METHOD OF MAKING HYDROCARBON LIQUIDS

Abstract

A method of marking a hydrocarbon liquid includes the step of adding to the liquid, as a tracer compound, a compound of Formula I:

##STR00001##

wherein at least one of R.sup.1-R.sup.4 is selected from: i. a bromine or fluorine atom; ii. a partially or fully halogenated alkyl group; iii. a branched or cyclic C.sub.4-C.sub.20 alkyl group; iv. an aliphatic substituent linking two positions selected from R.sup.1-R.sup.4 in Formula I to one another; or v. a phenyl group substituted with a halogen atom, an aliphatic group or halogenated aliphatic group. The tracer compounds are resistant to removal from the fuel by chemical laundering or by contact with absorbents such as charcoal.

Claims

1. A composition comprising a hydrocarbon fuel or octane and a tracer compound, characterised in that said tracer compound comprises a compound of Formula I: ##STR00004## wherein at least one of R.sup.1-R.sup.4 is selected from a group consisting of: i. a bromine or fluorine atom; ii. a partially or fully halogenated alkyl group; iii. a branched or cyclic C.sub.4-C.sub.20 alkyl group; iv. an aliphatic substituent linking two positions selected from R.sup.1-R.sup.4 in Formula I to one another; and v. a phenyl group substituted with a halogen atom, an aliphatic group or halogenated aliphatic group; and further wherein none of R.sup.1-R.sup.4 consists of a hydroxyl group or an amino group.

2. The composition according to claim 1, wherein said tracer compound is present at a concentration of from 1 to 500 ppbv.

3. The composition according to claim 1, comprising more than one tracer compound.

4. The composition according to claim 1, wherein said hydrocarbon fuel or octane comprises a diesel fuel, a gasoline fuel or a solvent.

5. The composition according to claim 1 wherein at least 50% of the tracer compound is retained in the hydrocarbon fuel or octane after a sample of the hydrocarbon fuel or octane containing from 10 to 15 ppbv of the tracer compound has passed through a column of fresh activated charcoal.

6. The composition according to claim 1, wherein at least 50% of the tracer compound is retained in the hydrocarbon fuel or octane after a sample of the hydrocarbon fuel or octane containing from 10 to 15 ppbv of the tracer compound has passed through a column of fresh powdered sepiolitic clay.

7. The composition according to claim 1, wherein at least 50% of the tracer compound is retained in the hydrocarbon fuel or octane after a sample of the hydrocarbon fuel or octane containing from 10 to 15 ppbv of the tracer compound has been vigorously agitated in contact with 10% aqueous HCl.

8. The composition according to claim 1, wherein at least 50% of the tracer compound is retained in the hydrocarbon fuel or octane after a sample of the hydrocarbon fuel or octane containing from 10 to 15 ppbv of the tracer compound has been vigorously agitated in contact with 10% aqueous NaOH.

9. The composition according to claim 1, wherein at least 50% of the tracer compound is retained in the hydrocarbon fuel or octane after a sample of the hydrocarbon fuel or octane containing from 10 to 15 ppbv of the tracer compound has been vigorously agitated in contact with methanolic KOH.

Description

COMPARATIVE EXAMPLE

[0038] The compound shown below, corresponding to Dye 7 of EP 1580254, was made according to the following procedure.

##STR00003##

[0039] Aniline (1.517 ml) was added to a beaker containing hydrochloric acid (2 ml) and de-ionised water (10 ml). The mix was then placed into an ice bath and cooled to <5 C. Once the mix was cold enough, a solution of sodium nitrite (1.808 g) in water (20 ml) was prepared and added to the aniline mix slowly over 10 minutes, keeping the temperature below 5 C. The mixture was then left to stir in an ice bath for 30 minutes. After 30 minutes, sulfamic acid (1.62 g) was added to the mixture. A solution of nonylphenol (3.68 g) in toluene (20 ml) was added to the reaction mix and stirred vigorously. A solution of sodium acetate (20 g) in water (100 ml) was added to the reaction mix as a buffer over 30 minutes ensuring that it was kept cold. The mixture was then left to stir for another 5 hours and allowed to warm in the process.

[0040] The reaction mix was then added to a separating funnel and diluted with toluene (20 ml). The mixture was shaken and then left to settle. The organic phase was then washed with de-ionised water (100 ml) three times. It was then dried over anhydrous magnesium sulphate and the solvent removed on a rotary evaporator yielding a dark yellow oil.

[0041] A 10 mg/L solution of the prepared comparative dye was prepared in a synthetic test fuel, made

[0042] by mixing together 76% iso-octane, 16% toluene, 5% t-butyl methylether and 3% ethanol (all quantities vol/vol). 10 ml of synthetic test fuel marked with the test tracer compound was

[0043] shaken vigorously for 1 minute with 0.5 g of activated charcoal (decolourising) obtained from Sigma Aldrich (product number 161551). The mixture was allowed to stand

[0044] for 1 minute and then shaken for a further minute before being filtered to remove the

[0045] adsorbent. A sample of the fuel was analysed by UV/Vis spectrophotometry and the percentage of the tracer remaining was calculated.

[0046] This test procedure was repeated for a sample of the synthetic fuel containing bis(3,5-bis trifluoromethyl-phenyl)-diazene (T1), with the analysis of the sample being made by GC-MS because T1 is not susceptible to detection by UV/vis. Both results are shown in Table 4. The test shows that T1 is more resistant to removal by shaking with activated charcoal than the comparative example containing a phenolic moiety described in EP1580254.

TABLE-US-00004 TABLE 4 % of original concentration remaining after treatment Tracer compound with activated charcoal Dye 7 of 16% EP1580254 T1 87%