FI83456B - Method for detection of the marking agent of petroleum products - Google Patents

Description

1 83456

Method for the detection of tracers in petroleum products

This invention relates to methods for detecting tracers in organic liquids containing a tracer, in particular petroleum-based fuels.

10 A dye is defined herein as a material that produces a visible color when dissolved in a colored product. Examples of dyes used to dye organic liquids are Solvent Red No. 24, Solvent Red No. 19, Solvent Yellow No. 14, Solvent Blue No. 15 and Solvent Green No. 3.

A tracer is defined herein as a substance that can be dissolved in an identifiable liquid and then detected by performing a simple chemical or physical test on the labeled liquid. Labelers that have been proposed or are in use include furfural, quinizarin, diphenylamine and radioactive substances. (Radioactive materials have not been approved in the West due to special equipment and precautions associated with their handling).

Dyes and tracers (collectively referred to herein as "labeling") are required to clearly separate chemically or physically similar liquids. For example, fuels are dyed to provide visually distinct species and quality designations for commercial and safety reasons. As another example, some lightly taxed products are marked to distinguish them from similar materials, which are subject to higher taxation. In addition, certain fuels are dyed or labeled to prevent fraudulent counterfeiting of high quality products with lower quality products, such as blending kerosene, fuel oil or diesel fuel with regular grade gasoline or blending standard grade gasoline with high quality gasoline. Identifying certain batches of bulk liquids to protect them from theft is another valuable 5 task for markers and dyes, especially for identifying fuels owned by large government, military or commercial consumers. Finally, traders of branded products label their products with dyes or markers to identify the substitution of their products 10 in their distribution system.

Dyes alone are not always sufficient to label liquids reliably and reliably. Many toners are easily removed by unauthorized persons. In addition, dyes can be blurred with other natural or added substances (especially dyes present in low concentrations in the fuel mixture). Because dyes alone have these shortcomings, the combination of dye and tracer is often used to label an organic liquid.

20

Many commercially used tracers are also less ideal for labeling bulk liquids. Knitsarine and diphenylamine are both quite sensitive tracers with simple detection procedures, but have the disadvantage of poor solubility in non-polar substances. Their solubility in commonly used petroleum solvents is less than 1%, which means that an undesirably large amount of concentrated tracer solution must be transported and handled to label a certain amount of fuel.

Furfural has previously been used as a tracer for medium-distillate fuels. It is extracted with 10% acetic acid in aniline to form a strongly colored bluish red complex in the lower reagent layer. While this test is quite sensitive, it has serious shortcomings.

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First, even the slightest residual furfural (sometimes used in oil refining) fuel contamination gives a false positive test result. Second, furfural is unstable in certain oils and may not be detectable in these oils after a normal storage period of 3-6 months. Third, medium fuel fuels tend to discolor significantly during storage. Aniline acetate extracts some of this discoloration and can partially or completely obscure the positive furfural grade, especially if the furfural-labeled fuel is used to counterfeit more expensive or highly taxed, unlabeled fuel.

As a typical example, furfural has been used in several 15 European countries as a fuel oil tracer in concentrations of 5-10 parts per million (ppm). Although certain relatively pure oils give a positive test result with only 0.5 ppm of furfural, inferior oils have not been found to give a distinguishable test result at even 2 ppm concentration. With such oils, no furfural tracer can be detected in mixtures containing 20-40% of labeled fuel. Thus, cheaper labeled fuel can be used in significant amounts as a diluent without being identified.

25

Furfural-labeled fuels are generally dyed red, using in particular the dyes Solvent Red No. 19, Solvent Red No. 24 or closely related derivatives. However, the aforementioned discoloration also obscures the color 30, thus visually preventing the fuel from being labeled.

Recent changes in oil refining procedures continue to threaten the usefulness of the furfural / red color combination label. In relatively pure and stable straight-run fuels, which have been prevalent until recently, furfural is an acceptable tracer. However, the combination of higher oil prices with the greatly increased demand for diesel 4 83456 fuel relative to the overall automotive fuel market has necessitated increased use of heavily cracked heavier grades of crude oil. Heavily cracked oils tend to be somewhat unstable, are relatively intensely colored when fresh, and tend to destroy the furfural used to label them. Staining and the tendency to destroy the furfural tracer both increase as these oils age. Experiments have shown that 30-40% of the furfura-10 list decomposes when stored for four days in such fuels.

Although current practice in many European refineries is to produce blends of straight-run and cracked fuel oil 15 containing 5-15% cracked product co-present with its furfural tracer, the share of heavily cracked fuel is estimated to exceed 30% in a few years. Under these conditions, furfural has little or no value as a tracer.

U.S. Patents 3,764,273 and 3,883,568 disclose 2- (2-ethylhexyl) -1,4-dihydroxyanthraquinone s

O OH

25 11 / C

[(3) 1 CH2CH (C2H5) CHaCH2CH2CH3

(T ^ OH

and other substituted anthraquinones in which the pendant alkyl moiety contains from 1 to 20 carbon atoms and are described in Patents 35 as being useful as markers for water-immiscible organic liquids. However, these tracers are shown to be colorless when used as tracers and thus do not act as both dyes and tracers at one and Selma concentrations.

U.S. Patent Nos. 3,519,117, 3,44,604 and 3,793,349 and GB Patent 1,549,873 disclose the following compounds, respectively: O NHa

NiOCHaCHaOCHaCHaOCHaCHaJa; @ φ ° τ O NHa 15 O NHa 20 O OH 25

O OH

; "

IS

35 / \ OR '/ \ 1 / / OCHaCN ^ ΓθΤ XR "; And 40

O OH

- (§0 ^ r “

O OH

In the latter compound, R is selected from the group consisting of propyl, isopropyl or ethyl and X is selected from the group consisting of chloride, bromide, cyanide and 1-4 carbon alkoxy. Typical examples of the amino substituent disclosed in the GB patent are as follows: -NHCHaCHaOCHa; 5 -NHCH2CH2CH2OCH3; -NHCH2CH (CH3) 0CH3; and -NHCH2CH2OCH2CH3.

The compounds disclosed in the four first-listed patents disclose, respectively, their utility as hair dyes, colorants, polyester fiber blue dyes, and pigments for transfer printing on polyesters, polyacrylonitriles, or paper. None of these compounds are shown to be useful as markers and dyes for organic liquids.

U.S. Patents 3,435,054 and 3,164,449, and GB Patent 452,421 disclose structurally related dyes. The dyes disclosed in the U.S. patents are for fuels and those disclosed in the GB patent are for cellulose esters and ethers.

Matsuoka et al., "A Novel 2-Amination of Quinizarin Promoted by Copper Ions", Dyes and Pigments 1: 27-37 (1980) describe the synthesis of 25 different 2-amino-1,4-dihydroxyanthraquinones.

The present invention makes it possible to determine novel labeling compounds for petroleum fuels and other liquids which are completely foreign to the compound in question. liquids; 2. may be supplied as highly concentrated solutions in compatible solvents; 3. is easy to detect by a simple field test; 35 4. are not cloudy by unstable natural components of liquids; 5. are stable during the estimated shelf life of the labeled liquid (usually 3-6 months); 7 83456 6. have characteristics which can be confirmed by laboratory methods; and 7. act as both a marker and a dye by simultaneously producing an acceptable strong red color and 5 acting as a marker in a low concentration labeled liquid.

These objects are achieved by substituted 1,4-hydroxyananthraquinones of the general formula: 10

O OH

1 ° 03Π '

O OH

Wherein R is an alkyl group selected from the group consisting of (1) groups having the following structure: - (CH 2 CH 2 CH 2 O) * (CH 2)> O (CH 2 x CH 3) wherein x is an integer from 0 to 3, y is an integer from 1 to 3 and z is 0 or 1, and (2) linear or branched hydrocarbons having n.

1-5 carbon atoms.

A preferred class of labeling compounds to be determined by the method of this invention is the class of substituted 1,4-hydroxyanthraquinones having the above structure wherein the R substituent is an ether group and z is 1. Typical examples of such compounds believed to be novel are: ( 1) 2- (methoxyethoxypropylamino) -1,4-dihydroxyanthraquinone; or (2) 2- (ethoxyethoxypropylamino) -1,4-dihydroxyanthraquinone. 40 8 83456

Another preferred class of such compounds is that wherein the R substituent is an ether group and z is 0. Typical examples of such compounds include: (3) 2- (butoxypropylamino) -1,4-dihydroxyanthraquinone; 5 (4) 2- (propoxypropylamino) -1,4-dihydroxyanthraquinone.

Examples of such compounds, the structure of which is disclosed in GB Patent 1,549,873 described above, but whose usefulness as labeling compounds combining the properties of fuel color and marker are not believed to be known, are: (5) 2- (methoxypropylamino) - 1,4-dihydroxyanthraquinone; (6) 2- (methoxyethylamino) -1,4-dihydroxyanthraquinone; and (7) 2- (ethoxyethylamino) -1,4-dihydroxyanthraquinone.

15

Additional examples of such compounds include the following: (8) 2- (methoxypropoxypropylamino) -1,4-dihydroxyanthraquinone; (9) 2- (ethoxymethylamino) -1,4-dihydroxyanthraquinone; (10) 2- (ethoxymethoxypropylamino) -1,4-dihydroxyanthraquinone; (11) 2- (ethoxypropylamino) -1,4-dihydroxyanthraquinone; (12) 2- (propylethylamino) -1,4-dihydroxyanthraquinone; (13) 2- (butoxyethylamino) -1,4-dihydroxyanthraquinone.

Typical examples of compounds in which the R substituent is a straight or branched chain hydrocarbon are as follows: (14) 2- (methylamino) -1,4-dihydroxyanthraquinone; (15) 2- (ethylamino) -1,4-dihydroxyanthraquinone; (16) 2- (n-propylamino) -1,4-dihydroxyanthraquinone; (17) 2- (n-butylamino) -1,4-dihydroxyanthraquinone; (18) 2- (n-pentylamino) -1,4-dihydroxyanthraquinone; 35 (19) 2- (2-propylamino) -1,4-dihydroxyanthraquinone; (20) 2- (2-butylamino) -1,4-dihydroxyanthraquinone; and (21) 2- (t-butylamino) -1,4-dihydroxyanthraquinone.

9 83456

One of ordinary skill in the art can use the General Overview above and the Special Examples as a guide to identify other species or mixtures thereof.

These double-acting labels are generally crystalline solids in pure form, but may be readily supplied as concentrates containing 10-30% pure compound dissolved in one or more high boiling aromatic solvents or high boiling aromatic solvents and co-solvents such as alkylphenols. The solvent chosen is also not critical provided that it is sufficiently soluble in the labeled fuel to allow the desired high final amount of label compound to be incorporated into fuel 15 and provided that the solvent does not interfere with the storage or use of labeled fuel and detection of label. Typical examples of boiling aromatic solvents useful herein are SURESOL No. 190, which consists primarily of a mixture of methylnaphthalenes and is available from Koch Refining Co., Corpus Christi.

Texas; and commercial grade xylene (mixed isomers). Typical examples of alkylphenols useful herein are commercial xylenols (which typically contain some phenols and cresols); ortho-sec-butyl-phenol; and para-nonylphenol. Significant fuel can also be used as a solvent.

The compounds are typically added to significant liquids to a concentration of 10-15 ppm as a pure compound or about 40-100 ppm as a concentrate. Such concentrations provide a color intensity comparable to that generally required for colored fuels. However, fuels that contain the lowest detectable and visible concentration of pure label compounds (less than 1 ppm) or higher concentrations of label are also within the scope of the invention. The amount of labeling compound is not critical provided that it is dissolved or stably suspended in a solvent and is as concentrated as its solubility allows.

The fuel labeled as described herein can be detected from fuel blends containing only 5-10% of the labeled fuel, whether detected visually in field inspection experiments or in the laboratory. Detection is possible in the presence of up to 25-50% heavily cracked fuel oil or gasoline, and the 10 new marking colors presented here are found to be substantially unchanged after at least three months of storage in the same fuels.

A suitable sample (20-50 ml) of the fuel suspected of containing the marked fuel is shaken or otherwise contacted with approximately 1/10 of its volume (2-5 ml) of alkaline, immiscible reagent in a suitably narrow beaker or bottle the volume is 30-120 ml and then allowed to stand.

The reagent contains about 20-60% glycerin, about 20-40% water and about 10-50% organic amine. Two preferred reagents for use herein are set forth in the Examples below. An alkaline, fuel-immiscible reagent is characteristic of these tracers, which means that the extraction of otherwise interfering alkaline reactive colored fuel components is minimized. The reagent settles to the bottom and turns bluish red if labeled fuel is present. If the sample does not contain any tracer, the reagent layer remains colorless (or very slightly yellow on some fuels).

The difference is very clear even with small amounts of tracers.

To determine the labeled fuel content in a semi-quantitative laboratory procedure, a measured sample of 35 (suitably 25 ml) of the suspected labeled fuel is passed through an activated alumina column to which all natural and added dyes adhere. Selective column washes are then used to remove substantially all of the colored material except the tracer, which is finally removed, collected, and diluted to a certain volume. The absorbance of the colored solution is measured with an instrument and related to the tracer concentration.

5

The essential features of the invention are set out in the appended claim.

The following examples are provided to illustrate how the invention may be utilized and demonstrated to be useful. These examples do not limit the scope of the present invention, but are defined by the claims that follow this specification.

Example 1 2- (Methoxypropylamino) -1,4-dihydroxyanthraquinone was prepared as follows: 60 g of 1,4-dihydroxyanthraquinone, 15.5 g of boric acid and 89 g of methoxypropylamine were slurried in 125 no water. The slurry was stirred and heated to 65 ° C and a strong stream of air was blown through it. These conditions were maintained for about 9 hours or until it was no longer possible to isolate 1,4-dihydroxyanthraquinone by thin layer chromatographic analysis of the reaction mixture.

The liquid mass (now homogeneous) was poured into a solution of 150 ml of concentrated hydrochloric acid and 300 ml of water while stirring. The crystals were allowed to agglomerate, after which the crystals were filtered, washed until free of acid and dried. The melting point of the resulting product 30 was 140 ° C.

A similar procedure is followed to form 2- (methoxyethoxypropylamino) -1,4-dihydroxyanthraquinone and the other 2-amino-substituted 1,4-dihydroxyanthraquinones 35 disclosed herein from the corresponding amine and 1,4-dihydroxyanthraquinone.

12 83456

Example 2 30 g of 2- (methoxyethoxypropylamino) -1,4-dihydroxyanthraquinone were dissolved in a mixture of 35 g of ortho-sec-butylphenol and 35 g of commercial xylene. The resulting clear, dark red solution remained pourable, stable and uniform up to -18 ° C indefinitely.

40 g of this solution was dissolved in 1,000 liters of straight-run heating oil No. 2 to form a red solution which was determined to be 100% labeled fuel. The color intensity measured by measuring instruments at its maximum absorption wavelength (512 nm) corresponded to the color intensity of a solution containing 5 g of Solvent Red No. 19 (color-15 index 26050) per 1 000 liters of heating oil measured at the maximum absorption wavelength of Solvent Red No. 19 (520 nm).

Example 3 50 ml of the 100% labeled heating oil of Example 1 was shaken in a 120 ml oil sample bottle together with 5 g of a reagent containing (by weight): 54% glycerin 2 6% water 20% methoxyethoxypropylamine

After the mixture stood for a few seconds, the reagent layer settled to the bottom and was found to stain intense red.

A 50 ml sample of sauna straight-run heating oil containing no tracer or dye was subjected to a sauna test. The reagent layer remained colorless or very slightly yellowish.

35 Example 4

The 100% labeled heating oil of Example 1 and the unlabeled control sample were stored together at ambient temperature in the dark for 3 months. The color test of Example 1 83456 and the field test of the tracer of Example 2 were repeated with essentially the same results.

Example 5 A mixture containing 10% by volume of the labeled heating oil of Example 1 and 90% of the unlabeled straight-run diesel engine No. 2 was tested according to the procedure of Example 2. The red color was again observed in the reagent layer and was clearly different from the color of the 10 reagents used to test unlabeled fuel.

Example 6

Examples 1-4 were repeated except that the fuel consisted of 15 commercial blends of 75% straight-run fuel and 25% heavily cracked fuel.

The visual and spectrophotometric color test was sometimes modified using unlabeled fuel oil in a reference-20 cell to take care of the contribution of natural oil dyes, but comparative field tests of the tracer were useful without modification. Substantially the same results were found.

Example 7 7.5 g of 2- (methoxypropylamino) -1,4-dihydroxyanthraquinone and 9.0 g of 2- (methoxyethoxypropylamino) -1,4-dihydroxyanthraquinone were dissolved to form a bright red solution in a solvent mixture containing 41.7 g of p -nonylphenol 30 and 41.7 g of mixed xylenes. The solution remained pourable, stable and uniform up to -18 ° C indefinitely.

67 g of this solution was easily dissolved in 1,000 liters of straight-35 distilled heating oil No. 2 to form a red solution, which was defined as 100% labeled heating oil. Its color intensity was equal to that of a solution of 5 g of Solvent Red nso 10 color per 1,000 liters of the same 14 83456 oil, the intensity of which was measured at the maximum absorption wavelength.

Examples 8-11 Examples 2-5 were repeated using the dye solution of Example 6 with essentially the same results.

Example 12 7.6 g of 2- (methoxypropylamino) -1,4-dihydroxyanthraquinone and 9.0 g of 2- (methoxyethoxypropylamino) -1,4-dihydroxyanthraquinone were dissolved in a solvent mixture containing 41.7 g of commercially available xylenols and 41 .7 g of commercial xylene to form a bright red solution. 67 g of this solution was easily dissolved in 1,000 liters of standard grade leaded gasoline with essentially the same results as in Example 6.

Examples 13-14 Examples 2 and 3 were repeated using the gasoline labeled in Example 11 as 100% unlabeled fuel. The results were essentially the same.

Example 15 A mixture of 10% by volume of labeled regular gasoline (prepared according to Example 11) and 90% of high quality leaded gasoline was tested according to the procedure of Example 2. The test for the labeling compound was clearly positive and the resulting reagent layer was easily distinguishable from the colorless or very slightly yellowish reagent layer obtained when the same test was performed on completely unlabeled high quality leaded gasoline.

35 Example 16 25 ml of commercial blended heating oil nso 2, containing 75% straight-run fuel and 25% highly cracked fraction and containing 65 ppm of the red label mixture defined in Example is 8 3 4 56 6, was calculated by gravity through an activated alumina column with a diameter of 10 mm and which was 50 mm long. The activated alumina was Alcoa Type F-20, chromatographic grade 5. The column was then washed with a small portion of isooctane to remove the heating oil adhering to it. At this point, the column turned a strong yellowish brown, especially near the top, while the drained fuel was clear. (The color intensity and distribution of the column depend on the natural color content of the 10 fuel samples.) Successive acetone and ethyl alcohol washings were passed through the column and eluted the natural yellow and brown colors of the fuel.

15 The labeling compound remained in the column as a purple zone, concentrated at the top of the column or spreading to some extent along most of its length depending on the fuel composition.

An eluent mixture having the following composition (by weight): 25% glycerin 35% water 40% cyclohexylamine was drained by gravity through the column. All 25 labeling compounds could normally be separated using less than 10 ml of eluent and the entire eluent was diluted to 10 ml in a volumetric flask.

The eluent was then clarified by passing it through a 0.45-0.60 30 micron particle retention membrane and its absorbance was measured at 556-557 nm. The concentration of the labeled fuel was determined by comparison with a calibration curve obtained by measuring the absorbance of fuels with known tracer concentrations.

Other primary amines such as n-amylamine, n-butylamine or methoxyethoxypropylamine were used in the above reagent without substantially altering the result, although maximum color stability was obtained with cyclohexylamine.

Claims (9)

A method for the detection of a labeling compound in organic liquids, in particular petroleum-based fuels, having either the formula 5 O OH NH (CH 2 CH 2 CH 2 O) z (CH 2) y O (CH 2) x CH 3 0 OH 15 where x is an integer from 0 to 3, y is an integer from 1 to 3 and z is an integer from 0 to 1, or the formula O OH 'ί ° Λ ° τ ..25 0 OH where R is linear or branched from 1 to 5 carbon atoms hydrocarbon, characterized in that method 30 comprises the steps of: A. taking a sample suspected of containing said label compound and a) carrying out a chemical reaction by contacting the sample B. with a reagent comprising: i. 20-60% glycerin; ii. 20 to 40 percent water; and. . iii. 10 to 50 percent organic amine; C. separate the reagent and the sample; and 40 D. determining whether the reagent develops a substantially bluish red color, indicating the presence of a label compound, or 83456 i.e. b) absorbing the label compound and concentrating it by B. passing the sample through an activated alumina chromatography column; 5 C. wash the organic liquid from the column; D. washing the natural colors of said organic liquid from the column; and E. eluting with a reagent comprising components i, ii and iii as described in aB, wherein a substantially purple zone is formed on the column, indicating the presence of said labeling compound. For the detection of markers in the form of or up to 15 times the number of markers used, the number of markers used in the formulation of the OH form is O OH or jC3TNH <CH2CH2CH2O) z (CH2) y0 (CH2) xCH3 25. OH color x is that it was 0-3, y it was 1-3 and it was 0-1, or it was 30. OH, (SOoT 0 OH 40 color R is the same as in the case of a piston with 1 to 5 collatants, which can be obtained from the following conditions: i9 83 456 A. that the present reaction number of these markers is used and (a) the chemical reaction reaction is carried out att brlnga provet 1 contact med 5 B. en reagents innehällande i. 20-60 percent glycerin; li. 20 to 40 percent watts; och lii. 10-50 percent organic Amine; C. reagents and separators; and 10 D. the best of the reagents used are substantially free of the reagents used in the light, or (b) the markers are absorbed and concentrated in the genome. B. B. the genome is activated by an alumina chromatographic column; C. the organolysis of the column; D. de naturliga färgerna av nämnda organlska vätska urätts ur kolonnen; and E. man eluting with the reagents of component 1, and in addition, the first 1 is used, the colors are substantially purple in the form of columns, and all of these are marked with these markers.