CA2040818A1 - Fuel compositions with enhanced combustion characteristics - Google Patents
Fuel compositions with enhanced combustion characteristicsInfo
- Publication number
- CA2040818A1 CA2040818A1 CA002040818A CA2040818A CA2040818A1 CA 2040818 A1 CA2040818 A1 CA 2040818A1 CA 002040818 A CA002040818 A CA 002040818A CA 2040818 A CA2040818 A CA 2040818A CA 2040818 A1 CA2040818 A1 CA 2040818A1
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- Prior art keywords
- fuel
- composition
- combustion
- nitrate
- range
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- Abandoned
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
- C10L1/00—Liquid carbonaceous fuels
- C10L1/10—Liquid carbonaceous fuels containing additives
- C10L1/14—Organic compounds
- C10L1/22—Organic compounds containing nitrogen
- C10L1/23—Organic compounds containing nitrogen containing at least one nitrogen-to-oxygen bond, e.g. nitro-compounds, nitrates, nitrites
- C10L1/231—Organic compounds containing nitrogen containing at least one nitrogen-to-oxygen bond, e.g. nitro-compounds, nitrates, nitrites nitro compounds; nitrates; nitrites
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
- C10L10/00—Use of additives to fuels or fires for particular purposes
- C10L10/02—Use of additives to fuels or fires for particular purposes for reducing smoke development
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- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Liquid Carbonaceous Fuels (AREA)
- Solid Fuels And Fuel-Associated Substances (AREA)
Abstract
Case EI-6116-A
FUEL COMPOSITIONS WITH ENHANCED COMBUSTION CHARACTERISTICS
Abstract of the Disclosure Fuels, methods of producing fuels, and methods of using fuels to reduce the amount of atomospheric pollutants (NOx, CO, and/or hydrocarbons) formed on combustion of middle distillate fuels in engines or burner apparatus. These results can be achieved without concomitant increases in emissions of particu-lates. The fuels contain less than 500 ppm of sulfur and at least one organic nitrate combustion improver.
FUEL COMPOSITIONS WITH ENHANCED COMBUSTION CHARACTERISTICS
Abstract of the Disclosure Fuels, methods of producing fuels, and methods of using fuels to reduce the amount of atomospheric pollutants (NOx, CO, and/or hydrocarbons) formed on combustion of middle distillate fuels in engines or burner apparatus. These results can be achieved without concomitant increases in emissions of particu-lates. The fuels contain less than 500 ppm of sulfur and at least one organic nitrate combustion improver.
Description
" Patent Case EI-6116-A
JFS:km i ,, FUEL COMPOSITIONS WITH ENHANCED COMBUSTION CHARACTERISTICS
"
This invention relates to preservation of the , environment. More particularly, this invention relates to fuel compositions and methods that reduce atmospheric pollution normally caused by the operation of engines or combus~ion llapparatus on middle distillate fuels.
,1 ~he importance and desirability of reducing the release ,of pollutants into the atmosphere are well recognized. Among the ;
~Ipollutants sought to be reduced are nitrogen oxides ("NOx"), carbon monoxide, unburned hydrocarbons, and particulates.
,1 ', This invention involves the discovery, inter alia, that ' lt is possible to reduce the amount of NOx or CO or unburned hydrocarbons released into the atmosphere during operation of ,engines or other combustion apparatus operated on middle distil-late fuel by employing as the fuel a middle distillate fuel ,having a sulfur content of 500 ppm or less and having dissolved 'therein a combustion improving amount of at least one organic nitrate combustion improver. In fact it has been found possible Ithrough use of such fuel compositions to reduce the amount of two ,,,and in some cases all three such pollutants (NOx, CO and ,unburned hydrocarbons) emitted by diesel engines. Moreover this important and highly desirable obiective has been and thus may be ,achieved without suffering an undesirable increase in the ,, ;
~, .
i.1 ' Case EI-6116-A
emission of particulates. This is a unique discovery since the available experimental evidence and mechanistic theories of combustion suggest that if N0x is reduced, the amount of particulates will be increased, and vice versa.
S Accordingly this invention provides in one of its embodi-ments a fuel composition characterized in that it comprises a ma;or proportion of a hydrocarbonaceous middle distillate fuel which has a sulfur content of less than 500 ppm (preferably 100 ppm or less and most preferably no more than 60 ppm) and in that ';said fuel contains a minor combustion-improving amount of at least one organic nitrate combustion improver dissolved therein.
By the term "hydrocarbonaceous" as used in the ensuing descrip-tion and appended claims is meant the middle distillate fuel is composed principally or entirely of fuels derived from petroleum by any of the usual processing operations. The finished fuels may contain, in addition, minor amounts of non-hydrocarbonaceous fuels or blending components such as alcohols, dialkyl ethers, or like materials, and/or minor amounts of suitably desulfurized auxiliary liquid fuels of appropriate boiling ranges (i.e., between about 160 and about 370-C) derived from tar sands, shale oil or coal. When using blends composed of such desulfurized auxiliary liquid fuels and hydrocarbonaceous middle distillate fuels, the sulfur content of the total blend must be kept below 500 ppm.
In another of its embodiments this invention provides improvements in combustion processes wherein a hydrocarbonaceous middle distillate fuel is subjected to combustion in the presence of air. Such improvement comprises providin~ as a fuel used in Case EI-6116-A
such process a hydrocarbonaceous middle distillate fuel having a sulfur content of less than 500 ppm (preferably lO0 ppm or less and most preferably no more than 60 ppm) and having dissolved therein a minor combustion improving amount of at least one organic nitrate combustion imprqver.
~, Still another embodiment of this invention provides improvements in the production of hydrocarbonaceous middle dis-tillate fuels. Such improvements comprise controlling or re-ducing the sulfur content of the fuel to a level of 500 ppm or less (preferably 100 ppm or less and most preferably no more than 60 ppm) and blending organic nitrate com~ustion improver with the resultant reduced sulfur-containing fuel.
Additional embodiments of this invention involve improve-ments in the operation of motor vehicles and aircraft which oper-ate on middle distillate fuels. These improvements involve fuel-ing the vehicle or aircraft with a hydrocarbonaceous middle dis-tillate fuel characterized by having a sulfur content of less than 500 ppm (preferably 100 ppm or less and most preferably no more than 60 ppm) and containing a minor combustion-improving amount of at least one organic nitrate combustion improver dis-solved therein.
In accordance with a particularly preferred embodiment of this invention, there is provided a hydrocarbonaceous middle distillate fuel having a sulfur content of not more than 500 ppm (preferably 100 ppm or less and most preferably no more than 60 ppm) and a 1~% boiling point (ASTM D-86~ in the range of about 154 to about 230C, said fuel containing a minor combustion improving amount of at least one fuel-soluble organic nitrate combustion improver. Such fuel compositions tend on combustion ` Z040818 -Case EI-6116-A
; to emit especially low levels of N0x. Without desiring to be bound by theoretical considerations, one explanation for such highly desirable performance is that fuels with higher 10%
boiling points cause a delay in the progression of combustion and consequent higher peak temperatures which increase the amount of N0x formation.
Pursuant to another particularly preferred embodiment of this invention there is provided a hydrocarbonaceous middle distillate fuel having a sulfur content of not more than 500 ppm (preferably 100 ppm or less and most preferably no more than 60 ppm) and a 90% boiling point (ASTM D-86) in the range of about 260' to about 320'C, said fuel containing a minor combustion improving amount of at least one fuel-soluble organic nitrate combustion improver. Such fuel compositions tend on combustion to emit especially low levels of particulates.
These and other embodiments are set forth in the ensuing description and appended claims.
In the accompanying drawings:
Fig. l is a least-squares plot of Nox emissions versus 10~ boiling temperatures of fuels having a nominal cetane number of approximately 50; and Fig. 2 is a least-s~uares plot of particulate emissions versus 90% boiling temperatures of fuels having a nominal cetane ; number of approximately 50.
The hydrocarbonaceous fuels utilized in the practice of this invention are comprised in general of mixtures of hydro-20~08~8 -, Case EI-6116-A
carbons which fall within the distillation range of about 160 to about 370C. Such fuels are frequently referred to as "middle distillate fuels" since they comprise the fractions which distill after gasoline. Such fuels include diesel fuels, burner fuels, kerosenes, gas oils, jet fuels, and gas turbine engine fuels.
Preferred middle distillate fuels are those charac-terized by having the following distillation profile:
10% 310 - 550 154 - 288 50~ 350 - 600 177 - 316 go~ 400 - 700 204 - 371 Diesel fuels having a clear cetane number (i.e., a cetane number when devoid of any cetane improver such as an organic nitrate) in the range of 30 to 60 are preferred. Particu-larly preferred are those in which the clear cetane number is in the range of 40 to 50.
The organic nitrate combustion improvers (also fre-quently known as ignition improvers) comprise nitrate esters of substituted or unsubstituted aliphatic or cycloaliphatic alcohols which may be monohydric or polyhydric. Preferred organic ni-trates are substituted or unsubstituted alkyl or cycloalkyl nitrates having up to about 10 carbon atoms, preferably from 2 to 10 carbon atoms. The alkyl group may be either linear or branched (or a mixture of linear and branched alkyl groups).
Specific examples of nitrate compounds suitable for use in the present invention include, but are not limited to, the follow-inq methyl nitrate, ethyl nitrate, n-propyl nitrate, isopropyl 20408~8 ' Case EI-6116-A
nitrate, allyl nitrate, n-butyl nitrate, isobutyl nitrate, sec-butyl nitrate, tert-butyl nitrate, n-amyl nitrate, isoamyl ni-trate, 2-amyl nitrate, 3-amyl nitrate, tert-amyl nitrate, n-hexyl ;
nitrate, n-heptyl nitrate, sec-heptyl nitrate, n-octyl nitrate, S 2-ethylhexyl nitrate, sec-octy~sJ~nitrate, n-nonyl nitrate, n-decyl nitrate, cyclopentylnitrate, cyclohexyl nitrate, methylcyclohexyl nitrate, isopropylcyclohexyl nitrate, and the like. Also suit-able are the nitrate esters of alkoxy substitued aliphatic alco-hols such as 2-ethoxyethyl nitrate, 2-(2-ethoxyethoxy)ethyl ni-trate, 1-methoxypropyl-2-nitrate, 4-ethoxybutyl nitrate, etc., as well as diol nitrates such as 1,6-hexamethylene dinitrate, and the like. Preferred are the alkyl nitrates having from 5 to 10 carbon atoms, most especially mixtures of primary amyl nitrates, mixtures of primary hexyl nitrates, and octyl nitrates such as 2-ethylhexyl nitrate.
As is well known, nitrate esters are usually prepared by the mixed acid nitration of the appropriate alcohol or diol. Mix-tures of nitric and sulfuric acids are generally used for this purpose. Another way of making nitrate esters involves reacting an alkyl or cycloalkyl halide with silver nitrate.
The concentration of nitrate ester in the fuel can be varied within relatively wide limits with the proviso that the amount employed is at least sufficient to cause a reduction in emissions. Generally speaking, the amount employed will fall in the range of about 250 to about ~0,000 parts by weight of organic nitrate per million parts by weight of the fuel. Preferred concentrations usually fall within the range of 1,000 to 5,000 parts per million parts of fuel.
Other additives may be included within the fuel composi-tions of this invention provided they do not adversely affect the 2~)408~8 , Case EI-6116-A
exhaust emission reductions achievable by the practice of this invention. Thus use may be made of such components as organic peroxides and hydroperoxides, corrosion inhibitors, antioxidants, antirust agents, detergents and dispersants, friction reducing agents, demulsifiers, dyes, inert diluents, and like materials.
The advantages achievable by the practice of this invention were demonstrated in a sequential series of engine tests in which a Detroit Diesel 11.1 liter Series 60 engine mounted to an engine dynamometer was used. The system was operated on the ~EPA Engine Dynamometer Schedule for Heavy-Duty Diesel Engines" set forth at pages 810-819 of Volume 40, Part 86, Appendix I, of the Code of Federal Regulations (7-1-86). In these tests, the first of five consecutive tests involved opera-tion of the engine on a conventional DF-2 diesel fuel having a nominal sulfur content in the range of 2000 to 4000 ppm. This test served as one of two baselines. In the next operation the engine was run using a low-sulfur diesel fuel having the follow-ing characteristics:
Sulfur, ppm 50 Gravity, API @ 60F 34.7 Pour Point, D F -5 Cloud Point, F 8 Copper Strip Distillation, D F
10% 430 50% 532 90% 632 Cetane Number 44.3 Viscosity ~ 40C, cS 2.96 In the third and fourth tests -- which represented the practice of this invention -- this same low-sulfur fuel was used except that it had blended therein a diesel ignition improver composed Z04(18~8 Case EI-6116-A
of 2-ethylhexyl nitrate. In the third test the concentration was 2000 ppm of the organic nitrate. In the fourth test, the fuel contained 5000 ppm of the organic nitrate. The fifth and final test involved another baseline run using the initial conventional DF-2 diesel fuel. In all inst~es the guantities of N0x, unburned hydrocarbons ("HC"), carbon monoxide ("C0") and particulates emitted by the engine were measured and integrated.
The results of these tests are summarized in the following table. The values shown therein for N0x, HC, C0, and Particulates, are presented in terms of qrams per brake horsepower per hour. Thus the lower the value, the lower the rate and amount of emissions.
Test No. NOx HC C0 Particulates 1 4.641 0.0861.414 0.227 2 4.345 0.0681.490 0.165 3 4.173 0.0511.312 0.164 4 4.208 0.0731 324 0.165 S 4.623 0.0781.5~5 0.223 In particularly preferred embodiments of this invention, use of fuels having certain boiling characteristics as well as low sulfur levels, results in still further reductions in either N0x or particulate emissions. Thus by use of fuels meeting the low sulfur parameters set forth hereinabove and additionally having a 10~ boiling point (ASTM D-86) in the range of 154-230C, 2~ the emissions of N0x can be reduced to extremely low levels.
Likewise, by use of fuels meeting the low sulfur parameters set forth hereinabove and additionally having a 90% boiling point (ASTM D-86) in the range of 260-320DC, particulate emissions tend to be reduced to especially low levels. To illustrate, a Detroit 3~ ~iesel Corporation Series 60 ~ngine in the 11.1 liter configura-tion and nominally rated at 320 hp at 1800 rpm was used in a Case EI-6116-A
series of emission tests. The engine was installed in a heavy-duty transient emission cell equipped with a constant volume sampler (CVS) system. A dilution tunnel permitted measurements 'of HC, CO, NOX and particulates according to the EPA Transient S Emissions Cycle Procedure. ~ S.J,~
For each individual test case, the engine was started and warmed up. It was then run for 20 minutes at rated speed and load. Rated power was validated. In addition, a power test was conducted, mapping engine torque vs. speed. These parameters are required as part of the EPA Transient Cycle Procedure. Once this information was obtained, two 20-minute EPA Transient Cycles were run and engine controls were adjusted to meet statistical operat-ing limits prescribed for the tests. The engine was shut down i and allowed to soak for 20 minutes. At the end of the soak period, the Hot Start EPA Transient Cycle was run to measure NOX, CO and particulate emissions. A second emissions evaluation was conducted after another two-minute soak. Results for the two Hot Transient Cycles were averaged into a final reported value. Whenever a fuel was changed, new fuel was introduced into the fueling system, new fuel filters were installed, and fuel lines were flushed.
Each fuel ~A through D) was evaluated by the same Hot Start EPA Transient Emissions Cycle Procedure. Fuels A, B, and C
contained 2-ethylhexyl nitrate in an amount sufficient to raise the cetane number of the respective fuels to a nominal value of 50. Fuel D which had a natural cetane number of 49.8 was used unadditized.
1 20408~8 Case EI-6116-A
I
Physical and chemical characterization data for unadditized fuels A through D are shown in the following table:
TABLE
Fuel Pro~ertv A ~3 C D
Hydrocarbon Composition, vol %
Aromatics 36.5 28.5 37.6 39.4 Olefins 1.2 1.1 2.2 2.9 Saturates 62.3 70.4 60.2 57.7 Carbon, wt% 86.35 86.49 86.12 87.32 Hydrogen, wt% 13.15 13.25 12.89 13.35 Nitrogen, ppm 5.3 285 356 152 Sulfur, ppm <1 225 219 476 Aniline pt., deg. C 70.1 60.0 65.4 69.4 Diene content, wt% ~0.1 0.2 ~0.1 <0.1 Viscosity, cSt Q 40 deg. C 2.99 2.20 3.10 3.53 @ 100 deg. C 1.22 0.97 1.23 1.34 Heat of combustion BTU/lb19,593 19,840 19,543 19,672 Boiling range, deg. C
10% 217 211 234 252 20% 233 222 246 262 30% 249 230 257 271 40~ 262 237 267 278 50% 274 244 276 284 60% 288 253 286 291 70% 300 263 294 298 80% 314 276 306 306 9o% 331 297 322 317 95% 344 319 338 329 Recovery, % 98.7 98.9 98.6 98.9 Gravity, deg. API 34.9 36.1 34.6 34.5 Specific gravity 0.850 0.~44 0.852 0.852 Calculated cetane index 48.1 44.0 48.9 51.7 Cetane index 48.5 43.8 48.3 49.7 Cetane number 45.3 39.6 47.7 49.8 In the above table, the following test methods were used:
Hydrocarbon composition - ASTM D-1319 Carbon - Carlo-Er~a 1106 Bydrogen - Carlo-Erba 1106 20408~8 Case EI-6116-A
Nitrogen - ASTM D-4629 Sulfur - ASTM D-3120 Aniline pt. - ASTM D-611 Diene content - UOP 326 Viscosity - ASTM D-445 ~~
Heat of combustion - ASTM D-2382 Boiling range - ASTM D-86 Gravity - ASTM D-287 Calculated cetane index - ASTM D-4737 Cetane index - ASTM D-976 Cetane number - ASTM D 613 Fig. 1 presents graphically the results of N0x emissions in relation to the 10% boiling temperatures of the four fuels.
It can be seen that the fuels in which the 10% boiling tempera-ture was below 230C had the lowest N0x emissions.
The results of the particulate determinations are graph-ically depicted in Fig. 2. In this case, the results are shown as a function of 90% boiling temperatures of the base fuels. A
trend toward lower particulate emissions with fuels having 90%
boiling points within the range of 260-320C was noted.
Methods for reducing the sulfur content of hydrocarbon-aceous middle distillate fuels or their precursors are reported in the literature and are otherwise available to those skilled in the art. Among such processes are solvent extraction using such agents as sulfur dioxide or furfural, sulfuric acid treatment, and hydrodesulfurization processes. Of these, hydrodesulfuriza-tion is generally preferred, and includes a number of specific 0408~8 ~ Case EI-6116-A
"
methods and operating conditions as applied to various feed-stocks. For example, hydrotreating or hydroprocessing of naph-thas or gas oils is generally conducted under mild or moderate ~severity conditions. On the other hand, sulfur removal by hydro-cracking as applied to distillate stocks is usually conducted under more severe operating conditions. Vacuum distillation of bottoms from atmospheric distillations is still another method ~or controlling or reducing sulfur content of hydrocarbon stocks used in the production of hydrocarbonaceous middle distillate fuels. Further information concerning such processes appears in ~Kirk-Othmer, Encyclopedia of Chemical Technoloay, Second Edition, Interscience Publishers, Volume 11, pages 432-445 (copyright 1966) and references cited therein; Idem., Volume 15, pages 1-77 and references cited therein; and Kirk-Othmer, Encyclopedia of Çhemiçal Technoloay, Volume 17, Third Edition, Wiley-Inter-science, pages 183-256 (copyright 1982) and references cited therein. All of such publications and cited references are incorporated herein by reference in respect of processes or methods for control of reduction of sulfur content in hydro-carbonaceous middle disillate fuels or their precursor stocks.
Another method which can be used involves treatment of the hydrocarbonaceous middle distillate fuel with a metallic desul-furization agent such as metallic sodium, or mixtures of sodium and calcium metals.
In summary, this invention involves the provision of a number of embodiments, some of which are set forth below.
A. A fuel composition characterized in that it comprises a major proportion of a hydrocarbonaceous middle distillate fuel ~0408~8 Case EI-6116-A
which has a sulfur content of $ess than 500 ppm and in that said fuel contains a minor combustion-improving amount of at least one organic nitrate combustion improver dissolved therein.
B. A composition of A ~erein the sulfur content of the base fuel is 100 ppm or less.
C. A composition of A wherein the base fuel is a diesel fuel further characterized by having a clear cetane number in the range of 30 to 60.
D. A composition of A wherein the base fuel has a sulfur content of 100 ppm or less and a clear cetane number in the range of 30 to 60.
E. A composition of A wherein the base fuel is further characterized by having the following distillation profile:
F C
10% 310 - 550 154 - 288 50% 350 - 600 177 - 316 90% 400 - 700 204 - 371 F. A composition of A wherein the base fuel has a sulfur content of 100 ppm or less and the following distillation.
profile:
F C
10% 310 - 550 154 - 288 50% 350 - 600 177 - 316 9o% 400 - 700 204 - 371 ' ~0408~L8 Case EI-6116-A
G. A composition of A wherein the base fuel has a clear cetane number in the range of 30 to 60 and the following distillation profile:
F C
10% 310 - 550 154 - 288 50% 350 - 600 177 - 316 90% 400 - 700 204 - 371 H. A composition of A wherein the base fuel has a sulfur content of 100 ppm or less, a clear cetane number in the range of 30 to 60, and the following distillation profile:
~F C
10% 310 - 550 154 - 288 50% 350 - 600 177 - 316 9o% 400 - 700 204 - 371 I. A composition of A wherein the base fuel has a sulfur content of 100 ppm or less and a clear cetane number in the range of 40 to 50.
J. A composition of any of A through I wherein the organic nitrate combustion improver consists essentially of a nitrate ester of an aliphatic or cycloaliphatic alcohol.
K. A composition of any of A through I wherein the organic nitrate combustion improver consists essentially of a nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule.
(- ~ 2040818 Case EI-6116-A
L. A composition of any of A through I wherein the organic nitrate combustion improver consists essentially of a mixture of 2-ethylhexyl nitrate.
M. A composition of ~y of A through I wherein the organic nitrate combustion improver consists essentially of a nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule and wherein said middle distillate fuel has a 10% boiling temperature (ASTM D-86) in the range of about 154C to about 230C.
N. A composition of any of A through I wherein the organic nitrate combustion improver consists essentially of a nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule and wherein said middle distillate fuel has a 90% boiling temperature (ASTM D-86) in the range of about 260C to about 320C.
0. A composition of any of A through I wherein said fuel contains an amount of said organic nitrate falling in the range of 250 to 10,000 parts by weight per million parts by weight of said fuel.
P. A composition of any of A through I wherein said fuel contains 1,000 to 5,000 parts by weight of at least one nitrate ester of at least one nitrate ester of an aliphatic or cycloaliphatic alcohol per million parts by weight of said fuel.
Q. A composition of any of A through I wherein said fuel contains 1,000 to 5,000 parts by weight of at least one nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule.
20408~8 Case EI-6116-A
R. A composition of any of A through I wherein said fuel contains 1,000 to 5,000 parts by weight of 2-ethylhexyl nitrate.
S. In a combustion process wherein a middle distillate fuel is subjected to combustion in the presence of air, the improvement which comprises providing as the fuel used in such process a hydrocarbonaceous middle distillate fuel having a sulfur content of less than 500 ppm and having dissolved therein a minor combustion improving amount of at least one organic nitrate combustion improver.
T. The improvement in accordance with S wherein the combustion is effected within the combustion chamber of a compression ignition engine being operated on a diesel fuel composition composed of (i) a major proportion of a hydrocarbon-aceous middle distillate fuel having a sulfur content of 100 ppm or less and a clear cetane number in the range of 30 to 60, and (ii) a minor combustion improving amount of at least one nitrate ester of at least one aliphatic or cycloaliphatic alcohol.
U. The improvement of T wherein the organic nitrate combustion improver consists essentially of a nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule.
V. The improvement of T wherein the organic nitrate combustion improver consists essentially of 2-ethylhexyl nitrate.
W. In a process for the production of a hydrocarbon-aceous middle distillate fuel, the improvement which comprises controlling the sulfur content of the fuel to a level of 500 ppm or less and blending organic nitrate combustion improver with the resultant reduced sulfur-containing fuel.
2040ala Case EI-6116-A
X. In the operation of a motor vehicle which operates on middle distillate fuel, the improvement which comprises fueling the vehicle with a hydrocarbonaceous middle distillate fuel characterized by having a sulfur content of less than 500 ppm and containing a minor combustion-i ~ roving amount of at least one organic nitrate combustion improver dissolved therein.
Y. In the operation of aircraft which operates on middle distillate fuel, the improvement which comprises fueling the aircraft with a hydrocarbonaceous middle distillate fuel characterized by having a sulfur content of less than 500 ppm and containing a minor combustion-improving amount of at least one organic nitrate combustion improver dissolved therein.
Z. The improvement of any of W through Y wherein the middle distillate fuel has a 10% boiling point (ASTM D-86) in the range of about 154 to about 230C and a 90~ boiling point (ASTM
D-86) in the range of about 260 to about 320C.
Other similar embodiments of this invention will readily occur to those skilled in the art from a consideration of the foregoing disclosure.
This invention is susceptible to considerable variation in its practice without departing from the spirit and scope of the ensuing claims.
JFS:km i ,, FUEL COMPOSITIONS WITH ENHANCED COMBUSTION CHARACTERISTICS
"
This invention relates to preservation of the , environment. More particularly, this invention relates to fuel compositions and methods that reduce atmospheric pollution normally caused by the operation of engines or combus~ion llapparatus on middle distillate fuels.
,1 ~he importance and desirability of reducing the release ,of pollutants into the atmosphere are well recognized. Among the ;
~Ipollutants sought to be reduced are nitrogen oxides ("NOx"), carbon monoxide, unburned hydrocarbons, and particulates.
,1 ', This invention involves the discovery, inter alia, that ' lt is possible to reduce the amount of NOx or CO or unburned hydrocarbons released into the atmosphere during operation of ,engines or other combustion apparatus operated on middle distil-late fuel by employing as the fuel a middle distillate fuel ,having a sulfur content of 500 ppm or less and having dissolved 'therein a combustion improving amount of at least one organic nitrate combustion improver. In fact it has been found possible Ithrough use of such fuel compositions to reduce the amount of two ,,,and in some cases all three such pollutants (NOx, CO and ,unburned hydrocarbons) emitted by diesel engines. Moreover this important and highly desirable obiective has been and thus may be ,achieved without suffering an undesirable increase in the ,, ;
~, .
i.1 ' Case EI-6116-A
emission of particulates. This is a unique discovery since the available experimental evidence and mechanistic theories of combustion suggest that if N0x is reduced, the amount of particulates will be increased, and vice versa.
S Accordingly this invention provides in one of its embodi-ments a fuel composition characterized in that it comprises a ma;or proportion of a hydrocarbonaceous middle distillate fuel which has a sulfur content of less than 500 ppm (preferably 100 ppm or less and most preferably no more than 60 ppm) and in that ';said fuel contains a minor combustion-improving amount of at least one organic nitrate combustion improver dissolved therein.
By the term "hydrocarbonaceous" as used in the ensuing descrip-tion and appended claims is meant the middle distillate fuel is composed principally or entirely of fuels derived from petroleum by any of the usual processing operations. The finished fuels may contain, in addition, minor amounts of non-hydrocarbonaceous fuels or blending components such as alcohols, dialkyl ethers, or like materials, and/or minor amounts of suitably desulfurized auxiliary liquid fuels of appropriate boiling ranges (i.e., between about 160 and about 370-C) derived from tar sands, shale oil or coal. When using blends composed of such desulfurized auxiliary liquid fuels and hydrocarbonaceous middle distillate fuels, the sulfur content of the total blend must be kept below 500 ppm.
In another of its embodiments this invention provides improvements in combustion processes wherein a hydrocarbonaceous middle distillate fuel is subjected to combustion in the presence of air. Such improvement comprises providin~ as a fuel used in Case EI-6116-A
such process a hydrocarbonaceous middle distillate fuel having a sulfur content of less than 500 ppm (preferably lO0 ppm or less and most preferably no more than 60 ppm) and having dissolved therein a minor combustion improving amount of at least one organic nitrate combustion imprqver.
~, Still another embodiment of this invention provides improvements in the production of hydrocarbonaceous middle dis-tillate fuels. Such improvements comprise controlling or re-ducing the sulfur content of the fuel to a level of 500 ppm or less (preferably 100 ppm or less and most preferably no more than 60 ppm) and blending organic nitrate com~ustion improver with the resultant reduced sulfur-containing fuel.
Additional embodiments of this invention involve improve-ments in the operation of motor vehicles and aircraft which oper-ate on middle distillate fuels. These improvements involve fuel-ing the vehicle or aircraft with a hydrocarbonaceous middle dis-tillate fuel characterized by having a sulfur content of less than 500 ppm (preferably 100 ppm or less and most preferably no more than 60 ppm) and containing a minor combustion-improving amount of at least one organic nitrate combustion improver dis-solved therein.
In accordance with a particularly preferred embodiment of this invention, there is provided a hydrocarbonaceous middle distillate fuel having a sulfur content of not more than 500 ppm (preferably 100 ppm or less and most preferably no more than 60 ppm) and a 1~% boiling point (ASTM D-86~ in the range of about 154 to about 230C, said fuel containing a minor combustion improving amount of at least one fuel-soluble organic nitrate combustion improver. Such fuel compositions tend on combustion ` Z040818 -Case EI-6116-A
; to emit especially low levels of N0x. Without desiring to be bound by theoretical considerations, one explanation for such highly desirable performance is that fuels with higher 10%
boiling points cause a delay in the progression of combustion and consequent higher peak temperatures which increase the amount of N0x formation.
Pursuant to another particularly preferred embodiment of this invention there is provided a hydrocarbonaceous middle distillate fuel having a sulfur content of not more than 500 ppm (preferably 100 ppm or less and most preferably no more than 60 ppm) and a 90% boiling point (ASTM D-86) in the range of about 260' to about 320'C, said fuel containing a minor combustion improving amount of at least one fuel-soluble organic nitrate combustion improver. Such fuel compositions tend on combustion to emit especially low levels of particulates.
These and other embodiments are set forth in the ensuing description and appended claims.
In the accompanying drawings:
Fig. l is a least-squares plot of Nox emissions versus 10~ boiling temperatures of fuels having a nominal cetane number of approximately 50; and Fig. 2 is a least-s~uares plot of particulate emissions versus 90% boiling temperatures of fuels having a nominal cetane ; number of approximately 50.
The hydrocarbonaceous fuels utilized in the practice of this invention are comprised in general of mixtures of hydro-20~08~8 -, Case EI-6116-A
carbons which fall within the distillation range of about 160 to about 370C. Such fuels are frequently referred to as "middle distillate fuels" since they comprise the fractions which distill after gasoline. Such fuels include diesel fuels, burner fuels, kerosenes, gas oils, jet fuels, and gas turbine engine fuels.
Preferred middle distillate fuels are those charac-terized by having the following distillation profile:
10% 310 - 550 154 - 288 50~ 350 - 600 177 - 316 go~ 400 - 700 204 - 371 Diesel fuels having a clear cetane number (i.e., a cetane number when devoid of any cetane improver such as an organic nitrate) in the range of 30 to 60 are preferred. Particu-larly preferred are those in which the clear cetane number is in the range of 40 to 50.
The organic nitrate combustion improvers (also fre-quently known as ignition improvers) comprise nitrate esters of substituted or unsubstituted aliphatic or cycloaliphatic alcohols which may be monohydric or polyhydric. Preferred organic ni-trates are substituted or unsubstituted alkyl or cycloalkyl nitrates having up to about 10 carbon atoms, preferably from 2 to 10 carbon atoms. The alkyl group may be either linear or branched (or a mixture of linear and branched alkyl groups).
Specific examples of nitrate compounds suitable for use in the present invention include, but are not limited to, the follow-inq methyl nitrate, ethyl nitrate, n-propyl nitrate, isopropyl 20408~8 ' Case EI-6116-A
nitrate, allyl nitrate, n-butyl nitrate, isobutyl nitrate, sec-butyl nitrate, tert-butyl nitrate, n-amyl nitrate, isoamyl ni-trate, 2-amyl nitrate, 3-amyl nitrate, tert-amyl nitrate, n-hexyl ;
nitrate, n-heptyl nitrate, sec-heptyl nitrate, n-octyl nitrate, S 2-ethylhexyl nitrate, sec-octy~sJ~nitrate, n-nonyl nitrate, n-decyl nitrate, cyclopentylnitrate, cyclohexyl nitrate, methylcyclohexyl nitrate, isopropylcyclohexyl nitrate, and the like. Also suit-able are the nitrate esters of alkoxy substitued aliphatic alco-hols such as 2-ethoxyethyl nitrate, 2-(2-ethoxyethoxy)ethyl ni-trate, 1-methoxypropyl-2-nitrate, 4-ethoxybutyl nitrate, etc., as well as diol nitrates such as 1,6-hexamethylene dinitrate, and the like. Preferred are the alkyl nitrates having from 5 to 10 carbon atoms, most especially mixtures of primary amyl nitrates, mixtures of primary hexyl nitrates, and octyl nitrates such as 2-ethylhexyl nitrate.
As is well known, nitrate esters are usually prepared by the mixed acid nitration of the appropriate alcohol or diol. Mix-tures of nitric and sulfuric acids are generally used for this purpose. Another way of making nitrate esters involves reacting an alkyl or cycloalkyl halide with silver nitrate.
The concentration of nitrate ester in the fuel can be varied within relatively wide limits with the proviso that the amount employed is at least sufficient to cause a reduction in emissions. Generally speaking, the amount employed will fall in the range of about 250 to about ~0,000 parts by weight of organic nitrate per million parts by weight of the fuel. Preferred concentrations usually fall within the range of 1,000 to 5,000 parts per million parts of fuel.
Other additives may be included within the fuel composi-tions of this invention provided they do not adversely affect the 2~)408~8 , Case EI-6116-A
exhaust emission reductions achievable by the practice of this invention. Thus use may be made of such components as organic peroxides and hydroperoxides, corrosion inhibitors, antioxidants, antirust agents, detergents and dispersants, friction reducing agents, demulsifiers, dyes, inert diluents, and like materials.
The advantages achievable by the practice of this invention were demonstrated in a sequential series of engine tests in which a Detroit Diesel 11.1 liter Series 60 engine mounted to an engine dynamometer was used. The system was operated on the ~EPA Engine Dynamometer Schedule for Heavy-Duty Diesel Engines" set forth at pages 810-819 of Volume 40, Part 86, Appendix I, of the Code of Federal Regulations (7-1-86). In these tests, the first of five consecutive tests involved opera-tion of the engine on a conventional DF-2 diesel fuel having a nominal sulfur content in the range of 2000 to 4000 ppm. This test served as one of two baselines. In the next operation the engine was run using a low-sulfur diesel fuel having the follow-ing characteristics:
Sulfur, ppm 50 Gravity, API @ 60F 34.7 Pour Point, D F -5 Cloud Point, F 8 Copper Strip Distillation, D F
10% 430 50% 532 90% 632 Cetane Number 44.3 Viscosity ~ 40C, cS 2.96 In the third and fourth tests -- which represented the practice of this invention -- this same low-sulfur fuel was used except that it had blended therein a diesel ignition improver composed Z04(18~8 Case EI-6116-A
of 2-ethylhexyl nitrate. In the third test the concentration was 2000 ppm of the organic nitrate. In the fourth test, the fuel contained 5000 ppm of the organic nitrate. The fifth and final test involved another baseline run using the initial conventional DF-2 diesel fuel. In all inst~es the guantities of N0x, unburned hydrocarbons ("HC"), carbon monoxide ("C0") and particulates emitted by the engine were measured and integrated.
The results of these tests are summarized in the following table. The values shown therein for N0x, HC, C0, and Particulates, are presented in terms of qrams per brake horsepower per hour. Thus the lower the value, the lower the rate and amount of emissions.
Test No. NOx HC C0 Particulates 1 4.641 0.0861.414 0.227 2 4.345 0.0681.490 0.165 3 4.173 0.0511.312 0.164 4 4.208 0.0731 324 0.165 S 4.623 0.0781.5~5 0.223 In particularly preferred embodiments of this invention, use of fuels having certain boiling characteristics as well as low sulfur levels, results in still further reductions in either N0x or particulate emissions. Thus by use of fuels meeting the low sulfur parameters set forth hereinabove and additionally having a 10~ boiling point (ASTM D-86) in the range of 154-230C, 2~ the emissions of N0x can be reduced to extremely low levels.
Likewise, by use of fuels meeting the low sulfur parameters set forth hereinabove and additionally having a 90% boiling point (ASTM D-86) in the range of 260-320DC, particulate emissions tend to be reduced to especially low levels. To illustrate, a Detroit 3~ ~iesel Corporation Series 60 ~ngine in the 11.1 liter configura-tion and nominally rated at 320 hp at 1800 rpm was used in a Case EI-6116-A
series of emission tests. The engine was installed in a heavy-duty transient emission cell equipped with a constant volume sampler (CVS) system. A dilution tunnel permitted measurements 'of HC, CO, NOX and particulates according to the EPA Transient S Emissions Cycle Procedure. ~ S.J,~
For each individual test case, the engine was started and warmed up. It was then run for 20 minutes at rated speed and load. Rated power was validated. In addition, a power test was conducted, mapping engine torque vs. speed. These parameters are required as part of the EPA Transient Cycle Procedure. Once this information was obtained, two 20-minute EPA Transient Cycles were run and engine controls were adjusted to meet statistical operat-ing limits prescribed for the tests. The engine was shut down i and allowed to soak for 20 minutes. At the end of the soak period, the Hot Start EPA Transient Cycle was run to measure NOX, CO and particulate emissions. A second emissions evaluation was conducted after another two-minute soak. Results for the two Hot Transient Cycles were averaged into a final reported value. Whenever a fuel was changed, new fuel was introduced into the fueling system, new fuel filters were installed, and fuel lines were flushed.
Each fuel ~A through D) was evaluated by the same Hot Start EPA Transient Emissions Cycle Procedure. Fuels A, B, and C
contained 2-ethylhexyl nitrate in an amount sufficient to raise the cetane number of the respective fuels to a nominal value of 50. Fuel D which had a natural cetane number of 49.8 was used unadditized.
1 20408~8 Case EI-6116-A
I
Physical and chemical characterization data for unadditized fuels A through D are shown in the following table:
TABLE
Fuel Pro~ertv A ~3 C D
Hydrocarbon Composition, vol %
Aromatics 36.5 28.5 37.6 39.4 Olefins 1.2 1.1 2.2 2.9 Saturates 62.3 70.4 60.2 57.7 Carbon, wt% 86.35 86.49 86.12 87.32 Hydrogen, wt% 13.15 13.25 12.89 13.35 Nitrogen, ppm 5.3 285 356 152 Sulfur, ppm <1 225 219 476 Aniline pt., deg. C 70.1 60.0 65.4 69.4 Diene content, wt% ~0.1 0.2 ~0.1 <0.1 Viscosity, cSt Q 40 deg. C 2.99 2.20 3.10 3.53 @ 100 deg. C 1.22 0.97 1.23 1.34 Heat of combustion BTU/lb19,593 19,840 19,543 19,672 Boiling range, deg. C
10% 217 211 234 252 20% 233 222 246 262 30% 249 230 257 271 40~ 262 237 267 278 50% 274 244 276 284 60% 288 253 286 291 70% 300 263 294 298 80% 314 276 306 306 9o% 331 297 322 317 95% 344 319 338 329 Recovery, % 98.7 98.9 98.6 98.9 Gravity, deg. API 34.9 36.1 34.6 34.5 Specific gravity 0.850 0.~44 0.852 0.852 Calculated cetane index 48.1 44.0 48.9 51.7 Cetane index 48.5 43.8 48.3 49.7 Cetane number 45.3 39.6 47.7 49.8 In the above table, the following test methods were used:
Hydrocarbon composition - ASTM D-1319 Carbon - Carlo-Er~a 1106 Bydrogen - Carlo-Erba 1106 20408~8 Case EI-6116-A
Nitrogen - ASTM D-4629 Sulfur - ASTM D-3120 Aniline pt. - ASTM D-611 Diene content - UOP 326 Viscosity - ASTM D-445 ~~
Heat of combustion - ASTM D-2382 Boiling range - ASTM D-86 Gravity - ASTM D-287 Calculated cetane index - ASTM D-4737 Cetane index - ASTM D-976 Cetane number - ASTM D 613 Fig. 1 presents graphically the results of N0x emissions in relation to the 10% boiling temperatures of the four fuels.
It can be seen that the fuels in which the 10% boiling tempera-ture was below 230C had the lowest N0x emissions.
The results of the particulate determinations are graph-ically depicted in Fig. 2. In this case, the results are shown as a function of 90% boiling temperatures of the base fuels. A
trend toward lower particulate emissions with fuels having 90%
boiling points within the range of 260-320C was noted.
Methods for reducing the sulfur content of hydrocarbon-aceous middle distillate fuels or their precursors are reported in the literature and are otherwise available to those skilled in the art. Among such processes are solvent extraction using such agents as sulfur dioxide or furfural, sulfuric acid treatment, and hydrodesulfurization processes. Of these, hydrodesulfuriza-tion is generally preferred, and includes a number of specific 0408~8 ~ Case EI-6116-A
"
methods and operating conditions as applied to various feed-stocks. For example, hydrotreating or hydroprocessing of naph-thas or gas oils is generally conducted under mild or moderate ~severity conditions. On the other hand, sulfur removal by hydro-cracking as applied to distillate stocks is usually conducted under more severe operating conditions. Vacuum distillation of bottoms from atmospheric distillations is still another method ~or controlling or reducing sulfur content of hydrocarbon stocks used in the production of hydrocarbonaceous middle distillate fuels. Further information concerning such processes appears in ~Kirk-Othmer, Encyclopedia of Chemical Technoloay, Second Edition, Interscience Publishers, Volume 11, pages 432-445 (copyright 1966) and references cited therein; Idem., Volume 15, pages 1-77 and references cited therein; and Kirk-Othmer, Encyclopedia of Çhemiçal Technoloay, Volume 17, Third Edition, Wiley-Inter-science, pages 183-256 (copyright 1982) and references cited therein. All of such publications and cited references are incorporated herein by reference in respect of processes or methods for control of reduction of sulfur content in hydro-carbonaceous middle disillate fuels or their precursor stocks.
Another method which can be used involves treatment of the hydrocarbonaceous middle distillate fuel with a metallic desul-furization agent such as metallic sodium, or mixtures of sodium and calcium metals.
In summary, this invention involves the provision of a number of embodiments, some of which are set forth below.
A. A fuel composition characterized in that it comprises a major proportion of a hydrocarbonaceous middle distillate fuel ~0408~8 Case EI-6116-A
which has a sulfur content of $ess than 500 ppm and in that said fuel contains a minor combustion-improving amount of at least one organic nitrate combustion improver dissolved therein.
B. A composition of A ~erein the sulfur content of the base fuel is 100 ppm or less.
C. A composition of A wherein the base fuel is a diesel fuel further characterized by having a clear cetane number in the range of 30 to 60.
D. A composition of A wherein the base fuel has a sulfur content of 100 ppm or less and a clear cetane number in the range of 30 to 60.
E. A composition of A wherein the base fuel is further characterized by having the following distillation profile:
F C
10% 310 - 550 154 - 288 50% 350 - 600 177 - 316 90% 400 - 700 204 - 371 F. A composition of A wherein the base fuel has a sulfur content of 100 ppm or less and the following distillation.
profile:
F C
10% 310 - 550 154 - 288 50% 350 - 600 177 - 316 9o% 400 - 700 204 - 371 ' ~0408~L8 Case EI-6116-A
G. A composition of A wherein the base fuel has a clear cetane number in the range of 30 to 60 and the following distillation profile:
F C
10% 310 - 550 154 - 288 50% 350 - 600 177 - 316 90% 400 - 700 204 - 371 H. A composition of A wherein the base fuel has a sulfur content of 100 ppm or less, a clear cetane number in the range of 30 to 60, and the following distillation profile:
~F C
10% 310 - 550 154 - 288 50% 350 - 600 177 - 316 9o% 400 - 700 204 - 371 I. A composition of A wherein the base fuel has a sulfur content of 100 ppm or less and a clear cetane number in the range of 40 to 50.
J. A composition of any of A through I wherein the organic nitrate combustion improver consists essentially of a nitrate ester of an aliphatic or cycloaliphatic alcohol.
K. A composition of any of A through I wherein the organic nitrate combustion improver consists essentially of a nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule.
(- ~ 2040818 Case EI-6116-A
L. A composition of any of A through I wherein the organic nitrate combustion improver consists essentially of a mixture of 2-ethylhexyl nitrate.
M. A composition of ~y of A through I wherein the organic nitrate combustion improver consists essentially of a nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule and wherein said middle distillate fuel has a 10% boiling temperature (ASTM D-86) in the range of about 154C to about 230C.
N. A composition of any of A through I wherein the organic nitrate combustion improver consists essentially of a nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule and wherein said middle distillate fuel has a 90% boiling temperature (ASTM D-86) in the range of about 260C to about 320C.
0. A composition of any of A through I wherein said fuel contains an amount of said organic nitrate falling in the range of 250 to 10,000 parts by weight per million parts by weight of said fuel.
P. A composition of any of A through I wherein said fuel contains 1,000 to 5,000 parts by weight of at least one nitrate ester of at least one nitrate ester of an aliphatic or cycloaliphatic alcohol per million parts by weight of said fuel.
Q. A composition of any of A through I wherein said fuel contains 1,000 to 5,000 parts by weight of at least one nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule.
20408~8 Case EI-6116-A
R. A composition of any of A through I wherein said fuel contains 1,000 to 5,000 parts by weight of 2-ethylhexyl nitrate.
S. In a combustion process wherein a middle distillate fuel is subjected to combustion in the presence of air, the improvement which comprises providing as the fuel used in such process a hydrocarbonaceous middle distillate fuel having a sulfur content of less than 500 ppm and having dissolved therein a minor combustion improving amount of at least one organic nitrate combustion improver.
T. The improvement in accordance with S wherein the combustion is effected within the combustion chamber of a compression ignition engine being operated on a diesel fuel composition composed of (i) a major proportion of a hydrocarbon-aceous middle distillate fuel having a sulfur content of 100 ppm or less and a clear cetane number in the range of 30 to 60, and (ii) a minor combustion improving amount of at least one nitrate ester of at least one aliphatic or cycloaliphatic alcohol.
U. The improvement of T wherein the organic nitrate combustion improver consists essentially of a nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule.
V. The improvement of T wherein the organic nitrate combustion improver consists essentially of 2-ethylhexyl nitrate.
W. In a process for the production of a hydrocarbon-aceous middle distillate fuel, the improvement which comprises controlling the sulfur content of the fuel to a level of 500 ppm or less and blending organic nitrate combustion improver with the resultant reduced sulfur-containing fuel.
2040ala Case EI-6116-A
X. In the operation of a motor vehicle which operates on middle distillate fuel, the improvement which comprises fueling the vehicle with a hydrocarbonaceous middle distillate fuel characterized by having a sulfur content of less than 500 ppm and containing a minor combustion-i ~ roving amount of at least one organic nitrate combustion improver dissolved therein.
Y. In the operation of aircraft which operates on middle distillate fuel, the improvement which comprises fueling the aircraft with a hydrocarbonaceous middle distillate fuel characterized by having a sulfur content of less than 500 ppm and containing a minor combustion-improving amount of at least one organic nitrate combustion improver dissolved therein.
Z. The improvement of any of W through Y wherein the middle distillate fuel has a 10% boiling point (ASTM D-86) in the range of about 154 to about 230C and a 90~ boiling point (ASTM
D-86) in the range of about 260 to about 320C.
Other similar embodiments of this invention will readily occur to those skilled in the art from a consideration of the foregoing disclosure.
This invention is susceptible to considerable variation in its practice without departing from the spirit and scope of the ensuing claims.
Claims (21)
1. A fuel composition characterized in that (i) it comprises a major proportion of a hydrocarbonaceous middle distillate fuel which has a sulfur content of less than 500 ppm and a 10% boiling point (ASTM D-86) in the range of about 154° to about 230°C, and in that (ii) said fuel contains a minor combustion-improving amount of at least one organic nitrate combustion improver dissolved therein.
2. A composition as claimed in Claim 1 wherein the base fuel is a diesel fuel further characterized by having a clear cetane number in the range of 30 to 60.
3. A composition as claimed in Claim 1 wherein the base fuel is a diesel fuel further characterized by having a clear cetane number in the range of about 30 to about 45.
4. A composition as claimed in Claim 3 wherein the nominal cetane number of the fuel composition containing said at least one organic nitrate combustion improver is in the range of about 45 to about 55.
5. A composition as claimed in Claim 3 wherein the nominal cetane number of the fuel composition containing said at least one organic nitrate combustion improver is approximately 50.
6. A composition as claimed in Claim 1 wherein the base fuel has a sulfur content of 100 ppm or less and a clear cetane number in the range of 40 to 50.
7. A composition as claimed in Claim 1 wherein the Case EI-6116-A
organic nitrate combustion improver consists essentially of a nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule.
organic nitrate combustion improver consists essentially of a nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule.
8. A composition as claimed in Claim 1 wherein the organic nitrate combustion improver consists essentially of 2-ethylhexyl nitrate.
9. A composition as claimed in Claim 1 wherein said fuel contains 1,000 to 5,000 parts by weight of at least one nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule.
10. A fuel composition characterized in that (i) it comprises a major proportion of a hydrocarbonaceous middle distillate fuel which has a sulfur content of less than 500 ppm and a 90% boiling point (ASTM D-86) in the range of about 260° to about 320°C, and in that (ii) said fuel contains a minor combustion-improving amount of at least one organic nitrate combustion improver dissolved therein.
11. A composition as claimed in Claim 10 wherein the base fuel is a diesel fuel further characterized by having a clear cetane number in the range of about 30 to about 50.
12. A composition as claimed in Claim 10 wherein the nominal cetane number of the fuel composition containing said at least one organic nitrate combustion improver is in the range of about 45 to about 55.
13. A composition as claimed in Claim 10 wherein the nominal cetane number of the fuel composition containing said at Case EI-6116-A
least one organic nitrate combustion improver is approximately 50.
least one organic nitrate combustion improver is approximately 50.
14. A composition as claimed in Claim 10 wherein the base fuel has a sulfur content of 100 ppm or less and a clear cetane number in the range of about 40 to about 50.
15. A composition as claimed in Claim 10 wherein the organic nitrate combustion improver consists essentially of a nitrate ester of at least one primary alkanol having 5 to 10 carbon atoms in the molecule.
16. A composition as claimed in Claim 10 wherein the organic nitrate combustion improver consists essentially of 2-ethylhexyl nitrate.
17. In a combustion process wherein a middle distillate fuel is subjected to combustion in the presence of air, the improvement which comprises providing as the fuel used in such process a hydrocarbonaceous middle distillate fuel having a sulfur content of less than 500 ppm and a 10% boiling point (ASTM
D-86) in the range of about 154° to about 230°C; said fuel having dissolved therein a minor combustion improving amount of at least one organic nitrate combustion improver.
D-86) in the range of about 154° to about 230°C; said fuel having dissolved therein a minor combustion improving amount of at least one organic nitrate combustion improver.
18. The improvement in accordance with Claim 17 wherein the combustion is effected within the combustion chamber of a compression ignition engine being operated on a diesel fuel composition composed of (i) a major proportion of a hydrocarbon-aceous middle distillate fuel having a sulfur content of 100 ppm or less, a 10% boiling point (ASTM D-86) in the range of about 154° to about 230°C, and a clear cetane number in the range of Case EI-6116-A
about 30 to about 50, and (ii) a minor combustion improving amount of at least one nitrate ester of at least one aliphatic or cycloaliphatic alcohol.
about 30 to about 50, and (ii) a minor combustion improving amount of at least one nitrate ester of at least one aliphatic or cycloaliphatic alcohol.
19. The improvement as claimed in Claim 18 wherein the organic nitrate combustion improver consists essentially of 2-ethylhexyl nitrate.
20. In a process for the production of a hydrocarbon-aceous middle distillate fuel, the improvement which comprises (i) controlling the sulfur content of the fuel to a level of 500 ppm or less and the 10% boiling point (ASTM D-86) of the fuel to a level within the range of about 154° to about 230°C; and (ii) blending organic nitrate combustion improver with the resultant fuel.
21. In the operation of a motor vehicle which operates on middle distillate fuel, the improvement which comprises fueling the vehicle with a hydrocarbonaceous middle distillate fuel characterized by (i) having a sulfur content of less than 500 ppm and a 10% boiling point (ASTM D-86) falling in the range of about 154° to about 230°C, and (ii) containing a minor combustion-improving amount of at least one organic nitrate combustion improver dissolved therein.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US52449890A | 1990-05-17 | 1990-05-17 | |
| US524,498 | 1990-05-17 | ||
| US61532290A | 1990-11-19 | 1990-11-19 | |
| US615,322 | 1990-11-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2040818A1 true CA2040818A1 (en) | 1991-11-18 |
Family
ID=27061515
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002040818A Abandoned CA2040818A1 (en) | 1990-05-17 | 1991-04-19 | Fuel compositions with enhanced combustion characteristics |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0457589B1 (en) |
| JP (1) | JP2931698B2 (en) |
| AU (1) | AU642242B2 (en) |
| CA (1) | CA2040818A1 (en) |
| DE (1) | DE69118583T2 (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5308365A (en) * | 1993-08-31 | 1994-05-03 | Arco Chemical Technology, L.P. | Diesel fuel |
| US5669938A (en) * | 1995-12-21 | 1997-09-23 | Ethyl Corporation | Emulsion diesel fuel composition with reduced emissions |
| WO2000053698A1 (en) * | 1999-03-09 | 2000-09-14 | Idemitsu Kosan Co., Ltd. | Additive for fuel oil or additive for lubricating oil |
| US7029506B2 (en) | 2000-04-14 | 2006-04-18 | Jordan Frederick L | Organic cetane improver |
| EP1290113A4 (en) * | 2000-04-14 | 2008-08-20 | Oryxe energy int inc | Organic cetane improver |
| GB0021970D0 (en) | 2000-09-07 | 2000-10-25 | Octel Starreon Llc | Diesel fuel stabiliser |
| US20030097783A1 (en) | 2001-03-22 | 2003-05-29 | Jordan Frederick L. | Method and composition for using organic, plant-derived, oil-extracted materials in gasolines for reduced emissions |
| US7396450B2 (en) * | 2003-09-18 | 2008-07-08 | Afton Chemical Corporation | Method of reducing amount of peroxides, reducing fuel sediments and enhancing fuel system elastomer durability, fuel stability and fuel color durability |
| US7615085B2 (en) * | 2003-11-04 | 2009-11-10 | Afton Chemical Corporation | Composition and method to reduce peroxides in middle distillate fuels containing oxygenates |
| US8292976B2 (en) * | 2009-11-06 | 2012-10-23 | Afton Chemical Corporation | Diesel fuel additive for reducing emissions |
| GB2522621B (en) * | 2014-01-29 | 2016-01-06 | Rosario Rocco Tulino | Formulation of a new diesel fuel suitable for diesel engines |
| US10781386B2 (en) | 2017-11-02 | 2020-09-22 | Exxonmobil Research And Engineering Company | Cetane improver in fuel oil |
| US11046903B2 (en) * | 2019-08-22 | 2021-06-29 | Exxonmobil Research And Engineering Company | Fuel additives with low NOx emissions |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2031497A (en) * | 1933-01-21 | 1936-02-18 | Du Pont | Fuel |
| US2158050A (en) * | 1937-03-04 | 1939-05-16 | Euphime V Bereslavaky | Motor fuel |
| GB697730A (en) * | 1950-05-09 | 1953-09-30 | Charles Walter Hodgson | Improvements in and relating to liquid fuel catalysts and fuels resulting therefrom |
| FR1349941A (en) * | 1962-10-09 | 1964-01-24 | Exxon Research Engineering Co | Improvement of the combustion characteristics of fuel oils |
| US4073626A (en) * | 1974-04-18 | 1978-02-14 | Ferrous Corporation | Hydrocarbon fuel additive and process of improving hydrocarbon fuel combustion |
| US3957628A (en) * | 1974-12-30 | 1976-05-18 | Exxon Research And Engineering Company | Removal of organic sulfur compounds from hydrocarbon feedstocks |
| US4328005A (en) * | 1980-10-10 | 1982-05-04 | Rockwell International Corporation | Polynitro alkyl additives for liquid hydrocarbon motor fuels |
| AU574045B2 (en) * | 1982-08-16 | 1988-06-30 | Ethyl Corporation | Diesel fuel composition |
| DE3233834A1 (en) * | 1982-09-11 | 1984-03-15 | Ruhrchemie Ag, 4200 Oberhausen | Diesel fuels from coal hydrogenation middle distillates |
| US4448587A (en) | 1983-03-28 | 1984-05-15 | Ethyl Corporation | Synergistic cetane improver |
| US4561862A (en) * | 1985-04-08 | 1985-12-31 | Olin Corporation | Use of selected beta-nitroalkenes as cetane number boosters for diesel fuel |
-
1991
- 1991-04-19 CA CA002040818A patent/CA2040818A1/en not_active Abandoned
- 1991-04-26 AU AU76156/91A patent/AU642242B2/en not_active Ceased
- 1991-05-15 JP JP3138585A patent/JP2931698B2/en not_active Expired - Fee Related
- 1991-05-16 DE DE69118583T patent/DE69118583T2/en not_active Revoked
- 1991-05-16 EP EP91304405A patent/EP0457589B1/en not_active Revoked
Also Published As
| Publication number | Publication date |
|---|---|
| DE69118583T2 (en) | 1996-09-19 |
| DE69118583D1 (en) | 1996-05-15 |
| AU642242B2 (en) | 1993-10-14 |
| AU7615691A (en) | 1991-11-21 |
| EP0457589B1 (en) | 1996-04-10 |
| EP0457589A1 (en) | 1991-11-21 |
| JPH04227990A (en) | 1992-08-18 |
| JP2931698B2 (en) | 1999-08-09 |
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