Biodiesel fuel mixtures

Abstract

Provided herein are biodiesel fuel mixtures having improved properties for reducing NOx emissions as well as total particular matter emissions, CO emissions, and total hydrocarbon emissions.

What is claimed is: 
     
         1 . A biodiesel fuel mixture 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   one or more additives, including_from 0.060 to 0.350 vol. % 2-ethylhexyl nitrate; and   1-20% aromatics by volume;   wherein the amount of 2-ethylhexyl nitrate is sufficient to reduce on average total particulate matter, to cause the fuel mixture to have no negative impact on NO x  emissions, and to reduce at least one of CO emissions, total hydrocarbon emissions, or NO x  emissions of an engine, said emissions being relative to the emissions from the base petroleum diesel fuel without biodiesel and without 2-ethylhexyl nitrate.   
     
     
         2 . The biodiesel fuel mixture of  claim 1 , wherein none of the one or more additives are classified as outside of a Baseline Category and the biodiesel fuel mixture is classified under the Baseline Diesel category per the United States Environmental Protection Agency regulations as defined in 40 CFR § 79.56(1997). 
     
     
         3 . The biofuel mixture of  claim 1 , wherein the base petroleum diesel fuel has:
 a maximum sulfur content of 15 ppm,   a maximum polycylic aromatics content of 10 wt. %,   a maximum nitrogen content of 10 ppm,   a minimum cetane number of 48,   an American Petroleum Institute (API) gravity of 33 to 39,   a minimum flash point of 130 ° F., and   a viscosity @ 40 ° C., cSt of 2.0 to 4.12.   
     
     
         4 . The biofuel mixture of  claim 3 , wherein the base petroleum diesel fuel has a distillation profile comprising the following properties:
 an initial boiling point of 340 ° F. to 420 ° F.;   T10% (400 to 490 ° F.);   T50% (470 to 560 ° F.);   T90% (550 to 610 ° F.); and   an end point of (580 to 660 ° F.).   
     
     
         5 . The biodiesel fuel mixture of  claim 1 , wherein the mixture decreases CO emissions of an engine by 15 to 25%. 
     
     
         6 . The biodiesel fuel mixture of  claim 1 , wherein the mixture decreases total hydrocarbon emissions of an engine by 15 to 25%. 
     
     
         7 . The biodiesel fuel mixture of  claim 1 , wherein the mixture decreases NOx emissions of an engine by 1 to 7%. 
     
     
         8 . The biodiesel fuel mixture of  claim 1 , wherein the mixture decreases total particulate matter emissions of an engine by 20 to 25%. 
     
     
         9 . The biodiesel fuel mixture of  claim 1 , wherein the fuel mixture comprises 7.5-20% aromatics by volume. 
     
     
         10 . The biodiesel fuel mixture of  claim 1 , wherein the fuel mixture comprises 9-20% aromatics by volume. 
     
     
         11 . The biodiesel fuel mixture of  claim 1 , wherein none of the one or more additives or the biodiesel fuel mixture are classified under an Atypical category per United States Environmental Protection Agency regulations as defined in 40 CFR § 79.56(1997).