/

AD,

CCL REPORT NO. 204

INTERIM REPORT

INVESTIGATION OF THE AUTOXIDATIONOF PETROLEUM 11'UELS

BY

MR FTDFRA•.M. S(*'W MAUR ICE E. LE PERATEC1IN(C'.4 IN:-1-MrMATOA-N, D D C

"-dcoy M-orafiehai 1IJLJNE 1966"'n--

V3 319664

DISTRIBUTION OF THIS DOCUMENT IS UNLIMITED

U. S. ARMY COATING & CHEMICAL LABORATORYAberdeen Proving Ground

Maryland

a0oo4jo 9 4`b'7

BEST AVAILABLE COPY

Si

DOC AVAILABILITY NOTICE •Qualified requesters may obtain copies of this report from Defense ) IDocumentation Center, Cameron Station, Alexandria, Virginia 22314

Copies Available at Clearinghouse for Federal Scientific and TechnicalInformation, CFSTI, $2.00.

THE FINDINGS IN THIS REPORT ARE NOT TO BE CONSTRUED AS AN OFFICIALDEPARTMENT OF THE ARMY POSITION, UNLESS SO DESIGNATED BY OTHERAUTHORIZED DOCUMENTS.

DESTROY THIS REPORT WHEN IT IS NO LONGER NEEDED. DO NOT RETURN ITTO THE ORIGINATOR.

,.i

* *j.* I I I

.•t4

UNCLASSIFIED

CCL REPORT NO. 204

INTERIM REPORT

INVESTIGATION OF THE AUTOXIDATION OF PETROLEUM FUELS

By

MAURICE E. LE PERA

JUNE 1966

AMCMS CODE NO. 5025.11.800

DEPARTMENT OF THE ARMY PROJECT NO.IC024401A106

U.S. ARMY COATING AND CHEMICAL LABORATORYABERDEEN PROVING GROUND

MARYLAND

DISTRIBUTION OF THIS DOCUMENT IS UNLIMITED

UNCLASSIFIED

.9

ABSTRACT

The deterioration of petroleum fuels was studied by investigationof their autoxidation susceptibilities. Federal and Military Specifi-cation fuels and coa..erclal gasolines were subjected to a six-week ac-celerated aging test with analyses for generated hydroperoxides deter-mined at weekly intervals. The resuiLing peroxide-time curves rovealedautoxldation tendencies to vary considerably. Under the conditions ofthis aging technique, there is evidence that the bulk storage supply"of combat gasoline (MIL-G-3056B) at Aberdeen Proving Ground is exper-iencing a gradual depletion cf antioxidant quality.

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TABLE OF CONTENTS

Page 4.

TITLL PAGE ............................................. I

ABSTRACT ............................................... ii

INTRODUCTION . ........................................... 1

DETAILS OF TEST ........................................ 2 - 3

RESULTS AND DISCUSSIONS ................................ 33- 6

CONCLUSION ............................................. 6

RECOMMENDATIONS ........................................ 6 - 7

LITERATURE CITED ....................................... 7 - 9

DISTRIBUTION LIST ...................................... 10 - II

APPENDIX A ............................................. 12

Tables I - IV ........................................ 12 - 15

APPENDIX B ................... ......................... 16

Figures I .-4. ........................................ 16 - 19

Supplement for Fig. I - 4 ............................ 20 - 21

DO FORM 1473 ........................................... 22

Iiii

I• I NTRODUCT I ON

The major problems arising from the bulk storage of petroleumfuels are primarily the results of fuel instability. Fuel stabilitymay be defined as the property of resistance to significant materialchange or to deterioration (I). Deterioration in petroleum fuels oc-curs by autoxidation (2), which Initially may be described as the seif-oxidation of organic materials under mild conditions (ambient tempera-ture and atmospheric pressure). The tendency of a specific petroleumfuel to autoxidize is directly related to its hydrocarbon type, withthe order of decreasing reactivity t.owards autoxidation generally re-garded as diolefins, aromatic o!efins, aliphatic olefins, alkyl aroma-tics, naphthenes, and paraffins (3). Autoxidatiorn 's defined as a freeradical-initialed, chain reaction decomposition with the process occur-

Ing by a two step mechanism (4,5,6;13). initially, hydrocarbons reactslowly with an :.. : xygen to givte 0ikyl or aryl hydroperoxides,the first products of molecular oxidation (5,7,9,11). Then decomposi-ti *n of the "relatively unstable" hydroperoxides produces free radicalchain carriers, which react to form secondary oxidation products (4)(I e. aldehydes, ketones, hemiacetais, esters, etc.). The latter arethe monorfer ingredients for the po'ymeric complexes eventually forming"insoluble gums". The rate of autoxidation Is dependent on the rateof disassociation of the hydroperoxides (9). The latter is dependenton the presence of trace amounts (P.P.B.) of heavy metals such ascopper and cobalt (10).

It has been reported that the presence of hydroperoxide speciesIn petroleum fuels has resulted in the following:

(I). Hydroperoxides decreaise the octane rating of a gasoline,an increase in one hydroperoxide number causing a unit decrease InMctor Octane Number (18). (2). hydroperoxide - containing distillatefuels have Invariably been shown to produce severe tube deposits inthe ASTM D-1660 Thermal Stability Test for Aviation Fuels (4); and (3).unsatisfactory engine cleanliness has been exoerlenced where thermaland catalytically cracked gasolines showed hydroperoxlde numbers aslow as 0.40 milliequlvalents of active oxygen per liter (21). However,the latter statement should not be utilized as the maximum allowablel vel for evaluating fuels, since the correlation between sensitivityand response of different gasoline types has not yet been definitelyestablIshed.

Since it has been shown that the first step in the autoxidatlonof hydrocarbons is the formation of hydroperoxides, the analysis forthese compounds In petroleum fuels with respect to exposure time shouldgive a meaningful evaluation of storage stability. Furthermore, ithas been reported that the hydroperoxide concentration is useful forrate comparison during Initial stages of autoxidation (12). The deter-mination of autoxidation products other than peroxides is very difficult

" , , , ' i I II I I I I I I I

(It4) due to the complexity 3f compound types.

This Interim report, a preliminary study of fuel stability, cov-ers the Initial evaluation of petroleum fuel autoxidation using hydro-peroxide number-time curves to measure oxidative deterioration at150|F. In addition. the use of current standard procedures to assessthis deterioration is discussed.

II. DETAILS OF TEST

A. Perox Ide Determination

Organic peroxides are determined by their oxidatioe proper-ties. Iodometric methods, as well as ferrous ion methods, have beenused for the determination of peroxides In oxidized organic materialb.The most common criticism of the former has been that Iodine liberatedin the reaction disappears by addition to the olefinic bond in unsat-urated hydrocarbons. resuiting t n excessively high values (15, 25).The ferrous method has been shown to be subject to error, aid cannotbe relied on for accuracy (16). The arsenious oxide methcd for theanalysis of perioxides In petroleur products (17) was selefcted due toIts increased sensitivity and lack of olefinic Interference (26). Inaddition, the accuracy of the arsenious oxide method in petroleumproduct applications has been confirmed by recent work (18).

B. Accelerated Exposure

Using conventional storage exposure where ambient tempera-ture is not subject to appreciable fluctuation, the time required toautoxidize a petroleum fuel is much too great for laboratory procedures.This laboratory has worked extensively with evaluating the compatibil-ity of fuel resistant coatings in petroleum fuel environments and hasobtained satisfactory correlation with field storage data using anaccelerated 150*F. test of sealed fuel containers. This exposure tem-"perature was selected for the autoxidation study. Representativepetroleum fuels were exposed at 150°F. for a total of 6 weeks. Asample was removed each week and its hydroperoxide number (17) repre-senting the number of milliequivalents of active oxygen per liter wasdetermined the same day to prevent additional shelf aging. Six indi-vidual bottles were used for each fuel type to prevent any discrepan-cies arising from non-uniformities of fuel-vapor volurzs resultingfrom sampling. The storage containers (sample bottles) were amber500 ml., narrcw-mouth, screw-cap bottles, which were acid washed,rinsed twice with distilled water, and oven dried, to minimize solventcontamination prior to use. The screw caps were fitted with gasketscut from 1/161 Viton AHV elastomer sheet stock. Before filling thesample bottle, the fuel was chilled at 50*F. to prevent loss of themore volatile hydrocarbon ingredients. Aftr~r filling the sample bottle

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with 200 ml. of fuel, the vapor area above the fuel was gently purgedwith oxygen for 30 seconds before sealing to insure maximum availabilityof oxygen for the six-weeks storage period. The 300 ml. (approximately25 ;.iilliequivalents at ambient temperature) of oxygen in the storagebottle provides a sufficient excess, since the maximum pick up in thesestudies (obtained only once) was a hydroperoxide number of 70 milli-equivalents per liter (:orresponding to only 21 milliequivalents con-sumed per 300 ml. sample).

Ill. RESULTS AND DISCUSSIONS

A. Military & Federal Specification Automotive & Aircraft Fuels.

The effects of accelerated autoxidation, exposure at 150*F.In an oxygen atmosphere, on different military and federal specifica-tion fuels was measured by hydroperoxide number-time curves are illus-trated In Figure I (Appendix B). The sample demonstrating the maximumrate of autoxidatlon was the Federal Specification VV-G-109 Gasoline,Unleaded. This fuel, being lead-free, contains additions of aromatic,iscparaffinic, and olefinic hydrocarbons, high in octane number, inorder that the finished fuel blend satisfy the current octane numberrequirements normally attained by the addition of lead aikyl compounds.The reason for the extremely rapid uptake of oxygen, chemically react-ing to form hydroperoxides, may be the appreciable contents of olefinsand alkyl aromatic hydrocarbons which are particularily susceptible toautoxidation.

The reason for the VV-G-76 Gasoline, Regular Grade, apparentlyexhibiting a greater resistance towards autoxidation than MIL-G-3056Gasoline, Combat, which is blended to possess maximum oxidation resis-tance for long storage periods, is the "fresh" condition of VV-G-76 dueto bi-monthly delivery from local refineries. As was anticipated be-cause of its primarily isoparaffinic hydrocarbon composition, the MIL-G-5572C Gasoline, Aviation, was very resistant to autoxidation as evi-denced by the relatively slow increase in hydroperoxide concentration.The rather limited response of the MIL-J-5624 F Jet Fuel, Grade JP-4and MIL-F- 4 5 121B Fuel, Compression-Ignition and Turbine tnoine to hydro-peroxide formation is due to the presence of disulfide compounds whichexist in trace quantities. It h3s been r'tported that disulfides eithe.-react directly with oxygen preventing hydaiperoxlde formation, or re-act so rapidly with any hydroperoxides that may be found that the formercannot be detected (19).

B. Commercial Motor Gasolines.

The effects of the accelerated autoxidation on commercialregular and premium gr;,de gasolines are shown in Figure 2 (Appendix B).It is to be noted that the fuels selected for this investigation wereobtained from service stations having rapid turnover of their products,

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thereby minimizing the preliminary pre-oxidation which may occur intheir storage tanks. The gasoline demonstrating the maximum rate ofautoxidation was Premium Brand 0, while the maximum resistance to au-toxIdIation or minimum rate of autoxidation was shown by Premium Brand1. The other four gasolines, Regular Brand A, Premium Brand A, Regu-tar Brand B, & Premium Brand C, appear to be similar In their tenden-cies to autoxidize; and their curves lie approximately midway betweenthe maximum (Premium Brand 0) and minimum (Premium Brand B) rates ofautoxleat ion.

A comparison of the autoxldatlon tandencles of these coin.er-cial fuels (Figure 2) and the previously discussed military and federalspecification fuels (Figure 1) indicates distinct similarities. All ofthe fuels fall into one of three groups, each group demonstrating a dif-ferent degree of autoxidation. The first group, including PremiumBrand 0 and IV-G-109, is characterized by an initial, extremely rapidIncrease In autoxidation, with the maximum attained after approximatelyone week of aging at 150*F., followed by almost as sharp a decrease inthe rate of autoxidation. This type of peroxide-time curve is indica-tive of fuels expected to have poor storage stability. Although thesefuels exhibit extremely rapid peroxide-uptake reactions in the 1509F.accelerated aging test, their autoxidation rates would be less pro-nounced at ambient temperatures. They would, however, have P markedtendency to oxidize.

It would seem that the Initial steep positive slope of thehydroperoxide number-time curve represents a primary oxidation stagein which trace amounts of free radicals, formed by the action of aninitiator, abstracting hydrogen from olefinic or tertiary carbon con-figurations, with hydroperoxides formed at the site of abstraction.The hydroperoxides eventually being to dissociate (22) because of theirInstability, thus intoiating a secondary oxidation stage, which ischaracterized by a greater peroxide dissociation rate than generationrate. This Is reflected in the sharp decrease of the hydroperoxidenumber-time curve. The second group of fuels has curves showing verysmall rates of autoxldation, Fuels MIL-F-45121B and MIL-J-5624F arecharacteristic of this group. After 6 weeks exposure at 1500 F., theirhydroperoxide number is low and has shown no significant increase, in-dicating good storage stability. A third group of fuels, exemplifiedby VV-G-76 and MIL-G-5572C, have hydroperoxide number-curves which in-dicate a relatively sirq increase in peroxide concentration, withneither fuel having attained a maximum rate of autoxidation after 6weeks exposure at 150OF.

C. Repeatability of Autoxidation Rates.

The determination of autoxidation rates was accomplished bythe analysis of the exposed fuel samples at different time intervals.The repeatability of test results was not determined because of limited

4.

exposed fuel sample for analysis (200 ml. total sample), varying samplesize requirements (See Table I, Appendix A) and time required for anal-ysls. Howoeverp a measure of their precision was obtained by evaluatingtwo identical samples of MIL-G-30568 simultaneously. The results (Ta-ble lip Appendix A) show good repeatibility for the technique. In ad-ditlon, a sample of VV-G-76, obtained two months after the InitialVV-G-76 sample, was evaluated to confirm the reproducibility of theInitial test results. A comparison of the two sets of obtained results(Table I1, Appendix A) Indicate the validity of this technique with re-spect to test repeatibility.

D. Depletion of Antioxidant Q1uality of MIL-G-30568 in Bulk Storage.

Figure 3 (Appendix 8) is a graphical representation of theautoxidation sustained by MIL-G-30568 in bulk storage facilities (Ab-erdeen Proving Ground) during a 17 week interval, as Illustrated byhydroperoxide number-time curves. Samples were removed from the bulk

storage tank at the start of the test, after 6 weeks and after 17 weeks,and then Individually evaluated by the accelerated autoxidation technique.Using the sample removed initially, 30 December 1964, as a basis forcomparison, It is evident that the longer the fuel remains in bulk stor-age., the greater the susceptibility towards hydroperoxide formation at150*F. in presence of oxygen. This Increasing tendency towards autoxi-dation (under these conditions) can be attributed to the depletion ofantioxidant quality. This particular quantity of MIL-G-30568 was deliv-ered to Aberdeen Proving Ground in August 1964. To maintain qualityassurance, personnel from Supply Division periodically withdraw samplesfrom the bulk storage supply and send these samples to Schenectady Army.Depot, Petroleum Division, for complete specification analysis. Thetabulation of test results, directly related to stability, which wasobtained from Supply (Table II1, Appendix A) does not reveal any sig-nificant decrease in storage stability or deterioration.

Concurrent with this test series, additional tests were con-ducted to evaluate this accelerated aging of the MIL-G-3056 fuel. Ithas been reported that the filtration of fuels through carbon blackremoves the precursors of induction system deposits (20). A sample ofMIL-G-3056 was filtered through carbon black and the filtered fuel eval-uated by the accelerated autoxidation technique. In addition, a sampleof the MIL-G-3056 not filtered through the carbon black was treated asprescribed in paragraph 6.1 of Federal Specification VV-G-800 Gasoline,Gum Preventative. This involvei the addition of a prescribed amount ofthe following composition: 41 grams of alkylated phenol antioxidantand 10 grams metal deactivator dissolved in 1 gallon of toluene. Itshould be noted that although this gum preventative is not intended foruse with MIL-G-3056, it was employed for screening purposes due to thenon-availability of commercial antioxidants. Figure 4 (Appendix B)illustrates the beneficial effects of these two pretreatments. Fromthe limited test data, there appears to be a correlation between

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auta|idation susceptibility and Induction system deposit tendency.

E. Comparison of the Autoxidatlon Results with Standard ASThStability Procedures.

The fuels In this investigation were concurrently evaluated

using standard procedures for determining fuel Instability given InI AST14 Standards.on Petroleum Products (23) (Table IV, Appendix A). InASTh 0-525, Oxidation Stability of Gasoline, all the gasolines bothmilitary and commerclal, exhibited satisfactory induction periods whichare indicative of gasolines possessing oxidation resistance. However,the results of this investigation have shown that VV-G-109 and PremiumBrand D, while giving the highest Induction periods of all automotivegasolines, had relatively no resistance towards autoxidation under theconditions of the accelerated 150*F. autoxidation test. It should benoted th#t the test conditions for ASTM D 525 are 212°F. at 100 psigoxygen lereas the conditions of the technique developed for this inves-tigation are 150 F. at 0 psig oxygen.

The ASTM D-381 Test for Existent Gum measures the tendency ofa petroleum fuel to form Insoluble "gum'" deposits, this tendency beingrelated directly to its oxidation resistance. The obtained "gum" values(fable IV, Appendix B) for the military and commercial fuels did notdiffer appreciably. However, the two fuels, VV-G-109 and Premium D,which exhibited very poor autoxidation resistance, had very low "gum"values. The significant disagreement of test data between ASTh pro-cedures and the autoxidation evaluations indicate the varying insensi-tivity of current methods to measure actual fuel deterioration.

IV. CONWLUSION

The results of this Investigation illustrate the need for a moreprecise manner of determining fuel instability. The technique developedfor this Investigation permits an accurate determination of the initialautoxidation rate which can be utilized to anticipate the degree of fuelstabilitIy. However, the time required to obtain results is somewhatlengthy for an accelerated bench scale technique. The results haveshown that the response level of blended fuels towards autoxidation issufficient to give a measurable differentiation.

V. RECOMMENDATIONS

It is recommended that this work be continued to develop a labora-tory, bench-scale test for determining the rates of autoxidation direcly.

This requires the application of a Walberg-Respirometer apparatusto measure the amount of oxygen absorption at various temperature levels,eliminating the exposure or storage periods. Recent work (24) employing

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a direct-reading oxygen absorption device (a Walberg Respirometer) hasbeen conducted whereby the oxidation stability of lubricating oils weredetermined. Concurrent with the proposed test development, a secondphase would be Initiated to determine the deposit formation of motorfuels utilizing a developed bench-scale procedure (20). Ultimately, ItIs desired to establish a correlation between the Initial rate of autox-idation and the deposit tendency of petroleum fuel.

Vi. LITERATURE CITED

I. Bertolette, W., "Symposium on Stability of Distillate Fuel",A.S.T.M. Special Technical Publication No. 244, Boston (1958).

2. Navy - C.R.C. B Storage Proqram Coordinating ResearchCouncil, New York 0959).

3. Lundberg, W. 0., Autoxidatvon and Antloxidants Vol. flb p. 716,Interscience Publishers, New York, 1962.

4. Dukek, W. G., journal of Institute of Petroleum Y.1. No.491, p. 273 (1964)).

5. Walsh, Transactions Faraday Society Vol. !!L p. 297 (1947).

6. Barnett, E., Mechanism of Organic Reactions p. 246, Inter-science Publishers, New York, 1957.

7. Lundberg, W. 0., Autoxidation and Antioxidants Vol. J.6 p. 138;Interscience Publishers, New York, 1961.

8. Waliers, Minor, and Yabroff, Industrial and EngineeringChemistry Vol. 41 p. 1723 (1949).

9. Kennerly, G. W., and Patterson, W. L., Industrial andEngineering Chemistry. Vol. !, No. 10, p. 1917 (1952).

10. Lodwick, J. R., Journal of Institute of Petroleum, Vol. 50.,No. 491, p. 297 (1964).

I]. Boozer, Hamilton, and Peterson, Journal of American ChemicalSociety, p. 3380 (1955).

12. Rigg, W. and Gisser, E., Journal of American Chemical Society,p. 1415, (1953).

13. Medley and Cooley, Advances in Petroleum Refining Vol. IIIp. 309, J. Wiley & Sons, New York, 1960.

14. Journal of Institute of Petroleum Vol. ! p. 260 (1958).

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IS. Sigglap S., Quontitative 0rognlc Analysis Via FunctionalGroup 3rd ed., p. 255, John Wiley and Sons, Inc., New York, 1963.

16. Kolti.offs I. M.9 and Medallal A. I., Analytical Chemistry 2jP. 595, (1951).

17. Walker, 0. C.p and Conway, H. S., Analytical Chemistry 2_jp. 923 (1953).

18. Nixon, Minor and Calhoun, Industrial and Engineering ChemistryVol. _8 p. 1875 (1956).

19. Bachman, Kenneth, "Heat Transfer Unit Evaluates Performanceof Jet Fuels for Supersonic Transport Aircraft"V, SAE Paper No. 650803,Society of Automotive Engineers, 1965.

.20. k S. Army Fuels and Lubricants Research Laboratory, MonthlyProgress Report No. 19 (January 1964), Southwest Research institute.

21. Koppers Technical Bulletin C-5-179, Chemical DivlsionpKoppers Company, Inc.

22. Waters, W. A., Mechanisms of Oxidation of Organic Compoundsp. 285, John Wiley and Sons, Inc., New York, 1964.

23. A.S.T.M.Standards Part 21L 1964, ed., American Society forTesting and Materials, Philadelphia 1964.

24. Mertwoy, H. E. and Gisser, H., nd. En_. Chem. Prob. Res.Devel., L 180, (1964).

25. Tobolsky, A. V. and R. B. MesrobIan, Organic Peroxides p. 53,

Intersclence Publishers, New York, 1954.

26. 1810, P. 55

27. Military Specification MIL-F-45121B, Fuel, Compression-Ignition and Turbine Engine.

28. Miltary Specification MIL-G-3056B, Gasoline, AutomotiveCombat Grade.

29. Military Specification MIL-G-5572C, Gasoline, Aviation,Grade 115/145.

30. Military Specification MIL-J-5624F, Jet Fuel, Grade JP 4.

31. Federal Specification VV-G-76, Gasoline, Regular Grade.

8

32. Federal Specification VY-G-109, Gasolines Unleaded.

33. Federal Specification VV-G-800, Gum Preservative, Gasoline.

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, , A

APPENOIX A

TABLE I

_ MLE SIZE REQUIREMENT FOR HYD!OPEROXIOE 10* AKALYSIS

AntIclpated HydroperoxIde No. Sample Slze Required, mI.

0 to I 100.0

I to 5 50.0

5 to 1O 25.0

10 to 50 10.0

50 to 100 5.0

100 to 1000 0.50

* NIIequivelents of active oxygen per liter

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TABLE II

REPEATABILITY OF AUTOXMDATION RATES

A. For Identical MIL-G-3056 Samples -

Hydroperoide No. Weeks Exposed

Sample A Sample B At 150*F.

0.30 0.25 10.75 0.71 24.31 4.40 3

44.56 43.47 431.60 30.95 518.60 18.00 6

B. For Different VY-G-76 Samples -

.Hydroperoxide No. Weeks Exposed

Samjple a C* Sple • At I5OF.

0.35 0.15 I0.73 0.46 21.05 0.92 32.44 1.86 42.86 3.87 510.19 15.10 6

* Initial sample of VV-G-76*Sample of WV-G-76 obtained one month later

13

TABLEI lItI

MIL-G-3056 QUJALITY ASSUJRANCE INSPECTION RESULTS

ASTh4-0381, ASTH-D525.,Date SaVle Existent Gum,, Oxidation-Withdrawn mQ/l0OIs1* Stability, Min.

August 1964 0.6 720

October 1964. 1.4 480 +

January 1965 1.2 480 +

P~arch 1965 3.4 480 +

July 1965 1.9 480 +

*Figures listed are average of three determinations.

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TABLE IV

DETERMINATION OF FUEL STABILITY USING CURRENT ASTh PROCEDURES(Oxidation Stability)

ASTH 0-381* ASTH D-525** ASTH O-873***Existent Gum, Induction Potential Gum,

Fuel Evaluated .m2/100m.. Period, min. mg/lOOml.

M I L-G-5572C,Aviation Gasoline 1.4 1320 --

MI L-G-30568,Combat Gasoline 1.2 200 --

VV-G-76,Regular Gasoline 1.0 600 --

VV-G- 109

Unleaded Gasoline 1.8 1260 --

Regular Brand A 4.2 480 --

Premium Brand A 0.8 300 --

Regular Brand B 0.8 1260 --

PremIum Brand B 1.0 600 --

Premium Brand C 1.6 870 --

Premium Brand 0 4.0 360 --

MIL-F-45121B,C.I.'.E. Fuel 0.8 -- 16.6

MI L-J-5627.9JP-4 Fuel 0 -- 14.0

15

*~ FIGURE PENI I~ AUTOXICATKI4 OF SPECIFKATION FUELS

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FIGURE 2: AUTOXIDATION OF COMIIERCIAL GASOLINES

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-UnclassifiedSecurity Classification

I ORIGINATING ACTIVITY rCoe.soie. owthoe) 20 R.EPOR SECURITY C L.ASSIVICA TION

INVESTIGATION OF THE AUiTOXiCATION OF PETROLEUM FUELS

4.DESCRIPTIVE NOTES rTyps of ssetv an IR*A.eetw doett)

Interim reportS, AUTHOR(S) (Loss Rome. brat n.nt. In~ito)

Le Pera, Maurice E.

6. NEPOP" CAT 7.. TOTAI. "0. OF PA0ES 7S. ;e. a, Rteps

June 66 - ,3@a. CONTRACT 0R GRANr NO. On. ORIGIN6ATOR'S REPORT HUM84II(S)

AI4CMS Code No. 5025.11.8006. PIRojecT mO, CCL #204IC024401A10641. 96. OT70R1 RE 411T mo(S) (An~y oter .num., h ot Aata.. S. s.essiod

10. A VA IL ADILITY/LIMITATION NOTICES

Qualified requesters may obtain copies of this report from Defense DocumentationCenter. Distribut~on of this document is unlimited.

11. SUPPLEUPPITARY NOTES 12-SPONSORING MILIT. 'Y ACTIVITY

U.S. Army Materiel CamnandWashington, D. C. 220315

13. ABSTRACT

'i The deterioration of petroleum fuels was studied by Investigation of theirautoxidation susceptibilities. Federal and Military Specification fuels andcommuercial gasolines were subjected to a six-week accelerated aging test withanalyses for generated hydroperoxides determined at weekly Intervals. The re-sulting peroxide-time curves revealed autoxidation tendencies to vary considerably.Under the conditions of this aging technique, there is evidence that the bulkstorage supply of combat gasoline (MIL-G-30568) at Aberdeen Proving Ground isexperiencing a gradual depletion of antioxidant quality.

DD FJAON6m4 1473 UnclassifiedSecurity Classification

Scunity Classification

I.LINK A LINK a LINK C

ROLE a , NOK WYA?( y

fuel InstabilityAu taxIda t ionPerox ide format ionDeterioration[Accelerated storageFree-radical chain reaction

INSTIOCTIONsi

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2b. GROUP Automatic downgrading Is specified in DOD Di. reoPrt by DOC is not authorized&"v lilve S20.10 aid Armed Forces, Industrial ManuaL Enter (3) 1U. S. Government agencies may obtain copies of

the group number. Also. wham applicable, show that optional this report directly from DMC Other qualified DDCmarkings have been used for Group 3 and Gr oup 4 as author. users shall request through

3. REPORT TIT~LE. Enter the comptate report title in all (4) 11U. S. military agencies may obtain copies of thiscapital tatters. Titles in all cases should be unclassifiad report directly from DDC. Other qualified usersIf a meaningful title cannot be selected without classifics- sihall request throughtion. show title classification in all capitaln in pairenthesisimmediately following the title. ______________________

4. DESCRIPTIVE NOTES: If appropriate, enter the type of (S) "All distribution of this report is controlled. Quell-report. e.g.. interim, progress, summary, annual, or final. ified DDC users shall request throughGive the inclusive date* when a specific reporting period iscovetead.

S. ATI~(S~tEntr te nae~s of uthr~s as how on If the report has been furnished to the Office of TechnicalS. ATHO(SX nte th ites(* of uthr~s as how On Services, Department of Commerce. for salei to the public. indi-or in the report. Enter last name, first name, middle initial. asti atadetrtepie fkonIf military, show rank and branch of service. The name ofthe principal author is ln absolute minimum requirement. IL. SUPPLEMENTARY NOTES- Use for additional explana-

&. REPORT DATE~ Enter the date of the report as day, toynesmonth, year. or month. yean If tmoe than one data appears 12. SPONSORING MILITARY ACTIVITY, Enter the name ofon the report, use date of publication, the departmental project office or laboratory spionsoring (Par-

7s. TOTAL NUMBER OF PAGE&: The total page count ind for) tha reteauch and development. Include address.should follow normal pagination procedures, iLe, enter the 13. ABSTRACT: Enter an abstract giving 6 brief and factualnumber of pages containing information. summary of the document indicative of the report, even though

it may also appear elsewhere in the body of the technical re-7b. NUMBER OF REFERENCES: Enter the total number of port. If additional space is required, a continuation sheetreferences cited in the report. %hall be attached.Se. CONTRACT OR GRANT NUMBER: If appropriate, enter It is highly desirabie that the abstract of classified re-the applicable number of the contract or grant under which ports be unclassified. Each paraerraph of the abstract shallthe r"port was W.ittsn. end with an indication of the military security classificationSb. or. II S~d. PROJECT NUMBER Enter the appropriate of the information in the paragraph, represented as (TS), (S).military department identification, such as project number. (C). or (V)).subproject number, system numbers, task number, etc. There is no limritation on the length of the abstract. H~ow-9s. ORIGINATOR'S REPORT NUMBER(S): Enter the offi. ever, the suggested length is from 150 to 225 words.cial report number by which the documenit will be identified 14. KEY WORDS: Key % irds are technically meaningful termsand controlled by the originating activity. This number must or short phiraaes that chs -acterize a report and may be used asbe unique to this report, index entries for cataloging the report. Key words must be

Pb. THE REORTNUMBR(S: I th reprt aa een Selecteo so that no security classification is requires,. Iden.assigned any other report numbers (either by the originator frs uha qimn oe eintotaenm.'iior by the sponsor). also enter this number(s). tary project code name. geographic location. may be used as

key words but will be followed by an indication of technicalcontext. The assignment of links, rules, and weights is

4 optional.

Unc lass ifiedSecutity classificatiton