US2392620A - Identifying petroleum products - Google Patents

Description

Patented Jam 8, I946 IDENTIFYING PETROLEUM PRODUCTS Joseph W. Sparks, Hammond, Ind., assignor to Standard Oil Company, Chicago, Ill., a corporation of Indiana No Drawing. Application August 20, 1942, Serial No. 455,549

mum's. (01. 250-11) The present invention relates to improvements in the marking of normally liquid or solid hydrocarbons, particularly petroleum products so that the same can be readily detected when admixed with other materials.

'It is an object of the invention to provide a method whereby admixture or adulteration of various petroleum products can be detected. Another object'of the invention is to provide petroleum products with a material which will permit the detection or identification of such petroleum products when admixed with other petroleum products. Still another object is to provide a rapid means for. determining the presence of certain hydrocarbon materials in admixture with other similar materials. Other objects and advantages of the invention will become apparent from the following description thereof.

The desirability of being able to determine when certain petroleum products are admixed with other petroleum products or other materials is very great. For example, in pumping crude petroleum from various sources through pipe lines I it ishighly desirable to be able to determine whether oil from one source is being mixed with oil from another source. In refinery operations in which various types of oils and various oil fractions are frequently obtained from a central source it is highly desirable to be able to detect any inter-mixing of various stocks with other stocks. It is also frequently desirable to incorporate in the finished petroleum products certain substances as "markers" so that unlawful use or adulteration of such products can be detected.

I have discovered that the addition of very minute uantities of umbelliferone or umbelliferone derivatives in petroleum products provides a very efficient and effective method of attaining the above stated objects. From about 0.0000000l% to about 0.001% of umbelliferone or its derivatives such as, for example, beta methyl umbelliferone, alpha, beta dimethyl umbelliferone, or 6-chloro umbelliferone can be suitably employed for this purpose. Umbelliferone and its derivatives are strongly fluorescent infaintly alkaline media and very minute quantities of these may be done by matching the intensity of fluorescence given off by the sample being tested with a set of standards which will indicate approximatch; the degree of admixture, or adulteration.

Certain petroleum products, particularly certain petroleum crude oils, contain natural iiuorescing materials which mask the fluorescence of umbelliferone and its derivatives when they are added to such petroleum materials. Furthermore, the extraction of such petroleum products, such as crude oil and distillates therefrom, with aqueous acid media, produceextracts which fluoresce when subjected to suitable source of light. On the other hand, such petroleum products yield, on extraction with an aqueous alkaline solution, an extract which does not fluoresce when tested under a source of light. Umbelliferone and its derivatives fluoresces strongly blue in alkaline solution and this property vanishes in acid solutions. Therefore, to detect umbelliferone or its derivatives, petroleum products containing them are extracted with an aqueous alkaline solution such as an aqueous sodium bircarbonate solution, and the clear aqueous solution is separated from the oil. This clear aqueous solution is then subjected to a suitable source of light whereby excitation of fluorescence indicates the presence of the umbelliferone or its derivatives, while the absence of is used, sufllcient of the special crude is pumped materials can be detected under "ultraviolet light" such as that obtained with the General Electric type B-4 black bulb. For the detection of adulteration or unlawful use of petroleum products it is suiiicient to determine qualitatively the presence of the umbelliferone or its derivatives in the material being tested. If for various reasons it is desired to make a quantitative determination of the extent of adulteration 'or intermixing, this so that the first portion of the receipts can be considered as a wash to remove the residue left by the previous crude. This wash portion of the new crude is repeated for a period of time, which experience has shown should be sufficient to clean the entire line. However, it is obvious that ,the time required to remove all contamination may vary from crude to crude, or change with temperature conditions. Thus there is no certainty as to the exact point at which the switch over to uncontaminated crude can be made with safety.

when simultaneous pumpings ar proceeding through different pipes in the line, undesirable crude inay enter the special stream through leak in: valves in the cross-overs, operators mistakes points for various fractions.

or by contamination in the tanks which are floating on the line.

To detect the presence of undesirable crude in the desired crude oil the former is marked by adding thereto small amounts of umbelliferone or a derivative thereof such as beta methyl umbellii'erone. Thus. if it is desired to detect with certainty 1% oi the undesired crude in the desired crude the former is marked by adding thereto 1 gramo! umbelliferone in acetone solution to each 6.3 barrels oi the'undesired crude oil. This solution is equivalent to about 1 gram of the marker in 1,000,000 cc. of the oil. To detect the amount of contamination about 75 cc. of the suspected crude is extracted with cc. of a saturated solution of sodium bicarbonate and after settling for about 10 minutes the clear lower aqueous solution is poured into a suitable container and examined under ultraviolet light. By. matching the intensity oi the fluorescence with a setof standards the approximate degree of contamination can be determined.

In testing for the presence of the marker, precautions should be exercised to use clean equipment and to avoid the use of alcohol in the extraction. By clean" equipment, such as bottles, I mean equipment which when rinsed out with a saturated soda solution, will not produce a fluorescing solution. water is usually suflicient to remove the traces of the umbelliferone from a previous test.

While this invention is particularly well adapted in detecting contamination of a crude oil by another crude oil or the contamination or adulteration of normally liquid or solid petroleum products in general it is also well adapted for use in the distillation of hydrocarbon mixtures, such as petroleum oils, as well as vegetable and animal oils or fatty acid mixtures to determine the out This can be accomplished by adding to the material being distilled umbelliferone or derivatives thereof, having boiling points corresponding to the volatilizetion characteristics of the desired fractions to be separated. The invention is also well suited for investigating the migration of crud oils through oil-bearing strata.

While I have described my invention by a preferred embodiment thereof it is to be understood that the invention is not to be limited thereby except in so far as defined by the appended claims.

I claim:

1. The method of detecting the presence of a hydrocarbon in admixture with other hydrocarbons comprising adding to the first named hydrocarbon a small amount or afluorescent marker selected from the class consisting of umbelliferone and umbelliferone derivatives, extracting the hydrocarbon mixture with an aqueous alkaline solution,, and then examining th extract under suitable light means for detecting the fluorescence of said marker.

2. The method of identifying a normally non-gaseous hydrocarbon comprising dissolving therein a small amount of a fluorescent marker selected from the class consisting of umbelliferone and umbelliferone derivative, xtracting the A thorough rinsing with hot 1 hydrocarbon with an aqueous alkaline solution and subjecting the aqueous alkaline solution xtract to light means capable of detecting the fluorescence of said marker.

3. The method of identifying normally liquid and solid petroleum products comprising dissolving therein a small amount of a fluorescent marker selected from the class consisting of an umbelliferone and umbelliferone derivatives, extracting the petroleum product with an aqueous alkaline solution, and detecting the presence of said marker by subjecting the aqueous alkaline extract of the petroleum product to light means capable of exhibiting the fluorescence of said marker.

4. The method described in claim 3 in which the umbelliferone derivative is beta methyl umbelliferon.

' 5. The method described in claim 3 in which the marker is umbelliferone.

6. The method of detecting the contamination of a petroleum oil by another petroleum oil comprising adding to the latter, prior to admixture with the former, a small amount of a fluorescent marker selected from the class consisting of umbelliferone and umbelliferone derivatives, extracting the admixed petroleum oils. with an'aqueous alkaline solution and examining the alkaline extract under suitable light means for detecting the fluorescence of said marker.

7. The method of detecting the contamination of crude oil by another crude oil comprising adding to the latter, prior to admixture with the former, a small amount of a fluorescent marker selected from the class consisting of umbelliferone and umbelliferone derivatives, extracting the admixed crude oils with an aqueous alkaline solution, separating the clear alkaline aqueous solution fromthe oil and subjecting the clear alkaline aqueous solution to ultraviolet light for detecting the presence of the fluorescent marker therein.

8. The method of identifying normally liquid and normally solid petroleum products comprising dissolving therein a small amount of a ketone solution of a fluorescent marker selected, from the class consisting of umbelliferone and an umbelliferone derivative, extracting the petroleum product with an aqueous alkaline solution and subjecting the alkaline solution to a suitable li ht source adapted to exhibit the fluorescence of said marker.

9. The method described in claim 7 in which the alkaline solution is a solution of sodium