Alcohol-Gasoline Blends LEO M . CHRISTENSEN The Chemical Foundation of Kansas Company, Atchison, Kans.
gallons per year, and each year important expansions are announced. The scientific literature is replete with reports of the characteristics of such fuels, but an economic analysis based solely upon these data is certain to be inadequate. The influence of this development upon employment, improvement in farm practices, freedom from the vagaries, of international trade, provision for an imminent petroleum deficiency, and other factors must be given the full consideration due them.
Types of Alcohol Fuel I n general, two types of alcohol-containing fuel have been employed. I n one, alcohol is the principal constituent, and ordinarily ethanol or methanol is used. These fuels are especially designed for racing engines of very high compression pressure, and many speed records have been established with such blends. The second type is of greater general interest since it is designed for use in present-day commercial sparkignition engines. This type ordinarily contains 5 to 25 per cent of alcohol by volume, and ethanol is generally used although methanol, isopropanol, and isobutanol have also been studied. It is reported that Germany will shortly be using blends containing methanol as well as ethanol, the latter serving as a blending agent for methanol which alone is not satisfactorily miscible with gasoline. Sometimes other hydrocarbons than gasoline are employed in such blends. I n particular benzene has been used, alone or in combination with gasoline. Alcohol-benzene-gasoline blends are reported to be popular in Germany and in England. The greatest interest, however, is in the use of ethanol alone in blends with gasoline, and the present discussion will be limited to fuels of this type.
HE interest in alcohols as fuels for internal combustion engines arose with the first efforts to build and operate engines of this type. Ethanol was of particular value then because of its well-nigh universal availability and its favorable physicalchemical properties. The potential supply and low cost of gasoline, then a worthless by-product from the refining of petroleum, soon turned attention from alcohols to hydrocarbon fuels and a number of years elapsed before there v a s again a consideration of alcohols as motor fuels. Within the past fifteen years there has been a renewal of interest in alcohols suitable for use in internal combustion engines. The universal trend toward national self-containment, has, in part, been responsible for this development; Physical-Chemical Properties of Ethanol- Gasothose countries without adequate domestic supplies of petroline Blends leum are looking to alcohols, made from the products of agriculture or from carbon monoxide and hydrogen, to supply a The commercial utilization of ethanol-gasoline blends has part of their motor fuel requirements. The second reason is been entirely dependent upon the development of satisfactory often of even greater impor: m e t h o d s for dehydrating tance. T h e v e r y l a r g e the alcohol. Several methmarket for farm products ods are now used commerw h i c h t h i s field affords, cially, a n d a n h y d r o u q Various types of alcohol blends are in through c o n v e r s i o n of ethanol is a common article common use in practically every country, starch and sugars to of commerce. The old fear the usual blends distributed commere t h a n o l , has been very that it was strongly hycially containing 5 to 25 per cent of ethanol attractive since there has groscopic has been entirely or of methanol and ethanol. Anhydrous been an almost universal Anhydrouh d i s p e 11e (1. need to find means for exethanol is m i s c i b l e with ethanol is miscible with gasoline in all panding the o p e r a t i o n s gasoline in all proportions. proportions : methanol ordinarily reand the employment in this and such mixtures are stable quires the addition of a stabilizer, ethanol most basic of all industries. to -60" C. or lower. The being entirely satisfactory for this purPower alcohol is now an imaddition of water to the pose. portant part of the agriculalcohol or to the blend raises tural p r o g r a m s of many the critical solution temProperly prepared alcohol blends, connations. perature, and as a consetaining not more than about 25 per cent Thus the a l c o h o l fuel quence there has been some of alcohol by volume, may be used intersituation is not one of purely concern about the stability changeably with gasoline of equal antitechnical nature; there are of such blends in commerknock rating. Such blends may safely also involved certain ecocial storage and distribunomic and s o c i o l o g i c a l tion be stored and distributed in modern comaspects which prevent the Bridgeman and Querfeld mercial equipment. Used in this type of exact treatment and analy(F), Bayky and Hopkins blend, the alcohols are not substitutes for sis that could be applied if ( d ) , and C h r i s t e n s e n , gasoline but serve the purpose of increast h e s e f a c t o r s were not, H i x o n , a n d Fulmer (9) ing the antiknock value and otherwise operating. The world conrecently reported studies on sumption of power alcohol. the water-holding capacity improving the fuel. It is on this basis largely ethanol, is not exof ethanol blends, their rethat the value of these alcohols must be actly known. The incomsults agreeing quite closely determined, although in many countries plete data available indicate with t h o s e p r e v i o u s 1y other economic and sociological factors a consumption considerably presented by Hubendick are being given justifiable consideration. i n e x c e s s of 200 million ( I S , 19, 20). I n general, 1089
INDUSTRIAL AND ENGINEERING CHEMISTRY
€“hano/
content of b/ond- vohme psrcenf
FIQURE 1. WATERABSORPTION BY ALCOHOL-GASOLINE BLENDS A . 50 cc. in 100-cc. Erlenmeyer flask with 2-mm. vent: 100 per cent relative humidity. 0-38’ C. change daily. 15-day exposure. B. Same as A’but a t 50 per cent re1ati;e humidity. C. 500 cc. in 1-liter bottle with 2-mm. vent: stored out of doors 30 days.
the addition of water to the extent of more than about 1 per cent of the alcohol produces a dangerous situation in winter weather, while not more than about 3 per cent can be tolerated during the summer. These limits apply reasonably well with blends containing from 5 to 25 per cent of ethanol; the safe water addition is larger in blends of higher alcohol content and smaller with lower concentrations of alcohol. The safe limits are also affected by the character of the gasoline, being smaller with saturated aliphatic hydrocarbons and greater with unsaturated or aromatic hydrocarbons. The water-holding capacity is secondary in importance to the rate of water accumulation by blends under commercial storage and distribution conditions. Spausta (52), and Christensen, Hixon, and Fulmer (IO)studied the rate of water absorption of blends under various storage conditions. Figures 1 and 2 show the results obtained in the latter investigation; the rate of water absorption is markedly influenced by the alcohol content of the blend and by the surface-volume ratio. TABLEI. CiHsOH Content per Water-Holding Capacity per 100 c c . 100 Cc. Blend 0 O C . +20°C. Blend -20” C . Cc.
cc.
1 2 4 6 8 10 15 20 30
cc.
0 0.008 0.018 0.045 0.080 0.112 0.150 0.251 0.355 0.541
... ...
0 0.013 0.030 0.080 0.131 0.188 0.245 0.417 0.589 0.938
0 0.019 0.043 0.104 0.180 0.261 0.347 0.589 0 832 1,357
...
...
...
Cc.
cc.
Evapn. Loss by Wt.C 1 hr. 3 hr. 17 hr.
Reid Vapor Pressure (Dry) G./sq.
% ._
% .11.5
% ..
S p Gr. 2 5 j 4 O c‘.
Calorific Air-Fuel Value, Fall in Ratio Lower, Temp. on for Com- Includ- L a t e n t Evapn. plete Ing La- H e a t of of CorCombus- tent H e a t E v a p n . rect Airtion by a t ConFluidit at. Fuel at 25’8. Wt. s t a n t Vol. Atm. Ratio Cali cc.
cn.d
0
0.010
...
day.
of blend in 1000-cc. bottle with 2-mm. v e n t exposed 15 days out of doors. 100 cc. of blend in 150-00. beakers a t 29’ C., exposed for indicated time G./sq. cm. Cal./cc. 70,38 lb./sq. in. o.0665 B. t. u./gal.
b 500 cc. 6
&.
BLENDS (9-1.2) . .
Gal.! cc.
c.
529 0.7212 216.3 14.8 7700 54.5 18.8 0 6.0 27.0 12.2 218.9 14.7 7675 54.4 19.4 0.005 6.3 28.3 . . . 0.7214 7650 0.014 .,. 0.7217 219.1 14.7 11.3 29.5 56.5 20.0 6.3 0.018 217.6 14.6 7600 58.5 21.2 7.8 0.014 0.061 529 0.7225 13.3 32.7 22.4 214.5 14.5 ... 0.7236 0.101 12.9 33.3 7550 60.5 6.4 0.008 549 0.7246 213.9 14.3 7510 62.5 23.6 0 6.4 0.148 13.5 35.5 207.6 14.2 7470 64.8 24.8 0 590 0.7257 0.218 5.5 10.9 34.5 7450 70.5 200.6 13.9 611 0.7292 0.338 0 5.4 11.6 32.1 27.9 7240 605 0.7323 32.3 75.8 30.8 191.6 13.6 5.3 11.3 0.396 0 175.1 13.1 7000 86.4 36.8 611 0.7384 0.550 28.6 0 4.5 11.6 111.6 6540 49.1 143.5 11.9 486 0.7520 24 1 50 0 0 8.3 3.5 97.1 9.0 170.2 5380 79.3 0 0 1 0 . 2 Negligible 0.7859 2.3 0.7 100 50 cc. of blend in 100-cc. Erlenmeyer flask with 2-mm. vent, exposed 15 days i n satturated atmosphei‘e f or 12 houra a t 0’ C a n d 12 hours a t 38’ C. each
0
.4
cc.
Of particular interest is the history of an alcohol blend in actual commercial storage. Curve D, Figure 2, shows a steady decline in the critical solution temperature and therefore of the water content during storage. This behavior is due to the distillation of an azeotropic ternary mixture of hydrocarbon, water, and ethanol, resulting in dehydration of the stored blend, a phenomenon earlier observed by Hubendick (20). The properties of ethanol and gasoline are not additive, a8 shown by the graphs of Figure 3 which were prepared with data reported by Christensen, Hixon, and Fulmer (11, 12). Balada (3) was the first t o show that the volume of a mixture of ethanol and gasoline is greater than the sum of the two, which results in a smaller increase in density than would be expected. Perhaps the greatest deviation from a linear relation is in the case of the fluidity. I n spite of the fact that ethanol is less fluid than gasoline, the fluidity of blends containing up to about 5 per cent of ethanol is actually greater than that of the gasoline alone. A consideration of these physical-chemical properties shows clearly that it is those blends containing not more than about 25 per cent ethanol that are of the greatest value for use in present-day gasoline engines. These blends differ from the gasoline base t o about the same degree that various commercial gasolines vary, except in the case of the latent heat of vaporization which increases rapidly as the alcohol content is increased. The influence of this change within the range of 5 to 25 per cent alcohol content is offsetby the increase in vapor pressure in so far as ease of starting or tendency toward vapor lock are concerned. The distillation curves of Figure 4 show the formation of azeotropic mixtures of minimum boiling point with certain of the hydrocarbons of gasoline. Up to about 25 per cent of ethanol by volume, the initial and final boiling points are practically unaffected, but the curve for the 50 per cent blend shows the effect of dilution of these fractions by alcohol. The sag resulting from the azeotropic mixtures, known as the “alcohol flat,” probably has little practical significance; the generalizations relating distillation data and performance characteristics which apply in the case of hydrocarbon fuels probably cannot be applied to alcohol blends. The initial rates of evaporation of freshly prepared alcohol blends of less than 25 per cent alcohol content are practically the same as those of the gasoline used in their preparation, which might be expected from these distillation data. But the rate of evaporation of such a blend becomes greater than that of gasoline alone after the loss of the more volatile frac-
SUMMARY O F PHYSICAL-CHEMICAL PROPERTIES O F ALCOHOL
Water Absor tion per 100 Blend A4 Bb
VOL. 28, NO. 9
-
‘
.
IKDUSTRIAL AND ENGINEERING CHEMISTRY
SEPTEMBER, 1936
tions, which constitute approximately 10 per cent of the gasoline by volume. This is due to the greater volatility of the binary azeotropic mixtures as compared with that of the hydrocarbons involved in the formation of these azeotropes. T h a t is, after evaporation of the most volatile 10 per cent of the hydrocarbons present in the blend, the evaporation of the alcohol-hydrocarbon azeotropes becomes predominant. If the initial alcohol content is greater than about 25 per cent, the lower volatility of the alcohol is evident in a decreased initial evaporation rate as shown by Christensen, Hixon, and Fulmer (11). A summary of the physical-cheinical properties of ethanolgasoline blends is given in Table I. Alcohol is an excellent solvent for the gums which are deposited by gasoline in the fuel system or formed during combustion. Kaphtali (26) found that alcohol is also of value as a n inhibitor in the formation of gum in some kinds of cracked gasoline. The action of alcohol in decarbonizing a fouled engine probably is due to its property of removing gums and thus loosening the carbon scale. This ability to dissolve gum accumulations sometimes causes trouble with clogged fuel screens when alcohol blends are first used in a fuel system in which there is a heavy gum deposition. The few reports of abnormal corrosion of engine and fuel systems due to alcohol fuels have been traced to the use of corrosive denaturants. Wawrziniok (33) reported results of tests on the corrosion of various metals by liquid alcohol and showed that, except in the case of tin, less corrosion is produced by alcohol than by gasoline. Hubendick (20, 21) stated that the products of combustion of alcohol blends containing not more than about 25 per cent of ethanol are the same as those of gasoline. He stated further that, in the longtime distribution of 20 per cent alcohol blends in Sweden, no abnormal corrosion of any kind was observed. Both ethanol and methanol react with magnesium and aluminum a t elevated temperatures, and it is possible that some corrosion of these metals might occur within the combustion chamber if fuels of high alcohol content were used and entered the cylin-
-
0
&
x)
7ih6
Of
80
eXpOSURQ-
90
50
60
d0yS
FIGURE 8. WATERABSORPTIONBY 10 PERCENTETHANOL90 PER CENT GASOLINE A . 50 cc. in 100-cc. Erlenmeyer flask with 2-mm. vent: 100 per cent relative humidity: 0-38' C. changed once daily. E . Same a8 A b u t a t 50 per cent relative humidity. C. 600 cc. in 1-liter bottle with 2-mm. v e n t , outdoor exposure. D . 50,000-gallon commercial storage; t a n k emptied in 66 days.
1091
der in the liquid state. Corrosion due to acetic acid formation might also occur with fuels of very high alcohol content if certain metals-for example, copper-were present in the combustion chamber. These are problems associated only with the use of fuels consisting primarily of alcohol. The value of alcohol as an antiknock agent has been of considerable importance in the development of alcohol blends. The data reported by L. T. Brown ('7)) G. G. I3rown (6),Kuhring (dd), Gray (16),and others show that ethanol raises the octane rating of gasoline of 60 to 70 octane number approximately 0.9 unit per volume per cent of alcohol added, within the limits of 5 to 20 per cent of alcohol. Table I1 gives the data reported by Kuhring ( 2 2 ) . S a s h and Hon-es (27') calculated the benzene equivalent of methanol as approximately 2.0 and that of ethanol as 2.2. The antiknock effect of both ethanol and methanol is greater with gasolines of low octane rating, and may reach 1.5 units per volume per cent with a 50octane base.
TABLE11. IXFLUEXCE O F ETHASOL COXTENT UPON OCTANE RATIXG OF ETHANOL-GASOLINE BLENDS( 2 2 )
Gasoline Sample No.
A
B
C
Content of Blend, % by Vol. Gasoline Ethanol
100 95 90
85 100 95 60 85 100 95 90 85
0 5
10 15 0 5 10 15 0 5 10 15
- - - - O c t a n e No.Highest By C . F. R. B y C. F. R. Useful research motor Compression method method Ratio 68 63 6.10:l 67.5 6.25:l 71 75 72 6.40:l 79 76.5 6.82:l 67 61.5 5.90:l 66 6.00:l 70 6.10:l 74 70.5 75 6.40:l 78.5 5.83:l 65 61 66.4 5.90:l 67.5 70.4 6,OO:l 71.5 75 6.26:l 76.5
The theoretically correct air-fuel ratio for complete combustion of ethanol is given by Ricardo (29) as 9.0 (corrected to a water-free basis) ; that for gasoline averages about 14.8. Thus, even though the alcohol blend may give the same airfuel ratio as gasoline with a given carburetor setting, the mixture strength is effectively leaner. This should result in a decrease in power output, with the carburetor settings actually used in practice, and there should also occur a decrease in carbon monoxide content of the exhaust gases. Brown and Christensen (8) showed that the latter result is observed but that the power output is not generally reduced; in fact, i t is generally increased even when the mixture ratio is leaner than that for maximum power output. The data reported show also that the air-fuel ratio is practically unchanged when a 10 per cent alcohol blend is substituted for gasoline and all engine adjustments are left unchanged. S a s h and Howes (28) attribute the increase in power output to the higher latent heat of vaporization of the alcohol, resulting in a greater weight of charge per cylinder, and Brown and Christensen observed the lowering of temperature which Ricardo's data (29) indicate should be expected-a drop 11" C. greater with the 10 per cent blend than with gasoline. This difference is not large enough to explain the increase in power which they observed. Presumably the lower flame temperature and slower rate of flame propagation with alcohol-containing fuels may in part account for this improrement.
Power and Economy Tests Many reports have been made of comparative tests of ethanol-gasoline blends and gasoline as regards power output and specific fuel consumption, and a great variety of results has been recorded. Hubendick (19, 20) and Roes and Ormandy (SO) clearly showed that the air-fuel ratio is a factor of the greatest importance in determining the relative values of
Ih-DUSTRIAL d N D ENGINEERING CHEMISTRY
1092
TABLE111.
POWER .4ND
ECONOMY TESTSFOR ENGINE (SO)
A
TWE
BES
(Four cylinders, 100 mm. X 140 mm., compression ratio 4 . 4 t o 1) Brake (A C)100 ( B - CllOO Horse-Sp. Fuel Consumptionapower A' E c A B -Liters per b. h. p . h.b-Lean mixture -4.28 0.390 -3.73 26.0 -2.72 -2.75 27.0 0.377 -2.52 -3.67 28.0 0.367 -2.51 4.0% 0.362 29.0 - 2-. 2~. 7 0.360 -4.04 29.5 30.0 0.358 -1.13 -2.87 -1.43 30.5 0.357 =o.oo 0.357 31.0 f1.38 t0.00 fl.10 0.358 f3.24 31.5 32.0 0.360 4-5.26 f3.23 32.5 0.362 +5.00 4-7.65 33.0 0.366 f9.86 f6.63 0.374 4-7.67 33.5 f12.40 34.0 0.385 ... f9.41 35.0 0.435 Rich mixture A Shell Yo. 1 gasoline; B = L. G. 0. gasoline; C = 90% L. G. 0. gasoline 10% alcohol. L'ters per b' h' p' h ' = U. 9 . pints per b Liters per brake horsepower hour. 0.273 b. h. p. h.
larly when the engine is operated a t part throttle and with air-fuel ratios lower than that for maximum economy, a condition more apt than not to obtain in ordinary commercial applications.
-
...
... I . .
-+
T.4BLE
Ikr.
...
P O W E R .%SD ECOXOMY TESTS FOR
ENGISE( 1 )
...
c. F. R . RESE.4RCH
(600 r. p. m full throttle, each fuel tested a t compression ratio a n d spark ;dvance for i h i p i e n t detonation, jacket water temperature 100' F., various air-fuel ratihs)
Indicated Horsepower Lean mixture 2.6 2.7 2.8 2.9
3.0
3.1 3.2 Rich mixture
-Sp.
Fuel Consumption10% E t O H blend -Liters p e r b. h. p . h . 7
Gasoline 0.311 0.309 0.307 0.306 0.304 0.305 0.322
A
- B(100) ..l
0.324
-4.5
0.318 0.310 0.306 0.300 0.296 0.306
-2.9 -0.5 10.0
+1.3 +3.0 +5.0
the two fuels. With air-fuel ratios greater than that for maximum economy, the heat content of the fuel becomes the limiting factor, prorided detonation is absent, and the increase in fuel consumption with the blend is about 3 per cent for each 10 per cent of alcohol present, unless the compression is raised to take advantage of the higher antiknock value when theoretically little or no difference would be found. K i t h mixtures richer than that for maximum economy, these alcohol blends containing up to about 20 per cent of alcohol give lower specific fuel coilsumption than does gasoline under the same conditions. The data reported by Ross and Ormandy (SO) were used in preparing Table 111. This same result was also obtained by the National Bureau of Standards in cooperation with the American Automobile Association (1), as shown in Table IV which was prepared from graphs of the original data. Miller (IS, Id), Waivrziniok (33), Gray ( I B ) , and others hare emphasized the importance of the compresqion ratio of the test engine and the throttle opening as they influence the relative fuel consumptions of the two fuels. Kuniber of cylinders, shape of combustion chamber, character of air-fuel distribution system, and many other factors also appear to influence the relative fuel consumptions with blends and gasoline. It may be concluded, however, that the substitution of alcohol blends containing not more than about 25 per cent of ethanol by volume for gasoline, in engines in common use and without change in ignition or carburetor adjustments from those found satisfactory with gasoline, will result in no decrease in power output or increase in specific fuel consumption. Instead, there may be a gain in power output and lowering in specific fuel consumption, and this will be the case particu-
VOL. 28, NO. 9
Road Tests The road tests reported by Moyer and Paustian (25) with twelve automobiles supplied by private owners for this purpose show the variability in relative mileages with the 10 per cent ethanol blend and gasoline that would be expected. The mean values show a gain in mileage with the blend amounting to 5 per cent a t 20 miles per hour and falling to 1 per cent a t speeds of 40 miles per hour or greater. Probably this change is largely due to variation in air-fuel ratios obtained a t the various engine speeds. These data are shown in Table V. The National Bureau of Standards has reported a number of road tests ( 2 ) . I n one series fifteen cars were tested over a course of 89.2 miles through average city traffic. Two gasolines and the 10 per cent ethanol blends were used, each a t several carburetor adjustments. Four of the fifteen cars showed more than one per cent poorer fuel economy with the gasoline than with the alcohol-gasoline blends, while six cars shoTved more than one per cent poorer fuel economy with the blends. The average fuel economy with the two gasolines was 15.91 miles per gallon: with the two blends containing 10 per cent of absolute alcohol it was 15.85 miles per gallon. A second series of tests was conducted by the bureau in cooperation with the American Automobile $ssociation. Four cars were used in tests over a 10-mile course. Several carburetor settings were used, and comparison was made between gasoline and the 10 per cent alcohol blend with the same gasoline. The tests were made a t 40 miles per hour. The inean fuel economy with gasoline was 16.54 miles per gallon;
e.
1
€ttn?no/ / n bland- 'k
6y vo/ums
FIGURE 3. PHYSICAL-CHEMICAL PROPERTIES OF ALCOHOL-GASOLINE BLENDS A . Latent heat of vaporization B. Reid vapor pressure
C. Density D . Heating value E . Theoretical air-fuel ratio F. Fluidity
SEPTERIBER, 1936
INDUSTRIAL AND ENGINEERING CHEMISTRY
1093
TABLE v. ROADTEsrs (8.5) (Relative fuel consumption for a 10 per cent alcohol blend and for gasoline a t varying car Fuel Consumption a t Actual Car Speed of: 10 m. p. h. 20 m. p. h. 30 m. p. h. 40 m. p. h. h-o. of GasoGasoGasoGasoTest Car Cylinders line Blend line Blend line Blend line Blend Milea oer aallon 4 Ford roadster 1930 2 7 . 5 28.6 26 3 2 6 . 6 2 4 . 1 24.6 21.9 2 1 . 6 4 Ford coup6 1931 28.0 28.3 25.4 26.9 23.7 26.0 20.3 20.7 4 Ford sedan 1932 22.6 22.8 23.2 23.4 21.5 21.5 19.3 1 9 . 7 6 Dodge coup6 1928 19.0 20.8 20.3 23.1 21.3 22.2 19.7 21.9 6 12.0 1 3 . 4 Studebaker coup6 1932 15.6 16.4 17 5 17 0 16.6 15.8 Plymouth coup6 1933 2 0 . 5 24 3 6 19.3 21.8 18 6 1 9 . 9 17.5 18.3 Buick sedan 1927 21.6 22.2 6 21 5 2 1 . 2 19.6 19.6 1 7 . 8 18 0 23.7 2 2 . 5 Oakland coach 1928 21.0 21.0 6O 18.7 1 7 . 3 15.6 15.9 Oakland coach 1928 2 1 . 8 22 1 6b 18.8 20,i 16.5 17.8 15 0 1 6 . 3 8 1 4 . 2 17.; Hudson sedan 1931 1 8 . 4 18 6 1 6 . 8 17.2 16.3 1 6 . 3 Buick coup6 1931 8 1 2 . 1 12 13.5 1 4 . i 12.1 12.2 12.4 12.8 2 3 . 8 22.6 8 Ford coupe 1932 23 1 23.4 21 7 2 1 . 1 19.2 1 9 . 2 Mean 2 0 . 7 21.5 20.5 21.5 19.4 19.6 1 7 . 6 18 0
,
__c_
--w
-v
L__
0.8 3.9
1 0 5 0
0.2 1.0
0.4 2.3
Gain, miles/gal Per cent With high compre3sion head
b
-
speeds) 50 m. p. h. Gasoline Blend 18.7 18.0 18.1 17 5 14.8 15.5 17.0 14.5 14.2 14.7 11 6 16 4 15.9 L
Y
18.4 18.1 18.5 18.5 14.0 15.5 17.2 14.5 14 2 14.7 11.6 16.7 16 0 -
0 1 0.6
60 m. p. h Gasoline Blend
-..
..
1 6 ’ 0 18:O
ii 8 i i : 9 1 4 . 5 13.9 1 2 . 4 12 4 13 9
14 0
L_
_c-
n i
(1 7
With low compreision head
--_____
vith the blend it n.as 16.02 miles per gallon. There were tlifficultw with vaporization of the fuels in the lines and results 15 ere erratic, which throws considerable doubt upon the value c ~ fthe data obtained. Hone\ ( 1 7 ) reported tests a i t h ten cars on a 17-mile course 171th g:isoline and a 10 per cent methanol blend. Seven of the cars showed better economy with the blend, and three g a l e better economy with the gasoline. The differences were not large Gray (16) and Sauve (31) reported comparative tests of alcohol fuels in tractors. I n general, the 10 per cent alcohol blend gave lover fuel consumption than did gasoline, 3 to 6 per cent better economy being usual. These tests were made 11 ithout changing any engine adjustments.
0
M
4
$
0
6
0
6
0
Disfi//od
FIGURE 4. DISTILL.LTION CHARACTERISTICS OF ALCOHOL-GASOLINE BLENDE .
