CA1224628A - Diesel fuels - Google Patents

Abstract

ABSTRACT
A surfactant-free, phase-stable, aqueous diesel/alcohol fuel composition containing a diesel fuel, water, a C1 to C3 aliphatic alcohol or mixtures thereof and a C4 to C8 aliphatic alcohol or mixtures thereof, as well as a method for producing said fuel compositions.

Description

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~ 1 --Brle~ Summar~_ ~ Inven~:ion ~echnical Field This invention pertains to diesel ~uel compo~itions for use in dies~l engine~s and to a method Ior preparing said compos~tions.
Back round or the Invention The use ot diesel ~uel compositions so power lignt-du~y ana heavy-duty engines and tnelr importance throughout ~he wor~d is well known.
However, it is also well known that there is a definite need to decrease the exhaust emissions from such aiesel-~owered engines, es~eci~lly in the area o~ visible smoke particulates an~ oxides or nitrogen (NOX~. In addition to satisfying obvious environment~1 concerns and related Environmental Protection ~gency re~ul~tions~ it is important to achieve a reduction in smoke/yar~iculate formation because o~ its relationship to lubricating oil de~erioration and atten~an~ accelerated englne wear.
Moreover, diesel ruels are sensitive to wa~er con~amina~ion and u~on such contamin~tlon exhibit no phase stability for wa~er even at temperatures o~ well above 0C. Operational problems ~ttendant with such water contamination are well known ln the ar~. Tnus ther~ is also a need to improve the aqueous phase stability or diesel fuels and ~nereby eliminate or at least minimize ~he obvious operating yrobl~ms ~hat may be asso ia~ea with ~he utilization or water contaminated diesel ruels.
Consequently, the discovery o~ a diesel fuel composition that would no~ only exhibit . ~' ~-13696 ~2~62~

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decreased particulate emissions, and would-also exhibi~ improYed phase stability not only upon ~torage, but towards water a~ well, would obviously be o~ no small importance to the state o~ the art~
The search for improved diesel fuel compositions is a constant one as seen, e.g. by the ~ollowing prior art.
The art~cle UDiesel Fuel-Aqueous Ethanol Microemulsions" by AoW~ 5chwa~ et al appearing in J.
Dispersion Science and Technolog~, 3Sl), yp. 45-60 (1982) which relates to a study of two-phase mixtures of diesel fuel and aqueous e hanol as well as a detergen~less system o~ a diesel fuel, aqueous ethanol an~ butanol.
U.~. Patent Appllcation ~erial No. 256,~06 filed April 21, 1981 entitled "Diesel Fuel-Aqueous Alcohol Microemulsions" by A.W. Schwab available from the National ~echnical Information Service, PB81-248619, which is directed to hybridizing diesel fuel with high levels of water and a Cl ~o C3 alcohol which are held in a 8 able microemulsion at low temperatures by means ot a sur~actant.
The article "Microemulsions as Diesel Fuels" by G. Gillberg et al in Am. Chem. Soc.
~Y~e~ Of the 172 Meeting o~ the American Chemical Society, San Francisco, Aug. 31 - Sept. 1, 1976 ~pp 221 eo 231) which discloses that emulsifiers can be used to reduce exhaust emissions in di*sel fuels.
U.S. Patents 4,162,143; 4,182,614 and 4,244,?al all of which disclose methods ~or reducing exhaust e~issions of fuel oils using aqueous emulsified fuel~.

D~13696 Society of Automotive Engineers (SAE) rechnical Paper Series #790g25 (1979), s~hich disclo~es the use of water and alcoholic diese} fuel emulsic:ns to reduce particulate exhau~;'c emissions S SAE Technical Paper Series ~79095fi (1979) which discloses a review of alcohol-diesel fuels~.
SAE Technical Paper Series ~810250 (1981) which discloses a study of the effec~ of water in diesel fuels.
SAE Technical Paper Series ~810254 ~1981) which discloses a ~tudy on the use of alcohol in diesel fuel emulsions.
SAE Technical Paper Series ~700736 (1970) which discloses a study on the effect~ of emulsified fuels and water induction on diesel combustion.
It has now been discovered, for the first time, ~hat phase-stable aqueous d~esel/alcohol fuel compositions can be prepared having a cloud point of 0C or below without the aid of surfactant emulsification and that certain of s~ch surfactant-free, aqueous diesel/alcohol fuel compositio~s have also exhibited improved anti pollutant characteristics.
Disrlosure of this Inventlon 2~ Thus it is an object of this invention to provide novel surfactant-free, phase~stable, aqueous dieseIfalcohol fuel compositions having improved anti-pollutant characteristics. Another object of this invention is So provide a novel method

3~ ~proce~s) for preparing ~aid diesel/alcohol fuel compositions. Oth~r objects and advantages of this invention will b~come readily apparen~ from ~he fQllowing description and appended claim 2~il More specifically, this invelltion i~
direc~ed to a surfactant-free, phase-~able, agueous diesel/alcohol fuel composition having a cloud point o~ 0C vr below, and consisting essen~ially o~ about 0.1 to abou~ 1.0 weight percent wa~er~ about 1 to a~out 19 weight percent of ~ Cl to C3 aliphatic al~ohol or ~ixtures thereof, and about 1 to about lB
weight percent of a C4 to C8 aliphatic alcohol or mixtures thereof, the remainder of said composi~ion consistiny essentially o~ diesel fuel.
Alternatively, this invention may be described as a ~ethod ~or ~reparing a surfactant-~reer phase-stable, aqueous diesel/alcohol Xuel com~osition suitable ~or use in diesel engines, which com~rises mixing a diesel fuel with water, a Cl to C3 aliphatic alcohol or mixtures thereor and a C~ to C8 aliphatic alcohol or mixtures th~reof, wherein said composition has a cloud point o~ 0C or below, and 2Q consists es~en~ially of ~bout 0~1 to about 1~0 weight percent water~ about 1 to about 19 wçight percent of said Cl to C3 aliphatic alcohol or mixtures thereor, and about 1 to about 18 weight percent of said C4 to C8~aliphatic 21cohol or mixtures thereo~, the rem~inder o~ said composition consisting essentially of said die~el fuel.
Detailed Description The primary component of the diesel/alcohol fuel composition of thi~ inventions is of cours~ a bas~ diesel Euel whi~h is present in a major amountO The base diesel fuel component employable in the present invention can be any conventionally known diesel fuel oil~ including hydrocarbon fu~l ~2'16i~

oil mixtures having a diesel boiling range o~ about 175C to abou~ 400C. Such diesel fuel oils and~or method~ for their ~reparation are well known in the art.
The Cl to C3 ali~hatic alcohol employable in the present invention includes methanol, e~banol, n~propanol and isopropanol, the most pre~er~red lower alcohol being isopropanol. O~
course mixtures or said Cl to C3 aliphatic alcohols can also be employed if desired.
The C4 to C8 aliphatic alcohol employable in the present invention includes butanols, pentanols, hexanols, heptanols and octanols, as well as mixtures o~ such alcohols, if desired~ The more preferred higher alcohols are the primary alcohols of said C4 to C8 alcohols, especially n-bu~anol; isobutanol, n-~entanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-ethylhexanol, and mixtures thereof.
It is ~o be understood that the surfactant-free, phase-stable, aqueous diesel/alcohol fuel compositions o~ ~his invention are single-phase, clear, transpar*nt, homogeneous mixtures which are chara~erized by their thermodynamic stability over a wide range of temperatures as seen by the fact-tha~ they possess a cloud point o a~ lea~t 0C or below. As employed herein the term ~cloud point~ represents tha~
temperature at which the fuel composition changes from a clear and transparent ~luid to one which is cloudy. ~oreover as not~d above, the diesel/alcohol fuel compositions of this invention are ~surfactant~re~N, i.eO, no surfactant is necessary for the aqueous diesel/alcohol ~uel composition of D-136g6 this invention to achieve a cloud poin~ ot at least 0C or below. Accordinyly, the aqueous di~sel/alcohol ~uel composltions o~ this invention are not to be confused wit~ emulsions, or even microemulsions, o~ diesel ~uels which depend upon the presence of a sur~ac~ant to obtain their aqueous clou~ point stabili~y.
The components o~ the dies~l~alcohol ruel compositions of this invention may be employed sinyularly or as mixtures and mixea ln any order using any mixing or blendiny apparatus and technique desired. Indeed the ruel compositions o~ this invention are characterized by their spontaneous formation u~on the proper choice and amounts ot components employed. Moreover, while the selection of the various ~uel oomposition component Amounts required to achieve the results desired will be dependent upon one's e~perlence in the utilization of the subject lnvention, only a minimum measure ot e~eri~entation should be necessary in oraer ~a asoertain those com~onent amounts which will be su~rioien~ to produce t~e ~esired results ~or any given situation.
For inst~nce, in general the amount of C~
25 to C3 aliphatic alcohol or mintures thereo~
present in ~he ~uel compositions or this invention may generically range Lrom about l to about l9 weight percent based o~ the ~o~al weigh~ o~ the f uel composition. Likewise the generic range oI t~e 30 remaining components o~ the $uel com~ositions o~
this invention, based on the total weight of the partlcular ~uel oomposi~ion desire~, include fro~
about 0.1 to about }.0 weiyht percen~ oi water, ~he more pre~erred upper limit o~ water being about 0.7 2;2'~6;~

weight percent, a~d ~rom about 1 to about 18 weight per~ent o~ a C~ to C~ aliphatic alcohol or mixtures thereof, tne xemainder of the fue}
composition consisting essentially of ~he base diesel fuel employed.
~ ore specifically, pre~erred phase-stable fuel compositions having a cloud point of at least 0C or below and containing up t.o about 0.7 weight percent water may be obtained when the composition contains ~rom about 1 to 19 weight percent o~
isopropanol and about 1 to 18 weight percent o~ a butanol or a pen~anol; and when the compo~ition contains ~rom about 10 to about 18 weight percent of isopropanol and about 2 to about 7 weight percen~ of 2-ethylhexanolO
In fuel compositions that contain a 50:50 weight percent mixture of methanol and ethanol as the lower aliphatic alcohol, preferred phase-stabls compositions having a cloud point o~ at least 0C or below and containing up to about-0.4 weight percent water may be obtained when the composition contains ~rom about 1 to about 5 weight percen~ of said methanol/ethanol ~ixture and about 10 to about 18 weight percent o~ a buta~ol; when the composition contains about 1 to abou~ 7 weight percent of said methanol/ethanol mixture and about 7 to about 18 weight percen~ o~ a pentanol; and when ehe compo~ition contains from about 1 to about 7 weigh~
percent o said methanol/ethanol mixture and about 10 to about 18 weight percent of 2-ethylhexanol.
In fuel compositions that contai~ methanol a the lower ~lipha~ic alcohol, pre~erred phase-stable fuel composition~ having a cloud point of at least 0C or below and containing up to abou~

~Z2~1~;2~3 0.~5 weight percent water may be obtained wherein the composition contains about 1 to about 5 weight pe cent methanol and about 10 to about 18 weight percent of a butanol; when the composition contains about 1 to about 8 weight percent of methanol and about 7 to abou 18 weight percent o~ a pentanol;
and when the ~omposition contains about 1 ~o a~out 8 weight percent of methanol and about 12 ~o 18 weight percent of 2-ethylhexanol.
1~ In ~uel compositions that contain ethanol as the lower aliphatic alcohol, preferred phase-stable ~uel compositions having a cloud point o~` at least 0C or below and containing up to about 0.5 weight per~ent water may be obtained wherein the composition contains about 1 to about 7 weight percent ethanol and about 1~ to about 18 weight percent of a butanol; when the composition con~ains about 1 to about 9 weigh~ percent o~ ethanol and abou~ 8 to abo~t 18 weight percent of a pentanol;
and when the composition contains about 5 to about 10 weight percent of ethanol and about 7 to about 12 weight percent of 2-ethylhexanolO
The subject inventi~n is indeed unique and beneficial in that it ~r7vides surfactant-free, 25 highly phase-stable, aqueous diesel/alcohol fuel composi~ions sui~able ~or routine utilization in diesel engines o conveneional design. Moreover, it is a common occurrence ~or certain unadultera~ed diesel fuels ~o appear slightly hazy on pouring, and 30 upon standing for a few days to form a darker sediment-lik~ layer on ~he bottom of the fuel wbich could cause operational probIems such as plugging ot fuel filters and injector nozzles. However, an added benefi~ of the diesel~alcohol fuel D~13696 ~22'~;2~

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compositions of this invention is ~neir clear and transpara~t characteristics and the ~ac~ that they have not been round to form such sedi.ment eYen upon long periods or storage.
Fur~her, in addition to the excellent thermodynamis~ally stable charactelistis:s (cloud point o~ at least ODC or below) o~ the diesel/alcalhol ruel compositions o~ this invention, isopropanol con~aininy diesel/alcohol co~osi~io~s o this invention have been found to subs~antially reduce ~he amount of visi~le smoke and particulates as well as oxid~s of nitrogen (NOx) in the exhaust emissions of the ~uel compositions as com~ared to t~at o~ the unadulterated base diesel ruel em~loyed. Such excellent anti-pollutant characteristics should also translate into better engi~e wear characteristics as well. Moreover, wnile the diesel/alcohol fuel compositions oi this invention do possess a lower cetane number (ignition quality~ than the base diesel ruel pPr se, such a drawback should be able tO be overcome by the additional use or small amounts o~ any suitable conventional cetane improver such as an alkyl ni~rate, and the like, i~ desired. Thus it is tO be understood that, i~ desired, ~he fuel compositlons or this invention may contain minor amounts i.e.
less than l weiyh~ perc~nt o~ any conventional cetane improver, as well as such amounts o~ any sui~able conventional corrosion inhibi~Or~ me~al deactivator or antioxidant.
The ~ollowing examples are illustrative o~
the present invention and are not to be regarded as limitative~ It is to be unders~ood tnat all ol the parts, percentages and proportions rererred to ~2Z'~ 8 -- 10 ~

herein a~d in the appended claims are by weight unless otherwise noted.
EXAMP~E 1 A series of fuel compositi~n.s were prepared wherein various amoun~s o~ a diesel ~uel, ~ Gul~) which had an unadulterated cloud point o~ ~15C, were mixed With various amounts of isopropanol, water and a 50:50 weigh~ percent mixture o~
n-butanol and isobutanol an~ the cloud point o~ each composition determined as outlinea below ~ixture o~
Diesel Isopro- n-butanol &
Fuel panol Wa~er isobutanol Cloud Com~sition ~ ~wt ~) (wt ~) ~wt ~) Point C
b) 81.84 8.50 0.579.09 -15 c) 85.66 5.43 0.~28.20 6 d) 84.79 5.38 0~719.13 -5 e) 83~94 5.32 0.7010.04 -12 f) ~3.60 5.30 0~7010.~0 -15 O~ the a~ove compositions, composition "~ n was mos~ pre~erred bec~use o~ its low cloud point : and hiyh water conten~. Compositions corresponding to "dn, en, and ~r~ were subse~uently ~re~ared using a diesel ~uel [XH-CAT (Caterpillar lGlH
Reference ~uel ~rom Howell, ~y~rocarbons Inc.~l that had an unadulterated cloud point oS -3C and the aqueous cloud point~ o~ the three compositions so prepared were ~ound to be 5C, -2C and -5C, respectively. In addition a ruel composition containing abou~ 84.78 grams ~90.~ wt. 4~ oi said #2 Gulf di~sel fuel which had an unadulterated cloud ~ poin~ o~ ~15C, about 8.45 grams (9.0 wt. ~) i~opro~anol and 0.56 grams (0.6 wt. %) water was cloudy at room temperature indicating tAat the contained wat~ was not in stable form.

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Example 2 A series of fuel compositions were prepared ~y mixing various amounts of a diesel fuelr ~#2 Gulf) which had an unadulterated cloud poant of -15C, with various a~ounts of isopropanol, wat r, and a mixture of primary amyl alcohols [analysis:
about 98.7 wt. ~ total primary amyl alcohol; about 66.14 wt. % n-pentanol and about 32~ 56 wt. ~
2-me~hyl-1-butanol arld 3-methyl-1-butanolJ. The c:ompositions so prepared along with their cloud points were as follows.
~. Mixture of Die~el Isopro- Primary ~myl 15Fuel panol ~ater Alcohols Cloud Composition (wt.9~) (wt.%) ~t ~) ~wt.%~ Point C
~) 86.918.66 0.58 3.85 4 b) 84.928.B2 0.59 5.66 ~9 c) 82.598.59 01~6 8.26 -13 20d) 85. 338 . 86 0 . 60 5. 21 -6 e) 78.7510.75 Q.66 9O84 -12 f) 84.138~74 ~.59 6.5~
. 9) 85.738.90 0.60 4.76 -3 Above compositions "b", "f" and ''9~ were subsequently prepared using another diesel fuel [I~-CAT (Caterpillar lGlH Reference Fuel ~rom ~owell Hydrocarbons Inc.)] having an unadultera~ed cloud point of -3C. The cloud point~ of these three compositions so prepared were -3C, -7C and -1C, respectively.

A series of ~uel compositions were prepared by mixing various amounts of a diesel fuel, (#2 Gulf) which had an unadulterated cloud point of -15C, with various amounts of isopropanol, water and i~o-butanol. The compositions so prepared along with their cloud points were ~5 followsc ~2~6~

~ 12 o Diesel IsoprQ-Fuel panol Water Isobutanol Cloud Compos tion (wt.%L (wt.~) ~wt.~) (w~ L~ Point C
a) 86.91 8.66 0,583~85 5 b~ 85.73 8.gl 0.504~,76 c3 84.92 8.83 0.5B5.66 -4 d) 84.13 8.74 0.596.54 -7 e) 82.59 8.~9 0~568026 -}4 f~ 81.84 8.5~ ~.579O0~ -15 9) ~1~74 7.36 0.681~.22 -12 Three compositions corresponding to : composition n~ above were prepared wherein the isobutanol was ~eplaced with n-bu~anol, n-pentanol and 2-ethylhexanol, respectively, and their respective cloud points were ~ound to be -13C, -14C and -7C.
Example 4 A series o~ ~uel compositions were prepared consisting o~ about 81~7.8 wt. ~ o~ a diesel ~uel, (~2 Gulf) having an unadultered cloud point of -15C, and about S.56 w~, ~ of anhydrous (200 proor) : ethanol, about 0.57 wt. ~ water and about 9.09 wt.
; of a higher alcohol. The cloud points or` said composition~ were as ~ollows.
25 ~ Cloud Point (C~
n-butanol ~ 14 iso-butanol 17 n-pentanol -2 Mixture of pri~ary amy~ alcohols*
30 2-ethylhexanol -2 *(Analysis: about 98.7 wt. ~ tota} amyl alcohol;
abou~ 66-14 wt. ~ n-peAtanol and about 32.56 wt.
~methyl~ butanol and 3-me~hyl-1-butanol).

Two fuel oompo~itions were prepared by mixing a diesel fuelr ~2 Gulf) which had an ~-13696 ~2Z~6~

unadulterated cloud point o~ C, with me~hanol,water and a mix~ure of primary amyl alcohols (analysis: about 98.7 wt. ~ total amyl alcohvls;
about 66.14 wt. ~ n~pPntanol and about 32~56 wt.
2-methyl-1-butanol and 3-methyl-1-bu~a~ol). The compositions so prepared alo~g with their cloud points were as. ~ollows:
~ixture o~
Diesel Meth- Primary amyl Fuel ano~ Water Alcohols Cloud Composition (wt.~) ~wt~) (wt.%) (wt.~) Point C
a) 84.04 4.17 0.2~ 11.50 ~9 b~ 75.59 7.92 0.53 15.97 Another fuel composition consisting of 15 74.3B wt. ~ diesel ~uel, (#2 Gul~) which had an unadulterated cloud point of -15C, 7.75 wt. 4 ~eehanol, 0.52 wt. ~ water and 17.36 wt. ~
iso~utanol, had a cloud point of only 20~C.
Example 6 20 A series o~ fuel compositions were prepared by mixing various amounts o~ a diesel ~uel, (#2 Phillips P troleum) which had an unadulterated ~loud poin~ o~ C; with various amounts o~ isopropanol, water and iso-butanol. The compositions 50 prepared along with their cloud points were as ~ollows.
Diesel Isopro-Fuel panol Water Isobutanol Cloud (wt.%l (w~0~) (wt~) (wt.~?_ Point C
a~ 81.43 ~~~7 0.713.90 -18 30 b) 84~413.97 0.710.92 -14 c) 80.~415.89 0.72098 -3 ~) 8304~7.94 ~.77.94 -8 e) 95.193.27 0.121.42 -17 f) 34.803.24 0.181.78 ~3 ~5 9) g~243022 0.182.36 -8 h) 93.673c21 0.182.94 ~16 i) g3.333.77 ~.~02.70 -16 jJ 95.223.72 0.1~0.94 -9 k) 9S.192.79 0.121~90 -12 2~62~3 1)94.91 20 78 0~122.19 -17 95.17 1.~6 ~.12~.85 -16 n~95.15 0.93 . 0.123.80 -16 ol94.20 3.72 0. 18lo ~0 ~5 ~
A series of fuel compositions were prepared by ~ixiny various amounts o~ a diesel ~uel, (~2 Phillips Petroleum) which had an unadulterated clou~
point of -18C, wi~h various amoun~s o~ isopropanol, water, and a mixture of primary amyl alcohols (analysis: about 98.7 wt. æ total primary amyl alcohol; about 6~.14 wt. ~ n-pentanol and about 32.56 wt. ~ 2-methyl-1-butanol and 3-methyl-1-butanol). The compositions so prepared along with their cloud points were as follows:
~ixture of Diesel Isopro-- P~imary Amyl Fuel panol Water Alcohols Cloud Composition (wt.%~ (wt.~) Iwt~ 4) Point C
20 a)82.00 5.30 0.7012.00 -17 b)82.C014.30 0~703.00 -6 85.50 6.8~ 0.7~7.~0 -1~
d~86.0011.30 0.702.00 ~18 ~ .00 8.30 0.705O00 `+5 25 f)94~55 4~30 OolS1~01) ~10 g)94~07 4~29 O~lS1~49 ~3 )93~ 624~ 2~i 0~ 15lo 97 -13 i)95~19 2~7~ 0~121~90 -17 A ~eries o~ ~ue} compositions were prepared : by mixing various amounts sf a diesel ruel, (~2 Phillips Petroleum) which had an unadulterated cloud point of -18C, with various amounts of i~opropanol, water and 2-ethylAexanol. The compositions so prepared along with their cloud points were as follows.

Diesel Isopro- 2-Ethyl-Fuel panol Wa~er hexanol Cloud omposition ~ wt.~ L Polnt C
a) 82.00 11.30C.70 6.00 -17 ij) 8100(~ 17.3!~0~70 loC~0 ~;2 c ) 83~00 13~3~70 3~00 -6 ~1) 8~ o ~010 ~ 3~ 0~ 70 S~ 01~
Another fuel composi~ion consisting of B6.25 wt. ~ diesel fuel, (~2 Gulf) having an unadulterated cloud point of -15C~ 8.60 wt.
isopropanol, 0.57 w~O ~ water and 4.58 wt. ~
2-ethylhexanol had a cloud point o only 15~C.
~, A series of ~uel compositions were ~repared wherein various amounts of diesel fuel, (#2 Phillips Petroleum) which had an unadulterated cloud point of -18C, wexe mixed with various amounts o~ a 50:50 weigh~ percent mix~ure o~ methanol and ethanol, water and isobutanol and the cloud point o~ each composition de~ermined as outlined below Diesel Iso- Cloud : Compo- Puel ~e~hanol Ethanol Water butanol Point sition ~ wt.~) (wt ~L (wt ~) (wit ~)- C
b) 87.64 0O80 0~80 0~4010~36 -4 c) ~7.64 1.50 1.50 0.408.96 +15 ~ .
Example 10 .. .
A ~eries of fueL com~ositions were prepared by mixing various amounts of a diesel ~uel, (~2 Phillips Petroleum) w~ich had an unadulterated cloud point of -18C, with various amounts of a 50:50 wt.
~ mixtu~e of methanol and ethanol, water and a mixture of primary amyl alcohol~ (analysis: about 98.7 wt. ~ total amyl alcohol; about 66.1~ wt. ~
n-pentanol and about 32~56 wt~ ~ 2-methyl-1-butanol ~-136~6 ~4621~

and 3-methyl-1-butanol). The cDmposi~ions so prepared along with thelr cloud points were as gollows:
Mix~ure o~
Primary Di~sel amyl Cloud Compo- Fuel Methanol Ethanol Water Alcohols Point sition (w~wt ~) (wt.~) (wt.4) (wt.~) a) 80.68 2 49 2.49 0.4013.94 -18 b~ 87.14 1~25 1.25 0.409.9S ~18 c) 85.66 1.99 1.99 0.409.96 -12 d~ 82.16 3.74 3.74 0.409.96 ~8 Exam~le 11 A series o~ ~uel compositions were pre~ared wherein various amounts of a diesel fuel, (#2 Phillips Petroleum) which had an unadulterated cloud point of -18C, were mixed with various amounts of a : 50:50 weight p~rcent mixture o~ methanol and ethanol, water and 2-ethylhexanol and the cloud point of each composition determined as outlined below Diesel 2-Ethyl Cloud Compo- Fuel Methanol Ethanol Water ~exanol Point sition ~ (wt.~ ~w~ wt.~L ~wt.~)C
a) 80.27 2.7g2.79 0.4013075 -17 b3 82.66 3.49~.49 0.40g.96 ~8 c~ ~1.68 ~.991.99 0.4013.94 ~7 d) 81.67 2.492.49 0.4012.95 -~
e) 80.B7 30393.39 0.4011.95 -16 Example 12 A series o~ ~uel compositions were prepared by mixing various amounts oE a di2s~1 fuel, (~2 Phillips Petroleum) which had an unadulterated cloud point of ~18C, with various amounts o methanol, water and isobutanol. The compositions ~o ~repared along with their cloud points were as follows.

D~13696 ~2;~gL621~

Diesel Fuel ~ethanol Wa~er ~sobutanol Cloud omposition ~ (wt.~ ~wt.4) (s~t.~) Point ~C
a) 86.78 2000 0.2510.~7 -16 b) 81.79 3.93 0.25:L3.97 -10 c~ 84.79 2.99 ~.25~L1~97 ~8 d~ B5.78 ~99 0.2~ 8.98 +27 Example 13 series of uel composi~ions were prepar~d by mixing various amounts o a diesel ~u~ 2 Phillips Petroleum) which had an unadulterated cloud point of -18C, with various amoun~s of methanol, water and 2-ethy~hexanol. The compositions so ~repare~ along with their cloud points were as follows.
Diesel 2~Ethyl-Fuel ~ethanol Water hexanol Cloud ~omposition (wt ~) Iw~ wt %? (wt ~) Point C
20 b) 8L.79 3.99 0.2513.97 -17 c) 83~79 3.99 0.2511.97 -8 : d) 84.79 3.99 0.2510.97 +1 e) 81080 6.98 0.2510.97 +6 xam~le 14 A series of fuel compositions were prepared by mixing various amounts of a diesel ~uel, (~2 Phillips Petroleum) whic~ had an unadulterated cloud point of -18C, with various amounts of me~hanol, wa~er and a mixture of primary amyl alcohols (analysis: about 98. 7 ~t. ~ total prim~ry amyl alcohol; about 66.14 wt.~ n-pentanol and about 32.56 wt.% 2-methyl-1-butanol and 3-methyl-1-butanol~.
The compositions ~o prepared along with their cloud p~ints were a~ follows.

~gL6~

~ixture Diesel of Primary Cloud Fuel Methanol Water ~myl Alco- Poin~
Composition ~wt~ L_ (wt.~) ho~ C
a) 8g.771, ao o. 2~ 8.9~ -lS
b) 810196.68 0O25 11.83 ~18 c) 86.003.~5 0.25 10.0~ -12 ~3 90.~02,25 0.25 7.50 -10 e~ 89.~899 0.25 6.98 ~5 ~) 88.782.99 0.25 7.98 -10 ~) 81.007.7~ 0.25 11.00 -~7 h~ 81.835.99 0.20 11.9~ -12 i) 81.~65.98 0.30 11.96 -~
j) R5.833.99 0.20 9.98 ol3 k) 8S.743.99 0.30 9.97 ~4 Example.15 A series of ~uel compositions were prepared by mixing various amounts or a diesel ~uel, (~2 Phillips Petroleum) which had an unadulterated cloud point of ~18C, with various amounts of ethanol, water and i~obutanol. Tha compositions so prepared along with their c~oud points were as follows.
Diesel Isobu-Fuel Et~anol Water tanol Cloud ~ L~ (wt.%)_ Point C
a) 80.591.0~ 0.5017.91 -18 b) 87.551.~0 0.5010.95 -}0 c) 85.562.99 ~.5010.9~ ~
d) 83.583.g8 0.5011.94 -11 e) 85.573.98 0.509.9S +2 ~) 79-605 D 9 7 0-5013.93 13 A series of fuel compositions were p~epared by ~ixing various amounts of a diesel fuel, ~2 Phillips Petroleum) which had an unadulte~ated cloud point o~ -18~C, with various amounts of ethanol, - water and a mixture of primary amyl alcohols (analysis: abou~ 98.7 wt.~ total primary amyl alcohol; about 66.14 wt.~ n-pentanol a~d about 32.56 D~13696 .

~2~62~

~t.~ 2-~ethyl-l-butanol and 3-methyl-l-hutanol).
The compositions so prepared along with their cloud points were as follows, ~ixture Diesel Q~ Primary Cloud Fuel Ethanol ~ater Amyl Alco- Poin~
Composi~ion (w ~) (wt.%)_ (wt.~) ~ols ~wt.~) C
a~ 80.59 l.00 0.50 17~91 -17 b) 86~56 1.99 O.S0 10.~5 -17 c) 79.59 fl.96 G.50 10.95 -16 d) 81.58 8.~6 0.50 8096 -S
~) 85.~6 4.g8 0.50 8.96 -12 ~) 85.57 5.97 0.50 7.96 ~2 A serie~ o~ fuel composltions were prepared by mixing various amounts of a die~el ~uelr (~2 Phillips Petroleum) which had an unadulterated cloud poi~t o -18C, with various amounts o~ etha~ol, water and 2-ethylhexanol. The compositions so prepared along with their cloud points were as : follo~s.
Diesel ~-Ethyl-Fuel ~thanol Water hexanol Cloud Composition ~wt.~ L~ 5wt.%) ~wt.~) Point C
a) 82.58 Ç097 0.5~ 9095 -17 b~ 83.57 6.97 0.50 8.g6 -4 ~) 81.59 g.9~. 0.50 7.96 -2 d) 83.57 8.96 0.50 6.97 +8 Example 18 A fuel composition designated ~D4~ which consisted o~ abou~ 830~4 wt.~ of a diesel fuel [IH-CAT ~Caterpillar lGl~ Reference Fuel from Howell ~ydrocarbon Inc.)~ whicb had an unadulterated cloud point of -3C, about 5.30 wt.~ o~ isopropa~ol, about 35 0070 wt.~ ~a~er and about 10.40 wt.~ of SQ:50 w~.
mixture o~ n~bu~anol and isobutanol, said D~13696 ~Z~28 . ~ 20 -c~mposition ~D4a having a cloud point of -5C~ 9 along with another composition designat~d ~D5u which c~nsisted o~ about 85.73 wt.~ oE the same diesel fuel em~loyed in composition D4, about 8. 90 wt.~ of isopropanol, about O.SO wt.~ water ana aDoUt

4 . 76 w~. % of a mixture of primary amyl alcohols ~analysis: about 98.7 wt.~ total amyl alcohol;
abQut 66.14 wt.~ n~pentanol and about~32.56 wt.#
2-methyl-1-butanol and 3-methyl-1-butanol), said com~osition UD5" having a cloud point of -1C., were prepared ~n~ evaluated ver~us the same unadulterat~d base diesel ~ue~ employed in preparing each oomposition D4 and DS in terms of exhaust emission~ and ~uel economy.
The ~er~ormance tests were conducted on a 6 cylinder diesel engine geared to a dynamometer capable of loading the engine to SOOHP wet gap. The performance of ~uel composition D4 ~as compared with the performance o~ the base dies~l fuel at two en~ine modes . (a) 1200 RP~/557 lbs. load (which corresponds to an engine operation in a very rich fuel (excess fuel) Mode) and (b) 1400 RP~/600 lbs.
load (which corresponds to a normal operation or the engine under considerable load (e.g. climbing a hlll). The per~orma~ce of ~uel composition D5 was also compared with the per~ormance of the base diesel fuel at engine modes (a) 1200 RPM/560 lbs.
load and (b) 1400 RPM~605 lbs. load. In addition the per~ormance o~ composi~ion D5 was assessed at an engine mo~e (c) 2090 RPM/475 lbs. load as sompared to the base diesel ~uel at an engine mode of 2Q84 RPM/508 lbs. load (which corresponds to an ~ngine operation a~ high speed and high load).

The tes results are reported below tU~l economy value~ being an average o~ ~ive measurements; all smoke measurements being an average o five mea~urements and all particulate measurements being an aver3ge o~ ~hree measuremen~s.
Fuel Concumption (lbs./hour~
Operating ~ode Base Diesel Fuel Comp. Fuel Comp.
Fuel D-4 D-5 1200/557 83.20 87.0~ -10 1200/5S0 ~3.10 - ~4.gl 1400/600 101.98105.14 1400/605 10~.36 - 101.99 2084/508 ~32.51 - -~090/~75 _ - 127.5 15 Particulates (Grams) Operating Mode Base Diesel ~uel Comp. Fuel Comp.
Fu~l D-4 _ D-5 1200/557 .0163 .0174 1200/560 .0175 - .~167 20 1400/5~0 .0104 .00~1 -14~0/605 .0140 .0143 2084/508 .~024 - -~090/~75 ~ ~ .0~14 Smoke (~ O~acity) Opera~ing Mode ~ase Diesel Fuel Comp. Fuel Comp.
Fuel _ D-4 D-5 1~00/557 1~.74 11.9 1200/560 12~7~ 8 1400~600 ~.30 5.0~ -30 1400/505 9.38 - 7.52 2084/508 2.18 2090/475 - - 1.64 T~e above da~a shows that operation of ~he engine wi~h ~uel composi~ions D4 and D5 of this Dol3696 ~z~

invention resulted in a s~grlif icant reduction in both smoke opacity and particulate content of the exhaust over that shown when employing the ba~e diesel fuel if the engine is not strained l:o a

5 maximum. As aeen the average decrea~;e in smoke opacity for DA a~ modes 12û0/55 7 and 1400/600 was

6 . 3% and 45% and for D5 at ~des 1200/560 and 1400/605 was 7.1~6 and 20.2%7 Likewise the average decrease in particulate content for D4 at mode 1400/600 was 41.3~ ~mode 1200/557 showing an average increase of 6.7~ and for D5 at mode 1200/560 was 4.6% 5mode 1400/~05 showing an average increase of ~.1%). It should be noted that smoke and particulate formation is a complex phenomena, so these measurements will not necessarily always coin~ide. ~owever, it is possible to have both reduced opacity in smoke emission, ~nd at the same time, a decrease in parti~ulate emission~ Moreov~r due to the inherent difficulties with particulate 2~ analysi~ one should consider trends in the data and ~ot absolute Yalues. While operation with D4 at modes 1200/557 and 1400/600 showed an average loss in fuel economy of 4.6% and 3.0% respectively, and operation of D5 at modes 1200/560 and 1400/605 showed an average loss in fuel economy of 2.2~ and 1.6~ respectively. ~owever, with D4 the varia~ion in ~uel consumption is good compared to what industry accepts as a variatlon. Moreover the engine ran ~uite well with the D4 and ~5 fuels.
3~ Mor*over, while a one to one comparison between the data of ~ at mode 2090/475 and th~
base diesel fuel a~ mode 20~4/50~ cannot be made ~ince the data can not be normalized because the fuel consumption o~ D5 was less than the ba~e fuel ~-~3~9~ .

~z2~2~

- ~3 -and D5 was not pullinq the same engine load as the base fuel and thus had a different power performan~e, which makes it difficult to say just how large the effect is, nonetheless it is clear ~ that D~ exhibit~d a signifi~ant positive effect on : smoke and particulate emission and also on the fuel consumption as seen by its unnormaliz~d average i~crease sf 3.8~ in ~uel economy and unnormalized average d~creases o~ 27.3~ in smoke opacity and 42 in particulate cOntent of the exhaust.

The physical properties as listed in ASTM-D975, except f~r cetane number7 water and sediment~ of fuel compositions D4 and D5 as well as of the base diesel fuel (I~-CAT~ employed in Example 18 are listed belowO

D-4 D-5 ~ CAT
Flash Point, F 45 56 170 Cloud Point, ~F 18 18 20 Carbon Residue, ~ 0.21 0.21 0.06 Ash, wt. % 0.01 ~0.005 0.003 Viscosity at 40C, cSt2.97374 2.957543.31@100~C
Sulfur, wt. % 0.3717 0~3608 0.399 25 Copper Strip Corrosion l-A l-A l-A
Distillation, F
.
Initial :3Oilins~ Point~ F 174 176 334 10~ 33vaporated 215 20~ 466 2096 Evaporated 352 352 488 30 50% Evaporat~d 506 506 52 7 90~6 Evaporated 589 590 611 End Point, nF 636 610 664 ecGvered 98 9 7O 599. 0 % Residue 1.5 1.5 1~0 35 % Loss 0 5 1~ 0 The above e~aluation shows that fuel compositions D~ and D5 of this invention meet all the standard pecifications for No. 2 diesel ~2Z'~62~

- 2~ -fuels (ASTM-D-975) except for the ~lash point.
Another e~aluation of the flash points of D-4, D-5 and the I~-C~T showed 80F, 69F and 169F, respectively.
~xample 20 A fuel composition designated ~D6"
consis~ing of about 83~ ~0 wt. % of a diesel fuel, (#2 Phillips P~troleum~ which had a cloud point of -18C, about 5.30 wt. % of isopropanol, abou~ 0.70 10 wt. ~ water and about 10~40 wt. % of a 50:50 wt. ~
mixture of n-butanol and isobutanol said composition having a cloud point of -18C, along with a fuel composition designated ~D7" which was th~ same as composition "D~n, but al50 contained about 0015 wt~ o a commercial cetane improver ~an alkyl nitrate) were prepared and evaluat~d versus the same unadulterated base diesel fuel employed in preparing each composition D6 and D7 in terms of exhaust emissions and fuel economy. The performance tests were conducted on a chassis-mounted 5.7 liter Oldsmobile and followed standard cold-start Feaeral Test Procedures (CFR, Title 40, Part 86, SubPart B). The results of ~aid tests based on an average o~ duplica~e runs for each fuel were as follows:

~~_ EMISSIONS tq/mile) Fuel fi8~eer Particula~es Nx ~r~ons M~n~xl~e MPG
Base Diesel 48 0.389 1.34 0.327 1.21 21~3 30 D6 4~ 0.311 1.27 0.390 1.46 21~2 D7 46 0.322 1.27 0.386 1.40 21.4 The above results how that operation of the e~gine witb fuel compositions D~ and D7 of this invention resulted in a ~ignificant reductiQn in both particulates and oxides o~ nitrogen in the 2~6~

~xhau~t ~ver that shown when employing ~he base diesel fuel while fuel economy remained essentially the ~ame.
Various modifications and varia~ions of S this invention will be obvious to a worker skilled in the art and it is ~o be understood that such modifications and variations are to be included wienin the pur~iew o~ this application and the spirit and scope of the appended claims.

Claims (26)

Claims

1. A surfactant-free, phase-stable, aqueous diesel/alcohol fuel composition having a cloud point of 0°C or below and consisting essentially of a diesel fuel, about 0.1 to about 1.0 weight percent water, about 1 to about 19 weight percent of a C1 to C3 aliphatic alcohol or mixtures thereof, and about 1 to about 18 weignt percent of a C4 to C8 alcohol or mixtures thereof, the remainder of said composition consisting essentially of said diesel fuel.

2. A composition as defined in claim 1, wherein the lower aliphatic alcohol is isopropanol and wherein the composition contain about 0.1 to 0.7 weight percent water.

3. A composition as defined in claim 2, wherein the higher alcohol is selected from the group consisting of n-butanol, isobutanol, 2-methyl-1-butanol, 3-methyl-1-butanol, n-pentanol and 2-ethylhexanol, or mixtures thereof.

4. A composition as defined in claim 3, wherein the higher alcohol is a mixture of n-butanol and isobutanol.

5. A composition as defined in claim 3, wherein the higher alcohol is a mixture of primary amyl alcohols.

6. A composition as defined in claim 3, wherein the higher alcohol is isobutanol.

7. A composition as defined in claim 3, wherein the higher alcohol is n-butanol.

8. A composition as defined in claim 3, wherein the higher alcohol is n-pentanol.

9. A composition as defined in claim 3, wherein the higher alcohol is 2-ethylhexanol.

10. A composition as defined in claim 1, wherein the lower alcohol is a mixture of methanol and ethanol.

11. A composition as defined in claim 1, wherein the lower alcohol is methanol.

12. A composition as defined in claim 1, wherein the lower alcohol is ethanol.

13. A composition as defined in claim 1, wherein an alkyl nitrate cetane improver is also present in said composition.

14. A method for preparing a surfactant-free, phase-stable, aqueous diesel/alcohol fuel composition for use in diesel engines, which comprises mixing a diesel fuel with water, a C1 to C3 aliphatic alcohol or mixtures thereof and a C4 to C8 aliphatic alcohol or mixtures thereof, wherein said composition has a cloud point of O°C or below, and consists essentially of about 0.1 to about 1.0 weight percent water, 1 to about 19 weight percent of said C1 to C3 aliphatic alcohol or mixtures thereof, and about 1 to about 18 weight percent of said C4 to C8 aliphatic alcohol or mixtures thereof, the remainder of said composition consisting essentially of said diesel fuel.

15. A method as defined in claim 14, wherein the lower aliphatic alcohol is isopropanol and wherein the composition contains about 0.1 to about 0.7 weight percent water.

16. A method as defined in claim 15, wherein the higher alcohol is selected from the group consisting of n-butanol, isobutanol, 2-methyl-1-butanol, 3 methyl-1-butanol, n-pentanol and 2-ethylhexanol, or mixtures thereof.

17. A method as defined in claim 16, wherein the higher alcohol is a mixture of n-butanol and isobutanol.

18. A method as defined in claim 16, wherein the higher alcohol is a mixture of primary amyl alcohols.

19. A method as defined in claim 16, wherein the higher alcohol is isobutanol.

20. A method as defined in claim 16, wherein the higher alcohol is n-butanol.

21, A method as defined in claim 16, wherein the higher alcohol is n-pentanol.

22. A method as defined in claim 16, wherein the higher alcohol is 2-ethylhexanol.

23. A method as defined in claim 14, wherein the lower alcohol is a mixture of methanol and ethanol.

24. A method as defined in claim 14, wherein the lower alcohol is methanol.

25. A method as defined in claim 14, wherein the lower alcohol is ethanol.

26. A method as defined in claim 14, wherein an alkyl nitrate cetane improver is also present in said composition.