Abstract:
A method and matter of composition for controlling NO 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 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:
This invention w as made with Government support under contract DE-AC05-84OR21400 awarded by the U.S. Department of Energy to Martin Marietta Energy Systems, Inc., and the Government has certain rights in this invention. 
    
    
     This is a continuation of application Ser. No. 08/220,144, filed on Mar. 30. 1994, now abandoned. 
    
    
     FIELD OF THE INVENTION 
     The subject invention relates to a method, and a composition therefor, for decreasing NO 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 x  emissions produced during the combustion of the base constituent. 
     BACKGROUND OF THE INVENTION 
     The Clean Air Act mandates decreases in NO 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 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 x  emissions from stationary diesel engines typically involve direct reduction of NO 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 x  emissions, they will be described to illustrate the mechanisms of this group of related technologies. 
     Cyanuric acid systems, which can decrease NO x  by two orders of magnitude, are currently marketed under the names &#34;RAPRENO x  &#34; and &#34;NO x  TECH&#34;, 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° 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 &#34;RAPRENO x  &#34; 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 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 &#34;thermal unzipping of free hydroxyl groups on s-triazines will generate the NO x  reducing agent, isocyanic acid  Column 3, lines 38-40!.&#34; 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 x . The utility of this material in decreasing NO 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 x  emissions from mobile and stationary diesel engines. 
     It is therefore an object of the invention to provide a method for reducing NO x  emissions produced by engines, without modifying the structure of currently existing engines. 
     It is another object of the invention to reduce NO 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 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 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 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 x  emissions produced by diesel engines used in transport and power generation. The subject invention makes it possible to decrease NO 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 x  were measured. Air flow was calculated from inclined manometer readings using the manufacturer&#39;s equation and a calibration curve. The Beckman 951 NO/NO 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 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 2  O 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 2  O 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 2  O 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 2  O 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 2  O 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 2  O 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 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.