Stabilized biodiesel fuel compositions

Abstract

Disclosed are stabilized biodiesel fuel compositions, which compositions comprise a biodiesel fuel, for example the methyl esters of the fatty acids of rapeseed or soy oil, and one or more additives selected from the group consisting of the 3-arylbenzofuranones and the hindered amine light stabilizers, and optionally, one or more hindered phenolic antioxidants.

1 . A biodiesel fuel composition stabilized against the deleterious effects of heat, light and oxygen, which composition comprises 
 a biodiesel fuel and    an effective stabilizing amount of    one or more additives selected from the group consisting of the 3-arylbenzofuranone stabilizers and the hindered amine light stabilizers and    optionally, one or more additives selected from the group consisting of the hindered phenolic antioxidants.    
   
   
       2 . A composition according to  claim 1  comprising one or more 3-arylbenzofuranone stabilizers of formula I  
     
       
         
         
             
             
         
       
     
     in which, if n is 1, 
 R 1  is unsubstituted or C 1 -C 4 alkyl-, C 1 -C 4 alkoxy-, C 1 -C 4 alkylthio-, hydroxyl-, halo-, amino-, C 1 -C 4 alkylamino-, phenylamino- or di(C 1 -C 4 alkyl)amino-substituted naphthyl, phenanthryl, anthryl, 5,6,7,8-tetrahydro-2-naphthyl, 5,6,7,8-tetrahydro-1-naphthyl, thienyl, benzo[b]thienyl, naphtho[2,3-b]thienyl, thianthrenyl, dibenzofuryl, chromenyl, xanthenyl, phenoxathiinyl, pyrrolyl, imidazolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolizinyl, isoindolyl, indolyl, indazolyl, purinyl, quinolizinyl, isoquinolyl, quinolyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinnolinyl, pteridinyl, carbazolyl, β-carbolinyl, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl, isoxazolyl, furazanyl, biphenyl, terphenyl, fluorenyl or phenoxazinyl, or R 1  is a radical of the formula II  
                     
 and  
 if n is 2,  
 R 1  is unsubstituted or C 1 -C 4 alkyl- or hydroxy-substituted phenylene or naphthylene; or is -R 12 —X—R 13 —,  
 R 2 , R 3 , R 4  and R 5  independently of one another are hydrogen, chlorine, hydroxyl, C 1 -C 25 alkyl, C 7 -C 9  phenylalkyl, unsubstituted or C 1 -C 4 alkyl-substituted phenyl; unsubstituted or C 1 -C 4 alkyl-substituted C 5 -C 8 cycloalkyl; C 1 -C 18 alkoxy, C 1 -C 18 alkylthio, C 1 -C 4 alkylamino, di(C 1 -C 4 alkyl)amino, C 1 -C 25 alkanoyloxy, C 1 -C 25 alkanoylamino, C 3 -C 25 alkenoyloxy, C 3 -C 25 alkanoyloxy which is interrupted by oxygen, sulfur or  
 C 6 -C 9 cycloalkylcarbonyloxy, benzoyloxy or C 1 -C 12 alkyl-substituted benzoyloxy; or else the radicals R 2  and R 3  or the radicals R 3  and R 4  or the radicals R 4  and R 5 , together with the carbon atoms to which they are attached, form a benzo ring, R 4  is additionally —(CH 2 ) p —COR 15  or —(CH 2 ) q OH or, if R 3 , R 5  and R 6  are hydrogen, R 4  is additionally a radical of the formula III  
                     
 in which R 1  is defined as indicated above for n=1, R 6  is hydrogen or a radical of the formula IV  
                     
 where R 4  is not a radical of the formula III and R 1  is defined as indicated above for n=1, R 7 , R 8 , R 9 , R 10 , and R 11  independently of one another are hydrogen, halogen, hydroxyl, C 1 -C 25 alkyl, C 2 -C 25 alkyl interrupted by oxygen, sulfur or  
                     
 C 1 -C 25 alkoxy, C 2 -C 25 alkoxy interrupted by oxygen, sulfur or  
                     
 C 1 -C 25 alkylthio, C 3 -C 25 alkenyl, C 3 -C 25 alkenyloxy, C 3 -C 25 alkynyl, C 3 -C 25 alkynyloxy, C 7 -C 9 phenylalkyl, C 7 -C 9 phenylalkoxy, unsubstituted or C 1 -C 4 alkyl-substituted phenyl; unsubstituted or C 1 -C 4 alkyl-substituted phenoxy; unsubstituted or C 1 -C 4 alkyl-substituted C 5 -C 8 cycloalkyl; unsubstituted or C 1 -C 4 alkyl-substituted C 5 -C 8 cycloalkoxy; C 1 -C 4 alkylamino, di(C 1 -C 4 alkyl)amino, C 1 -C 25 alkanoyl, C 3 -C  25 alkanoyl interrupted by oxygen, sulfur or  
                     
 C 1 -C 25 alkanoyloxy, C 3 -C 25 alkanoyloxy interrupted by oxygen, sulfur or  
                     
 C 1 -C 25 alkanoylamino, C 3 -C 25 alkenoyl, C 3 -C 25 alkenoyl interrupted by oxygen, sulfur or  
                     
 C 3 -C 25 alkenoyloxy, C 3 -C 25 alkenoyloxy interrupted by oxygen, sulfur or  
                     
 C 6 -C 9 cycloalkylcarbonyl, C 6 -C 9 cycloalkylcarbonyloxy, benzoyl or C 1 -C 12 alkyl-substituted benzoyl; benzoyloxy or C 1 -C 12 alkyl-substituted benzoyloxy;  
                     
 or else, in formula II, the radicals R 7  and  
 R 8  or the radicals R 8  and R 11 , together with the carbon atoms to which they are attached, form a benzo ring,  
 R 12  and R 13  independently of one another are unsubstituted or C 1 -C 4 alkyl-substituted phenylene or naphthylene,  
 R 14  is hydrogen or C 1 -C 8 alkyl,  
 R 15  is hydroxyl,  
                     
 R 16  and R 17  independently of one another are hydrogen, CF 3 , C 1 -C 12 alkyl or phenyl, or R 16  and  
 R 17 , together with the C atom to which they are attached, form a C 5 -C 8 cycloalkylidene ring which is unsubstituted or substituted from 1 to 3 times by C 1 -C 4 alkyl;  
 R 18  and R 19  independently of one another are hydrogen, C 1 -C 4 alkyl or phenyl,  
 R 20  is hydrogen or C 1 -C 4 alkyl,  
 R 21  is hydrogen, unsubstituted or C 1 -C 4 alkyl-substituted phenyl; C 1 -C 25 alkyl, C 2 -C 25 alkyl interrupted by oxygen, sulfur or  
                     
 C 7 -C 9 phenylalkyl which is unsubstituted or substituted on the phenyl radical from 1 to 3 times by C 1 -C 4 alkyl; C 7 -C 25 phenylalkyl which is unsubstituted or substituted on the phenyl radical from 1 to 3 times by C 1 -C 4 alkyl and interrupted by oxygen, sulfur or  
                     
 or else the radicals R 20  and R 21 , together with the carbon atoms to which they are attached, form a C 5 -C 12 cycloalkylene ring which is unsubstituted or substituted from 1 to 3 times by C 1 -C 4 alkyl;  
 R 22  is hydrogen or C 1 -C 4 alkyl,  
 R 23  is hydrogen, C 1 -C 25 alkanoyl, C 3 -C 25 alkenoyl, C 3 -C 25 alkanoyl interrupted by oxygen, sulfur or  
                     
 C 2 -C 25 alkanoyl substituted by a di(C 1 -C 6 alkyl)phosphonate group;  
 C 6 -C 9 cycloalkylcarbonyl, thenoyl, furoyl, benzoyl or C 1 -C 12 alkyl-substituted benzoyl;  
                     
 R 24  and R 25  independently of one another are hydrogen or C 1 -C 18 alkyl,  
 R 26  is hydrogen or C 1 -C 8 alkyl,  
 R 27  is a direct bond, C 1 -C 18 alkylene, C 2 -C 18 alkylene interrupted by oxygen, sulfur or  
                     
 C 2 -C 18 alkenylene, C 2 -C 20 alkylidene, C 7 -C 20 phenylalkylidene, C 5 -C 8 cycloalene, C 7 -C 8 bicycloalkylene, unsubstituted or C 1 -C 4 alkyl-substituted phenylene, or  
                     
 R 28  is hydroxyl,  
                     
 R 29  is oxygen, —NH— or  
                     
 R 30  is C 1 -C 18 alkyl or phenyl,  
 R 31  is hydrogen or C 1 -C 18 alkyl,  
 M is an r-valent metal cation,  
 X is a direct bond, oxygen, sulfur or  13  NR 31 —,  
 n is 1 or 2,  
 p is 0, 1 or 2,  
 q is 1, 2, 3, 4, 5 or 6,  
 r is 1, 2, or 3, and  
 s is 0, 1 or 2.  
 
   
   
       3 . A composition according to  claim 2  wherein the 3-arylbenzofuranones are of formula I wherein n=1, R 1  is phenyl which is unsubstituted or substituted in para-position by C 1 -C 18 alkylthio or di(C 1 -C 4 alkyl)amino; mono- to penta-substituted alkyphenyl containing together a total of at most 18 carbon atoms in the 1 to 5 alkyl substituents; naphthyl, biphenyl, terphenyl, phenanthryl, anthryl, fluorenyl, carbazolyl, thienyl, pyrrolyl, phenothizinyl or 5,6,7,8-tetrahydronaphthyl, each of which is unsubstituted or substituted by C 1 -C 4 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 alkylthio, hydroxy or amino.  
   
   
       4 . A composition according to  claim 2  wherein the 3-arylbenzofuranones are of formula I wherein n is 2, R 1  is —R 12 —X—R 13 —, R 12  and R 13  are phenylene, X is oxygen or —NR  31 —, and R 31  is C 1 -C 4 alkyl.  
   
   
       5 . A composition according to  claim 2  wherein the 3-arylbenzofuranones are selected from the group consisting of 3-[4-(2-acetoxyethoxy)phenyl]-5,7-di-tert-butyl-benzofuran-2-one; 5,7-di-tert-butyl -3-[4-(2-stearoyloxyethoxy)phenyl]benzofuran-2-one; 3,3′-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)benzofuran-2-one]; 5,7-di-tert-butyl-3(4-ethoxyphenyl) benzofuran-2-one; 3-(4-acetoxy-3,5-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one; 3-(3,5-dimethyl-4-pivaloyloxy-phenyl)-5,7-di-tert-butyl-benzofuran-2-one; 5,7-di-tert-butyl-3-phenylbenzofuran-2-one; 5,7-di-tert-butyl-3-(3,4-dimethylphenyl)-benzofuran-2-one and 5,7-di-tert-butyl-3-(2,3-dimethylphenyl)-benzofuran-2-one.  
   
   
       6 . A composition according to  claim 1  comprising one or more hindered amine light stabilizers that contain at least one moiety of formula  
     
       
         
         
             
             
         
       
     
     where G 1 , G 2 , G 3 , G 4  and G 5  are independently alkyl of 1 to 8 carbon atoms or G 1  and G 2  or G 3  and G 4  together are pentamethylene.  
   
   
       7 . A composition according to  claim 6  where the hindered amine stabilizers are selected from the group consisting of 
 1) 1-cyclohexyloxy-2,2,6,6-tetramethyl-4-octadecylaminopiperidine,    2) bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate,    3) bis(1-acetoxy-2,2,6,6-tetramethylpiperidin4-yl) sebacate,    4) bis(1,2,2,6,6-pentamethyl-4-yl) sebacate,    5) bis(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,    6) bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate;    7) bis(1-acyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,    8) bis(1,2,2,6,6-pentamethyl-4-piperidyl) n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate    9) 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-(2-hydroxy-ethylamino-s-triazine,    10) bis(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) adipate,    11) 2,4-bis[(1-cyclohexyloxy-2,2,6,6-piperidin4-yl)butylamino]-6-chloro-s-triazine,    12) 1-(2-hydroxy-2-methylpropoxy)-4-hydroxy-2,2,6,6-tetramethylpiperidine,    13) 1-(2-hydroxy-2-methylpropoxy)-4-oxo-2,2,6,6-tetramethylpiperidine,    14) 1-(2-hydroxy-2-methylpropoxy)-4-octadecanoyloxy-2,2,6,6-tetramethylpiperidine,    15) bis(1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,    16) bis(1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl) adipate,    17) 2,4-bis{N-[1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl]-N -butyl-amino}-6-(2-hydroxyethylamino)-s-triazine,    18) 4-benzoyl-2,2,6,6-tetramethylpiperidine,    19) di-(1,2,2,6,6-pentamethylpiperidin-4-yl) p-methoxybenzylidenemalonate,    20) 4-stearyloxy-2,2,6,6-tetramethylpiperidine,    21) bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl) succinate,    22) 1,2,2,6,6-pentamethyl-4-aminopiperidine,    23) 2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro[4,5]decane,    24) tris(2,2,6,6-tetramethyl-4-piperidyl) nitrilotriacetate,    25) tris(2-hydroxy-3-(amino-(2,2,6,6-tetramethylpiperidin-4-yl)propyl) nitrilotriacetate,    26) tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butane-tetracarboxylate,    27) tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butane-tetracarboxylate,    28) 1,1′-(1,2-ethanedlyl)-bis(3,3,5,5-tetramethylpiperazinone),    29) 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decan-2,4-dione,    30) 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,    31) 3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidin-2,5-dione,    32) 3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-2,5-dione,    33) N,N′-bis-formyl-N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine,    34) the reaction product of 2,4-bis[(1-cyclohexyloxy-2,2,6,6-piperidin-4-yl)butylamino]-6-chloro-s-triazine with N,N′-bis(3-aminopropyl)ethylenediamine),    35) the condensate of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid,    36) linear or cyclic condensates of N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine,    37) linear or cyclic condensates of N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine and 4-cyclohexylamino-2,6-dichloro-1,3,5-triazine,    38) linear or cyclic condensates of N,N′-bis-(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine,    39) linear or cyclic condensates of N,N′-bis-(1,2,2,6,6-pentamethyl-4-piperidyl)-hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine,    40) the condensate of 2-chloro-4,6-bis(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine and 1,2-bis(3-aminopropylamino)ethane,    41) the condensate of 2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine and 1,2-bis-(3-aminopropylamino)ethane,    42) a reaction product of 7,7,9,9-tetramethyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospiro[4,5]decane and epichlorohydrin,    43) poly[methyl,(3-oxy-(2,2,6,6-tetramethylpiperidin-4-yl)propyl)] siloxane, CAS#182635-99-0,    44) reaction product of maleic acid anhydride-C 18 -C 22 -α-olefin-copolymer with 2,2,6,6-tetramethyl-4-aminopiperidine,    45) the oligomeric compound which is the condensation product of 4,4′-hexamethylene-bis(amino-2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine,    46) the oligomeric compound which is the condensation product of 4,4′-hexamethylene-bis(amino-1,2,2,6,6-pentaamethylpiperidine) and 2,4-dichloro-6-[(1,2,2,6,6-pentaamethyl-piperidin-4-yl)butylamino]-s-triazine end -capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine,    47) the oligomeric compound which is the condensation product of 4,4′-hexamethylene-bis(amino-1-propoxy-2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(1-propoxy-2,2,6,6-tetra-methylpiperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine,    48) the oligomeric compound which is the condensation product of 4,4′-hexamethylene-bis(amino-1-acyloxy-2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(1-acyloxy-2,2,6,6-tetra-methylpiperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine and    49) product obtained by reacting a product, obtained by reacting 1,2-bis(3-amino-propylamino)ethane with cyanuric chloride, with (2,2,6,6-tetramethylpiperidin-4-yl)butylamine.    
   
   
       8 . A composition according to  claim 6  where the hindered amine is an N—H, N-methyl, N-methoxy, N-propoxy, N-octyloxy, N-cyclohexyloxy, N-acyloxy or an N-(2-hydroxy-2-methyl-propoxy) substituted amine.  
   
   
       9 . A composition according to  claim 1  comprising one or more 3-arylbenzofuranone stabilizers and one or more hindered phenolic antioxidants.  
   
   
       10 . A composition according to  claim 9  where the 3-arylbenzofuranone stabilizers are of formula I  
     
       
         
         
             
             
         
       
     
     in which, if n is 1, 
 R 1  is unsubstituted or C 1 -C 4 alkyl-, C 1 -C 4 alkoxy-, C 1 -C 4 alkylthio-, hydroxyl-, halo-, amino-, C 1 -C 4 alkylamino-, phenylamino- or di(C 1 -C 4 alkyl)amino-substituted naphthyl, phenanthryl, anthryl, 5,6,7,8-tetrahydro-2-naphthyl, 5,6,7,8-tetrahydro-1-naphthyl, thienyl, benzo[b]thienyl, naphtho[2,3-b]thienyl, thianthrenyl, dibenzofuryl, chromenyl, xanthenyl, phenoxathiinyl, pyrrolyl, imidazolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolizinyl, isoindolyl, indolyl, indazolyl, purinyl, quinolizinyl, isoquinolyl, quinolyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinnolinyl, pteridinyl, carbazolyl, β-carbolinyl, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl, isoxazolyl, furazanyl, biphenyl, terphenyl, fluorenyl or phenoxazinyl, or R 1  is a radical of the formula II  
                     
 and  
 if n is 2,  
 R 1  is unsubstituted or C 1 -C 4 alkyl- or hydroxy-substituted phenylene or naphthylene; or is —R 12 —X—R 13 —,  
 R 2 , R 3 , R 4  and R 5  independently of one another are hydrogen, chlorine, hydroxyl, C 1 -C 25 alkyl, C 7 -C 9 phenylalkyl, unsubstituted or C 1 -C 4 alkyl-substituted phenyl; unsubstituted or C 1 -C 4 alkyl-substituted C 5 -C 8 cycloalkyl; C 1 -C 18 alkoxy, C 1 -C 18 alkylthio, C 1 -C 4 alkylamino, di(C 1 -C 4 alkyl)amino, C 1 -C 25 alkanoyloxy, C 1 -C 25 alkanoylamino, C 3 -C 25 alkenoyloxy, C 3 -C 25 alkanoyloxy which is interrupted by oxygen, sulfur or  
                     
 C 6 -C 9 cycloalkylcarbonyloxy, benzoyloxy or C 1 -C 12 alkyl-substituted benzoyloxy; or else the radicals R 2  and R 3  or the radicals R 3  and R 4  or the radicals R 4  and R 5 , together with the carbon atoms to which they are attached, form a benzo ring, R 4  is additionally —(CH 2 ) p —COR 15  or —CH 2 ) q OH or, if R 3 , R 5  and R 6  are hydrogen, R 4  is additionally a radical of the formula III  
                     
 in which R 1  is defined as indicated above for n=1,  
 R 6  is hydrogen or a radical of the formula IV  
                     
 where R 4  is not a radical of the formula III and R 1  is defined as indicated above for n=1,  
 R 7 , R 8 , R 9 , R 10  and R 11  independently of one another are hydrogen, halogen, hydroxyl, C 1 -C 25 alkyl, C 2 -C 25 alkyl interrupted by oxygen, sulfur or  
                     
 C 1 -C 25 alkoxy, C 2 -C 25 alkoxy interrupted by oxygen, sulfur or  
                     
 C 1 -C 25 alkylthio, C 3 -C 25 alkenyl, C 3 -C 25 alkenyloxy, C 3 -C 25 alkynyl, C 3 -C 25 alkynyloxy, C 7 -C 9 phenylalkyl, C 7 -C 9 unsubstituted or C 1 -C 4 alkyl-substituted phenyl; unsubstituted or C 1 -C 4 alkyl-substituted phenoxy; unsubstituted or C 1 -C 4 alkyl-substituted C 5 -C 8 cycloalkyl; unsubstituted or C 1 -C 4 alkyl-substituted C 5 -C 8 cycloalkoxy; C 1 -C 4 alkylamino, di(C 1 -C 4 alkyl)amino, C 1 -C 25 alkanoyl, C 3 -C  25 alkanoyl interrupted by oxygen, sulfur or  
                     
 C 1 -C 25 alkanoyloxy, C 3 -C 25 alkanoyloxy interrupted by oxygen, sulfur or  
                     
 C 1 -C 25 alkanoylamino, C 3 -C 25 alkenoyl, C 3 -C 25 alkenoyl interrupted by oxygen, sulfur or  
                     
 C 3 -C 25 alkenoyloxy, C 3 -C 25 alkenoyloxy interrupted by oxygen, sulfur or  
                     
 C 6 -C 9 cycloalkylcarbonyl, C 6 -C 9 cycloalkylcarbonyloxy, benzoyl or C 1 -C 12 alkyl-substituted benzoyl; benzoyloxy or C 1 -C 12 alkyl-substituted benzoyloxy;  
                     
 or else, in formula II, the radicals R 7  and R 8  or the radicals R 8  and R 11 , together with the carbon atoms to which they are attached, form a benzo ring,  
 R 12  and R 13  independently of one another are unsubstituted or C 1 -C 4 alkyl-substituted phenylene or naphthylene,  
 R 14  is hydrogen or C 1 -C 8 alkyl,  
 R 15  is hydroxyl,  
                     
 R 16  and R 17  independently of one another are hydrogen, CF 3 , C 1 -C 12 alkyl or phenyl, or R 16  and  
 R 17 , together with the C atom to which they are attached, form a C 5 -C 8 cycloalkylidene ring which is unsubstituted or substituted from 1 to 3 times by C 1 -C 4 alkyl;  
 R 18  and R 19  independently of one another are hydrogen, C 1 -C 4 alkyl or phenyl, R 20  is hydrogen or C 1 -C 4 alkyl,  
 R 21  is hydrogen, unsubstituted or C 1 -C 4 alkyl-substituted phenyl; C 1 -C 25 alkyl, C 2 -C 25 alkyl interrupted by oxygen, sulfur or  
                     
 C 7 -C 9 phenylalkyl which is unsubstituted or substituted on the phenyl radical from 1 to 3 times by C 1 -C 4 alkyl; C 7 -C 25 phenylalkyl which is unsubstituted or substituted on the phenyl radical from 1 to 3 times by C 1 -C 4 alkyl and interrupted by oxygen, sulfur or  
                     
 or else the radicals R 20  and R 21 , together with the carbon atoms to which they are attached, form a C 5 -C 12 cycloalkylene ring which is unsubstituted or substituted from 1 to 3 times by C 1 -C 4 alkyl;  
 R 22  is hydrogen or C 1 -C 4 alkyl, R 23  is hydrogen, C 1 -C 25 alkanoyl, C 3 -C 25 alkenoyl, C 3 -C 25 alkanoyl interrupted by oxygen, sulfur or  
                     
 C 2 -C 25 alkanoyl substituted by a di(C 1 -C 6 alkyl)phosphonate group; C 6 -C 9 cycloalkylcarbonyl, thenoyl, furoyl, benzoyl or C 1 -C 12 alkyl-substituted benzoyl;  
                     
 R 24  and R 25  independently of one another are hydrogen or C 1 -C 18 alkyl,  
 R 26  is hydrogen or C 1 -C 8 alkyl,  
 R 27  is a direct bond, C 1 -C 18 alkylene, C 2 -C 18 alkylene interrupted by oxygen, sulfur or  
                     
 C 2 -C 18 alkenylene, C 2 -C 20 alkylidene, C 7 -C 20 phenylalkylidene, C 5 -C 8 cycloalkylene, C 7 -C 8 bicycloalkylene, unsubstituted or C 1 -C 4 alkyl-substituted phenylene, or  
                     
 R 28  is hydroxyl,  
                     
 R 29  is oxygen, —NH— or  
                     
 R 30  is C 1 -C 18 alkyl or phenyl,  
 R 31  is hydrogen or C 1 -C 18 alkyl,  
 M is an r-valent metal cation,  
 X is a direct bond, oxygen, sulfur or —NR 31 —,  
 n is 1 or 2,  
 p is 0, 1 or 2,  
 q is 1, 2, 3, 4, 5 or 6,  
 r is 1, 2 or 3, and  
 s is 0, 1 or 2.  
 
   
   
       11 . A composition according to  claim 10  wherein the 3-arylbenzofuranones are of formula I wherein n=1, R 1  is phenyl which is unsubstituted or substituted in para-position by C 1 -C 18 alkylthio or di(C 1 -C 4 alkyl)amino; mono- to penta-substituted alkyphenyl containing together a total of at most 18 carbon atoms in the 1 to 5 alkyl substituents; naphthyl, biphenyl, terphenyl, phenanthryl, anthryl, fluorenyl, carbazolyl, thienyl, pyrrolyl, phenothizinyl or 5,6,7,8-tetrahydronaphthyl, each of which is unsubstituted or substituted by C 1 -C 4 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 alkylthio, hydroxy or amino.  
   
   
       12 . A composition according to  claim 10  wherein the 3-arylbenzofuranones are of formula I wherein n is 2, R 1  is —R 12 —X—R 13 —, R 12  and R 13  are phenylene, X is oxygen or —NR  31 —, and R 31  is C 1 -C 4 alkyl.  
   
   
       13 . A composition according to  claim 10  wherein the 3-arylbenzofuranones are selected from the group consisting of 3-[4-(2-acetoxyethoxy)phenyl]-5,7-di-tert-butyl-benzofuran-2-one; 5,7-di-tert-butyl-3-[4-(2-stearoyloxyethoxy)phenyl]benzofuran-2-one; 3,3′-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)benzofuran-2-one]; 5,7-di-tert -butyl-3-(4-ethoxyphenyl) benzofuran-2-one; 3-(4-acetoxy-3,5-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one; 3-(3,5-dimethyl-4-pivaloyloxy-phenyl)-5,7-di-tert-butyl-benzofuran-2-one; 5,7-di-tert-butyl-3-phenylbenzofuran-2-one; 5,7-di-tert-butyl-3-(3,4-dimethylphenyl)-benzofuran-2-one and 5,7-di-tert-butyl-3-(2,3-dimethylphenyl)benzofuran-2-one.  
   
   
       14 . A composition according to  claim 9  where the hindered phenolic antioxidants are selected from the group consisting of butylated hydroxytoluene, butylated hydroxyanisole, tocopherol, benzylphosphonates, esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or polyhydric alcohols, esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols and esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono- or polyhydric alcohols.  
   
   
       15 . A composition according to  claim 1  comprising one or more hindered amine light stabilizers and one or more hindered phenolic antioxidants.  
   
   
       16 . A composition according to  claim 15  where the hindered amine light stabilizers contain at least one moiety of formula  
     
       
         
         
             
             
         
       
     
     where G 1 , G 2 , G 3 , G 4  and G 5  are independently alkyl of 1 to 8 carbon atoms or G 1  and G 2  or G 3  and G 4  together are pentamethylene.  
   
   
       17 . A composition according to  claim 15  where the hindered amine stabilizers are selected from the group consisting of 
 1) 1-cyclohexyloxy-2,2,6,6-tetramethyl-4-octadecylaminopiperidine,    2) bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate,    3) bis(1-acetoxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,    4) bis(1,2,2,6,6-pentamethyl-4-yl) sebacate,    5) bis(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,    6) bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate;    7) bis(1-acyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,    8) bis(1,2,2,6,6-pentamethyl-4-piperidyl) n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate    9) 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-(2-hydroxy-ethylamino-s-triazine,    10) bis(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) adipate,    11) 2,4-bis[(1-cyclohexyloxy-2,2,6,6-piperidin-4-yl)butylamino]-6-chloro-s-triazine,    12) 1-(2-hydroxy-2-methylpropoxy)-4-hydroxy-2,2,6,6-tetramethylpiperidine,    13) 1-(2-hydroxy-2-methylpropoxy)-4-oxo-2,2,6,6-tetramethylpiperidine,    14) 1-(2-hydroxy-2-methylpropoxy)-4-octadecanoyloxy-2,2,6,6-tetramethylpiperidine,    15) bis(1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,    16) bis(1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl) adipate,    17) 2,4-bis{N-[1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl]-N -butyl-amino}-6-(2-hydroxyethylamino)-s-triazine,    18) 4-benzoyl-2,2,6,6-tetramethylpiperidine,    19) di-(1,2,2,6,6-pentamethylpiperidin-4-yl) p-methoxybenzylidenemalonate,    20) 4-stearyloxy-2,2,6,6-tetramethylpiperidine,    21) bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl) succinate,    22) 1,2,2,6,6-pentamethyl-4-aminopiperidine,    23) 2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro[4,5]decane,    24) tris(2,2,6,6-tetramethyl-4-piperidyl) nitrilotriacetate,    25) tris(2-hydroxy-3-(amino-(2,2,6,6-tetramethylpiperidin-4-yl)propyl) nitrilotriacetate,    26) tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butane-tetracarboxylate,    27) tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butane-tetracarboxylate,    28) 1,1′-(1,2-ethanedlyl)-bis(3,3,5,5-tetramethylpiperazinone),    29) 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decan-2,4-dione,    30) 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,    31) 3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidin-2,5-dione,    32) 3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-2,5-dione,    33) N,N′-bis-formyl-N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine,    34) the reaction product of 2,4-bis[(1-cyclohexyloxy-2,2,6,6-piperidin-4-yl)butylamino]-6-chloro -s-triazine with N,N′-bis(3-aminopropyl)ethylenediamine),    35) the condensate of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid,    36) linear or cyclic condensates of N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine,    37) linear or cyclic condensates of N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine and 4-cyclohexylamino-2,6-dichloro-1,3,5-triazine,    38) linear or cyclic condensates of N,N′-bis-(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine,    39) linear or cyclic condensates of N,N′-bis-(1,2,2,6,6-pentamethyl-4-piperidyl)-hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine,    40) the condensate of 2-chloro-4,6-bis(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine and 1,2-bis(3-aminopropylamino)ethane,    41) the condensate of 2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine and 1,2-bis-(3-aminopropylamino)ethane,    42) a reaction product of 7,7,9,9-tetramethyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospiro [4,5]decane and epichlorohydrin,    43) poly[methyl, (3-oxy-(2,2,6,6-tetramethylpiperidin-4-yl)propyl)] siloxane, CAS#182635-99-0,      44 ) reaction product of maleic acid anhydride-C 18 -C 22 -α-olefin-copolymer with 2,2,6,6-tetramethyl-4-aminopiperidine,    45) the oligomeric compound which is the condensation product of 4,4′-hexamethylene-bis(amino-2, 2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine,    46) the oligomeric compound which is the condensation product of 4,4′-hexamethylene-bis(amino-1,2,2,6,6-pentaamethylpiperidine) and 2,4-dichloro-6-[(1,2,2,6,6-pentaamethyl-piperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine,    47) the oligomeric compound which is the condensation product of 4,4′-hexamethylene-bis(amino-1-propoxy-2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(1-propoxy-2,2,6,6-tetra-methylpiperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine,    48) the oligomeric compound which is the condensation product of 4,4′-hexamethylene-bis (amino-1-acyloxy-2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(1-acyloxy-2,2,6,6-tetra-methylpiperidin -4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine and    49) product obtained by reacting a product, obtained by reacting 1,2-bis(3-amino-propylamino) ethane with cyanuric chloride, with (2,2,6,6-tetramethylpiperidin-4-yl)butylamine.    
   
   
       18 . A composition according to  claim 15  where the hindered amine is an N—H, N-methyl, N-methoxy, N-propoxy, N-octyloxy, N-cyclohexyloxy, N-acyloxy or an N-(2-hydroxy-2-methyl-propoxy) substituted amine.  
   
   
       19 . A composition according to  claim 15  where the hindered phenolic antioxidants are selected from the group consisting of butylated hydroxytoluene, butylated hydroxyanisole, tocopherol, benzylphosphonates, esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or polyhydric alcohols, esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols and esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono- or polyhydric alcohols.  
   
   
       20 . A process for the stabilization of a biodiesel fuel against the deleterious effects of heat, light and oxygen, which process comprises 
 incorporating into a biodiesel fuel    an effective stabilizing amount of    one or more additives selected from the group consisting of the 3-arylbenzofuranone stabilizers and the hindered amine light stabilizers and    optionally, one or more additives selected from the group consisting of the hindered phenolic antioxidants.