 93.3 ° C. To this mixture became the polyacrylate A (PAA) prepared in Example 1 was added at the same temperature. The tables below show the extraordinary drop in pour points as well the synergistic effect achieved by a combination of polyacrylate and residual oil.

Table 3 shows the properties of the vacuum gas oil and the vacuum residue, and Table 4 shows the pour points

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Polyacrylate A Polyacrylate B 1.4545 1.4540 0.8580 0.8495 47 48 196 115 81 4-9 55 48 23,000 20,000

the mixtures of vacuum gas oil, PAA and / or residual oil. The mixtures labeled B, F and H are heating oils according to the invention, and those labeled A, C, E and G are comparative mixtures. As can be seen from Table 4, there is practically no reduction in the pour point if only vacuum residue is added, even if its proportion is 10% by weight. However, if polyacrylate alone is added in a proportion of 0.1% by weight, the reduction in the pour point is approximately 8.3 ° C. When residue and polyacrylate are added together, the drop in pour point is on average about 16.6 ° C. For fuel oils of the composition given in Table 4, the ASTM pour point requirement is usually 15.6 ° C maximum. While the addition of the residue alone has practically no lowering of the pour point, the addition of the polyacrylate alone lowers the pour point to 15.6-18.3 ° C., which is at the limit of permissibility. The synergistic effect of adding residue and polyacrylate to the vacuum gas oil lowers the pour point to about 10 C, which meets the pour point specification well.

Table 3 Properties of the components

Desulfurized vacuum residue heavy vacuum gas from Arab. Lt. oil from Arab, Lt.

Density, ⁰ API 28.2

Spec. Wt. (15.6 / 15.6 ° C) _ '1.013

Kin. Visc. cSt at 37.8 ⁰ C (gj§ 37.73 (176)

at 65.6 ⁰ C 13.35

at 93.9 ° C 5.69 660.8

Upper ASTK Stockp., ⁰ C 26.7 35

Sulfur, wt% (X-ray) 0.20 3.9

Coke residue, wt% - 19.4

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Influence of B. PAA- Tabel 4th F. on pour point H I. A. 100 C. and or 95.0 G 97.5 V ⁿ Zxisaaimensetzg. the
Mixtures 100 0 90.0 D. Residue additive 5.0 97.5 2.5 ¹ Arabian Lt.-DS
HVGO, wt% 0 0.10 10.0 90.0 E. 0.10 2.5 0.10 Arabian Lt.-Vak
Residue, wt .-% 0 0 10.0 95.0 0 PAA,% by weight 0.10 5.0 properties +18.3 0 - +10 *) Stockp., ⁰ C +26.7 +15.6 +24 +12.8 +26.7 +10 Upper ASTH piece. ⁰ C +26.7 5.61 +24 +10 6.39 +24 5.99 Highest floor, ⁰ C 5.69 7.47 + £ 7 +21 6.00 Kin. Visc., CSt. at
98.9 ⁰ C 7.35 +24 6/42

) The highest pour point indicates to what extent the pour point of a heating oil is stable. To determine the highest pour point, the subject gas oil eawa 30 is heated to 104.4 ⁰ O min, then rapidly cooled to -17.8 C. This low temperature triggers the crystallization of the paraffin present. After 12 or more hours, the heating oil is allowed to warm to room temperature. Then the ASTM stake point is measured. ^ ₀ Distillates containing residual heating oil sometimes show an increase in the £ 3 pour point on storage. No increase in pour point was found in the heating oil mixtures according to the invention. 00

Claims (1)

Claim a) a vacuum gas oil with a boiling range of about 232 - 566 ° C and a paraffin content of about 0.5 - 20 wt .- # as the main ingredient, b) a petroleum distillation residue with an asphalt content of about 4-15% by weight, a Density of about 5-20 ° API and a coke residue of about 5-25% by weight in a proportion of about 1-20% by weight, and c) a proportion of about 0.002-3% by weight of a poly (n-alkyl acrylate) copolymer which lowers the pour point and has a molecular weight of about 3,000-100,000 and in which the n-alkyl groups have at least about 18 carbon atoms , at least about 70 % of the n-alkyl groups have 20-24 carbon atoms, about 2-65% by weight of C ^ Q-alkyl groups, about 18-65% by weight of C ^ -alkyl groups and about 8- 35 wt .-% consist of C ^ -alkyl groups find the copolymer was incorporated into the mineral oil mixture at a temperature above the dissolution point of the paraffin content. 40981 9/0635