Diesel fuel composition

Abstract

A diesel fuel composition which essentially comprises only paraffins, and which is characterised in that 1) the normal paraffins with 18 or fewer carbons constitute not less than 12% by mass, and 2) the proportion of the total peak area of the peak group at chemical shifts of 1.45 to 2.25 ppm relative to the total peak area of the peak group at chemical shifts of 1.00 to 1.45 ppm is less than 6.5% in proton nuclear magnetic resonance ( 1 H-NMR) spectra, and which has an oxidation index OI of less than 1.10. OI is represented by the equation OI=0.247X−0.001Y−0.053, wherein X is the proportion (%) of the total peak area of the peak group at chemical shifts of 1.45 to 2.25 ppm relative to the total peak area of the peak group at chemical shifts of 1.00 to 1.45 ppm in proton nuclear magnetic resonance ( 1 H-NMR) spectra; and Y is the content (mass %) of normal paraffins with 18 or fewer carbons.

1 . A diesel fuel composition comprising essentially of paraffins, and wherein
 1) the normal paraffins with 18 or fewer carbons constitute not less than 12% by mass, and   2) the proportion of the total peak area of the peak group at chemical shifts of 1.45 to 2.25 ppm relative to the total peak area of the peak group at chemical shifts of 1.00 to 1.45 ppm is less than 6.5% in proton nuclear magnetic resonance ( 1 H-NMR) spectra,   and which has an oxidation index OI represented by the following equation of less than 1.10:
   OI=0.247 X− 0.001 Y− 0.053 
   
       wherein X is the proportion (%) of the total peak area of the peak group at chemical shifts of 1.45 to 2.25 ppm relative to the total peak area of the peak group at chemical shifts of 1.00 to 1.45 ppm in proton nuclear magnetic resonance ( 1 H-NMR) spectra; and Y is the content (mass %) of normal paraffins with 18 or fewer carbons. 
     
     
         2 . The diesel fuel composition of  claim 1  wherein the increase in the total acid number between before and after an oxidation stability test is not more than 1.3 mg KOH/g. 
     
     
         3 . The diesel fuel composition of  claim 2  wherein the increase in the total acid number between before and after an oxidation stability test is not more than 1.0 mg KOH/g. 
     
     
         4 . The diesel fuel composition of  claim 3  wherein the increase in the total acid number between before and after an oxidation stability test is not more than 0.9 mg KOH/g. 
     
     
         5 . The diesel fuel composition of  claim 2  wherein the oxidation stability test is performed as in ASTM D2274 under conditions of oxygen bubbling for 16 hours at a test temperature of 115° C. 
     
     
         6 . The A diesel fuel composition of  claim 1 , which has an oxidation index OI of less than 0.9. 
     
     
         7 . The diesel fuel composition of  claim 6  which has an oxidation index OI of less than 0.7. 
     
     
         8 . The diesel fuel composition of  claim 1 , wherein the main constituent thereof does not contain styrene compounds or diene compounds, or condensed polycyclic aromatics. 
     
     
         9 . The diesel fuel composition of  claim 1 , wherein the total mass or volume of isoparaffins and normal paraffins is not less than 99% of the composition.