Medium-chain alkanols in additive concentrates for improving foam reduction in fuel oils

Abstract

C 5 - to C 15 -alkanols are suitable for improving the defoamer action of a silicon-containing anti-foam in fuel oils, especially in biofuel oils, which comprise at least one additive with detergent action. Such alkanols are used in additive concentrates which also comprise aromatic hydrocarbons or hydrocarbon mixtures having a boiling point of 100 to 250° C. or C 5 - to C 12 -alkyl nitrates, and also silicon-containing antifoams, additives with detergent action and optionally commercial dehazers.

1 . The use of a C 5 - to C 15 -alkanol for improving the defoamer action of a silicon-containing antifoam in fuel oils which comprise at least one additive with detergent action. 
     
     
         2 . The use according to  claim 1  in fuel oils which consist
 (a) to an extent of 0.1 to less than 100% by weight of at least one biofuel oil based on fatty acid esters, and 
 (b) to an extent of more than 0 to 99.9% by weight of middle distillates of fossil origin and/or of vegetable and/or animal origin, which are essentially hydrocarbon mixtures and are free of fatty acid esters. 
 
     
     
         3 . The use according to  claim 1  or  2 , wherein the defoamer action of the silicon-containing antifoam is improved to such an extent that at least one of the following criteria is met:
 (α) reduction in the foam volume with respect to the defoamer action of the same silicon-containing antifoam in the same fuel oil in the absence of a C 5 - to C 15 -alkanol by at least 10%, determined by the BNPe NF-M 07-075 foam test; 
 (β) reduction in the foam collapse time with respect to the defoamer action of the same silicon-containing antifoam in the same fuel oil in the absence of a C 5 - to C 15 -alkanol by at least 20%, determined by the BNPe NF-M 07-075 foam test. 
 
     
     
         4 . The use according to  claims 1  to  3 , wherein the C 5 - to C 15 -alkanol is n-octanol, 2-ethylhexanol, n-nonanol, 2-propylheptanol, n-decanol, n-undecanol, n-dodecanol, n-tridecanol or isotridecanol. 
     
     
         5 . The use according to  claims 1  to  4 , wherein the silicon-containing antifoam is a polyether-modified polysiloxane. 
     
     
         6 . The use according to  claims 1  to  5 , wherein the additive with detergent action is a compound with moieties which are derived from succinic anhydride and have hydroxyl and/or amino and/or amido and/or imido groups. 
     
     
         7 . An additive concentrate comprising
 (A) 0.1 to 10% by weight of at least one C 5 - to C 15 -alkanol,   (B) 0.5 to 80% by weight of either (i) at least one aromatic hydrocarbon or hydrocarbon mixture having a boiling point or a predominant boiling range within the temperature range from 100° C. to 250° C. or (ii) at least one C 5 - to C 12 -alkyl nitrate or (iii) a mixture of (i) and (ii), with the proviso that the amount of component (B) is at least five times the amount of the C 5 - to C 15 -alkanol of component (A),   (C) 0.01 to 2% by weight of at least one silicon-containing antifoam,   (D) 1 to 30% by weight of at least one additive with detergent action and   (E) 0 to 5% by weight of at least one commercial dehazer,   
       where the sum of components (A) to (E) is 100% by weight in each case, and with the proviso that at least one of the following criteria is additionally met:
 (γ) the amount of the additive with detergent action in component (D) is at least ten times the amount of the silicon-containing antifoam in component (C); 
 (δ) the amount of the C 5 - to C 15 -alkanol of component (A) is at least three times the amount of the silicon-containing antifoam of component (C). 
 
     
     
         8 . The additive concentrate according to  claim 7 , wherein the C 5 - to C 15 -alkanol is n-octanol, 2-ethylhexanol, n-nonanol, 2-propylheptanol, n-decanol, n-undecanol, n-dodecanol, n-tridecanol or isotridecanol. 
     
     
         9 . The additive concentrate according to  claim 7  or  8 , wherein the silicon-containing antifoam is a polyether-modified polysiloxane. 
     
     
         10 . The additive concentrate according to  claims 7  to  9 , wherein the additive with detergent action is a compound with moieties which are derived from succinic anhydride and have hydroxyl and/or amino and/or amido and/or imido groups. 
     
     
         11 . The use of the additive concentrate according to  claims 7  to  10  for improving foam reduction in fuel oils. 
     
     
         12 . An additized fuel oil comprising a major amount of base fuel oil which consists
 (a) to an extent of 0.1 to 100% by weight of at least one biofuel oil based on fatty acid esters, and   (b) to an extent of 0 to 99.9% by weight of middle distillates of fossil origin and/or of vegetable and/or animal origin, which are essentially hydrocarbon mixtures and are free of fatty acid esters, and a minor amount of the additive concentrate according to  claims 7  to  10 .