Utilization of 2,2=Dinitropropane as a Cetane Number Improver R. E. Albright, F. L. Nelson, and L. Raymond SOCONY-VACUUM LABORATORIES, PAULSBORO, N. J.
quantities of this material are currently available. Further development and utilization of 2,2-dinitropropane are dependent upon future demands for Diesel fuels of high cetane number and, possibly, upon reduction in dinitropropane cost as a result of increased production to meet demands for uses other than the improvement of cetane number.
T h e technical aspects of using 2,2-dinitropropane for improving Diesel fuel cetane number are summarized. Although detailed data are given in certain instances, only a fraction of the data obtained over a period of 6 years has been, or could be, presented in this paper. From a technical viewpoint, use of 2,Z-dinitropropane appears satisfactory and pilot plant
T
"
H E rapid-demand growth in recent years for Diesel power 2,2-dinitropropane and the field test work that has been conand the ccnsequent demand for increased volumes of Diesel ducted are discussed individually. fuel have been discussed in detail ( 1 , 7'), as has the rapid development of cracking processes for the manufacture of increased Effectiveness in Raising Cetane Number volumes of gasolines of high octane number ( I , 6). These trends, Summarized data on the improvement of cetane number obtaken together, intensify the need for a means of raising the tained by the addition of 2,2-dinitropropane t o various Diesel cetane number of Diesel fuels. Admittedly, this can be done fuels are given in Figure 1 and Table I. For purposes of com(and is being done) by solvent treating methods such as the parison, the effectiveness of isoamyl nitrate is shown also. (IsoEdeleanu process. However, solvent treating for this purpose amyl nitrate is slightly more effective than commercial amyl is an expensive operation and, of major importance, requires a nitrate.) As can be seen from Figure 1, there is a slight scattering very sizable capital investment for a unit of even modest capacof points; nevertheless, the trends of cetane number improveity. ment a t the various concentration levels are pronounced. The To the refining industry, the most appealing answer to this inconsistencies in the data may be attributed in part to the problem is the development of an additive material for Diesel inaccuracies of the CFR cetane number determinations. fuels analogous t o tetraethyllead for gasolines. This, obviously, On studying Figure I , the following significant facts can be is a large order and it is impossible a t this time to state whether ascertained: or not this order can be filled on the basis of present knowledge. One material that offers considerable promise is 2,a-dinitroCetane number improvement with 2,2-dinitropropane appears propane. This paper presents, for general consideration, the to be the same for straight-run and catalytically cracked stocks. results of work conducted over the past 6 years in the developCetane number improvement with 2,2-dinitropropane is a ment and utilization of this material as a cetane number imfunction of the cetane number of the base fuel. This holds true for isoamyl nitrate also. prover. Since August 1945 the Commercial Solvents Corpora2,2-Dinitropropane gives a good initial cetane number inition has collaborated in research and pilot plant development of provement response a t a very low concentration (about 0.1% methods of producing 2,2-dinitropropane and the carrying out of by weight). tests concerning its properties. The effectiveness of 2,2-dinitropropane decreases with concentration in the fuel. For simplicity, the requirements laid down by Broeze and Hinze (b) for evaluating a Diesel fuel additive are employed in considering the status Table I. Cetane Number Improvement with 2,2-Dinitropropane of 2,2-dinitropropane. Briefly stated, these criteria are: Effectiveness in raising cetane number Solubility in fuel Solubility in water Effect of acids on additive Storage stability Safety in handling and use Ease of manufacture Corrosive tendencies cost
In addition to these requirements which, for the most part can be determined in the laboratory, field testing of products containing the additive is required. These nine criteria as applied to
A.P.I. Fuel Gravity Catalytically cracked fuels 30.4 U. S. N a v y 30.8 Sone and Fleming 30.8 U. S. N a v y 28.7 Paulsboro 33.1 Panlsboro 25.4 Paulsboro General Petroleum General Petroleum Straight-run fuels 36.7 Paulsboro 31.9 General Petroleum 33.6 General Petroleum 31.6 General Petroleum 39.8 Paulsboro 29.0 U. S. N a v y General Petroleum 3616 Paulsboro 27.4 Pauleboro General Petroleum General Petroleum General Petroleum General Petroleum 35:4 Paulsboro
.. I .
.. .. ..
929
I.B.P.
A.S.T.M. Distillation 10 50 90
434 436 437 456 404 424 439 454
466 453 467 481 484 456
492 474 492 518 536 500
...
...
376 378 340 383 386 494 355 382 43s 410 388 390 386 330
502 447 451 458 435 532 468 501 508
...
... ... ... ... 388
...
559 534 513 527
...
569 530 557 556
... ... ... ...
432
540 510 532 589 614 582
... ...
606 648 634 650 572 682 567 601 627
*..
...
... 490
C F R Cetane No. of Blends with 2,Z-DNP
E.P.
Clear
0.1%
578 545
38.6 32.7 38.0 38.0 50.3 24.0 41.0 35.0
.. ......
633 669 632 662 624
650 676 700 728 614 65+
642 684 667 710 630 646 534
56.5 41.6 42.5 40.5 55.6 43.8 39.1 59.5 39.7 44.0 41.0 41.0 35.5 40.7
0.5% 46.5 4A:O 40.0 62.7 35.1
44:5 37 .O
~. ..
....
68.8 48.9 52.0
4411 60.9
.. .. ..
5i:o 45.5 43.0 40.0
..
1.0% 45:5 43:s 63.5 37.5 ~.
.. .. 5i 15
65:5 51.7 47.9 73.2 47.5 53.5
..
..
7f:O 53.3
.* ..
.. .. ..
50:6
55:s
Vol. 41, No. 5
INDUSTRIAL AND ENGINEERING CHEMISTRY
As discussed in a previous article ( 8 ) , cetane improving additives impart but little improvement to the cold starting characteristics of fuels. However, it was also shown that even large increases in the natural cetane number of the fuel do not constitute a solution to the cold starting problem. Preliminary work has indicated that dinitropropane provides the same reduction in combustion shock as does an equivalent increase in natural cetane number. This particular performance characteristic of fuels is difficult to measure reproducibly and final results mill not be known until the completion of improvements being made in t,he technique for measuring combustion shock. The effect of 2,2-dinitropropane on exhaust smoke is discussed in the section on field tests.
Solubility in Fuel
35
2 40 3
45
55
50
60
'Po date, no studies of the solubility phase relationships of 2,2-dinitropropane and Diesel fuels have been undertaken. However, experience in laboratory blending has shown that 2,2dinitropropane is soluble in Diesel fuels of all types beyond concentrations of 5.070 by weight, a concentration far exceeding the limits of practical use. 2,2-Dinitropropane is a n opaque white solid which melts a t about 125' F. to a thin oily liquid. The current practice in preparing tank car blends of Diesel fuel and dinit,ropropaneis simple and has been accoinplished by educt'ing melted 2,2-dinit,ropropane into a flowing stream of warmed (100 t,o 125 O F.) Diesel fuel. This method has been found convenient,, although it is equally feasible to dissolve the additive from the solid state when only the fuel. is heated.
65
CETANE NUMBER CLEAR
Solubility in Water
Pigure 1. [Composite Graphs Showing Relative Approximate Cetane Number Improvements for Additions of 2,P-Dinitropropane and Isoamyl Nitrate
Z,2-Dinitropropane is soluble to only a very 1ixnit.ed extent in water. This characteristic is a necessary prerequisite for Diesel fuels when considering the common practice of storing fuels in t'anks with water bottoms, To illust'rate the resistance of 2,2-dinitmropropane to "washing out,'' equal volumes of water and a Diesel fuel blend containing 0.5 weight yo (nominal) of dinitropropane were shaken together for 10 minutes, the layers were separat,ed, and the fuel blend was analyzed for dinitropropane content by infrared spectroscopy. The results oht,ained were as follows:
The addition of 2,2-dinitropropane t o a fuel of 35 cetane lluinber or higher will effect a greater cetane number improvemrnt than the addition of an equal weight of isoamyl nitrate. The data summarized in Figure 1 show 2,2-dinitropropane to iw wbstantially effective as a Diesel fuel ignition accelerator. . ~ increase n of 7 to 10 cetane numbers can be expected by blending d Diesel fuel of 35 to 40 cetane number with 0.5% by neight 2,2-
2 , 2 - D S P , yo Wt. 0.48 0.02 0.47 0.02
Sample Base fuel not contacted with HrO Rase fuel agitated with H20 €or 10 minutes at 80' 1.'.
dinitropropane. Of possibly even greater significance is the 3 to 8 cetane number improvement resulting from the addition of 0.1 % by weight 2,2-dinitropropane. The effectiveness of dinitropropane as a cetane number improver is perhaps more significantly determined in terms of its nhility t o provide the fuel performance characteristics for mhich natural cetane number is reported to be beneficial. These performance characteristirs are: improved cold starting, reduced cornbustion shock, and reduced rxhaust smoke.
Effect of Acids on Additive To date, no detailed studies have been made of the reactivity of acids with 2,2-dinitropropane. Reaction.: of acids probably do occur, depending on the concentrations of the acids, trm-
Table 11. 2,2-Dinitropropane Storage Stability Laboratory Test Data Z,P-Dinitropropane, % W t . ( 10.02)
Iron Form Xone Turnings
hdded
Powder Sone None Turnings Ferrous sulfate a
Aqueous Solution Added Tspe J11. None None Synthetic sea water 10 Synthetic sea water 10 Synthetic sea u a t e r 10 Synthetic sea water 10 Distilled 1320 10 Synthetic 6 8 8 water 10 Distilled 11~0 10 Synthetic sea water 10
____I_-
Grame
&:a 5.0 1. o
0.1 2.5 I . .
i:i 2 .O
j
j
.
I
____
24 l1ours 0.40 0.49 0.22 0.41 0.45 0.06 0.48 0.48 0.42 0.49
-
Closed BottleQ, 150° F.
48
72
~-
9G
hours
hours
hours
0.50 0.48
0.48 0.48 0.05 0.28 0.40
0.48 0.48 0.02 0.24 0.39
0.12 0.33 0.43 0.05 0.47 0.47 0.39
..
100 nil. of fuel blend in stoppered 250-ml. Erlenmeyer flask. Original fuel contains 0.5
.; .~ * , .. ..
* 0.02
.. .~ ..
0:48
~ t ";b. 2,2DNP
120 hour8 0.46
..
~. ..
0103 0.46 0.48 0.18
..
INDUSTRIAL AND
May 1949
E N G I N E E R I N G CHEMISTRY
93 I
Diesel fuel additives was employed along with glass bottles containing polished Glass Bottle with Polished Iron Strip0 Navy Containera iron strips, Following the Navy proceWith With with Synthetic Tank Car a n d dure (Table IV), synthetic sea water was Distilled Water *Synthetic Sea Water Sea Water 10,000-Gal. Tanka 2.2-DNP 2,2-DNP 2.2-DNP Storage 2.2-DNP used in the Navy sandblasted iron conconcn., concn., Cetane Cetane Cetane concn., Period, Cetane concn., tainer. I n the glass bottle tests, both wt. % No. wt. % No. wt. 70 No. wt. % No. Weeks distilled water and synthetic sea water 0 49.3 0.50 49.3 0.50 49.3 0.50 49.3 0.50 4 n AZ 0.26 0.48 0 44 were used. n 90 n AU 6 0.51 0.40 8 0.48 0.15 0.46 0.40 The field test data reported covered 8 10 0.47 0.09 0.47 0.37 weeks' storage in a tank car (during 16 49.6 0.45 42.8 0.06 49.0 0.48 48.7 0.36 which time the fuel was shipped from a 3 weeks t a n k car, 13 weeks tank: Sept.-Dee. 1947. b Outdoor storage; Sept.-Dec. 1947. Paulsboro, N. J., t o Boston, Mass.) fol0 Laboratory storage, 70° F.; 1200 ml. of fuel blend in 2-quart bot>tlevented to atmosphere. lowed by 13 weeks' storage in a bulk Original fuel contains 0.5 0.02 wt. yo 2.2-DNP. terminal 10,000-gallon tank. The ratios of metal surface t o oil volume for these several types of storage are shown in the following tabulation along with the-ratio for an80,OOO-barrel tank peratures, and contact times. On considering the probable of the type commonly employed for storage purposes. concentrations of acids in Diesel fuels, the storage temperatures, the lengths of storage periods, and the fact t h a t straight-run Ratio of Metal Surface t o Oil Volume, and catalytically cracked stocks are usually stable enough not Square Inches per Container Gallon to require acid treating, it appears evident t h a t the conditions Navy can (sea water bottom) are such that loss of additive due t o acid reaction would be 109 Glass bottle with iron strip 20 negligible. 10,000-gal. tank car (dry) 12 7 10,000-gal. t a n k (water bottom) Among the limited studies on the effect of acids on dinitro80,000-bbl. t a n k (water bottom) I. propane blended with Diesel fuel, a test similar t o that described Supplementing the data reported in Table I11 on dinitroproabove was conducted. Equal volumes of a 5% hydrochloric pane concentration over the storage period of 16 weeks, cetane acid in water solution and a Diesel fuel again containing a number determinations on the original and final samples are also nominal dinitropropane concentration of 0.5% by weight were reported. From these data a number of pertinent conclusions shaken together. I n t h k case, the results were as follows: can be drawn. Table 111. 2,P-Dinitropropane Storage Stability Laboratory and Field Test Data
f
Sample Base fuel not agitated with HC1 solution Base fuel agitated with 5% HC1 solution for 10 minu t w at 80° F.
2,2-DNP, % ' Wt. 0 . 4 8 ;t: 0 02 0.46
f
0.02
Storage Stability Numerous tests have been run on the storage stability of 2,2dinitropropane in blend with Diesel fuels. These tests have been run under a wide variety of conditions by several laboratories, including those of the Socony-Vacuum Oil Company, Commercial Solvents Corporation, and U. S. Naval Engineering Experimental Station at Annapolis, Md. Summarized results of laboratory and field tests conducted by the Socony-Vacuum Laboratories are presented in Tables I1 and 111. The laboratory tests reported in Table I1 were conducted with a fuel containing, initially, 0.5 weight % dinitropropane stored in glass bottles a t a temperature of 150" F. for 120 hours. The tests were run on the base fuel itself and on the base fuel with modifications such as the addition of iron turnings, iron powder, ferrous sulfate, distilled water, and synthetic sea water. The laboratory tests reported in Table I11 were again conducted with a fuel blend having a n initial concentration of 0.5 weight yo dinitropropane. In this work the type of container specified in the U. S. l i a v y procedure for stability testing of
Table IV.
Details on Navy Storage Container and Synthetic Sea Water
10 X 10 inch cylindrical containers are fabricated from 16-gage, hot-rolled black iron sheet. All joints are welded. A cover of t h e same material is turned down around the edge for about 1 inch a n d equipped with a handle a n d curved breather pipe. T h e interior of t h e container is sandblasted, wiped with a cloth, and rinsed with t h e base fuel prior to use. Fuel blends are stored for t h e most p a r t , i n the presence of synthetic sea water. I n all cases, 10,600 ml. of t h e fuel blend are e m loyed and, in cases where a synthetic sea water bottom is used, 1000 ml. of t t e following composition are added t o t h e container:
&fgclz,6HzO CaClt (anhydrous) NazSOa (anhydrous) NaCl Distilled water t o make
1 1 . 0 grams 1 . 2 grams 4 . 0 grams 2 5 . 0 grams 1 liter
Additive concentration remains essentially unchanged when the fuel is stored by itself, in the presence of iron, in the resence of distilled water, and in the presence of distilled water anxiron. I n storage with synthetic sea water and a high ratio of iron surface t o oil volume, there is a marked reduction in dinitropropane concentration over the storage periods employed. This is noted particularly in the Navy container data (Table 111). In storage with synthetic sea water, additive reduction is proportional t o the amount of iron surface present. Iron in the form of ferrous sulfate does not have the effect noted for iron turnings and powdered iron. For storage in a relatively small tank (10,000 gallons) where the ratio of metal surface t o oil volume is high by commercial standards, the loss of dinitropropane in 4 months' storage is relatively small. Of considerable significance is the observation t h a t decrease in cetane number with additive loss is smaller than would be calculated on the basis of the reduction in additive concentration. These data and the foregoing observations lead t o the general conclusion that, for practical usage, the stability of 2,a-dinitropropane in storage is satisfactory.
Safety in Handling and Use The safety of 2,2-dinitropropane has been considered extensively from two principal viewpoints-explosive tendency and toxicity. Shock and Temperature Stability. Work on the explosive tendencies of 2,2-dinitropropane itself has been conducted by the U. S. Army Ordnance Department and by the Bureau of Explosives, Association of American Railroads. I n t h e report by the Ordnance Department (9) the explosive characteristics of dinitropropane are described briefly as follows: Sensitivity, Comparable with T N T Stability. Does not explode in 5 seconds below 360" C. (680"
F.1
Ballistic power.
123 ( T N T = 100)
I n the report prepared by the Bureau of Explosives (3) the following statement is made:
A portion of the sample was maintained at a temperature of 75" C. for 48 hours in a loosely stoppered glass vessel. During
INDUSTRIAL A N D E N G I N E E R I N G CHEMISTRY
932
Table V. Immediate Toxicity of 2,P-Dinitropropane Administered Orally to Rabbits and Rats Dose, S+1n./Kg. of Body Keight
K O . of Animals No. of Employwl Fa talit,iea
Longt,h of Survival of Those That Died, Horirp
lioss of Wriylii, '% of Initia.1 \TPiEtl t
K n hllits
1.G 2 . 1 5 0 6 7
0 x 4 7 Hili>
0.94
0.62 0.42 0.28
8
3
3 2
3
2
0 1)
1.8--11.-1 1,4.5-13,8
.... ,..
2 . 2 6.4 6 .O-7.4 7.0--11 ,I) R 4~ 5 6
chis priiod of heating about two thirds of the bairlple vola tilized There w a no ~ sudden or explosive decomposition. A portion of the material was placed in the brass block ai room temperatwe and I h r temperature raised slowly to 350" C . T h material volatilized or sublimed completely withoui any explosive decomposition. Small portions of the sample 11 ere exposed suddenly to teniperatures as high as 350' C. on the block without explosion The cover mas removed from one bottle containing about 0.5 pound of the material and this placed in a blazing wood fire on the testing ground. The material appeared t o melt quietly, ignite, and burn nithout explosion. The material did not explode when subjected to a 12-inch din]) 111 the impact apparatus. A portion of the sample was melted and poured into abomf din equal volume of dry wood saxdust: This saturated sawdust was subjected t o detonation by a blast>ing:cap. There resulted a very mild explosion that fragmented the pasteboard containel but did not make any visual impression on the ground. A blasting cap was inserted into the center of a 4-ounce solid portion of the sample and this placed inside a wood box made of 0.5-inch lumber. On detonation of the cap, the box was fragmented somewhat and some pieces were projected about 10 feet. Small bits of undecomposed nitropropane were scattered by t h r detonation which was not a complete explosion of the material. A further portion of the sample was melted and caused to cool in a coarse grained porous mass. 4 blasting cap was inserted in the center of this mass and the whole placed in a ~ o o box. d On detonation of the cap, thc dinitropropane was scat twed in the box and none apparcmtlv exploded The hou !\a. not sigriifirantlv fragmented. This arork way wiiriucLed O N 8,~-diriitiopioptirir itself. 111 addition, numerous tests have been run on Diesel fuels containing dinitropropane in concentrations of 0.05 to 2.0 weight %. Such tests have included deteimination of distillatiori and Aasli point characteristics, carbon residue, d f u r content, ash rontent, ip c o roqion. ~ heah of combustion, and copper These and other laboratory tests as well as testing in continuous ronibustion uliits have been conducted satisfactorily without indication ctf any difficuliy that might be attributed to the additive. Toxicity. The toxic properticis of 2,2-dinitiopropaiie have been studied by the Kettering Laboratorj of Applied Physiology, College of Medicine, University of Cincinnati (6). The purpose of this investigation was to determine the inirnediate toxicity o f 2,2-dinit ropropane when administered to animals 01 allv in one dobe and in small doses repeatedly and M hen xpplircl upon thrir intart skin. The conclusions are a u follom~ T h e minimum lethal dose of 2,2-dinitropropane when administered orally t o rabbit. lias between. 0.18 and 0.28 gram per kg. of body xeight In the case of rats, the COI I esponding value is greater than 0.42 and less than 0.62 pram per kg. [These data are givexi in Table V.] For purposes of comparison, the toxicitv of several other compound", atrrived at hv corre3ponding
Table VI.
Vol. 41, No. 5
means 111thr caase ot labbits, i b "-q)r III siiiiilai terms: monomethylanilinc~0.18 t o 0.28 gram p 0.28 gram per kg., 1,l-dichloro-1-nitrc per kg., and 1-chloro-1-nitroethane 0.10 No cumulative effects were observed when rabbits were given an oral dose of 23 mg. prr kg. on h of 50 days during a period of 58 days. Apparently the material is not absorbed rapidly or in physiolpgically significant quantities through the intact, skin of rabbits, qince a group of these animals sufferrd no demonstrahlr illness or injury when each was subjected t o an application thereon of either 0.75 gram per kg. in olive oil or 6.5 grams per kg. in ethyl alcohol, over a period of 6 t o 7 houis. T h e e of four rabbits died within a peiiod of 7 u r r k i duiing which 2,2-dinitropropane in olive oil waa applied upon the intart -kin foi 2 hours on 6 days of each \%eel have been found that a,Zdinitiopiopane posbesses coirosive properties when stored in iron containers by itself or when blended with Diesel fuels. I s shown in Table VII, copper strip coirovion te4ts ( 3 hours X L 2 I 2 I' F.) were run on five Diesel fuek of various types, earh con-
Laboratory Production of 2,2-Dinitropropane Ultimatc
__
Materials In, Moles per Hour 2-h-itroHXOs propane Water Propane L 23 1 23 1 80 0 78 0 78 I 30 1'15
- Run Cond1trons _ _ _ Pressure, Temp., Space Ih./sq. in. F. Velocity 900 400 0 85 900 400 0 g5 I
~ i t t e r i i t l >0u6, Moles per Hou: 2,2Dinitro%Nitropropane propane 0 110 L 00 0 048 0 93
o/o
Based on Nitric Acid 47 ih
INDUSTRIAL AND ENGINEERING CHEMISTRY
May 1949
taining 1.0% weight 2,2-dinitropropane. A11 the blends passed the copper strip test satisfactorily. I n addition, i t may be noted that the addition of dinitropropane to the fuels did not raise the “performed gum” content of the blends. The A.S.T.M. test for this work was modified t o provide a n evaporation temperature of 400 O F. instead of the specified 320’ F.
Table VII.
Corrosiveness and Stability of Diesel Fuels Blended with 1.0 Weight % 2-Dinitropropane Cu Strip A.S.T.M.. Corrosion, Gum 3 Hr. a t (400° Y.1, 212O F. hfg:./lOO M I . Pass 123 Pass 125 Pass 257 Pass 178 Pass 41 Pass 43 Pa& 95 Pass 80 Pass 363 Pass 333
Stock Paidffinic straight r u n DNP Paraffinic straight run Naphthenic straight run Naphthenic straight r u n 4- DiXP Paraffinic cat cracked DNP Paraffinic cat cracked Naphthenic cat cracked Saphthenic cat cracked -t D N P Thermal gas oil Thermal gas oil DNP
+
+
~~
+
933
ation of the vehicles on test fuel RG-13.4, two other coaches were operated in similar fashion, using the commercial fuel shown in Table VIII. These coaches averaged 32,050 miles each during the same test period. The observations during this time showed comparable vehicle performance and fuel and oil economy. The sole difference noted by both coach drivers and test observers was that smoke and exhaust odor from the coaches on test fuel seemed t o tic. less than that from the coaches on the commercial fuel. At the conclusion of the 30,000+ miles of operation, the test was terminated as planned and the engines were disassembled for inspection. The two coaches on the commercial fuel were also brought into the shop and the engines torn down for examination. I n this inspection all component engine parts were examined with regard t o wear and deposits. Included in the examination were the fuel injectors, combustion chambers, intake ports, exhaust valves, valve guides, pistons, piston rings, cylinder walls, and overhead rocker assembles. Differences in wear and deposits among the engines operated on the test, fuel were slight; the extent of wear and the amount and nature of deposits were essentially the same for the engines on the test furl as for the engines operated on the commercial fuel.
cost So matter how technically sound a product or process may be, i i of little or no value unless the cost is low enough to make its use desirable on a commercial basis. Furthermore, until the market demand for a product is established quantitatively, it is often impossible t o state just what the manufacturing and marketing costs will be. In recent years this problem has been complicated still further by rapidly climbing material and labor costs. As a result, it is not possible a t the moment to state an absolute price for 2,2-dinitropropane. However, sufficient economic studies have been made on a relative basis t o indicate that the utilization of 2,2-dinitropropane is competitive with known solvent refining methods for improving cetane number. It
Table VIII.
Laboratory Inspections on Field Test Fuels
2 2-DNP, wt. 70 dravity, ~ A . P . I . A.S.T.M. distillation I.B.P. 1 0 7 received 5 0 d received 90% received
0
F.
Test Fuel RG-13A 0.5 38.4 330 388 432 490 534 136 52 51 0.04 0.02 134
E.P.
Aniline point, F. Diesel index Cetane No. Sulfur Carbon residue (10% bottle), Flash point, a F. Pour point, F.
