Methods and compositions for improving stability of biodiesel and blended biodiesel fuel

Abstract

Methods and compositions for improving stability of biodiesel fuel. The methods comprise adding to said biodiesel fuel, an effective amount of a combined treatment that includes a (I) hindered phenol and (II) a Mannich reaction product. The compositions comprise I and II dissolved or dispersed in an organic solvent.

1 . Method for improving the stability of biodiesel fuel comprising adding to said biodiesel fuel an amount effective for the purpose of (I) a hindered phenol and (II) a Mannich reaction product. 
   
   
       2 . Method as recited in  claim 1  wherein (I) is added in an amount of about 50-2,500 ppm based upon one million parts of said biodiesel fuel and wherein (II) is added in an amount of about 1-100 ppm based upon one million parts of said biodiesel fuel. 
   
   
       3 . Method as recited in  claim 2  wherein said biodiesel fuel is blended with petroleum diesel fuel. 
   
   
       4 . Method as recited in  claim 2  wherein said hindered phenol (I) has the formula 
     
       
         
         
             
             
         
       
     
     wherein R 1  and R 2  may be the same or different and each is independently chosen from C 1 -C 20  alkyl, C 1 -C 30  alkaryl and substituted alkaryl; n is 0 or 1; R 3 , when present is selected from C 1 -C 20  alkyl, thiophenol, substituted thiophenol, C 1 -C 40  alkaneoic acid ester, C 1 -C 30  alkaryl, substituted C 1 -C 30  alkaryl, C 1 -C 6  alkylamino, C 1 -C 6  alkoxy, amine, polynuclear aryl and substituted polynuclear aryl. 
   
   
       5 . Method as recited in  claim 4  wherein said Mannich reaction product II is formed via reaction of components II(A), II(B), and II(C) wherein component IIA has the formula 
     
       
         
         
             
             
         
       
     
     wherein R 4  and R 5  are the same or different and are independently selected from alkyl, aryl, alkaryl or arylalkyl of from about 1 to about 20 carbon atoms and x is 0 or 1;
 wherein component II(B) has the formula 
 
     
       
         
         
             
             
         
       
     
     wherein Z is a positive integer, R 6  and R 7  may be the same or different and are independently selected from H, alkyl, aryl, araalkyl or alkaryl having from 1 to 20 carbon atoms, y may be 0 or 1; and wherein component II(C) is an aldehyde having the structure 
     
       
         
         
             
             
         
       
     
     wherein R 8  is selected from H and alkyl having from 1 to 6 carbon atoms. 
   
   
       6 . Method as recited in  claim 5  wherein in said Mannich reaction product II, said components are present in a molar ratio II(A):II(B):II(C) of 0.5-5:1:0.5-5. 
   
   
       7 . Method as recited in  claim 6  wherein said hindered phenol (I) is a member selected from the group consisting of BHT and DTBP and mixtures thereof. 
   
   
       8 . Method as recited in  claim 6  wherein said component II(A) of said Mannich reaction product (II) is a member or members selected from the group consisting of p-cresol, 4-ethylphenol, 4-t-butylphenol, 4-t-amylphenol, 4-t-octylphenol, 4-dodecylphenol, 2,4-di-t-butylphenol, 2,4-di-t-amylphenol, and 4-nonyl-phenol. 
   
   
       9 . Method as recited in  claim 6  wherein said component II(B) of said Mannich reaction product is selected from the group consisting of ethylenediamine and triethylenetetraamine. 
   
   
       10 . Method as recited in  claim 6  wherein said component II(C) of said Mannich reaction product is selected from the group consisting of formaldehyde and paraformaldehyde. 
   
   
       11 . Method as recited in  claim 6  wherein said component II(A) of said Mannich reaction product is 4-nonylphenol, said component II(B) of said Mannich reaction product is ethylenediamine and said component II(C) of said Mannich reaction product is formaldehyde or paraformaldehyde, said II(A):II(B):II(C) being present in a molar ratio II(A):II(B):II(C) of 2:1:2. 
   
   
       12 . Composition for stabilizing a biodiesel fuel, said composition comprising (I) and (II) dispersed or dissolved in an organic solvent, (I) being a hindered phenol and (II) being a Mannich reaction product. 
   
   
       13 . Composition as recited in  claim 12  wherein said components (I) and (II) are present in said composition in a weight ratio of about 5-15:1 (I):(II). 
   
   
       14 . Composition as recited in  claim 13  wherein said hindered phenol (I) has the formula 
     
       
         
         
             
             
         
       
     
     wherein R 1  and R 2  may be the same or different and each is independently chosen from C 1 -C 20  alkyl, C 1 -C 30  alkaryl and substituted alkaryl; n is 0 or 1; R 3 , when present is selected from C 1 -C 20  alkyl, thiophenol, substituted thiophenol, C 1 -C 40  alkaneoic acid ester, C 1 -C 30  alkaryl, substituted C 1 -C 30  alkaryl, C 1 -C 6  alkylamino, C 1 -C 6  alkoxy, amine, polynuclear aryl and substituted polynuclear aryl. 
   
   
       15 . Composition as recited in  claim 14  wherein said Mannich reaction product (II) is formed via reaction of components II(A), II(B), and II(C) wherein component II(A) has the formula 
     
       
         
         
             
             
         
       
     
     wherein R 4  and R 5  are the same or different and are independently selected from alkyl, aryl, alkaryl or arylalkyl of from about 1 to about 20 carbon atoms and x is 0 or 1;
 wherein component II(B) has the formula 
 
     
       
         
         
             
             
         
       
     
     wherein Z is a positive integer, R 6  and R 7  may be the same or different and are independently selected from H, alkyl, aryl, araalkyl or alkaryl having from 1 to 20 carbon atoms, y may be 0 or 1; and wherein component II(C) is an aldehyde having the structure 
     
       
         
         
             
             
         
       
     
     wherein R 8  is selected from H and alkyl having from 1 to 6 carbon atoms. 
   
   
       16 . Composition as recited in  claim 15  wherein in said Mannich reaction product (II), said components are present in a molar ratio II(A):II(B):II(C) of 0.5-5:1:0.5-5. 
   
   
       17 . Composition as recited in  claim 16  wherein said hindered phenol (I) is a member selected from the group consisting of BHT and DTBP and mixtures thereof. 
   
   
       18 . Composition as recited in  claim 17  wherein said component II(A) of said Mannich reaction product (II) is a member or members selected by the group consisting of p-cresol, 4-ethylphenol, 4-t-butylphenol, 4-t-amylphenol, 4-t-octylphenol, 4-dodecylphenol, 2,4-di-t-butylphenol, 2,4-di-t-amylphenol, and 4-nonyl-phenol;
 said component II(B) of said Mannich reaction product is selected from the group consisting of ethylenediamine and triethylenetetraamine;   and wherein said component II(C) of said Mannich reaction product is selected from the group consisting of formaldehyde and paraformaldehyde.   
   
   
       19 . Composition as recited in  claim 18  wherein said component II(A) of said Mannich reaction product is 4-nonylphenol, said component II(B) of said Mannich reaction product is ethylenediamine and said component II(C) of said Mannich reaction product is formaldehyde or paraformaldehyde, said II(A):II(B):II(C) being present in a molar ratio II(A):II(B):II(C) of 2:1:2. 
   
   
       20 . Composition as recited in  claim 19  wherein said organic solvent is heavy aromatic naptha.