Patent Publication Number: US-2022235287-A1

Title: Biodiesel fuel mixtures

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. § 120 as a continuation of U.S. patent application Ser. No. 16/050,872, titled “BIODIESEL FUEL MIXTURES,” filed Jul. 31, 2018 that claims the benefit of U.S. Provisional Application No. 62/539,027, filed Jul. 31, 2017, the entire contents of the aforementioned applications being incorporated herein by reference in their entireties. 
    
    
     BACKGROUND 
     Biodiesel, an alternative diesel fuel created from the esterification of fats and fatty acids, continues to gain significant interest as a renewable energy source. The biodiesel market is expected to reach 6,453 million liters in the U.S. by 2020 and 45,291 million liters globally. See GlobalData, Global Biodiesel Market Analysis and Forecasts to 2020, Accessed May 26, 2012 and Fuel Processing Technology 106 (2013) 526-532. Biodiesel is an attractive alternative fuel source worldwide because it operates in conventional engines, does not require special storage, has less odor offensive exhaust, and has a higher flash point, thereby making it a safer energy source than conventional diesel fuel. 
     Despite these advantages, a major impediment to the wide-spread committed use of biodiesel has been the observed increase in NO x  emissions. For example, for 100% biodiesel, NO x  emissions can increase by 13% or more. See Ener Conver and Manag, 50, (2009), 14-34. Excessive NOx emission causes smog, ground level ozone, and acid rain. See Journal of Scientific &amp; Industrial Industry Research, Vol. 73, March 2014, 177-180. This is a significant drawback, particularly since governmental agencies continue to impose new legislation on “cleaner air” and mandate higher emission standards for motor vehicles. Thus, a rising concern is that biodiesel may not be able to meet these heightened requirements. 
     The need therefore remains for biodiesel fuels which do not negatively impact NO x  emission, as well as other criteria pollutants such as particulate matter, total hydrocarbons and carbon monoxide. 
     SUMMARY 
     Provided herein are biodiesel fuel mixtures comprising a first biodiesel fuel, a second biodiesel fuel, a base petroleum diesel fuel, and an additive. The disclosed biodiesel fuel mixtures comprise a cetane number of 45 to 70 and have no negative impact on NO x  emissions. Indeed, the disclosed mixtures decrease NO x  emission by 1 to 7%. See e.g., Table 12. The disclosed mixtures also decrease total particular matter emissions, CO emissions, and total hydrocarbon emissions. See e.g., Table 12. 
     Process for manufacturing the disclosed biodiesel fuel mixtures are also provided. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a graphic representation of torque and speed commands for the transient cycle for heavy-duty engines. 
         FIG. 2  is a schematic of sampling system used for transient emission measurements. 
         FIG. 3  shows the engine performance maps for screening tests. 
         FIG. 4  shows the engine performance maps for screening tests at 3000 ppm additive. 
         FIG. 5  shows the engine performance maps for screening tests at 2000 ppm additive. 
         FIG. 6  illustrates additive concentration vs. NO x  results. 
         FIG. 7  shows a comparison of B20 blends. 
         FIG. 8  shows a comparison of B20 blends with 3000 ppm A1 
         FIG. 9  shows a comparison of B20 blends with 3000 ppm additive. 
     
    
    
     DETAILED DESCRIPTION 
     In a first embodiment, provided herein are biodiesel fuel mixtures comprising a first biodiesel fuel, a second biodiesel fuel, a base petroleum diesel fuel, and an additive, wherein the biodiesel fuel mixture has a cetane number of 45 to 70. 
     In a second embodiment, provided herein are biodiesel fuel mixtures comprising from 5 wt. % to 20 wt. % of at least one biodiesel; from 80 wt. % to 95 wt. % of a base petroleum diesel fuel; and an additive, wherein the biodiesel fuel mixture has a cetane number of 45 to 70. 
     1. Definitions 
     The term “biodiesel” means a fuel derived from vegetable oils or animal fats. Biodiesel includes fuels comprising mono-alkyl esters of long-chain fatty acids derived from the transesterification of fats obtained from vegetable oils or other fatty acids such as animal fats or waste cooking oils as well as fuel resulting from hydrotreating vegetable oils, animal fats or mono-alkyl esters of long-chain fatty acids. In one aspect, the biodiesel used herein comprises fatty acid methyl esters (FAMEs) derived from the transesterification of vegetable oil with methanol. 
     “Petroleum diesel fuel” and “base petroleum diesel fuel” are used interchangeably and refer to a combustible petroleum distillate used as fuel for diesel engines. Petroleum diesel fuel is typically formed from the fractional distillation of crude oil between 200 ° C. and 350 ° C. at atmospheric pressure, resulting in a mixture of carbon chains comprising between 8 and 21 carbon atoms per molecule. 
     The term “no negative impact” as in, wherein the mixture has no negative impact on NO x  emissions, means that there is no statistically significant increase in the amount of NO x  emission using the disclosed biodiesel fuel mixture when compared to petroleum diesel fuel in the same engine. Statistical significance is based from the known one-sided Student&#39;s t-statistics as set for in Snedecor and Cochran,  Statistical Methods  (7 th  edition). Pg 91, Iowa State University Press, 1980, e.g., a cut-off value of 0.5 or less. 
     2. Fuel Mixtures 
     In a third embodiment, the additive in the biodiesel fuel mixtures described herein is present in an amount of 0.050 to 0.400 vol. %, 0.060 to 0.350 vol. %, 0.070 to 0.320 vol. %, 0.075 to 0.300 vol. %, 0.075 vol. %, 0.150 vol. %, 0.225 vol. %, or 0.300 vol. %, wherein the remaining features are as described above in the first or second embodiment. 
     In a fourth embodiment, the at least one biodiesel in the fuel mixtures described herein is present in an amount of 5 wt. %, 10 wt. %, 15 wt. %, or 20 wt. %, wherein the remaining features are as described above in the first, second, or third embodiment. 
     In a fifth embodiment, the base petroleum diesel fuel in the fuel mixtures described is present in an amount of 80 wt. %, 85 wt. %, 90 wt. %, or 95 wt. %, wherein the remaining features are as described above in the first, second, third, or fourth embodiment. 
     In a sixth embodiment, the at least one biodiesel is a mixture of 12-15 wt. % of a first biodiesel fuel and 6-8 wt. % of a second biodiesel fuel, wherein the remaining features are as described above in the first, second, third, fourth, or fifth embodiment. 
     In a seventh embodiment, the biodiesel fuel mixtures described herein have a cetane number of 45 to 65, wherein the remaining features are as described above in the first, second, third, fourth, fifth, or sixth embodiment. Alternatively, the biodiesel fuel mixtures described herein have a cetane number of 45 to 60, 45 to 55, 55 to 65, 50 to 60, 48 to 51, or 58 to 60, wherein the remaining features are as described above in the first, second, third, fourth, fifth, or sixth embodiment. 
     In an eighth embodiment, the biodiesel fuel mixtures described herein comprise 25% or less of aromatics by volume, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, or seventh embodiment. Alternatively, the biodiesel fuel mixture described herein comprise 20% or less of aromatics by volume, 15% or less of aromatics by volume, 12% or less of aromatics by volume, 10% or less of aromatics by volume, or 20% to 25% aromatics by volume, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, or seventh embodiment. 
     In a ninth embodiment, the biodiesel fuel mixtures described herein comprise less than 7% polycyclic aromatics by weight, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, or eighth embodiment. Alternatively, the biodiesel fuel mixtures described herein comprise less than 5% polycyclic aromatics by weight or 4.5% to 5.5% polycyclic aromatics by weight, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, or eighth embodiment. 
     In a tenth embodiment, the weight ratio of total aromatics to polycyclic aromatics in the biodiesel fuel mixtures described herein is 5:1, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, or ninth embodiment. Alternatively, the weight ratio of total aromatics to polycyclic aromatics in the biodiesel fuel mixtures described herein is 4:1, 3:1, or 2:1, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, or ninth embodiment. 
     In an eleventh embodiment, the sulfur content in the biodiesel fuel mixtures described herein is less than 15 ppm, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, or tenth embodiment. Alternatively, the sulfur content in the biodiesel fuel mixtures described herein is less than 10 ppm, less than 5 ppm, less than 1.0 ppm, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, or tenth embodiment. 
     In a twelfth embodiment, the nitrogen content in the biodiesel fuel mixtures described herein is from 0 to about 800 ppm, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh embodiment. Alternatively, the nitrogen content in the biodiesel fuel mixtures described herein is from 50 ppm to about 600 ppm, from about 100 to about 400 ppm, from about 200 to about 800 ppm, from about 10 to about 600 ppm, and from about 250 to about 300 ppm, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh embodiment. 
     In a thirteenth embodiment, the fatty acid methyl ester content in the biodiesel fuel mixtures described herein is 15 to 25% or 19 to 21%, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, or twelfth embodiment. 
     In a fourteenth embodiment, the viscosity at 40° C. in the biodiesel fuel mixtures described herein is 1.9 to 4.1 centistokes, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, or thirteenth embodiment. 
     In a fifteenth embodiment, the additive in the biodiesel fuel mixtures described herein is present in an amount of 500, 1000, 1500, 2000, 2500, 3000, 3300, 4000, 5000, 6000, 7000, 8000, 9000 or 10,000 ppm, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, or fourteenth embodiment. Alternatively, the additive is present in an amount of 3300 ppm or 3000 ppm, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, or fourteenth embodiment. 
     In a sixteenth embodiment, the additive in the biodiesel fuel mixtures described herein is selected from an amine-based antioxidant, a phenol-based antioxidant, or a nitrated alkyl-based antioxidant, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, or fifteenth embodiment. Alternatively, the additive is selected from 2-ethylhexyl nitrate (2-EHN); di-tert-butyl peroxide (DTBP); tertiary butylhydroquinone (TBHQ); N,N-di-sec-butyl-1,4-phenylenediamine (DTBP), N,N′-diphenyl-1,4-phenylenediamine (DPPD); and N-phenyl-1,4-phenylenediamine (NPPD), wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, or fifteenth embodiment. In another alternative, the additive is 2-ethylhexyl nitrate, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, or fifteenth embodiment. 
     In a seventeenth embodiment, the biodiesel fuel mixtures described herein have no negative impact on NOx emissions, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, or sixteenth embodiment. 
     In an eighteenth embodiment, the biodiesel fuel mixtures described herein decrease NO x  emissions of an engine by 1 to 7%, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, sixteenth, or seventeenth embodiment. Alternatively, the biodiesel fuel mixtures described herein decrease NO x  emissions of an engine by 2 to 7%; by 3 to 7%; or by 5 to 7%, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, sixteenth, or seventeenth embodiment. In one alternative, the biodiesel fuel mixtures described herein comprise NO x  emissions equivalent to those of a reference fuel having the following specifications: sulfur (15 ppm maximum), aromatics (10 vol % maximum), polycyclic aromatics (10 wt % maximum), nitrogen (10 ppm maximum), unadditized cetane number (48 minimum), API gravity (33-39), flash point (130° F. minimum), viscosity @40° C., cSt (2.0-4.12), IBP (340 to 420° F.), 10% (400 to 490° F.), 50% (470 to 560° F.), 90% (550 to 610° F.), and EP (580 to 660° F.). 
     In a nineteenth embodiment, the biodiesel fuel mixtures described herein decrease total particular matter emissions of an engine by 20 to 25%, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, or eighteenth embodiment. 
     In a twentieth embodiment, the biodiesel fuel mixtures described herein decrease CO emissions of an engine by 15 to 25%, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, eighteenth, or nineteenth embodiment. 
     In a twenty-first embodiment, the biodiesel fuel mixtures described herein decrease total hydrocarbon emissions of an engine by 15 to 25%, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, eighteenth, nineteenth, or twentieth embodiment. 
     In a twenty-second embodiment, the engine used to test the properties of the biodiesel fuel mixtures described herein is a diesel engine such as a Detroit Diesel Corporation Series 60 heavy duty diesel engine or a Cummins ISM 370 diesel engine, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, eighteenth, nineteenth, or twenty-first embodiment. 
     In a twenty-third embodiment, the biodiesel fuel mixtures, and accompanying properties and features are as described below in the exemplification section, wherein the remaining features are as described above in the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, eighteenth, nineteenth, twenty-first, or twenty-second embodiment. 
     EXEMPLIFICATION 
     The following starting fuels and additives were blended at various concentrations. Table 1 provides codes for the six additives and Table 2 lists the fuel codes corresponding to each fuel blend and the concentrations. 
     
       
         
           
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                 Component % 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Additive Code 
                 2-EHN 
                 DTBP 
                 PDA 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 A1, A7 
                 100 
                 0 
                 0 
               
               
                   
                 A2 
                 91 
                 0 
                 9 
               
               
                   
                 A3 
                 91 
                 9 
                 0 
               
               
                   
                 A4 
                 0 
                 100 
                 0 
               
               
                   
                 A5 
                 82 
                 9 
                 9 
               
               
                   
                 A6 
                 0 
                 0 
                 100 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 2 
               
             
            
               
                   
                   
               
               
                   
                 Concentration, % a   
               
            
           
           
               
               
               
               
               
               
            
               
                 Fuel 
                 Base 
                   
                   
                   
                   
               
               
                 Code 
                 Fuel 
                 Biodiesel 1 
                 Biodiesel 2 
                 Biodiesel 3 
                 Additive/Conc. 
               
               
                   
               
               
                 F1 
                 — 
                 100  
                 — 
                 — 
                 — 
               
               
                 F2 
                 — 
                 — 
                 100  
                 — 
                 — 
               
               
                 F3 
                 — 
                 — 
                 — 
                 100  
                 — 
               
               
                 F4 
                 100 
                 — 
                 — 
                 — 
                 — 
               
               
                 F5 
                 80 
                 13 
                 7 
                 — 
                 — 
               
               
                 F6 
                 80 
                 — 
                 — 
                 20 
                 — 
               
               
                 F7 
                 80 
                 — 
                 — 
                 20 
                 3000 
               
               
                 F8 
                 80 
                 13 
                 7 
                 — 
                 3000 
               
               
                 F9 
                 80 
                 13 
                 7 
                 — 
                 1000 
               
               
                 F10 
                 80 
                 13 
                 7 
                 — 
                 2000 
               
               
                 F11 
                 80 
                 13 
                 7 
                 — 
                 1500 
               
               
                 F12 
                 80 
                 13 
                 7 
                 — 
                  3300 b   
               
               
                 F13 
                 80 
                 13 
                 7 
                 — 
                  3300 c   
               
               
                 F14 
                 80 
                 13 
                 7 
                 — 
                 2500 
               
               
                   
               
               
                   a Concentrations for fuel in percentage, concentration for additive in ppm, additive A1 1000 unless indicated 
               
               
                   b Additive A3 
               
               
                   c Additive A2 
               
            
           
         
       
     
     Fuel blends were tested using procedures similar to the one outlined in Title 13 California Code of Regulations Section 2882 “Aromatic Hydrocarbon Content of Diesel Fuel.” The actual screening plan is shown in Table 3. For screening, Alternative 3 was the Title 13 protocol selected. For the first two days of testing, duplicate tests with only a single “prep” were used to quickly move through a large number of fuels. After the first day of testing, the B100 blend with F1 (35 percent) and F2 (65 percent) was selected as the B100 for all subsequent testing. On the final two days of testing, the Alternative 3 procedure was followed to screen a 3000 ppm and 2000 ppm additive, respectively. The test results are reported below in Table 3. 
     The heavy-duty EPA transient cycle is described by means of percent of maximum torque and percent of rated speed for each one-second interval over a test cycle of 1199 seconds duration. To generate a transient cycle, an engine&#39;s full power curve is obtained from an engine speed below curb idle speed to maximum no-load engine speed. Data from this “power curve,” or engine map, are used with the specified speed and load percentages to form a transient cycle. A graphic presentation of the speed and torque commands which constitute a transient cycle is given in  FIG. 1  for illustration purposes. 
     In general, a transient test consists of a cold-start transient cycle and a hot-start transient cycle. The same engine command cycle is used in both cases. For the cold-start, the diesel engine was operated over a “prep” cycle, and then allowed to stand overnight in an ambient soak at a temperature between 68° F. and 86° F. The cold-start transient cycle begins when the engine is cranked for cold start-up. Upon completion of the cold-start transient cycle, the engine is stopped and allowed to stand for 20 minutes. After this hot-soak period, a hot-start cycle begins with engine cranking. In order to determine how well the engine follows the transient command cycle, engine performance was compared to engine command, and several statistics were computed. These computed statistics must be within tolerances specified in the CFR. In addition to statistical parameters, the cycle work actually produced should be between 5 percent above and 15 percent below the work requested by the command cycle. Emissions measurements included total hydrocarbon (THC), carbon monoxide (CO), oxides of nitrogen (NO), carbon dioxide (CO 2 ), and total particulate matter (PM). 
     
       
         
           
               
               
             
               
                 TABLE 3 
               
               
                   
               
               
                 Step 
                 Description 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 1 
                 Install engine. Perform emission instrument calibrations as 
               
               
                   
                 required. Calibrate torquemeter and check signal conditioning 
               
               
                   
                 systems. Validate CVS gaseous and particulate sampling systems 
               
               
                   
                 using propane recovery techniques 
               
               
                 2 
                 Change oil and filters. Operate engine for 5 hours with CARB 
               
               
                   
                 equivalent fuel to break-in the oil, Check engine condition using 
               
               
                   
                 in-house, low sulfur emissions type fuel, and note fault codes 
               
               
                   
                 if any. Bring engine oil level to “full”. 
               
               
                 3 
                 Perform fuel change procedure to operate on Fuel R (F4). Change 
               
               
                   
                 filter, purge fuel supply, etc. 
               
               
                 4 
                 Warm up engine, and operate at rated speed and load, then check 
               
               
                   
                 performance. 
               
               
                 5 
                 Conduct transient “full-throttle” torque map from low- to high-idle. 
               
               
                   
                 Compute and store resulting transient command cycle. 
               
               
                 6 
                 Run a 20-minute practice or conditioning transient cycle, and 
               
               
                   
                 adjust dynamometer controls to meet statistical limits for transient 
               
               
                   
                 cycle operation. 
               
               
                 7 
                 Soak the engine for 20-minutes. Run three hot-start transient tests 
               
               
                   
                 with a 20-minute soak between each. For each individual hot-start 
               
               
                   
                 test, determine THC, CO, NO x , CO 2 , and PM. 
               
               
                 8 
                 Change fuel to F5. Repeat Steps 6 and 7. Soak the engine for 20- 
               
               
                   
                 minutes. Run two hot- start transient tests with a 20-minute soak 
               
               
                   
                 between each. For each individual hot-start test, determine THC, 
               
               
                   
                 CO, NO x , CO 2 , and PM. 
               
               
                 9 
                 Change fuel to F6. Repeat Steps 6 and 7. Soak the engine for 20- 
               
               
                   
                 minutes. Run two hot- start transient tests with a 20-minute soak 
               
               
                   
                 between each. For each individual hot-start test, determine THC, 
               
               
                   
                 CO, NO x , CO 2 , and PM. 
               
               
                 10 
                 Change fuel to F7. Repeat Steps 6 and 7. Soak the engine for 20- 
               
               
                   
                 minutes. Run two hot- start transient tests with a 20-minute soak 
               
               
                   
                 between each. For each individual hot-start test, determine THC, 
               
               
                   
                 CO, NO x , CO 2 , and PM. 
               
               
                 11 
                 Change fuel to F8. Repeat Steps 6 and 7. Soak the engine for 20- 
               
               
                   
                 minutes. Run two hot- start transient tests with a 20-minute soak 
               
               
                   
                 between each. For each individual hot-start test, determine THC, 
               
               
                   
                 CO, NO x , CO 2 , and PM. 
               
               
                 12 
                 Change fuel to F9. Repeat Steps 6 and 7. Soak the engine for 20- 
               
               
                   
                 minutes. Run two hot- start transient tests with a 20-minute soak 
               
               
                   
                 between each. For each individual hot-start test, determine THC, 
               
               
                   
                 CO, NO x , CO 2 , and PM. 
               
               
                 13 
                 Change fuel to F10. Repeat Steps 6 and 7. Soak the engine for 20- 
               
               
                   
                 minutes. Run two hot-start transient tests with a 20-minute soak 
               
               
                   
                 between each. For each individual hot-start test, determine THC, 
               
               
                   
                 CO, NO x , CO 2 , and PM. 
               
               
                 14 
                 Change fuel to F11. Repeat Steps 6 and 7. Soak the engine for 20- 
               
               
                   
                 minutes. Run two hot- start transient tests with a 20-minute soak 
               
               
                   
                 between each. For each individual hot-start test, determine THC, 
               
               
                   
                 CO, NO x , CO 2 , and PM. 
               
               
                 15 
                 Change fuel to F4. Repeat Steps 6 and 7. Soak the engine for 20- 
               
               
                   
                 minutes. Run two hot-start transient tests with a 20-minute soak 
               
               
                   
                 between each. For each individual hot-start test, determine THC, 
               
               
                   
                 CO, NO x , CO 2 , and PM. 
               
               
                 16 
                 Change fuel to F8. Repeat Steps 6 and 7 except that the fuel filters 
               
               
                   
                 should be dumped, and the engine should be run for 20 minutes at 
               
               
                   
                 rated speed and load prior to Step 7. Soak the engine for 
               
               
                   
                 20-minutes. Run two hot-start transient tests with a 20-minute soak 
               
               
                   
                 between each. For each individual hot-start test, determine THC, 
               
               
                   
                 CO, NO x , CO 2 , and PM. 
               
               
                 17 
                 Change fuel to F13. Repeat Steps 6 and 7 except that the fuel 
               
               
                   
                 filters should be dumped, and the engine should be run for 20 
               
               
                   
                 minutes at rated speed and load prior to Step 7. Soak the engine 
               
               
                   
                 for 20-minutes. Run two hot-start transient tests with a 20-minute 
               
               
                   
                 soak between each. For each individual hot-start test, determine 
               
               
                   
                 THC, CO, NO x , CO 2 , and PM. 
               
               
                 18 
                 Change fuel to F12. Repeat Steps 6 and 7 except that the fuel 
               
               
                   
                 filters should be dumped, and the engine should be run for 20 
               
               
                   
                 minutes at rated speed and load prior to Step 7. Soak the engine 
               
               
                   
                 for 20-minutes. Run two hot-start transient tests with a 20-minute 
               
               
                   
                 soak between each. For each individual hot-start test, determine 
               
               
                   
                 THC, CO, NO x , CO 2 , and PM. 
               
               
                 19 
                 Change fuel to F5. Repeat Steps 6 and 7 except that the fuel filters 
               
               
                   
                 should be dumped, and the engine should be run for 20 minutes at 
               
               
                   
                 rated speed and load prior to Step 7. Soak the engine for 
               
               
                   
                 20-minutes. Run two hot-start transient tests with a 20-minute soak 
               
               
                   
                 between each. For each individual hot-start test, determine THC, 
               
               
                   
                 CO, NO x , CO 2 , and PM. 
               
               
                 20 
                 Change fuel to F14. Repeat Steps 6 and 7 except that the fuel 
               
               
                   
                 filters should be dumped, and the engine should be run for 20 
               
               
                   
                 minutes at rated speed and load prior to Step 7. Soak the engine 
               
               
                   
                 for 20-minutes. Run two hot-start transient tests with a 20-minute 
               
               
                   
                 soak between each. For each individual hot-start test, determine 
               
               
                   
                 THC, CO, NO x , CO 2 , and PM. 
               
               
                 21 
                 Change fuel to F4. Repeat Steps 4 through 8. 
               
               
                 22 
                 Change fuel to F8. Repeat Steps 4 through 8. 
               
               
                 23 
                 Change fuel to F4. Repeat Steps 4 through 8. 
               
               
                 24 
                 Change fuel to F10. Repeat Steps 4 through 8. 
               
               
                   
               
            
           
         
       
     
     For this screening work, a 1991 DDC Series 60 heavy-duty diesel engine was mounted in a transient-capable test cell. This engine had an inline, six cylinder configuration rated for 365 hp at 1800 rpm. It was turbocharged and used a laboratory water-to-air heat exchanger for a charge air intercooler. Table 4 lists the engine specifications and features. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 4 
               
               
                   
                   
               
               
                   
                 Engine Parameter 
                 Comment 
               
               
                   
                   
               
             
            
               
                   
                 Make 
                 Detroit Diesel 
               
               
                   
                 Model 
                 Series 60, 6067GU60 
               
               
                   
                 Engine Displacement and Configuration 
                 12.7 L, I-6 
               
               
                   
                 Emission Family 
                 MDD12.7FZAK 
               
               
                   
                 Rated Power 
                 365 bhp at 1800 rmp 
               
               
                   
                 Electronic Control Module 
                 DDEC-II 
               
               
                   
                 Aspiration 
                 Turbocharged 
               
               
                   
                   
               
            
           
         
       
     
     For emission testing, the exhaust was routed to a full flow constant volume sampler (CVS) that utilized a positive displacement pump (PDP), as illustrated in  FIG. 2 . Total flow in the tunnel was maintained at a nominal flow rate of about 2000 SCFM. Sample zone probes were connected to the main tunnel. These probes were used to collect samples for total particulate (PM) and for the gaseous emissions: NON, THC, CO, and CO 2 . The NO x  was analyzed using a chemiluminescent (CL) analyzer, the THC used a flame ionization detector (FID), and CO and CO 2  was performed using separate non-dispersive infrared (NDIR) detectors. Probes for background gas measurement were connected downstream of the dilution air filter pack, but upstream of the mixing section. Background concentrations were determined for all emissions, and the tunnel THC background was also determined before and after each test. This engine produced emission results less than or equivalent to the standards for that model year. Table 5 compares the 1991 emission standards, the average reference fuel emission results, and the percent of standard for these tests. The engine did not exceed 110 percent of the applicable emission standards for a 1991 model engine. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 5 
               
             
            
               
                   
                   
               
               
                   
                 Transient Emission, G/HP-HR 
                   
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Test Number 
                 THC 
                 CO 
                 NO x   
                 PM 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 1991 Standard 
                 1.3 
                 15.5 
                 5.0 
                 0.25 
               
               
                   
                 Reference Fuel 
                 0.1 
                 2.4 
                 4.5 
                 0.19 
               
               
                   
                 % of Standard 
                 7 
                 16 
                 90 
                 75 
               
               
                   
                   
               
            
           
         
       
     
       FIG. 3  shows a graphical representation of the torque map data for the screening tests, and  FIGS. 4 and 5  show the torque map data for the tests with 3000 ppm and 2000 ppm of the additive, respectively. Table 6 gives all of the emission results for THC, CO, NO x , PM, and brake specific fuel consumption (BSFC) obtained for each of the tests. This table groups the tests by fuels and additives rather than in the order that the tests were performed. The average, standard deviation, and coefficient of variation for each set of hot-start transient tests are also included for each fuel.  FIG. 6  shows the NOx emissions versus additive concentration with trend lines for a possible shift in baseline. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                 FUEL 
                 TRANSIENT EMISSIONS, g/hp-hr 
                 BSFC, 
                 WORK, 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 CODE 
                 RUN # 
                 CO 2   
                 CO 
                 THC 
                 NO X   
                 PM 
                 lb/hp-hr 
                 hp-hr 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 F4 
                 1308 
                 531.7 
                 2.5 
                 0.10 
                 4.521 
                 0.177 
                 0.371 
                 24.61 
               
               
                   
                 1309 
                 531.4 
                 2.5 
                 0.10 
                 4.501 
                 0.194 
                 0.371 
                 24.60 
               
               
                   
                 1310 
                 531.2 
                 2.5 
                 0.10 
                 4.506 
                 0.192 
                 0.371 
                 24.60 
               
               
                   
                 Average 
                 531.4 
                 2.5 
                 0.10 
                 4.509 
                 0.187 
                 0.371 
                 24.61 
               
               
                   
                 Std. Dev. 
                 0.247 
                 0.0 
                 0.00 
                 0.010 
                 0.010 
                 0.000 
                 0.002 
               
               
                 F4 
                 1340 
                 529.7 
                 2.5 
                 0.09 
                 4.475 
                 0.189 
                 0.370 
                 24.60 
               
               
                   
                 1341 
                 530.0 
                 2.5 
                 0.09 
                 4.487 
                 0.185 
                 0.370 
                 24.61 
               
               
                   
                 Average 
                 529.9 
                 2.5 
                 0.09 
                 4.481 
                 0.187 
                 0.370 
                 24.60 
               
               
                   
                 Std. Dev. 
                 0.232 
                 0.0 
                 0.00 
                 0.008 
                 0.003 
                 0.000 
                 0.002 
               
               
                 F4 
                 1362 
                 531.8 
                 2.4 
                 0.08 
                 4.553 
                 0.180 
                 0.371 
                 24.49 
               
               
                   
                 1363 
                 532.8 
                 2.4 
                 0.08 
                 4.560 
                 0.180 
                 0.371 
                 24.49 
               
               
                   
                 1364 
                 533.4 
                 2.4 
                 0.08 
                 4.565 
                 0.184 
                 0.372 
                 24.49 
               
               
                   
                 Average 
                 532.7 
                 2.4 
                 0.08 
                 4.559 
                 0.181 
                 0.372 
                 24.49 
               
               
                   
                 Std. Dev. 
                 0.808 
                 0.0 
                 0.00 
                 0.006 
                 0.002 
                 0.000 
                 0.003 
               
               
                 F4 
                 1370 
                 529.4 
                 2.5 
                 0.09 
                 4.463 
                 0.184 
                 0.370 
                 24.69 
               
               
                   
                 1371 
                 529.6 
                 2.4 
                 0.09 
                 4.474 
                 0.180 
                 0.370 
                 24.69 
               
               
                   
                 1372 
                 530.7 
                 2.5 
                 0.09 
                 4.483 
                 0.179 
                 0.371 
                 24.69 
               
               
                   
                 Average 
                 530.2 
                 2.5 
                 0.09 
                 4.478 
                 0.180 
                 0.370 
                 24.69 
               
               
                   
                 Std. Dev. 
                 0.759 
                 0.1 
                 0.00 
                 0.006 
                 0.001 
                 0.001 
                 0.001 
               
               
                 F5 
                 1312 
                 532.0 
                 2.3 
                 0.10 
                 4.601 
                 0.162 
                 0.380 
                 24.57 
               
               
                   
                 1213 
                 532.1 
                 2.2 
                 0.10 
                 4.607 
                 0.154 
                 0.380 
                 24.59 
               
               
                   
                 Average 
                 532.1 
                 2.3 
                 0.10 
                 4.604 
                 0.158 
                 0.380 
                 24.58 
               
               
                   
                 Std. Dev. 
                 0.086 
                 0.1 
                 0.00 
                 0.004 
                 0.005 
                 0.000 
                 0.011 
               
               
                 F5 
                 1355 
                 531.0 
                 2.2 
                 0.08 
                 4.595 
                 0.151 
                 0.379 
                 24.55 
               
               
                   
                 1356 
                 533.1 
                 2.2 
                 0.08 
                 4.630 
                 0.146 
                 0.381 
                 24.56 
               
               
                   
                 Average 
                 532.0 
                 2.2 
                 0.08 
                 4.613 
                 0.148 
                 0.380 
                 24.55 
               
               
                   
                 Std. Dev. 
                 1.476 
                 0.0 
                 0.00 
                 0.025 
                 0.003 
                 0.001 
                 0.01 
               
               
                 F6 
                 1315 
                 532.1 
                 2.2 
                 0.09 
                 4.622 
                 0.157 
                 0.380 
                 24.57 
               
               
                   
                 1316 
                 532.1 
                 2.2 
                 0.09 
                 4.620 
                 0.158 
                 0.380 
                 24.58 
               
               
                   
                 Average 
                 532.1 
                 2.2 
                 0.09 
                 4.621 
                 0.157 
                 0.380 
                 24.58 
               
               
                   
                 Std. Dev. 
                 0.026 
                 0.0 
                 0.00 
                 0.001 
                 0.001 
                 0.000 
                 0.008 
               
               
                 F7 
                 1318 
                 531.3 
                 2.0 
                 0.08 
                 4.420 
                 0.154 
                 0.379 
                 24.61 
               
               
                   
                 1319 
                 530.8 
                 2.0 
                 0.08 
                 4.416 
                 0.149 
                 0.379 
                 24.60 
               
               
                   
                 Average 
                 531.0 
                 2.0 
                 0.08 
                 4.418 
                 0.151 
                 0.379 
                 24.61 
               
               
                   
                 Std. Dev. 
                 0.350 
                 0.0 
                 0.00 
                 0.003 
                 0.004 
                 0.000 
                 0.004 
               
               
                 F9 
                 1324 
                 526.1 
                 2.2 
                 0.08 
                 4.390 
                 0.150 
                 0.376 
                 24.63 
               
               
                   
                 1325 
                 527.6 
                 2.2 
                 0.08 
                 4.403 
                 0.149 
                 0.377 
                 24.63 
               
               
                   
                 Average 
                 526.8 
                 2.2 
                 0.08 
                 4.397 
                 0.149 
                 0.376 
                 24.63 
               
               
                   
                 Std. Dev. 
                 1.080 
                 0.0 
                 0.00 
                 0.009 
                 0.000 
                 0.001 
                 0.00 
               
               
                 F11 
                 1330 
                 529.4 
                 2.1 
                 0.08 
                 4.419 
                 0.151 
                 0.378 
                 24.60 
               
               
                   
                 1331 
                 529.0 
                 2.0 
                 0.08 
                 4.419 
                 0.146 
                 0.378 
                 24.60 
               
               
                   
                 Average 
                 529.2 
                 2.1 
                 0.08 
                 4.419 
                 0.148 
                 0.378 
                 24.60 
               
               
                   
                 Std. Dev. 
                 0.291 
                 0.1 
                 0.00 
                 0.000 
                 0.004 
                 0.000 
                 0.004 
               
               
                 F10 
                 1327 
                 529.2 
                 2.0 
                 0.08 
                 4.405 
                 0.150 
                 0.378 
                 24.60 
               
               
                   
                 1328 
                 529.5 
                 2.1 
                 0.08 
                 4.401 
                 0.144 
                 0.378 
                 24.60 
               
               
                   
                 Average 
                 529.3 
                 2.1 
                 0.08 
                 4.403 
                 0.147 
                 0.378 
                 24.60 
               
               
                   
                 Std. Dev. 
                 0.206 
                 0.1 
                 0.00 
                 0.002 
                 0.004 
                 0.000 
                 0.004 
               
               
                 F10 
                 1374 
                 533.2 
                 2.1 
                 0.07 
                 4.449 
                 0.142 
                 0.381 
                 24.68 
               
               
                   
                 1375 
                 533.9 
                 2.0 
                 0.07 
                 4.459 
                 0.147 
                 0.381 
                 24.69 
               
               
                   
                 1376 
                 533.7 
                 2.1 
                 0.07 
                 4.459 
                 0.149 
                 0.381 
                 24.70 
               
               
                   
                 Average 
                 533.6 
                 2.1 
                 0.07 
                 4.455 
                 0.146 
                 0.381 
                 24.69 
               
               
                   
                 Std. Dev. 
                 0.362 
                 0.1 
                 0.00 
                 0.006 
                 0.004 
                 0.000 
                 0.012 
               
               
                 F14 
                 1358 
                 534.7 
                 2.2 
                 0.07 
                 4.483 
                 0.148 
                 0.382 
                 24.53 
               
               
                   
                 1359 
                 534.5 
                 2.1 
                 0.07 
                 4.485 
                 0.146 
                 0.382 
                 24.55 
               
               
                   
                 Average 
                 534.6 
                 2.1 
                 0.07 
                 4.484 
                 0.147 
                 0.382 
                 24.54 
               
               
                   
                 Std. Dev. 
                 0.104 
                 0.0 
                 0.00 
                 0.001 
                 0.001 
                 0.000 
                 0.012 
               
               
                 F8 
                 1321 
                 528.7 
                 2.0 
                 0.08 
                 4.356 
                 0.143 
                 0.377 
                 24.63 
               
               
                   
                 1322 
                 529.9 
                 2.0 
                 0.07 
                 4.337 
                 0.143 
                 0.375 
                 24.64 
               
               
                   
                 Average 
                 529.3 
                 2.0 
                 0.08 
                 4.347 
                 0.143 
                 0.376 
                 24.64 
               
               
                   
                 Std. Dev. 
                 0.865 
                 0.0 
                 0.00 
                 0.013 
                 0.000 
                 0.001 
                 0.009 
               
               
                 F8 
                 1346 
                 528.7 
                 2.0 
                 0.08 
                 4.386 
                 0.142 
                 0.378 
                 24.57 
               
               
                   
                 1347 
                 529.9 
                 2.0 
                 0.07 
                 4.402 
                 0.143 
                 0.378 
                 24.56 
               
               
                   
                 Average 
                 529.3 
                 2.0 
                 0.08 
                 4.394 
                 0.142 
                 0.378 
                 24.56 
               
               
                   
                 Std. Dev. 
                 0.865 
                 0.0 
                 0.00 
                 0.012 
                 0.001 
                 0.001 
                 0.009 
               
               
                 F8 
                 1366 
                 535.1 
                 2.1 
                 0.07 
                 4.473 
                 0.148 
                 0.382 
                 24.46 
               
               
                   
                 1367 
                 534.8 
                 2.0 
                 0.07 
                 4.480 
                 0.147 
                 0.382 
                 24.47 
               
               
                   
                 1368 
                 534.8 
                 2.1 
                 0.07 
                 4.472 
                 0.149 
                 0.382 
                 24.48 
               
               
                   
                 Average 
                 534.9 
                 2.1 
                 0.07 
                 4.475 
                 0.148 
                 0.382 
                 24.47 
               
               
                   
                 Std. Dev. 
                 0.147 
                 0.1 
                 0.00 
                 0.004 
                 0.001 
                 0.000 
                 0.006 
               
               
                 F13 
                 1349 
                 531.7 
                 2.0 
                 0.07 
                 4.409 
                 0.150 
                 0.380 
                 24.54 
               
               
                 A2 
                 1350 
                 532.5 
                 2.0 
                 0.07 
                 4.415 
                 0.152 
                 0.380 
                 24.55 
               
               
                   
                 Average 
                 532.1 
                 2.0 
                 0.07 
                 4.412 
                 0.151 
                 0.380 
                 24.54 
               
               
                   
                 Std. Dev. 
                 0.539 
                 0.0 
                 0.00 
                 0.004 
                 0.002 
                 0.000 
                 0.01 
               
               
                 F12 
                 1352 
                 528.0 
                 2.1 
                 0.07 
                 4.389 
                 0.152 
                 0.377 
                 24.58 
               
               
                 A2 
                 1353 
                 529.2 
                 2.1 
                 0.07 
                 4.411 
                 0.147 
                 0.378 
                 24.59 
               
               
                   
                 Average 
                 528.6 
                 2.1 
                 0.07 
                 4.400 
                 0.149 
                 0.378 
                 24.59 
               
               
                   
                 Std. Dev. 
                 0.0805 
                 0.0 
                 0.00 
                 0.016 
                 0.004 
                 0.001 
                 0.01 
               
               
                   
               
            
           
         
       
     
     Two different biodiesels were used. F3 was blended at a concentration of 20 percent biodiesel in the base fuel, F4 to make F6. The other B20 (20 percent biodiesel and 80 percent diesel) blend was a combination of F1 at a concentration of 35 percent and F2 at a concentration of 65 percent. See Table 2. The blend of these two biodiesels was then mixed with the base fuel to make a second B20 blend (F5).  FIG. 7  compares the emission results for both biodiesels when blended at a concentration of 20 percent biodiesel. F5 produced slightly less NO x  than the single component biodiesel blend. 
     The two B20 blends were then mixed with the additive (A 1 ) at a concentration of 3000 ppm. F8 was the B20 blend with a combination of F1 at a concentration of 35 percent and F2 at a concentration of 65 percent, and F7 was the B20 blend with F6 (See Table 2).  FIG. 8  compares the emission results for the two B20 blends with the additive at 3000 ppm. F8 produced slightly less NO x  than the single component biodiesel blend. 
     Two additional additives were blended with F8 at a concentration of 3300 ppm. The two additives were A2 and A3. The fuel codes were F13 and F12, respectively.  FIG. 9  compares the emission results for these two additive blends. 
     Tables 7 and 8 show the statistical approach for comparing the emission results with additive A7 at 3000 ppm and 2000 ppm, respectively. With this approach, the average emissions from the three (3) individual tests with the candidate fuel, Fuel C (Xc), were compared to the average emission results for three (3) individual tests with the reference fuel, Fuel R (XR), by using the one-sided t distribution. The average term for the reference fuel for each emission was adjusted by the tolerance, (1 percent of the average for NO x  and 2 percent of the average for CO and PM) and by a value that included: tolerance, δ and pooled standard deviation, S p . 
     Square root of two divided by the number of tests, n, for both reference plus candidate (in this case, n=14, to represent the potential result if the entire seven day test protocol was performed) One-sided upper percentage point of t distribution with a=0.15 and 2n-2 degrees of freedom. The equation for this comparison is X C &lt;X R +δ−(S p x √{square root over ( 2 /η)} xt(a, 2n-2)). See CCR Title 13, Chapter 5—Standards for Motor Vehicle Fuels, Article 3 -Specifications for Alternative Motor Vehicle Fuels. Values presented in Table 7 and 8 were based on a spreadsheet calculation. If the average for the candidate fuel is less than the adjusted average for the reference fuel, then the candidate fuel is comparable or better than the reference fuel. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 7 
               
               
                   
                   
               
               
                   
                 Statistical Criteria 
                 NO x   
                 CO 
                 PM 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Number of Test 
                 14 
                 14 
                 14 
               
               
                   
                 Points, n a   
               
               
                   
                 C Average, X c   b   
                 4.475 
                 2.081 
                 0.148 
               
               
                   
                 R Average, X R   b   
                 4.559 
                 2.364 
                 0.181 
               
               
                   
                 Tolerance Level, δ c   
                 0.046 
                 0.047 
                 0.004 
               
               
                   
                 Pooled std. Dev., Sp b   
                 0.005 
                 0.048 
                 0.002 
               
               
                   
                 Sqrt of 2/n 
                 0.378 
                 0.378 
                 0.378 
               
               
                   
                 Student&#39;s t, t d   
                 1.058 
                 1.058 
                 1.058 
               
               
                   
                 Adjusted R Average, 
                 4.603 
                 2.392 
                 0.184 
               
               
                   
                 Adj. X R   b,e   
               
               
                   
                 Is X c  &lt; Adj. X R   
                 Yes 
                 Yes 
                 Yes 
               
               
                   
                 Percent Reduction, r 
                 2.8 
                 13.0 
                 19.7 
               
               
                   
                   
               
               
                   
                   a For alternative 4, n = number of tests (plus reference candidate) 
               
               
                   
                   b Units are in g/bhp-hr 
               
               
                   
                   c Tolerance level is 1 percent for NO x  and 2 percent for CO and PM 
               
               
                   
                 One-sided student&#39;s t for 2n − 2 degrees of freedom and significance level of 0.15 
               
               
                   
                 Adj. X R  = X R  + δ − (S p  × √{square root over (2)}/η × t(a, 2n − 2)) where t(a, 2n − 2) is 1.055 
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 8 
               
               
                   
                   
               
               
                   
                 Statistical Criteria 
                 NO x   
                 CO 
                 PM 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Number of Test 
                 14 
                 14 
                 14 
               
               
                   
                 Points, n a   
               
               
                   
                 C Average, X c   b   
                 4.455 
                 2.090 
                 0.146 
               
               
                   
                 R Average, X R   b   
                 4.473 
                 2.475 
                 0.181 
               
               
                   
                 Tolerance Level, δ c   
                 0.045 
                 0.050 
                 0.004 
               
               
                   
                 Pooled std. Dev., Sp b   
                 0.008 
                 0.072 
                 0.003 
               
               
                   
                 Sqrt of 2/n 
                 0.378 
                 0.378 
                 0.378 
               
               
                   
                 Student&#39;s t, t d   
                 1.058 
                 1.058 
                 1.058 
               
               
                   
                 Adjusted R Average, 
                 4.515 
                 2.496 
                 0.183 
               
               
                   
                 Adj. X R   b,e   
               
               
                   
                 Is X c  &lt; Adj. X R   
                 Yes 
                 Yes 
                 Yes 
               
               
                   
                 Percent Reduction, r 
                 1.3 
                 16.3 
                 20.4 
               
               
                   
                   
               
               
                   
                   a For alternative 4, n = number of tests (plus reference candidate) 
               
               
                   
                   b Units are in g/bhp-hr 
               
               
                   
                   c Tolerance level is 1 percent for NO x  and 2 percent for CO and PM 
               
               
                   
                 One-sided student&#39;s t for 2n − 2 degrees of freedom and significance level of 0.15 
               
               
                   
                 Adj. X R  = X R  + δ − (S p  × √{square root over (2)}/η × t(a, 2n − 2)) where t(a, 2n − 2) is 1.055 
               
            
           
         
       
     
     F5 was used in a further blend as follows. 
     120 gallons of F4 base fuel used as the untreated diesel blend stock were transferred into a clean tote. 30 gallons of F5 and 1703 ml of 2-ethylhexyl nitrate fuel additive were added. The fuel was blended for one hour with an air-actuated stirrer, and a sample was taken for analysis. The fuel properties for the candidate fuel blend are shown in Table 9 together with the properties for base fuel F4. For the fatty acid methyl ester (FAME), the analysis showed that the concentration was 19.8 percent by volume. The resulting treated candidate fuel, Fuel C, was then identified as F15. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 9 
               
               
                   
               
               
                 F4 Base Fuel 
                 Value 
                 F15 Candidate Fuel 
                 Value 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Sulfur, ppm 
                 0.9 
                 Sulfur, ppm 
                 1.56 
               
               
                 Nitrogen, ppm 
                 1.7 
                 Nitrogen, ppm 
                 284.4 
               
               
                 Cetane number 
                 49.3 
                 Cetane number 
                 59.1 
               
               
                 API Gravity 
                 35.8 
                 API Gravity 
                 34.4 
               
               
                 Flash Point, ° F. 
                 197.5 (91.8) 
                 Flash Point 
                 190 (88) 
               
               
                 (° C.) 
               
               
                 Viscosity @ 40° C., 
                 3.00 
                 Viscosity @ 40° C., 
                 3.14 
               
               
                 cSt 
                   
                 cSt 
               
               
                 IBP, ° F. 
                 400 
                 IBP, ° F. 
                 409 
               
               
                 10%, ° F. 
                 451 
                 10%, ° F. 
                 461 
               
               
                 50%, ° F. 
                 490 
                 50%, ° F. 
                 521 
               
               
                 90%, ° F. 
                 592 
                 90%, ° F. 
                 629 
               
               
                 EP, F. 
                 636 
                 EP, F. 
                 644 
               
               
                 FAME Content, % 
                 — 
                 FAME Content, % 
                 19.8 
               
               
                   
               
            
           
         
       
     
     Fuel tests were performed utilizing Alternative 3 outlined above and in outlined in Title 13 California Code of Regulations Section 2882. Table 10 provides the testing protocol that was used. F4 is referred to as “Fuel R” for Reference Fuel and F15 is referred to as “Fuel C” for Candidate Fuel. 
     
       
         
           
               
               
             
               
                 TABLE 10 
               
               
                   
               
               
                 Step 
                 Description 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 1 
                 Install engine. Perform emission instrument calibrations as 
               
               
                   
                 required. Calibrate torquemeter and check signal conditioning 
               
               
                   
                 systems. Validate CVS gaseous and particulate sampling systems 
               
               
                   
                 using propane recovery techniques 
               
               
                 2 
                 Check engine condition using in-house, low sulfur emissions type 
               
               
                   
                 fuel, and note fault codes if any. Bring engine oil level to “full”. 
               
               
                 3 
                 Perform fuel change procedure to operate on Fuel R (F4). Change 
               
               
                   
                 filter, purge fuel supply, etc. 
               
               
                 4 
                 Warm up engine, and operate at rated speed and load, then check 
               
               
                   
                 performance. 
               
               
                 5 
                 Conduct transient “full-throttle” torque map from low- to high-idle. 
               
               
                   
                 Compute and store resulting transient command cycle. 
               
               
                 6 
                 Load dummy sample media, and run a 20-minute practice or 
               
               
                   
                 conditioning transient cycles, and adjust dynamometer controls to 
               
               
                   
                 meet statistical limits for transient cycle operation 
               
               
                 7 
                 Soak the engine for 20-minutes. Run three hot-start transient tests 
               
               
                   
                 with a 20-minute soak between each. For each individual hot-start 
               
               
                   
                 test, determine THC, CO, NO x , CO 2 , and PM. 
               
               
                 8 
                 Perform fuel change, and repeat Steps 3 through 7 with Fuel C. 
               
               
                 9 
                 On Day 2 of testing, repeat Steps 4 through 9 starting with Fuel C 
               
               
                   
                 and ending with Fuel R. 
               
               
                 10 
                 On Day 3 of testing, repeat Steps 4 through 9 starting with Fuel R 
               
               
                   
                 and ending with Fuel C. 
               
               
                 11 
                 On Day 4 of testing, repeat Steps 4 through 9 starting with Fuel C 
               
               
                   
                 and ending with Fuel R 
               
               
                 12 
                 On Day 5 of testing, repeat Steps 4 through 9 starting with Fuel R 
               
               
                   
                 and ending with Fuel C. 
               
               
                 13 
                 On Day 6 of testing, repeat Steps 4 through 9 starting with Fuel C 
               
               
                   
                 and ending with Fuel R. 
               
               
                 14 
                 On Day 7 of testing, repeat Steps 4 through 9 starting with Fuel R 
               
               
                   
                 and ending with Fuel C. 
               
               
                 15 
                 Summarize data and prepare the final report. 
               
               
                   
               
            
           
         
       
     
     Table 11 gives the emission results for HC, CO, NO x , PM, and brake specific fuel consumption (BSFC) obtained for each of the tests. The average for each set of triplicate hot start transient tests was also included for each fuel. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 11 
               
             
            
               
                   
               
               
                 TEST 
                 TRANSIENT EMISSIONS, g/hp-hr 
                 BSFC, 
                 WORK, 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 NUMBER 
                 CO 2   
                 THC 
                 CO 
                 NO X   
                 PM 
                 lb/hp-hr 
                 hp-hr 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 R1 
                 538.0 
                 2.437 
                 0.077 
                 4.621 
                 0.183 
                 0.378 
                 24.39 
               
               
                 R2 
                 538.1 
                 2.432 
                 0.081 
                 4.620 
                 0.182 
                 0.378 
                 24.39 
               
               
                 R3 
                 539.1 
                 2.530 
                 0.083 
                 4.620 
                 0.182 
                 0.378 
                 24.39 
               
               
                 Average 
                 538.4 
                 2.466 
                 0.080 
                 4.621 
                 0.183 
                 0.378 
                 24.39 
               
               
                 C4 
                 539.6 
                 2.122 
                 0.075 
                 4.540 
                 0.147 
                 0.388 
                 24.35 
               
               
                 C5 
                 540.4 
                 2.026 
                 0.071 
                 4.538 
                 0.146 
                 0.389 
                 24.35 
               
               
                 C6 
                 540.3 
                 2.026 
                 0.071 
                 4.542 
                 0.148 
                 0.389 
                 24.36 
               
               
                 Average 
                 540.1 
                 2.058 
                 0.072 
                 4.540 
                 0.147 
                 0.388 
                 24.35 
               
               
                 C7 
                 539.0 
                 2.121 
                 0.070 
                 4.513 
                 0.148 
                 0.388 
                 24.39 
               
               
                 C8 
                 539.9 
                 2.061 
                 0.066 
                 4.512 
                 0.149 
                 0.388 
                 24.38 
               
               
                 C9 
                 539.5 
                 1.997 
                 0.070 
                 4.523 
                 0.149 
                 0.388 
                 24.38 
               
               
                 Average 
                 539.5 
                 2.060 
                 0.069 
                 4.516 
                 0.149 
                 0.388 
                 24.38 
               
               
                 R10 
                 539.7 
                 2.485 
                 0.085 
                 4.597 
                 0.188 
                 0.379 
                 24.39 
               
               
                 R11 
                 539.9 
                 2.551 
                 0.086 
                 4.600 
                 0.188 
                 0.379 
                 24.38 
               
               
                 R12 
                 539.6 
                 2.469 
                 0.087 
                 4.615 
                 0.190 
                 0.379 
                 24.40 
               
               
                 Average 
                 539.7 
                 2.502 
                 0.086 
                 4.604 
                 0.189 
                 0.379 
                 24.39 
               
               
                 R13 
                 537.1 
                 2.543 
                 0.078 
                 4.567 
                 0.183 
                 0.377 
                 24.41 
               
               
                 R14 
                 538.0 
                 2.462 
                 0.079 
                 4.568 
                 0.185 
                 0.378 
                 24.43 
               
               
                 R15 
                 538.1 
                 2.438 
                 0.081 
                 4.584 
                 0.184 
                 0.378 
                 24.42 
               
               
                 Average 
                 537.7 
                 2.481 
                 0.079 
                 4.573 
                 0.184 
                 0.377 
                 24.42 
               
               
                 C16 
                 539.2 
                 2.035 
                 0.068 
                 4.513 
                 0.146 
                 0.388 
                 24.36 
               
               
                 C17 
                 538.9 
                 2.059 
                 0.071 
                 4.514 
                 0.149 
                 0.388 
                 24.35 
               
               
                 C18 
                 539.9 
                 2.143 
                 0.073 
                 4.526 
                 0.148 
                 0.388 
                 24.35 
               
               
                 Average 
                 539.3 
                 2.079 
                 0.071 
                 4.518 
                 0.148 
                 0.388 
                 24.35 
               
               
                 C19 
                 532.1 
                 2.045 
                 0.064 
                 4.432 
                 0.129 
                 0.383 
                 24.40 
               
               
                 C20 
                 532.9 
                 2.026 
                 0.067 
                 4.436 
                 0.144 
                 0.383 
                 24.40 
               
               
                 C21 
                 532.9 
                 2.029 
                 0.069 
                 4.447 
                 0.148 
                 0.383 
                 24.38 
               
               
                 Average 
                 532.7 
                 2.033 
                 0.067 
                 4.438 
                 0.141 
                 0.383 
                 24.39 
               
               
                 R22 
                 534.6 
                 2.558 
                 0.082 
                 4.553 
                 0.182 
                 0.375 
                 24.38 
               
               
                 R23 
                 535.3 
                 2.558 
                 0.085 
                 4.561 
                 0.190 
                 0.376 
                 24.38 
               
               
                 R24 
                 535.7 
                 2.496 
                 0.087 
                 4.564 
                 0.186 
                 0.376 
                 24.39 
               
               
                 Average 
                 535.2 
                 2.537 
                 0.085 
                 4.559 
                 0.186 
                 0.376 
                 24.38 
               
               
                 R25 
                 528.2 
                 2.485 
                 0.077 
                 4.482 
                 0.187 
                 0.371 
                 24.48 
               
               
                 R26 
                 529.0 
                 2.564 
                 0.080 
                 4.493 
                 0.187 
                 0.371 
                 24.48 
               
               
                 R27 
                 529.3 
                 2.475 
                 0.082 
                 4.502 
                 0.190 
                 0.372 
                 24.48 
               
               
                 Average 
                 528.8 
                 2.508 
                 0.080 
                 4.492 
                 0.188 
                 0.371 
                 24.48 
               
               
                 C28 
                 532.9 
                 2.155 
                 0.066 
                 4.437 
                 0.151 
                 0.383 
                 24.37 
               
               
                 C29 
                 532.9 
                 2.088 
                 0.066 
                 4.440 
                 0.152 
                 0.383 
                 24.37 
               
               
                 C30 
                 534.0 
                 2.207 
                 0.068 
                 4.447 
                 0.151 
                 0.384 
                 24.37 
               
               
                 Average 
                 533.3 
                 2.150 
                 0.067 
                 4.441 
                 0.151 
                 0.384 
                 24.37 
               
               
                   
               
            
           
         
       
     
     Table 12 shows the statistical approach for comparing the emission results. With this approach, the average for each of the triplicate results from the 21 individual tests with the candidate fuel, Fuel C (Xc), were compared to the average for each of the triplicate results for 21 individual tests with the average reference fuel, Fuel R (XR), by using the calculations describe above with X C &lt;X R +δ−(S p x √{square root over ( 2 /η)} xt(a, 2n-2)). 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 12 
               
               
                   
               
               
                 Statistical Criteria 
                 HC 
                 CO 
                 NO x   
                 PM 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 Number of Test 
                 14 
                 14 
                 14 
                 14 
               
               
                 Points, n a   
               
               
                 C Average, X c   b   
                 0.082 
                 2.509 
                 4.540 
                 0.187 
               
               
                 R Average, X R   b   
                 0.068 
                 2.080 
                 4.463 
                 0.147 
               
               
                 Tolerance Level, δ c   
                 0.002 
                 0.050 
                 0.045 
                 0.004 
               
               
                 Pooled std. Dev., Sp b   
                 0.003 
                 0.033 
                 0.065 
                 0.003 
               
               
                 Sqrt of 2/n 
                 26 
                 26 
                 26 
                 26 
               
               
                 Student&#39;s t, t d   
                 1.058 
                 1.058 
                 1.058 
                 1.058 
               
               
                 Adjusted R Average, 
                 0.082 
                 2.546 
                 4.560 
                 0.189 
               
               
                 Adj. X R   b,e   
               
               
                 Is X c  &lt; Adj. X R   
                 Yes 
                 Yes 
                 Yes 
                 Yes 
               
               
                 Percent Reduction, r 
                 17.5 
                 18.3 
                 2.1 
                 22.1 
               
               
                   
               
               
                   a For alternative 1, n = number of tests (plus reference candidate) 
               
               
                   b Units are in g/bhp-hr 
               
               
                   c Tolerance level is 1 percent for NO x  and 2 percent for HC, CO, and PM 
               
               
                   d df = 2(n − 1) 
               
               
                 One-sided student&#39;s t for 2n − 2 degrees of freedom and significance level of 0.15 
               
               
                 Adj. X R  = X R  + δ − (S p  × √{square root over (2)}/η × t(a, 2n − 2)) where t(a, 2n − 2) is 1.055 
               
            
           
         
       
     
     As shown, the candidate fuel was found to decrease the NO x  emissions by 2.1 percent when compared to the reference fuel. The PM emissions were decreased by about 22 percent and average HC and CO were lower (17.5 and 18.3 percent lower, respectively). 
     The contents of all references (including literature references, issued patents, published patent applications, and co-pending patent applications) cited throughout this application are hereby expressly incorporated herein in their entireties by reference. Unless otherwise defined, all technical and scientific terms used herein are accorded the meaning commonly known to one with ordinary skill in the art.