Essentially hydrocarbon compositions to be used as fuels with enhanced lubricating properties

Abstract

An essentially hydrocarbon composition comprising a refinery liquid fuel and from 1 to 25% by weight of a medium distillate essentially without alcoholic oxygen obtained starting from the product of a Fischer-Tropsch-type synthesis. This composition surprisingly has enhanced lubricating properties with respect to both of the original components and can advantageously be used as a fuel for Diesel or turbine engines, with an evident decrease in wear of the mobile parts in contact therewith.

1 . Hydrocarbon compositions, to be used as fuel for diesel or turbine engines, wherein at least 80% by weight has a distillation range comprised within 150 and 380° C., and consists of a mixture of the following components: 
 (A) from 80 to 99% by weight with respect to the overall weight of (A) and (B) of any refinery hydrocarbon mixture, having a distillation range comprised within 150 and 380° C.,  
 (B) from 1 to 20% by weight with respect to the overall weight of (A) and (B) of a hydrocarbon mixture essentially without oxygenated organic compounds, obtained by means of a process comprising a synthesis reaction of the Fischer-Tropsch type, having a distillation range comprised within 130 and 380° C.  
 
     
     
         2 . The composition according to the previous  claim 1 , consisting of from 90% to 100% by weight of said components (A) and (B), jointly.  
     
     
         3 . The composition according to any of the claims  1  or  2 , wherein said components (A) and (B), jointly have a distillation range comprised within 200 and 380° C.  
     
     
         4 . The composition according to any of the previous claims, wherein the proportions of said components (A) and (B) respectively range from 85 to 98% by weight and from 15 to 2% by weight with respect to the over-all weight of (A) and (B).  
     
     
         5 . The composition according to any of the previous claims, wherein said component (A) is a hydrocarbon mixture having a distillation range comprised within 200 and 370° C.  
     
     
         6 . The composition according to  claim 5 , wherein said component (A) essentially consists of a non-synthetic gas oil fraction with a distillation range comprised within 240 and 360° C.  
     
     
         7 . The composition according to any of the previous claims, wherein said component (A) has a sulfur content lower than 1000 ppm as S weight.  
     
     
         8 . The composition according to any of the previous claims, wherein said component (B) was obtained by a process comprising at least one hydrocracking step.  
     
     
         9 . The composition according to any of the previous claims, wherein at least 50% of said component (B) consists of branched paraffins.  
     
     
         10 . The composition according to any of the previous claims, wherein said component (A) and said component (B) have essentially overlapping distillation ranges.  
     
     
         11 . The composition according to any of the previous claims, wherein said component (B) has the following characteristics: 
 Cetane Number >60    Pour Point <−10° C.    Distillation range from 240 to 370° C.    
     
     
         12 . The composition according to any of the previous claims, comprising, in addition to said components (A) and (B), up to 20%, preferably up to 10% by weight with respect to the total weight, of one or more additives for fuel products.  
     
     
         13 . Use as engine fuel of the composition according to any of the previous claims from  1  to  12 .  
     
     
         14 . Use according to  claim 13 , as fuel for feeding Diesel engines.  
     
     
         15 . A method for improving the lubricating properties of an engine fuel, characterized in that a synthetic hydrocarbon mixture essentially without organic oxygenated compounds, obtained by a process comprising a synthesis reaction of the Fischer-Tropsch type, having a distillation range comprised within 130 and 380° C., preferably within 150 and 370° C., is added to said fuel, in a quantity ranging from 1 to 25% by weight with respect to the fuel itself.  
     
     
         16 . The method according to  claim 15 , wherein said fuel consists of a refinery hydrocarbon mixture, having a distillation range comprised within 150 and 380° C.  
     
     
         17 . The method according to any of the previous claims from  15  to  16 , wherein said synthetic mixture is added in a quantity ranging from 2 to 15% by weight with respect to said fuel.  
     
     
         18 . The method according to any of the previous claims from  15  to  17 , wherein said fuel is a refinery hydro-carbon mixture having a distillation range comprised within 200 and 370° C.  
     
     
         19 . The method according to any of the previous claims from  15  to  18 , wherein said fuel has a sulfur content lower than 1000 ppm as S weight.  
     
     
         20 . The method according to any of the previous claims from  15  to  19 , wherein said synthetic mixture was obtained by means of a process comprising at least one hydrocracking step.  
     
     
         21 . The method according to any of the previous claims from  15  to  20 , wherein said fuel and said synthetic mixture have essentially overlapping distillation ranges.  
     
     
         22 . The method according to any of the previous claims from  15  to  21 , wherein said synthetic mixture has the following characteristics: 
 Cetane Number >60  
 Pour Point <−10° C.  
 Distillation range comprised within 240 and 370° C.