Low emissions diesel fuel

Abstract

A method and matter of composition for controlling NO.sub.x emissions from existing diesel engines. The method is achieved by adding a small amount of material to the diesel fuel to decrease the amount of NO.sub.x produced during combustion. Specifically, small amounts, less than about 1%, of urea or a triazine compound (methylol melamines) are added to diesel fuel. Because urea and triazine compounds are generally insoluble in diesel fuel, microemulsion technology is used to suspend or dissolve the urea or triazine compound in the diesel fuel. A typical fuel formulation includes 5% t-butyl alcohol, 4.5% water, 0.5% urea or triazine compound, 9% oleic acid, and 1% ethanolamine. The subject invention provides improved emissions in heavy diesel engines without the need for major modifications.

Description

FIELD OF THE INVENTION

The subject invention relates to a method, and a composition therefor, for decreasing NO.sub.x emissions produced from the combustion of fuel. More particularly, the subject invention relates to the addition of an effective amount of urea or a triazine compound (methylol melamines) or a crystalline melamine cyanurate or urea derivatives (such as ethyl, dimethyl, and butyl urea) to a middle distillate base constituent to reduce the NO.sub.x emissions produced during the combustion of the base constituent.

BACKGROUND OF THE INVENTION

The Clean Air Act mandates decreases in NO.sub.x and particulate emissions from diesel engines used in transport and power generation. Combustion emissions. For example, the patents to Hazbun et al. (U.S. Pat. No. 4,744,796) and Schon et al. (U.S. Pat. No. 5,004,479) disclose the use of microemulsion fuel compositions to reduce combustion emissions.

The Clean Air Act Amendments mandate progressive decreases in NO.sub.x and particulate emissions from both stationary and mobile diesel engines. Strategies for reducing emissions from diesel engines include engine redesign, aftertreatments (various combinations of catalysts and emissions control compounds); modifications of fuel production processes, and direct addition of emissions control compounds to fuels. Although all of these technologies could find applications in stationary diesel engines, mobile engines typically used in transport must adjust to rapidly changing load and speed conditions. Additionally, little space is available in mobile for treatment equipment.

The emissions control potential of engine redesign is limited by physical constraints and by combustion chemistry. Similar constraints limit emissions control by catalytic converters.

The most effective systems for controlling NO.sub.x emissions from stationary diesel engines typically involve direct reduction of NO.sub.x by catalytically activated nitrogen compounds. Ammonia, urea, and cyanuric acid are typically vaporized, activated by passage over a hot metal oxide catalyst, and directly reacted with the exhaust gas stream. The gas mixture is typically held for a short period to permit the reaction to go to completion. As cyanuric acid systems provide the greatest reduction in NO.sub.x emissions, they will be described to illustrate the mechanisms of this group of related technologies.

Cyanuric acid systems, which can decrease NO.sub.x by two orders of magnitude, are currently marketed under the names "RAPRENO.sub.x " and "NO.sub.x TECH", respectively, by Robert Perry and by Cummins Engine Company. As disclosed in U.S. Pat. Nos. 4,731,231 and 4,886,650 to Perry, a typical system involves vaporization of cyanuric acid followed by catalytic activation of the resultant isocyanate stream. After a 1 second holding period at 1200.degree. F., the reaction is complete. Perry postulates a complicated series of chain reactions initiated by the isocyanate radical. (Similar reaction cascades exist for other nitrogen compounds.) A typical "RAPRENO.sub.x " installation includes a stationary engine, a cyanuric acid powder metering device, and a gas holding tank. This system adjusts slowly to changes in engine emissions.

Cummins Engine Company simplified this process by directly mixing cyanuric acid into the engine exhaust without prevaporization. However, a holding tank is still required to permit the reaction cascade to go to completion.

Fuels which either incorporated emissions control compounds or which, as a result of their composition, change combustion conditions, could be effective in management of NO.sub.x emissions from mobile systems. Several strategies have been developed for synthesis of emissions control fuels. California has mandated specific composition ranges for petroleum-based diesel fuels. Nitrogen, sulfur, and aromatic contents of these fuels are limited while ignition delay is minimized. Microemulsion compositions which minimize emissions by increasing fuel oxygenate content have also been described by Hazbun et al. (U.S. Pat. No. 4,744,796) and Schon et al. (U.S. Pat. No. 5,004,479).

Although fuels which contain cyanuric acid is nearly insoluble in hydrocarbons typical of diesel fuel. Several strategies have been developed to improve the solubility of cyanuric acid or related triazines. Sung et al. (U.S. Pat. No. 5,219,955) disclose the direct incorporation of s-triazines into diesel fuel for emissions control. The inventors postulate that "thermal unzipping of free hydroxyl groups on s-triazines will generate the NO.sub.x reducing agent, isocyanic acid �Column 3, lines 38-40!." However, synthesis of s-triazines is complicated. The portions of the molecule which permit dissolution and which provide protection during the early stages of combustion increase the weight of material needed to reduce a given amount of NO.sub.x. The utility of this material in decreasing NO.sub.x emissions from conventional mobile diesel engines has not been demonstrated.

SUMMARY OF THE INVENTION

The subject invention, by incorporating features from the previously described technologies, provides an effective method for controlling NO.sub.x emissions from mobile and stationary diesel engines.

It is therefore an object of the invention to provide a method for reducing NO.sub.x emissions produced by engines, without modifying the structure of currently existing engines.

It is another object of the invention to reduce NO.sub.x emissions by adding a small amount of urea, urea-based compound (such as ethyl urea) or a triazine compound to a middle distillate base constituent.

It is also another object of the invention to incorporate a microemulsion of urea or urea-based compound or a triazine compound directly into the base constituent.

Another object of the invention is to reduce NO.sub.x emissions produced by existing engines by providing a fuel composition containing small amounts of a microemulsion of urea, urea-based compound or a triazine compound.

These and other objects are achieved by the subject invention which comprises a fuel composition providing reduced NO.sub.x emissions from combustion. The fuel includes a microemulsion of an effective amount of an additive constituent, including urea, urea-based compound, or a triazine compound, added to a middle distillate base constituent, such as diesel fuel. Generally, the base constituent contains less than about 1% of urea, urea-based compound or a triazine compound by volume. As part of manufacturing the subject fuel, a microemulsion of the urea or triazine compound may be created by mixing either material with t-butyl alcohol, water, oleic acid, and ethanolamine.

By adding a small amount of a microemulsion of urea or a triazine compound to the base constituent, the subject invention decreases the NO.sub.x emissions produced by currently existing engines. Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which discloses a preferred but non-limiting embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

As previously discussed, the Clean Air Act mandates decreases in the NO.sub.x emissions produced by diesel engines used in transport and power generation. The subject invention makes it possible to decrease NO.sub.x emissions by adding a small amount, preferably less than about 10%, of an additive constituent including urea or a triazine compound (methylol melamines, melamine cyanurates, etc.) to a middle distillate base constituent, such as diesel fuel. It should be noted that diesel fuel is only one of many middle distillate base constituents that can be used in accordance with the subject invention.

As the art is well aware, a variety of triazine compounds are readily available. In one embodiment of the subject invention methylol melamine synthesized by reacting formaldehyde with melamine in basic solution has been used, and has shown positive results. Additionally, mono-, di-, and tri- methylol melamine have been utilized in accordance with the subject invention. However, any triazine compound that functions within the spirit of the subject invention may be used to produce fuel in accordance with the subject invention.

Since the triazine compounds used in accordance with the subject invention and urea are typically not soluble in middle distillate base constituents such as diesel fuel, microemulsion technology is used to suspend or dissolve the urea and triazine compound in the base constituent. Specifically, urea or a selected triazine compound is mixed with other materials which facilitate the incorporation of the urea or triazine compound into a microemulsion. A variety of mixtures are known within the art for producing a microemulsion within middle distillate base constituents.

It may also be possible to use urea or a triazine compound in extremely fine form which may not require the presence of an emulsifying agent.

Engine Test Procedure

The engine used for fuel screening was a Deutz F1L-511W single cylinder, indirect injection diesel engine with 0.824 liter displacement and 19:1 compression ratio, coupled to water-cooled eddy current dynamometer. Procedures as described in SAE paper 902101 were used to estimate cetane of fuels, if needed. During emissions tests, engine speed, torque, fuel flow, and NO.sub.x were measured. Air flow was calculated from inclined manometer readings using the manufacturer's equation and a calibration curve. The Beckman 951 NO/NO.sub.x analyzer, mounted inside a Beckman cabinet with sample pump, dryer, and filters, was periodically recalibrated using a gas of known composition. The Beckman analyzer provides measurements of NO or NO.sub.x in ppm. Tests on a standardized emissions control fuel, Phillips D2, were performed during each set of emissions tests. Additionally, Amoco premier diesel fuel and dodecane, which were used as blending bases, were also evaluated.

EXAMPLE 1.

0.5% Methylol Melamine

The following materials were mixed to prepare a fuel: 5 g methylol melamine, 45 g water, 50 g t-butyl alcohol, 90 g oleic acid, log ethanolamine, 800 g Phillips D2 emissions test diesel fuel, and 10 mg Mach I Superfine alpha Fe.sub.2 O.sub.3 catalyst. After mixing, the fuel was filtered to remove any large catalyst particles. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 1).

EXAMPLE 2.

0.5% Urea

The following materials were mixed to prepare a fuel: 5 g urea, 45 g water, 50 g t-butyl alcohol, 90 g oleic acid, log ethanolamine, 800 g Phillips D2 emissions test diesel fuel, and 10 mg Mach I Superfine alpha Fe.sub.2 O.sub.3 catalyst. After mixing, the fuel was filtered to remove any large catalyst particles. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 2a).

Conventional Fuel Performance for Examples 1 and 2

Emissions from the Deutz engine burning Phillips D2 emissions control fuel were evaluated to provide a base emissions level (See Table 2a).

EXAMPLE 3.

1% Astro Aricel PC-6N

The following materials were mixed to prepare a fuel: 20 g Astro Aricel PC-6N, 50 g water, 142 g t-butyl alcohol, 180 g oleic acid, 8 g ethanolamine, and 1600 g Amoco premier diesel fuel. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 3).

EXAMPLE 4.

2.5% Astro Aricel PC-6N

The following materials were mixed to prepare a fuel: 50 g Astro Aricel PC-6N, 50 g water, 143 g t-butyl alcohol, 180 g oleic acid, 7 g ethanolamine, and 1570 g Amoco premier diesel fuel. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 4).

EXAMPLE 5.

2.5% Astro Aricel PC-6N with Catalyst

To 500 g of the fuel of Example 4 was added 10 mg of Mach I superfine alpha Fe.sub.2 O.sub.3 catalyst. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 5).

EXAMPLE 6.

1.0% Astro Aricel PC-6N with Catalyst

To 500 g of the fuel of Example 3 was added 10 mg of Mach I superfine alpha Fe.sub.2 O.sub.3 catalyst. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 6).

EXAMPLE 7.

1% Urea

The following materials were mixed to prepare a fuel: 20 g urea, 100 g water, 100 g t-butyl alcohol, 180 g oleic acid, 20 g ethanolamine, and 1580 g Amoco premier diesel fuel. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 7).

EXAMPLE 8.

2.5% Urea

The following materials were mixed to prepare a fuel: 50 g urea, 100 g water, 100 g t-butyl alcohol, 180 g oleic acid, 20 g ethanolamine, and 1550 g Amoco premier diesel fuel. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 8).

EXAMPLE 9.

1.75% Urea

Equal weights of the fuels in Examples 7 and 8 were blended to give a fuel containing 1.75% urea. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 9).

EXAMPLE 10.

2.5% Urea with Catalyst

To 500 g of the fuel of Example 8 was added 10 mg of Mach I superfine alpha Fe.sub.2 O.sub.3 catalyst. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 10).

EXAMPLE 11.

1% Urea with Catalyst

To 500 g of the fuel of Example 7 was added 10 mg of Mach I superfine alpha Fe.sub.2 O.sub.3 catalyst. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 11).

Conventional Fuel Performance for Examples 3 through 11

Emissions from the Deutz engine burning Phillips D2 emissions control fuel and Amoco premier diesel were evaluated to provide base emissions levels (See Table 11a).

EXAMPLE 12.

4% Astro Aricel PC-6N and 2.5% Urea

The following materials were mixed to prepare a fuel: 40 g Astro Aricel PC-6N, 40 g water, 25 g urea, 50 g t-butyl alcohol, 94 g oleic acid, 75 g Kessco 792, 6.6 g ethanolamine, and 669 g Amoco premier diesel fuel. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 12). Kessco 792 is made by the Stepan Company of Maywood, N.J., and is diethylene glycol dioctanoate.

EXAMPLE 13.

5% Astro Celrez LA-4M-HS and 2.5% Urea

The following materials were mixed to prepare a fuel: 50 g Astro Celrez LA-4M-HS, 40 g water, 25 g urea, 50 g t-butyl alcohol, 94 g oleic acid, 75 g Kessco 792, 6.6 g ethanolamine, and 659 g Amoco premier diesel fuel. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 13).

EXAMPLE 14.

2.5% Astro Aricel PC-6N and 2% Urea

The following materials were mixed to prepare a fuel: 2.5 g Astro Aricel PC-6N, 40 g water, 20 g urea, 50 g t-butyl alcohol, 94 g oleic acid, 75 g Kessco 792, 6.6 g ethanolamine, and 669 g Amoco premier diesel fuel. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 14).

EXAMPLE 15.

1.25% Astro Aricel PC-6N, and 2.5% Astro Celrez LA-4M-HS

Equal weights of the fuels in Examples 4 and 13 were blended to give a fuel containing 1.75% urea. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 15).

Conventional Fuel Performance for Examples 12 through 15

Emissions from the Deutz engine burning Phillips D2 emissions control fuel was evaluated to provide a base emissions level (See Table 15a).

EXAMPLE 16.

2% Ethylurea

The following materials were mixed to prepare a fuel: 2% ethylurea, 15% t-butyl alcohol, 5% water, 13% oleic acid, 2.5% ethanolamine, 62.5% Amoco premier diesel fuel. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 16).

EXAMPLE 17.

2% n-t-Butylurea

The following materials were mixed to prepare a fuel: 2% n-t-butylurea, 15% t-butyl alcohol, 5% water, 13% oleic acid, 2.5% ethanolamine, 62.5% Amoco premier diesel fuel. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 17).

EXAMPLE 18.

Microemulsion Blending Base

The following materials were mixed to prepare a fuel: 15% t-butyl alcohol, 5% water, 13% oleic acid, 2.5% ethanolamine, 64.5% Amoco premier diesel fuel. Emissions performance was then determined in the Deutz engine. The following results were obtained (See Table 18).

Conventional Fuel Performance for Examples 16 through 18

Emissions from the Deutz engine burning Phillips D2 emissions control fuel was evaluated to provide a base emissions level (See Table 18a).

Synthesis of Methylol Melamine

Methylol melamine was made by reacting 1M melamine with 2M formaldehyde in basic solution. The residue was then dissolved in 1:4 isopropanol:water, filtered through a Whatman GF/A filter, and the filtrate lyophilized.

TABLE 1______________________________________0.5% Methylol Melamine Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO.sub.x g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________90 1398 14.3 30.13 1.18 16.05 845 43.5090 1372 9.8 36.56 1.17 15.91 670 41.4690 1435 5 46 1.24 16.85 350 28.8390 1407 0 69.38 1.22 16.59 170 20.7690 1399 14.8 29.12 1.2 16.32 870 44.0190 1925 18.5 19.1 1.78 24.09 425 20.83______________________________________ TABLE 2______________________________________0.5% Urea Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO.sub.x g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________91 1978 18.8 18.09 1.74 23.56 370 16.8091 1955 14.8 21.12 1.74 23.56 300 15.8991 1425 14.5 28.35 1.22 16.59 540 27.0491 1320 10.4 34.09 1.23 16.72 470 28.5091 1433 5 46.06 1.24 16.85 250 20.6291 1414 0 67.69 1.23 16.72 125 15.0191 1402 5.3 44.88 1.22 16.59 265 20.9691 1470 10.4 33.37 1.24 16.85 370 22.1491 1421 15.1 27.31 1.22 16.59 495 23.88______________________________________ ______________________________________Conventional Fuel Performance for Table 2a Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO.sub.x g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________Phillips 1966 8.2 32.99 1.78 24.09 450 37.99Phillips 1947 10 29.99 1.76 23.82 490 37.21Phillips 1950 15 23.94 1.76 23.82 600 36.40Phillips 1983 19 19.49 1.75 23.69 620 30.49Phillips 1400 5 53.48 1.18 16.05 560 51.04Phillips 1400 10 40.44 1.2 16.32 650 45.59Phillips 1400 15 32.27 1.2 16.32 810 45.39______________________________________ TABLE 3______________________________________1% Astro Aricel PC-6N Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________103 1955 5.4 35.6 1.76 23.82 220 19.6103 1955 9.9 28.5 1.76 23.82 245 17.5103 1955 14.8 22.1 1.74 23.56 310 17.1103 1963 20.0 17.7 1.72 23.29 420 18.3103 1949 14.9 22.4 1.72 23.29 355 19.5103 1951 9.9 28.6 1.74 23.56 245 17.4103 1951 5.1 38.4 1.75 23.69 210 20.1______________________________________ TABLE 4______________________________________2.5% Astro Aricel PC-6N Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________100 1959 5.3 36.0 1.77 23.96 205 18.6100 1949 9.9 28.2 1.76 23.82 235 16.6100 1948 15.0 21.4 1.73 23.42 280 14.8100 1964 19.7 17.6 1.74 23.56 365 16.0100 1946 15.2 22.2 1.72 23.29 370 20.2______________________________________ TABLE 5______________________________________2.5% Astro Aricel PC-6N with Catalyst Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________105 1955 5.0 36.7 1.76 23.82 220 20.2105 1956 9.9 28.2 1.76 23.82 235 16.6105 1952 14.6 22.3 1.74 23.56 310 17.2105 1952 20.0 17.4 1.73 23.42 400 17.2105 1960 15.0 21.4 1.74 23.56 330 17.5105 1962 10.0 27.3 1.74 23.56 335 22.7105 1947 5.1 37.1 1.74 23.56 250 23.0______________________________________ TABLE 6______________________________________2.5% Astro Aricel PC-6N with Catalyst Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________108 1945 5.2 36.4 1.78 24.09 195 18.0108 1952 10.1 27.4 1.76 23.82 210 14.5108 1958 14.9 22.0 1.74 23.56 330 18.0108 1950 19.8 17.5 1.72 23.29 410 17.7108 1953 15.1 22.0 1.72 23.29 310 16.8108 1960 10.2 27.7 1.74 23.56 260 17.9108 1945 5.0 38.1 1.74 23.56 205 19.3______________________________________ TABLE 7______________________________________1% Urea Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________102 1964 5.4 35.5 1.75 23.69 240 21.2102 1946 9.8 27.5 1.74 23.56 260 17.7102 1963 15.0 21.6 1.74 23.56 320 17.2102 1966 19.8 17.1 1.74 23.56 405 17.3102 1951 15.1 21.4 1.72 23.29 360 19.0102 1953 10.2 27.7 1.74 23.56 270 18.6102 1958 5.3 36.3 1.75 23.69 230 20.8______________________________________ TABLE 8______________________________________2.5% Urea Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________101 1960 5.1 35.0 1.74 23.56 250 21.7101 1959 10.1 27.0 1.74 23.56 280 18.8101 1959 15.2 20.9 1.72 23.29 370 19.1101 1953 19.9 17.0 1.70 23.02 455 18.8101 1954 15.1 21.2 1.70 23.02 385 19.8101 1958 10.2 26.8 1.72 23.29 305 20.1101 1943 5.2 35.9 1.72 23.29 260 22.9______________________________________ TABLE 9______________________________________1.75% Urea Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________104 1950 5.2 36.2 1.76 23.82 250 22.7104 1958 10.2 27.1 1.76 23.82 280 19.1104 1945 14.9 21.8 1.75 23.69 345 18.8104 1955 14.9 21.1 1.75 23.69 350 18.4104 1943 9.9 27.5 1.74 23.56 290 19.8104 1955 5.1 36.8 1.75 23.69 245 22.5______________________________________ TABLE 10______________________________________2.5% Urea with Catalyst Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________106 1957 5.1 35.6 1.77 23.96 230 20.6106 1946 10.0 27.3 1.75 23.69 265 18.1106 1959 14.7 21.3 1.75 23.69 340 18.1106 1960 20.2 16.8 1.74 23.56 425 17.8106 1952 15.1 21.2 1.72 23.29 370 19.3106 1958 10.0 27.1 1.74 23.56 295 19.8106 1949 5.3 35.5 1.74 23.56 240 21.1______________________________________ TABLE 11______________________________________1% Urea with Catalyst Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________107 1952 5.2 36.5 1.78 24.09 215 19.9107 1957 10.1 27.2 1.76 23.82 255 17.4107 1958 14.8 21.4 1.74 23.56 325 17.3107 1958 20.0 16.9 1.73 23.42 415 17.4107 1953 15.4 21.7 1.72 23.29 355 18.9107 1955 10.2 27.1 1.72 23.29 275 18.3107 1953 5.3 36.0 1.74 23.56 240 21.4______________________________________ TABLE 11a______________________________________Conventional Fuel Performance for Examples 3 through 11 Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________Phillips 1948 5.0 39.8 1.76 23.82 285 28.4Phillips 1964 10.2 28.9 1.76 23.82 340 24.6Phillips 1957 15.9 22.3 1.75 23.69 415 23.1Phillips 1956 20.0 18.2 1.73 23.42 485 21.8Phillips 1960 15.9 22.0 1.73 23.42 455 24.7Phillips 1955 10.4 29.2 1.74 23.56 360 26.0Phillips 1952 5.2 36.5 1.76 23.82 255 23.3Phillips 1955 15.1 22.3 1.74 23.56 440 24.4Phillips 1944 10.0 28.9 1.70 23.02 360 25.2Phillips 1957 5.4 36.6 1.72 23.29 280 25.1Phillips 1958 5.2 39.1 1.76 23.82 270 26.5Phillips 1960 10.0 30.5 1.75 23.69 310 23.6Phillips 1956 14.8 23.8 1.74 23.56 370 21.9Phillips 1952 20.0 19.1 1.72 23.29 460 21.6Phillips 1944 15.0 23.6 1.72 23.29 410 23.8Phillips 1957 10.2 30.2 1.73 23.42 385 28.6Phillips 1947 5.2 40.1 1.74 23.56 300 29.8Amoco 1949 5.1 39.7 1.75 23.69 240 23.7PDAmoco 1955 10.1 29.7 1.75 23.69 305 22.5PDAmoco 1949 15.0 23.7 1.74 23.56 380 22.3PDAmoco 1956 20.0 18.9 1.74 23.56 420 19.7PDAmoco 1958 15.3 22.7 1.73 23.42 390 21.8PDAmoco 1960 10.1 29.8 1.74 23.56 330 24.4PDAmoco 1955 5.1 40.1 1.74 23.56 270 26.8PD______________________________________ TABLE 12______________________________________4% Astro Aricel PC-6N and 2.5% Urea Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________109 1955 5.2 34.5 1.76 23.82 230 19.90109 1954 9.9 26.8 1.75 23.69 275 18.41109 1955 14.9 21.4 1.74 23.56 335 17.84109 1953 19.6 17.4 1.72 23.29 395 16.90109 1945 15.0 22.3 1.72 23.29 345 18.92109 1952 10.2 26.9 1.73 23.42 280 18.63109 1957 4.9 34.8 1.75 23.69 220 19.10______________________________________ TABLE 13______________________________________5% Astro Celrez LA-4M-HS and 2.5% Urea Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________110 1953 5.0 34.6 1.76 23.82 210 18.21110 1958 10.0 26.2 1.75 23.69 255 16.68110 1951 15.0 20.5 1.74 23.56 340 17.36110 1963 20.1 16.3 1.72 23.29 425 17.11110 1964 15.0 21.0 1.74 23.56 375 19.59110 1949 10.1 26.7 1.73 23.42 300 19.75110 1960 4.9 35.1 1.74 23.56 250 21.76______________________________________ TABLE 14______________________________________2.5% Astro Aricel PC-6N and 2% Urea Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________111 1945 5.3 34.6 1.75 23.69 215 18.55111 1948 10.1 26.6 1.74 23.56 280 18.49111 1959 14.8 21.2 1.74 23.56 350 18.42111 1947 19.4 17.5 1.73 23.42 425 18.39111 1947 15.2 21.2 1.73 23.42 390 20.44111 1965 10.1 26.5 1.75 23.69 310 20.54111 1955 5.1 35.4 1.75 23.69 270 23.84______________________________________ TABLE 15______________________________________1.25% Astro Aricel PC-6N, and 2.5% Astro Celrez LA-4M-HS Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________112 1953 5.1 35.5 1.75 23.69 210 18.61112 1955 10.1 26.8 1.75 23.69 250 16.70112 1956 15.1 20.9 1.74 23.56 320 16.60112 1960 19.8 16.9 1.73 23.42 400 16.78112 1943 15.2 21.0 1.72 23.29 360 18.62112 1949 10.0 27.1 1.73 23.42 275 18.42112 1949 5.0 35.8 1.74 23.56 230 20.41______________________________________ TABLE 15a______________________________________Conventional Fuel Performance for Examples 12 through 15 Inc. Fuel man. EINO.sub.x Speed Torque flow Inches Air, NO g NO.sub.x /Fuel ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________Phillips 1944 5.2 37.5 1.76 23.82 260 24.45Phillips 1945 10.0 28.8 1.75 23.69 305 21.94Phillips 1952 15.2 22.6 1.73 23.42 400 22.28Phillips 1956 19.8 18.0 1.72 23.29 460 20.38Phillips 1948 15.1 22.9 1.72 23.29 430 24.12Phillips 1946 10.4 29.1 1.73 23.42 350 25.10Phillips 1950 5.1 39.8 1.74 23.56 270 26.58______________________________________ TABLE 16______________________________________2% Ethylurea Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO.sub.x g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________205 1945 5.0 14.74 1.74 23.56 445 32.56205 1951 10.0 11.64 1.74 23.56 485 28.06205 1969 14.9 9.62 1.74 23.56 505 24.18205 1955 19.8 7.80 1.73 23.42 460 17.79______________________________________ TABLE 17______________________________________2% N-t-Butylurea Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO.sub.x g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________206 1957 5.2 15.95 1.77 23.96 415 33.40206 1952 9.9 12.47 1.75 23.69 755 47.05206 1969 14.9 10.09 1.75 23.69 815 41.15206 1950 19.7 8.34 1.75 23.69 615 25.70206 1940 15.1 10.33 1.72 23.29 950 48.27______________________________________ TABLE 18______________________________________Microemulsion Blending Base Inc. Fuel man. EINO.sub.xFuel Speed Torque flow Inches Air, NO.sub.x g NO.sub.x /ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________207 1963 5.4 16.94 1.77 23.96 450 38.46207 1949 9.8 13.11 1.76 23.82 730 48.08207 1950 14.8 10.42 1.73 23.42 1100 56.70207 1956 19.2 8.69 1.72 23.29 1150 49.22207 1950 15.1 10.31 1.72 23.29 1100 55.79207 1950 10.0 13.27 1.73 23.42 800 52.43207 1950 5.1 17.45 1.70 23.02 500 42.30______________________________________ TABLE 18a______________________________________Conventional Fuel Performance for Examples 16 through 18 Inc. Fuel man. EINO.sub.x Speed Torque flow Inches Air, NO.sub.x g NO.sub.x /Fuel ID RPM lb-ft s/10 cc Water cf/min ppm kg fuel______________________________________Phillips 1964 5.0 19.73 1.76 23.82 620 61.28Phillips 1953 10.0 14.16 1.74 23.56 1250 87.79Phillips 1943 15.0 11.06 1.74 23.56 1450 79.63Phillips 1955 19.8 9.44 1.72 23.29 1300 60.30Phillips 1945 14.9 11.30 1.71 23.16 1450 79.98Phillips 1949 9.9 14.64 1.72 23.29 1288 92.42Phillips 1944 5.1 19.27 1.73 23.42 760 72.15______________________________________

The subject invention is expected to find use in heavy diesel engines used for transport or power generation. It is expected that the subject invention will be used in areas where emission management is critical and where a cost effective emissions control method is needed. Although the market for the technology encompassing the subject invention is the direct result of a federal mandate, the new Clean Air Act, government use of the technology is expected only where government owned diesel engines require NO.sub.x emissions control.

The AriCel PC-6N referred to in the above Examples is made by ASTRO INDUSTRIES of Morganton, N.C. (a division of Borden, Inc.). It is a methylated melamine formaldehyde resin, which is completely soluble in water.

The foregoing Examples use different percentages of additive constituents. Preferred ranges for the urea, urea-based compounds and triazine compounds are between less than 1% to about 6.5%.

While advantageous embodiments have been chosen to illustrate the subject invention, it will be understood by those skilled in the out that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.

Claims

1. A fuel composition comprising:

a microemulsion containing a middle distillate base constituent and an additive constituent selected from the group consisting of urea, a urea-based compound, and a triazine compound in an amount sufficient to effect a reduction in NO.sub.x emissions from combustion.

2. A fuel composition according to claim 1, wherein said additive constituent comprises less than about 2% of said composition.

3. A fuel composition according to claim 2, wherein said microemulsion further includes about 5% t-butyl alcohol, about 4.5% water, about 0.5% of said urea or said triazine compound, about 9% oleic acid, and about 1% ethanolamine as added to said middle distillate base constituent.

4. A fuel composition according to claim 1, wherein said middle distillate base constituent is diesel fuel.

5. A fuel composition according to claim 4, wherein said microemulsion further includes about 5% t-butyl alcohol, about 4.5% water, about 9% oleic acid, and about 1% ethanolamine as added to said diesel fuel, and said additive constituent comprises about 0.5% of said urea or said triazine compound.

6. A method for reducing the NO.sub.x emissions resulting from the combustion of fuel, comprising the steps of:

forming a microemulsion by combining an effective amount of an additive constituent selected from the group consisting of urea, a urea-based compound, or a triazine compound and a middle distillate base constituent, thereby creating a fuel; and

combusting said fuel in an engine.

7. A method according to claim 6, wherein no more than about 1% of said urea, urea-based compound, and said triazine compound is added to said middle distillate base constituent.

8. A method according to claim 7, wherein said additive constituent further includes an emulsifying agent.

9. A method according to claim 8, wherein about 5% t-butyl alcohol, about 4.5% water, about 0.5% of said urea or said triazine compound, about 9% oleic acid, and about 1% ethanolamine.

10. A method according to claim 6, wherein said middle distillate base constituent is diesel fuel.

11. A method of making a fuel having reduced NO.sub.x emissions, comprising the step of:

forming a microemulsion which includes an additive constituent including urea or a triazine compound and a middle distillate base constituent.

12. A method according to claim 11, wherein no more than about 1% said urea or said triazine compound is added to said middle distillate base constituent.

13. A method according to claim 12, wherein about 5% t-butyl alcohol, about 4.5% water, about 0.5% of said urea or said triazine compound, about 9% oleic acid, and about 1% ethanolamine are added to said middle distillate base constituent.

14. A method according to claim 11, wherein said middle distillate base constituent is diesel fuel.

15. A reduced NO.sub.x emissions fuel composition comprising:

a microemulsion containing a middle distillate base constituent and an additive constituent selected from the group consisting of urea, a urea-based compound, and a triazine compound in an amount sufficient to effect a reduction in NO.sub.x emissions from combustion.

16. The composition according to claim 15, wherein said microemulsion further includes oleic acid.

17. A reduced NO.sub.x emissions fuel composition consisting essentially of:

a microemulsion containing a middle distillate base constituent, a NO.sub.x reducing additive constituent selected from the group consisting of urea, a urea-based compound, and a triazine compound, and t-butyl alcohol, water, oleic acid, and ethanolamine.

18. A reduced NO.sub.x emissions fuel composition consisting essentially of:

a microemulsion containing a middle distillate base constituent, a NO.sub.x reducing additive constituent selected from the group consisting of urea, a urea-based compound, a triazine compound.

19. A fuel composition comprising:

a microemulsion containing middle distillate base constituent; and

methylol melamine as an additive in an amount sufficient to effect a reduction in NO.sub.x emissions from combustion.

20. A method for reducing the NO.sub.x emissions resulting from the combustion of fuel, comprising the steps of:

forming a microemulsion by combining an effective amount of a methylol melamine added constituent to a middle distillate base constituent thereby creating a fuel; and

combusting said fuel in an engine.

21. A method of making a fuel having reduced NO.sub.x emissions resulting from the combustion of fuel, comprising the step of:

forming a microemulsion which includes an additive constituent including methylol melamine and a middle distillate base constituent.